[Federal Register Volume 76, Number 92 (Thursday, May 12, 2011)]
[Proposed Rules]
[Pages 27756-27799]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2011-11056]



[[Page 27755]]

Vol. 76

Thursday,

No. 92

May 12, 2011

Part II





Department of the Interior





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Fish and Wildlife Service



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50 CFR Part 17



Endangered and Threatened Wildlife and Plants; Withdrawal of the 
Proposed Rule To List the Mountain Plover as Threatened; Proposed Rule

  Federal Register / Vol. 76 , No. 92 / Thursday, May 12, 2011 / 
Proposed Rules  

[[Page 27756]]


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DEPARTMENT OF THE INTERIOR

Fish and Wildlife Service

50 CFR Part 17

[Docket No. FWS-R6-ES-2010-0038; MO 92210-0-0008-B2]
RIN 1018-AX26


Endangered and Threatened Wildlife and Plants; Withdrawal of the 
Proposed Rule To List the Mountain Plover as Threatened

AGENCY: Fish and Wildlife Service, Interior.

ACTION: Proposed rule; withdrawal.

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SUMMARY: We, the U.S. Fish and Wildlife Service (Service), announce our 
decision to withdraw the proposed listing of the mountain plover 
(Charadrius montanus) as a threatened species under the authority of 
the Endangered Species Act of 1973, as amended (Act). After a thorough 
review of all available scientific and commercial information, we have 
determined that the species is not endangered or threatened throughout 
all or a significant portion of its range. We make this determination 
because threats to the species as identified in the proposed rule are 
not as significant as earlier believed and currently available data do 
not indicate that the threats to the species and its habitat, as 
analyzed under the five listing factors described in section 4(a)(1) of 
the Act, are likely to endanger the species in the foreseeable future 
throughout all or a significant portion of its range.

DATES: The December 5, 2002 (67 FR 72396), proposal to list the 
mountain plover as a threatened species is withdrawn as of May 12, 
2011.

ADDRESSES: This finding is available for viewing on the Internet at 
http://www.regulations.gov (see Docket No. FWS-R6-ES-2010-0038) and 
http://www.fws.gov/mountain-prairie/species/birds/mountainplover and 
also by appointment, during normal business hours, at the U.S. Fish and 
Wildlife Service, Colorado Ecological Services Office, 134 Union 
Boulevard, Suite 670, Lakewood, CO 80225; telephone 303-236-4773; 
facsimile 303-236-4005. Please submit any new information, materials, 
comments or questions concerning this finding to the Colorado 
Ecological Services Field Office at P.O. Box 25486, DFC (MS 65412), 
Denver, Colorado 80225.

FOR FURTHER INFORMATION CONTACT: Susan Linner, Field Supervisor, U.S. 
Fish and Wildlife Service, Colorado Ecological Services Field Office 
(see ADDRESSES). If you use a telecommunications device for the deaf 
(TDD), call the Federal Information Relay Service (FIRS) at 800-877-
8339.

SUPPLEMENTARY INFORMATION: 

Background

Previous Federal Actions

    For a detailed description of Federal actions concerning the 
mountain plover, please refer to the February 16, 1999, proposed rule 
to list the species (64 FR 7587); the December 5, 2002, proposed rule 
to list the species with a special rule under section 4(d) of the Act 
(16 U.S.C. 1531 et seq.) (67 FR 72396); and the September 9, 2003, 
withdrawal of the proposed rule to list the species (68 FR 53083).
    The document we published on September 9, 2003 (68 FR 53083), 
withdrew the entire proposed rule we published on December 5, 2002 (67 
FR 72396), including our proposal to list the mountain plover as a 
threatened species and our proposed special 4(d) rule. The September 9, 
2003, document also addressed comments we received on both the 1999 and 
2002 proposals to list the mountain plover and summarized threat 
factors affecting the species. The withdrawal of the proposed rule was 
based on our conclusion that the threats to the mountain plover 
identified in the proposed rule were not as significant as previously 
believed and that currently available data did not indicate that 
threats to the species and its habitat, as analyzed under the five 
listing factors described in section 4(a)(1) of the Act, were likely to 
endanger the species in the foreseeable future throughout all or a 
significant portion of its range.
    On November 16, 2006, Forest Guardians (now WildEarth Guardians) 
and the Biological Conservation Alliance filed a complaint in the 
District Court for the Southern District of California challenging the 
September 9, 2003, withdrawal of the proposal to list the mountain 
plover (68 FR 53083). We entered into a settlement agreement with the 
plaintiffs, which was filed by the court on August 28, 2009. As part of 
the settlement agreement, we agreed to reconsider our decision to 
withdraw the proposed listing of the mountain plover and to submit to 
the Federal Register by July 31, 2010, a document reopening the 
December 5, 2002, proposal to list the mountain plover (67 FR 72396) 
that would also request public comments. We agreed to vacate our 2003 
withdrawal of the proposed rule upon publication of the Federal 
Register notice reopening public comment on the December 5, 2002, 
proposal to list the mountain plover (67 FR 72396). We further agreed 
to submit a final listing determination for the mountain plover to the 
Federal Register no later than May 1, 2011.
    On June 29, 2010, we published a document in the Federal Register 
notifying the public that we were reinstating that portion of our 
December 5, 2002, proposed rule to list the mountain plover as 
threatened under the Act (75 FR 37353). We did not reinstate that 
portion of the December 5, 2002, proposed rule regarding a proposed 
special rule under section 4(d) of the Act. The proposed special rule 
was designed to allow researchers to complete field research and 
analyze data for an ongoing study, and addressed agricultural 
activities only through December 31, 2004. To ensure that our review of 
the species' status was complete and based on the best available 
scientific and commercial information, we requested comments on the 
proposal to list the mountain plover as a threatened species, including 
all information related to the species' status and the proposed 
listing. We invited public comments on the proposed listing, new 
information relevant to our consideration of the status of the mountain 
plover, and comments and information regarding threats to the species 
and its habitat.

Species Information

    Our February 16, 1999, and December 5, 2002, proposed rules (64 FR 
7587 and 67 FR 72396, respectively), and our September 9, 2003, 
withdrawal of our 2002 proposal to list the mountain plover (68 FR 
53083) described the species' life history, ecology, and habitat use. 
For additional background on the natural history of the mountain 
plover, see the account of the species in The Birds of North America 
(Knopf and Wunder 2006).
    While the majority of relevant information directly pertaining to 
the mountain plover that has become available since our December 5, 
2002, proposal to list (67 FR 72396) and September 9, 2003, withdrawal 
of that proposal (68 FR 53083) has resulted from local or Statewide 
studies on the mountain plover's breeding range; two recent documents 
provide extensive review of current knowledge regarding the mountain 
plover:
    (1) Mountain Plover (Charadrius montanus) in Birds of North America 
(Knopf and Wunder 2006); and
    (2) Conservation Plan for the Mountain Plover (Charadrius 
montanus), Version 1.0 (Andres and Stone 2009).

[[Page 27757]]

    Numerous other recent documents are summarized in our June 29, 
2010, notification reinstating our December 5, 2002, proposed rule to 
list the mountain plover as threatened under the Act (75 FR 37353). 
These include over twenty peer-reviewed journal articles, and many 
other reports and summaries relevant to the status of the mountain 
plover that have become available since 2002.
    The following sections highlight and update information on the 
mountain plover with emphasis on information developed since 2002.
Taxonomy and Species Description
    The mountain plover (Charadius montanus) is a small bird in the 
order Charadriiformes, family Charadriidae. No subspecies are 
recognized. It is a migratory, terrestrial shorebird averaging 8 inches 
(21 centimeters) in body length. Mountain plover are light brown above 
and white below, but lack the contrasting dark breast band 
characteristic of several other plovers such as the more common 
killdeer (C. vociferus). Sexes are similar in appearance.
Feeding Habits
    Mountain plover feed on ground-dwelling invertebrates and flying 
invertebrates found on the ground, primarily beetles, crickets, and 
ants. They forage with a series of short runs and stops, feeding 
opportunistically as they encounter prey (Knopf and Wunder 2006, 
unpaginated).
Breeding
    Mountain plover return north to their breeding sites in the western 
Great Plains and Rocky Mountain States in spring. They arrive at their 
breeding grounds in northeastern Colorado in late March (Graul 1975, p. 
6). Arrival is earlier farther south and later in Montana and at higher 
elevations in South Park, Colorado (Knopf and Wunder 2006). Mountain 
plover are territorial during the breeding season, with males defending 
territories shortly after arrival (Knopf and Wunder 2006). Mountain 
plover are generally monogamous; they form pairs and begin courtship on 
arrival at their breeding grounds. Nests consist of a simple ground 
scrape. Egg laying in northeastern Colorado begins in late April and 
extends through mid-June (Graul 1975, p. 7). Graul (1973, p. 84) 
described mountain plover nesting as a ``rapid multi-clutch system.'' 
The female normally produces two clutches, typically three eggs each, 
at different nest sites; the male incubates the first nest site while 
the female incubates the second. If the first nest or brood is lost 
early in the breeding season, the adult may renest, so each pair can 
potentially make four attempts per year to raise a brood. This breeding 
system may increase breeding success given predation that occurs on 
mountain plover nests or broods. This breeding system, rare among bird 
species, may result in greater reproductive potential than in other 
shorebirds (Knopf and Wunder 2006). It may have developed in response 
to food fluctuations that typically occur in the shortgrass prairie, 
where insect populations likely fluctuate in response to annual, 
seasonal, and local fluctuations in precipitation (Graul 1973, p. 85).
    Average incubation period is 29 days (Graul 1975, p. 19). Chicks 
leave the nest within hours of hatching and obtain their own food. Only 
one adult normally tends each nest and brood. The minimum habitat 
requirement for mountain plover broods in Montana was 70 acres (ac) (28 
hectares (ha)) (Knopf and Rupert 1996, p. 33), and brood home ranges 
averaged 143 ac (57 ha) on rangeland in Colorado (Knopf and Rupert 
1996, p. 31). Brood home ranges appeared similar for three Colorado 
landscapes (Dreitz and Knopf 2007, p. 129). Parents stay with chicks 
until they fledge, which occurs at about 33 to 34 days (Graul 1975, p. 
25). Mountain plover breed their first spring and every year thereafter 
(Knopf and Wunder 2006).
Habitat and Range
    Although often thought of as a grassland species, the mountain 
plover may best be described as a species of disturbed prairie or semi-
desert habitat (Knopf and Miller 1994, p. 505). They are found on open, 
flat lands including xeric (extremely dry) shrublands, shortgrass 
prairie, barren agricultural fields, and other sparsely vegetated 
areas. On grasslands, they often inhabit areas with a history of 
disturbance by burrowing rodents such as prairie dogs (Cynomys spp.), 
native herbivores, or domestic livestock.
    Mountain plover breed from Canada (extreme southern Alberta and 
Saskatchewan) to northern Mexico (Figure 1) with greatest apparent 
numbers in Colorado and Wyoming, and substantial numbers in Montana, 
New Mexico, and Nebraska. In Mexico, breeding populations are suspected 
in the States of Chihuahua, Cohuila, and Nuevo Leon (Andres and Stone 
2009, p. 9).
BILLING CODE 4310-55-P

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[GRAPHIC] [TIFF OMITTED] TP12MY11.000

BILLING CODE 4310-55-C
    Mountain plover winter in similar habitat, many in California, but 
also in southern portions of Arizona, Nevada, New Mexico, Texas, and in 
northern Mexico. While California's Sacramento, San Joaquin, and 
Imperial Valleys support the greatest documented concentrations of 
wintering mountain plover, relatively little is known about wintering 
numbers or distribution in other areas.
Breeding Habitat
    Common elements of mountain plover breeding habitat include short 
vegetation, bare ground, and flat topography. The mountain plover 
historically nested in a region impacted by a variety of herbivores, 
including prairie dogs, bison (Bison bison), and pronghorn antelope 
(Antilocapra americana), because these heavily grazed or similarly 
disturbed landscapes support reduced height and density of vegetation, 
creating favorable breeding habitat for mountain plover. While the 
mountain plover is categorized as a shorebird, it is seldom found near 
margins of freshwater or marine estuaries. Dinsmore (2003, pp. 14-17) 
described four types of breeding habitat: Short- and mixed-grass 
prairie, prairie dog colonies, agricultural lands, and semi-desert.

[[Page 27759]]

    On the plains, the mountain plover is generally considered an 
associate of the shortgrass prairie, dominated by blue grama (Bouteloua 
gracilis) and buffalo grass (Buchloe dactyloides) (Knopf and Miller 
1994, p. 504). In the Pawnee National Grasslands (PNG) in northern Weld 
County, Colorado, an area that formerly supported the greatest known 
concentration of breeding mountain plover, breeding habitat was 
described as restricted to flat, heavily grazed areas (Graul 1973, p. 
69). Native prairie grasslands formerly presented a diverse ecosystem, 
shaped by low precipitation, grazing, and fire. Today, prairie 
landscapes often consist of grassland fragments where current cattle 
grazing practices tend to create relatively uniform grass coverage and 
height, which is not beneficial to mountain plover (Knopf 2008, pp. 55-
57). Typical range management practices such as rotational grazing, 
limited grazing, and improving soil moisture are designed to promote 
taller grasses that limit mountain plover use. Within these landscapes, 
areas of cattle concentration (loafing areas and near water), 
disturbance caused by prairie dogs, and plowed or fallow (unseeded for 
one or more seasons) agricultural fields create conditions favorable 
for mountain plover nesting (Knopf and Wunder 2006). Mountain plover 
are also attracted to burned areas in their breeding grounds, and 
burning may be valuable as a habitat management tool (Knopf 2008, pp. 
25-26, 57-58, 61; Andres and Stone 2009, p. 34).
    Prairie dog colonies create important habitat for mountain plover, 
and are especially important to maintaining mountain plover populations 
in the northern portions of their range (Dinsmore et al. 2003, pp. 
1024-1025; Dinsmore et al. 2005, p. 1552; Augustine et al. 2008, 
unpaginated; Childers and Dinsmore 2008, p. 705; Tipton et al. 2009, 
pp. 496-497; Dreitz 2009, pp. 875-877). Active prairie dog colonies 
provide exposed soils around burrows and, because prairie dogs keep 
surrounding vegetation clipped, an area of low-growing, perennial 
vegetation that is suitable as mountain plover breeding and brood-
rearing habitat. In addition, prairie dogs give alarm calls in response 
to the approach of predators and may alert mountain plover to predator 
presence. The density of mountain plover was found to be much greater 
on black-tailed prairie dog (C. ludovicianus) colonies than on other 
habitats in Montana (Childers and Dinsmore 2008, pp. 705-706). In 
north-central Montana, the size of the adult mountain plover population 
closely tracked annual changes in the area occupied by black-tailed 
prairie dogs (Dinsmore et al. 2003, p. 1024). Both prairie dog and 
mountain plover numbers declined sharply in the mid-1990s in response 
to an outbreak of sylvatic plague, which caused deaths of prairie dogs 
and resultant loss of favored mountain plover habitat. Mountain plover 
later increased in concert with subsequent increases in prairie dogs 
(Dinsmore et al. 2005, pp. 1550-1552).
    In the Colorado shortgrass prairie ecosystem, mountain plover 
densities observed on black-tailed prairie dog colonies were higher 
than those on dryland agriculture and much higher than those on 
grasslands without prairie dogs (Dreitz et al. 2006, p. 702; Tipton et 
al. 2009, p. 496). Mountain plover were significantly more abundant on 
black-tailed prairie dog colonies than on other rangeland within a 
bison pasture in northeastern New Mexico (Groguen 2010, pers. comm.). 
Prairie dog colonies occupied by mountain plover were, on average, 
larger in size than colonies with no mountain plover. In Utah, mountain 
plover nested in proximity to white-tailed prairie dog (C. leucurus) 
colonies (Manning and White 2001, p. 226). In northeastern Mexico, 
breeding mountain plover were associated with Mexican prairie dog (C. 
mexicanus) colonies (Gonzales-Rojas et al. 2006, p. 82).
    Mountain plover have been found to regularly use fallow or plowed 
agricultural fields for nesting (Shackford et al. 1999, entire; Dreitz 
and Knopf 2007, pp. 684-685; Bly et al. 2008, p. 127; McConnell et al. 
2009, pp. 30-33). Where mountain plover have an opportunity to choose 
between agriculture and prairie, they may use both equally (Knopf and 
Rupert 1999, p. 84). Shackford et al. (1999, entire) found mountain 
plover nesting on cultivated fields in Colorado, Oklahoma, Kansas, and 
Wyoming. Fifty percent of all nests they encountered during their 
research were on fallow or bare fields. While many nests were destroyed 
by farm machinery, they concluded that mountain plover were using 
cultivated fields successfully for nesting, especially in southern 
portions of the species' range (Shackford et al. 1999, p. 117).
    Recent studies addressed the mountain plover's nesting ecology, and 
attempted to identify the extent of breeding distribution and 
population size in Nebraska (Bly et al. 2008). They encountered 272 
nests on agricultural fields of cultivated wheat and millet (Bly et al. 
2008, p.123). Studies in Oklahoma encountered mountain plover on bare 
agricultural fields (90 percent of observations), with few (5 percent 
of observations) associated with prairie dog towns (McConnell et al. 
2009, pp. 31-32).
    It remains unknown whether Texas or Mexico crop fields support 
mountain plover breeding (Andres and Stone 2009, p. 24). Holliday 
(2010) reported that breeding season sightings of mountain plover from 
the Texas Panhandle tended to be in cultivated fields as in adjacent 
Oklahoma, although previously reported nesting in West Texas was in 
grazed, short-grass habitat.
    Knopf and Wunder (2006) described mountain plover as breeding 
``more predictably'' at semi-desert locations west of the shortgrass 
prairie in Colorado, Wyoming, and Montana. Beauvais and Smith (2003, 
entire) developed a model of mountain plover breeding habitat in shrub-
steppe habitat of western Wyoming. They related favored patches of 
mountain plover breeding habitat to poor soils, low precipitation, and 
wind scour, features they predicted would persist over time, especially 
on public lands. In such habitats, mountain plover are less dependent 
on prairie dog colonies to create breeding habitat. A Wyoming study 
located 55 mountain plover nests in grassland or desert scrub habitat 
in six counties (Plumb et al. 2005a, p. 225). All nest sites were 
grazed by ungulates with prairie dogs present at only 36 percent of 
nest sites, mostly in grassland (Plumb et al. 2005a, pp. 226-227). In 
Montana, Childers and Dinsmore (2008, p. 107) noted that sparsely 
vegetated, hardpan clay flats provided nesting habitat.
    In summary, mountain plover require short vegetation with some bare 
ground on their breeding sites. In grasslands, this usually requires 
disturbance, such as that provided by prairie dogs, cattle grazing, 
fire, or farming. In semi-desert environments, breeding habitat may 
persist without these forms of disturbance.
Migration and Wintering Habitat
    Southbound migration of mountain plover is prolonged, with post-
breeding flocks numbering in the hundreds forming in late June with 
some remaining on breeding areas until September or October (Bly et al. 
2008, p. 123; Andres and Stone 2009, p. 10). Mountain plover migrate 
southward across the southern Great Plains in late summer and early 
fall to Texas, New Mexico, and Mexico, with many then traveling west to 
California (Knopf and Wunder 2006). During spring migration, mountain 
plover move from their

[[Page 27760]]

wintering sites in early March and proceed quickly to breeding sites in 
eastern Colorado by mid-March and in Montana by mid-April (Knopf and 
Wunder 2006). Mountain plover are generally thought to use habitats 
similar to those on the breeding and wintering grounds during 
migration. During migration, they have also been reported using 
alkaline or mud soils, and sod farms (Knopf and Wunder 2006). Few 
studies have been conducted on stopover habitat, and little is known 
about stopover ecology or food resources exploited (Andres and Stone 
2009, pp. 14, 21, 37).
    In winter, mountain plover use habitats similar to those on their 
breeding grounds. Mountain plover are found wintering in California 
mostly on fallow and cultivated agricultural fields, but also on 
grasslands and grazed pastures (Hunting et al. 2001, p. 39; Knopf and 
Wunder 2006).
    Throughout the Central Valley of California, the field types used 
by mountain plover vary seasonally, from uncultivated lands in October 
and November, shifting toward cultivated lands over the winter (Hunting 
and Edson 2008, pp. 183-184). Mountain plover wintering in the San 
Joaquin Valley of California used tilled fields, grazed pastures, 
alkali flats, and burned fields, but they preferred native valley sink 
scrub (low vegetation dominated by alkali-tolerant shrubs) and 
nonnative grazed or burned grasslands over any of the more common 
cultivated land types (Knopf and Rupert 1995, pp. 747-749). Winter 
habitat availability in California's Carrizo Plain seems linked to a 
combination of livestock grazing and precipitation, with heavy grazing 
and dry conditions creating conditions most favorable to the mountain 
plover. Giant kangaroo rat (Dipodomys ingens) precincts (colonies) are 
also used, especially when wet years produce tall vegetation elsewhere 
(Sharum 2010, pers. comm.).
    Mountain plover exclusively used cultivated sites in the Imperial 
Valley of California (Wunder and Knopf 2003, pp. 74-75). While 
cultivated lands are abundant throughout the Imperial Valley, not all 
provide suitable feeding habitat. Mountain plover were found to favor 
irrigated farmland, including burned bermudagrass (Cynodan dactylon); 
harvested, grazed, or sprouting alfalfa (Medicago spp.) fields; and 
newly cultivated fields (Wunder and Knopf 2003, pp. 75-76; AMEC Earth 
and Environment 2003, p. 12). Fallow fields were used mostly for 
roosting, and melon and vegetable fields were rarely or never used 
(Wunder and Knopf 2003, pp. 75-76). Insect availability, furrow depth, 
size of dirt clods, and the vegetation on contiguous land parcels were 
all believed to influence the suitability of agricultural fields to 
mountain plover.
    In California, annual climatic variability, especially abundant 
rainfall, influences field conditions and can reduce mountain plover 
use of traditionally occupied wintering sites. For example, mountain 
plover became virtually absent from cultivated fields in the Imperial 
Valley during the rainy winter of 2004-2005 (Knopf and Wunder 2006). 
Movement patterns of wintering mountain plover in California are shown 
to be highly variable, with birds on several occasions moving more than 
34 miles (mi) (55 kilometers (km)) in a week (Knopf and Wunder 2006).
    In Arizona, mountain plover winter on sod farms and grazed 
pastures, and are observed using the same sites yearly. Their use of 
farm fields and other potential habitats is generally unknown, and 
these areas are rarely surveyed (Robertson 2010, p. 1). A few mountain 
plover have wintered in recent years on mowed grasses at Gila Bend Air 
Force Auxiliary Field (Mendelsohn 2010).
    In Texas, winter reports of mountain plover were correlated with 
barren fields and grazed pastures (Holliday 2010). In Williamson and 
Bell Counties, Texas, mountain plover winter only on large, flat, 
plowed fields, especially those with some corn or sorghum stubble 
(Fennel 2002, p. 29). In the Texas coastal bend area (Nueces and San 
Patricio Counties), wintering plover are largely limited to plowed 
fields rather than grasslands or fallow fields, with mountain plover 
often following tractors while feeding (Cobb 2009, pers. comm.). 
Wintering mountain plover in Texas have also been reported using burned 
fields (Knopf and Wunder 2006), sod farms (Cobb 2011, pers. comm.), 
coastal prairies, and alkaline flats (Andres and Stone 2009, p. 12).
    In Mexico, mountain plover are found wintering in grassland areas 
with high densities of prairie dogs (both black-tailed and Mexican) and 
on heavily grazed pastures (Andres and Stone 2009, p. 12; Macias-Duarte 
and Panjabi 2010, pp. 5, 7). Consistent with other areas, open habitat 
with low grass cover and sparse or no shrub cover are elements common 
to areas used by mountain plover in Mexico. However, significant 
mountain plover use of crop fields in Mexico has not been reported 
(Macias-Duarte and Punjabi 2010, p. 7).
    Wunder (2007) studied geographic population structure in mountain 
plover through color-banding and stable isotope concentrations in 
feathers. He concluded that there is widespread mixing of mountain 
plover populations in winter and that birds may use alternate wintering 
sites in different years (Wunder 2007, p. 118). While mountain plover 
appear annually at some favored wintering sites, site fidelity by 
individual birds appears low. Mountain plover can move long distances 
and use various sites even within a given winter.
Survival, Lifespan, and Site Fidelity
    A long-term study on mountain plover breeding grounds in Phillips 
County, Montana, provides much of what is known regarding population 
dynamics of the species. The annual survival rate of adult mountain 
plover of both sexes in Phillips County ranged from 0.74 to 0.96 yearly 
(Dinsmore 2008, p. 50). The annual survival rate for juvenile mountain 
plover (survival to 1 year of age) was 0.06 at hatching, but for those 
chicks that reached fledging age was 0.62 (Dinsmore 2008, p. 51). 
Survival estimates did not account for permanent emigration (birds 
surviving but returning in subsequent years to sites outside of the 
study area), so the actual annual survival may have been higher.
    Previous estimates of survival rates and of estimated mean lifespan 
of 1.92 years (Dinsmore et al. 2003, pp. 1020-1021) supported our 
December 5, 2002, conclusion that the mountain plover had a shorter 
lifespan than other plovers (Charadriidae) (67 FR 72397) and that this 
might impact its opportunity to reproduce. These conclusions 
underestimated adult mountain plover survival. The longer study of the 
same population over years with varying weather and habitat conditions 
modified the earlier conclusions regarding the mountain plover's 
longevity. Mountain plover of 5 to 7 years of age were frequently 
encountered, and a longevity record over 10 years was established 
(Dinsmore 2008, p. 52). Based on this additional research, survival 
rates for mountain plover appear comparable to those reported for other 
plovers, and the mountain plover is now considered a relatively long-
lived species (Dinsmore et al. 2010, unpaginated). We no longer believe 
that the mountain plover's lifespan is a liability that could 
contribute to the negative impact of natural or manmade events 
affecting the species.
    Mountain plover have a high nest survival rate compared to other 
ground-nesting species (Dinsmore et al. 2010), but nest success in 
mountain plover has varied greatly from study to study. Successful 
hatching (of at least one egg) ranged from 26 percent (Knopf and

[[Page 27761]]

Rupert 1996, pp. 29-30) to 65 percent (Graul 1975, p. 18). Dinsmore et 
al. (2002, pp. 3485-3486) found differences in nest success between 
nests incubated by males (49 percent) and females (33 percent). Dreitz 
and Knopf (2007, p. 684) found nest success of 37 percent with no 
appreciable difference between nests on agricultural fields and on 
native rangeland.
    There have been relatively few studies of chick survival (hatching 
to fledging) and results vary greatly. Dreitz (2009, p. 6) estimated 
that 30-day survival of chicks of mountain plover from prairie dog 
colony nesting habitat was 75 percent, and that 30-day survival on 
other grasslands and on agricultural fields was less than 25 percent. 
Following similar methodology, research on crop fields in Nebraska 
found 95 percent survival of chicks accompanying 31 adult mountain 
plover that were radio-tracked for the 36 days after eggs hatched 
(Blakesley and Jorgensen 2010). Radio contact was lost with other 
adults (due to birds leaving the area or transmitter failure), but even 
if assuming all chicks associated with these adults perished, chick 
survival was at least 58 percent (Blakesley and Jorgensen 2010). Dreitz 
et al. (2010) studied post-hatching chick survival (hatching to 
fledging) via radio-tracking in Colorado and Montana. The study 
targeted factors affecting survival, including landscape 
characteristics, with an objective of informing conservation and 
management efforts. Field studies in 2010 were hampered by unusually 
cold and wet weather. Of 93 chicks radio-tracked over three habitat 
types in Colorado, only 9 were confirmed to survive to 30 days (Dreitz 
et al. 2010, p. 3). Thirty-eight confirmed mortalities included 13 from 
avian predators, 8 from mammalian predators, and 17 from unknown 
predation, weather, and undetermined factors. Contact with other chicks 
was lost, and their fates were unknown. Results did not reflect higher 
chick survival on prairie dog towns than on other grasslands or 
agricultural fields. In Montana, only 1 of 39 chicks monitored on 
black-tailed prairie dog colonies was confirmed to survive to 30 days. 
Nineteen mortalities were documented, with 13 from heavy rains (Dreitz 
et al. 2010, p. 4). Sources of mortality differed among habitats in 
Colorado, with avian predation higher at black-tailed prairie dog towns 
(Dreitz et al. 2010, p. 6). However, results of the study are 
considered preliminary, and future work is planned.
    Few studies have estimated seasonal adult survival rates. Dreitz 
(2010, unpaginated) found 89 percent survival of adults with broods for 
the 30 days after hatching. A study of overwintering mountain plover in 
California showed nearly 95 percent survival of wintering birds from 
November 1 to March 15 (Knopf and Rupert 1995, p. 746). Since survival 
of adults during stationary periods is believed to be relatively high, 
and there is no estimate for adult survival during spring and fall 
migration, there is potential that losses of adults during migration 
may be significant and efforts to increase adult survival might be 
focused on migration periods (Dinsmore et al. 2003, p. 1023; Andres and 
Stone 2009, p. 1; Dinsmore et al. 2010). However, there is no 
scientific information available to indicate that high mortality during 
migration is occurring.
    A life stage-specific model based on data from three breeding 
areas, two in Colorado and one in Montana, found that mean adult 
survival was the parameter that most influenced modeled population 
growth (Dinsmore et al. 2010). The importance of adult survival was 
characterized as typical of long-lived bird species, for which repeated 
reproductive attempts throughout life are less important to population 
growth, as evidenced by low chick survival, than adult survival 
(Dinsmore et al. 2010). Nest survival was comparable to, or higher 
than, other ground-nesting shorebirds and was less important to 
population growth than survival of chicks, juveniles, and adults. Large 
variation in estimates of chick survival led to the conclusion that to 
improve population viability on breeding areas, management to increase 
chick survival should be a priority. The authors believed such 
management should be emphasized over past efforts to decrease nest 
losses and increase hatching success (Dinsmore et al. 2010). However, 
the authors conceded that management to improve chick survival is more 
difficult than improving hatching success and might require large-scale 
habitat improvement.
    Mountain plover were thought to have high site fidelity to nesting 
locations, returning to same area where they hatched each year (Graul 
1973, p. 71). Skrade and Dinsmore (2010, p. 672) quantified mountain 
plover dispersal on breeding sites in Montana and reported juvenile 
(natal) dispersal (hatching year to return at age 1) averaged 8.1 mi 
(13.0 km) for males and 6.3 mi (10.2 km) for females. Only 4 of 38 
banded chicks returning as adults arrived back at the same black-tailed 
prairie dog colony where they were banded. Knopf and Wunder (2006) 
noted a chick that had dispersed over 30 mi (50 km) in Colorado.
    The previous year's nesting success influences adult dispersal; 
unsuccessful adults disperse farther than successfully breeding adults 
(Skrade and Dinsmore 2010, p. 671). While adults rarely move far from 
the area where they nested the previous year, evidence of potential for 
year-to-year dispersal in adults is exemplified by an adult mountain 
plover banded on a breeding area in Colorado in 2009, that was found 
nesting approximately 25 mi (40 km) away in Nebraska in 2010 (Bly 
2010b, pers. comm.).
    Results from genetic studies suggest that gene flow among breeding 
areas is sufficient to offset genetic effects of small populations and 
reported adult fidelity to breeding areas (Oyler-McCance et al. 2008, 
pp. 496-497).
Population Size and Trends
    Mountain plover are difficult to detect because they are 
cryptically colored and in general are widely distributed at low 
densities (Knopf and Wunder 2006). Based on historical observations of 
mountain plover and extensive habitat changes, there is general 
agreement that the mountain plover is currently greatly reduced in 
numbers and range compared to their numbers and range prior to European 
settlement (Graul and Webster 1976, p. 265; Knopf and Wunder 2006). The 
mountain plover's historical breeding range is believed to have 
differed from that currently occupied primarily in its eastern extent, 
which may have encompassed the western thirds of North Dakota, South 
Dakota, and Nebraska, and more of western Kansas and the Texas 
Panhandle than is currently occupied (Graul and Webster 1976, p. 265, 
Knopf and Wunder 2008).
    Population estimates for the species, both historical and recent, 
appear imprecise. Graul and Webster (1976, p. 266) estimated that 
mountain plover populations in Montana, Wyoming, eastern Colorado, and 
New Mexico then totaled 214,200 to 319,220 birds, with 20,820 in the 
population stronghold of Weld County, Colorado. However, Knopf and 
Wunder (2008) cited Graul (pers. comm.) as saying that the estimates 
may have been off (i.e., high) by an order of magnitude (a factor of 
10).
    Knopf (1996, p. 12) estimated the total population of mountain 
plover to be about 8,000 to 10,000, based on a 1994 wintering survey in 
California and on assumptions regarding proportion of the wintering 
population observed (i.e., that only half of birds wintering in 
California had been counted and that 1,000 to 3,000 birds wintered in 
Texas and other areas). We cited this estimate in our

[[Page 27762]]

December 5, 2002, proposed rule (67 FR 72396). In our September 9, 
2003, withdrawal of our proposed listing (68 FR 53083), we again cited 
the Knopf estimate above and, using similar assumptions and newer 
California winter survey data (1998-2002), provided a rangewide 
estimate of 5,000 to 11,000 mountain plover. More recent studies, which 
estimated populations present on specific portions of the breeding 
range, have resulted in a higher rangewide estimate of the mountain 
plover breeding population. After investigating Wyoming populations, 
Plumb et al. (2005b, p. 15) estimated a minimum of 3,393 mountain 
plover in Wyoming (up from previous estimates of 500 to 1,500) and 
estimated a rangewide total of 11,000 to 14,000 mountain plover. Based 
on newer information, including an upward revision of estimated 
mountain plover numbers on the eastern Colorado plains (a conservative 
estimate of 8,577 birds), Tipton et al. (2009, p. 497) provided a 
rangewide estimate of 15,000 to 20,000 mountain plover. Andres and 
Stone (2009, p. 8) reviewed available data and provided a coarse, 
minimum rangewide estimate of 18,000 breeding mountain plover. Knopf 
and Dreitz (in press) concluded that the continental breeding 
population is ``certainly larger'' than the 17,500 birds estimated in 
Montana, Wyoming, and Colorado, citing small populations in contiguous 
States, a potentially significant population in New Mexico, and an 
unknown population in Mexico. Based on our review of recent data, 
including those from Nebraska (Van der Berg et al. 2010) and New Mexico 
(see Breeding Range below), we estimate that the current rangewide 
mountain plover breeding population exceeds 20,000 birds. This was 
supported by Knopf (2009, pers. comm.). We have no information to 
indicate that this estimate reflects an actual increase in rangewide 
mountain plover numbers over previous, lower estimates. Instead, it 
likely reflects the limitations of those earlier rangewide estimates 
(based on mountain plover wintering in California that largely 
discounted birds wintering elsewhere) and more accurate recent 
estimates of breeding populations.
    Accurate trend information for mountain plover numbers is generally 
lacking. Interpreting trends from the two long standing surveys, the 
Breeding Bird Survey (BBS) and the National Audubon Society's Christmas 
Bird Count (CBC), suffer from a variety of problems, including the 
inherent difficulties associated with using a survey of only a small 
portion of a total population to infer rangewide trends (Knopf and 
Wunder 2004, p. 1).
    The BBS is a large-scale survey of North American birds that began 
in 1966, and is conducted during the breeding season by observers 
driving along roads over established routes. Knopf (1996, p. 12) cited 
BBS data from 1966 through 1993 as indicative of a steep decline in 
mountain plover numbers across their breeding range (3.7 percent per 
year, a decline of approximately two-thirds over the period). However, 
Knopf and Wunder (2004, p. 1) suggested that the timing of surveys 
(which occur mostly in June when mountain plover are less conspicuous) 
and the low densities at which mountain plover occur prevent reliable 
trend estimates.
    Based on recent BBS data analysis (Sauer 2010a), the mountain 
plover has declined rangewide at an estimated rate of 2.6 percent per 
year for the period from 1966 to 2009 (95 percent confidence interval 
(CI) -6.7 to +0.6). However, for the period from 1999 through 2009, the 
estimated rate of decline decreased to 1.1 percent per year (95 percent 
CI -5.8, +9.6) (Figure 2). While neither estimate varies statistically 
from a stable population (at a 95 percent CI), the probability that the 
estimated long-term trend (1966 through 2009) is less than or equal to 
zero is 95 percent. The probability that the estimated short-term trend 
(1999 through 2009) is less than or equal to zero is 68 percent. The 
estimated long-term decline is consistent with the generally accepted 
conclusion that the mountain plover's rangewide population is currently 
smaller than it was in the 1960s. The more recent (1999 through 2009) 
estimated decline and associated CI lead us to conclude that most or 
all of the long-term decrease took place before 1999, that any recent 
declines are modest, and that the mountain plover population may be 
near stable.

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[GRAPHIC] [TIFF OMITTED] TP12MY11.001

    Sauer (2011, pers. comm.) concluded that limited regional data from 
the BBS (i.e., the low numbers of routes reporting the species and low 
numbers of mountain plover observed) resulted in imprecise trend 
estimates within individual States and for the time periods of 
interest. He also concluded that BBS data only provide an imprecise 
summary of mountain plover population dynamics, and the limited sample 
size likely reflects the limitations of the roadside sampling frame in 
sampling mountain plover breeding populations.
    We conclude that, while the BBS is the only long-term trend 
information available for the mountain plover on its breeding range, it 
is an imprecise indicator of mountain plover population trends. Given 
the wide confidence interval and the conclusion by Sauer (2011, pers. 
comm.) above, the data provide limited support for any recent (1999 
through 2009) trend in mountain plover numbers. Even so, we acknowledge 
that this is the best available information on trends for this species 
and BBS survey results suggest a recent (1999 through 2009) moderated 
rate of decline (Figure 2). We provide long-term and recent BBS trend 
estimates for three States where the sample size allowed for analysis 
(see Conservation Status and Local Populations below), but with the 
same reservations regarding precision.
    The CBC is an annual count performed around the end of December in 
which volunteers observe birds in 15-mi (24-km) radius count circles. 
While CBCs can be used to infer species population trends, spatial 
coverage is limited (Knopf and Wunder 2004, p. 1) and established count 
circles commonly coincide with populated areas where volunteers are 
available. The CBC data estimated an annual decrease of 2.8 percent in 
mountain plover observed from 1966 through 2007, but reliability was 
described as low (Butcher and Niven 2007, Appendix 1).
    The vast majority of mountain plover reported in CBCs come from 
California and, within California, from the South Salton Sea count. 
Pandolfino (2009, unpaginated) submitted his analysis of CBC data for 
California and recognized the data's limitations, but concluded that 
the data reflected long-term and recent declines in mountain plover 
numbers wintering in California. The CBC data on mountain plover 
numbers is highly variable from year to year. The Salton Sea South CBC, 
the only CBC in the Imperial Valley, is limited in scope and does not 
include portions of the valley where most mountain plover have been 
seen (Wunder and Knopf 2003, p. 76). Inherent limitations in data 
collection methods (volunteers surveying small areas relative to total 
winter range) and lack of sufficient detections of mountain plover in 
California count circles (Hunting et al. 2001, p. 40) render trend 
analysis uncertain. CBC data from other States and Mexico is even less 
representative

[[Page 27764]]

of wintering populations and provides no insight into possible trends 
for the mountain plover.
    We conclude, based on observations across the mountain plover's 
range and BBS trend data, that a historical decline of the mountain 
plover has occurred since the 1960s. However, we agree with the 
conclusion of Andres and Stone (2009, p. 3) that precise and accurate 
information on recent trends in mountain plover numbers is lacking. The 
recent (1999 through 2009) decline estimate from BBS data is modest 
(1.1 percent per year) and any difference from a stable population 
estimate (slope of 0.0) is statistically insignificant. However, we 
acknowledge that the BBS data is the best available information on 
trends for the mountain plover and that BBS results suggest a recent 
(1999 through 2009) moderated rate of decline (Figure 2). The CBC 
wintering data are highly variable and come mostly from California, but 
also suggest a long-term decline. No comprehensive trend data across 
the mountain plover's wintering range are available. The discussion 
below provides information on populations and trends within States, 
Canada, and Mexico, where available.
Conservation Status and Local Populations
    The mountain plover is listed as endangered in Canada, as a 
sensitive species in Alberta, and as a threatened species in Mexico 
(Andres and Stone 2009, p. 13; Gober 2010). The mountain plover is 
identified by the Service as a Bird of Conservation Concern (Service 
2008), is considered ``highly imperiled'' in the U.S. Shorebird 
Conservation Plan (2004, p. 2), a category assigned to species listed 
as threatened or endangered nationally, and all species with 
significant population declines and either low populations or some 
other high risk factor. It is also identified as ``G3-vulnerable'' by 
NatureServe (2010). The species is listed as a sensitive species by the 
U.S. Forest Service (USFS) (2010) and by the Bureau of Land Management 
(BLM) (2000a, 2006, 2010a). It is identified as a species of global 
conservation concern in the American Bird Conservancy and National 
Audubon Watchlist, and it is listed as ``near threatened'' by the 
International Union for the Conservation of Nature (IUCN) (BirdLife 
International 2010). The designations discussed above may, in part, 
reflect population estimates at the time those designations were 
established. The IUCN previously (from 2004 to 2007) listed the species 
as ``vulnerable,'' a higher level of concern than ``near threatened,'' 
but changed its rating as higher rangewide population estimates 
emerged. The U.S. Shorebird Conservation Plan provided a rangewide 
estimate of 9,000 mountain plover until 2006, when the estimate was 
revised upward to 12,500 (Morrison et al. 2006, p. 69).
    All States within the range of the mountain plover have included 
the species in their Comprehensive Wildlife Conservation Strategy or 
Wildlife Action Plans or both (State Plans) (Arizona Game and Fish 
Department 2006; University of California 2005; Colorado Division of 
Wildlife 2006; Wasson et al. 2005; Montana Fish, Wildlife and Parks 
2005; Schneider et al. 2005; New Mexico Department of Game and Fish 
2006; Oklahoma Department of Wildlife Conservation 2005; Texas Parks 
and Wildlife 2005; Wyoming Game and Fish Department 2005) as either 
``Species of concern'' or ``Species of greatest conservation need.'' 
Each State categorizes species under these designations based on 
available information about the status, distribution, and trend of the 
species in their State. They are not regulatory classifications, but 
rather are intended to guide resource managers in making proactive 
decisions regarding species conservation and data collection 
priorities. The State Plans are not intended to be specific action 
plans for any species. These designations do not result in any 
protection for the species. However, the mountain plover is identified 
as threatened in the State of Nebraska, the only State where the 
species is listed as endangered or threatened.
Breeding Range
Colorado
    In Eastern Colorado, the shortgrass prairie ecosystem provides 
flat, dry breeding habitat for the mountain plover. The species 
occupies grasslands within prairie dog colonies, grasslands without 
prairie dog colonies, and dry land agricultural fields (Dreitz et al. 
2005, pp. 129-130; Tipton et al. 2009, p. 496).
    Knopf and Miller (1994, p. 504) noted the PNG, Weld County, 
Colorado, as a breeding stronghold for the species, but in the mid-
1990s the population fell dramatically. The PNG now supports relatively 
few breeding mountain plover. In 2009, Knopf provided an overview of 
mountain plover studies on the PNG from 1986 through 2007. He suggested 
that mountain plover numbers on the PNG had been in decline since the 
late 1930s and early 1940s, and that the dramatic decline in the mid-
1990s was the abrupt endpoint of a process of deteriorating habitat, 
exacerbated by other factors such as wet spring weather, increased 
predation, and the relocation of breeding mountain plover to better 
habitats elsewhere (Knopf 2008, p. 61).
    Despite the virtual loss of the PNG population, over half of all 
mountain plover are thought to breed in Colorado (Andres and Stone 
2009, p. 15). A recent study reported a conservative estimate of 8,577 
breeding mountain plover in eastern Colorado (95 percent CI 7,511 to 
35,130) (Tipton et al. 2009, p. 497). A separate, higher elevation 
population in South Park, Park County, Colorado, was estimated at 2,310 
adults (Wunder et al. 2003, p. 661). Surveys through 2006 suggested a 
stable population in South Park, with any variation largely 
attributable to wet years and dry years affecting breeding conditions 
(Wunder 2010a). Small numbers of mountain plover also occur in 
Colorado's San Luis Valley (Hicks-Anderson and VerCauteren 2006, 
entire). Andres and Stone (2009, p. 8) provided population estimates 
for the United States, Canadian provinces, and Mexican States based on 
their review of all available information. Their estimate of 11,000 
mountain plover breeding in Colorado appears appropriate given 
information available.
    The BBS data from Colorado, 1966 through 2009 (-0.9 percent decline 
annually, 95 percent CI (-7.0 to 3.5)) and 1999 through 2009 (0.3 
percent increase annually, 95 percent CI (-5.5 to 14.7)) (Sauer 2010a), 
suggest little long-term or recent change in breeding numbers in 
Colorado. Based on these data, we conclude that the current breeding 
population in Colorado, which likely supports half or more of all 
breeding mountain plover, is relatively stable.
Wyoming
    Wyoming has the highest estimated number of breeding mountain 
plover outside of Colorado. The mountain plover is locally common and 
has been detected in every county of Wyoming (Smith and Keinath 2004, 
p. 3). A projected 20.5 million ac (8.3 million ha) of mountain plover 
habitat exists in Wyoming, with 59 percent occurring on public lands 
(Wyoming Natural Diversity Database (WYNDD) 2010; Emmerich 2010).
    Nesting of mountain plover in Wyoming occurs in both grassland, 
mostly in the eastern part of the State, and desert-shrub (Plumb et al. 
2005b, p. 20). Mountain plover densities were comparable across habitat 
types with overall density only slightly higher in grassland than in 
desert-shrub (Plumb et

[[Page 27765]]

al. 2005b, p. 20). Mountain plover appear to have less association with 
prairie dog habitat in Wyoming than elsewhere (Plumb et al. 2005a, p. 
226). Little of the mountain plover breeding range in Wyoming 
(approximately 12 percent) is on cropland Knopf and Rupert 1999, p. 
85).
    Plumb et al. (2005b, pp. 19-20) estimated a minimum population of 
3,393 mountain plover in Wyoming in 2002 and 2003. Andres and Stone 
(2009, p. 8) provide an estimate of 3,400 mountain plover breeding in 
Wyoming. This number is based on Plumb et al.'s estimate and, like that 
estimate, it reflects the minimum number likely present. Given that 
Plumb et al. (2005b, pp. 19-20) provided a conservative estimate, the 
actual breeding population is likely larger; however, we have no basis 
to provide a more accurate estimate.
    The BBS data from Wyoming (Sauer 2010a), 1966 through 2009 (-1.2 
percent decline annually, 95 percent CI (-5.7 to 3.3)) and 1999 through 
2009 (-2.3 percent decline annually, 95 percent CI -13.9 to 4.5)), 
suggest that both long-term and recent declines in breeding mountain 
plover numbers in Wyoming may have occurred.
Montana
    Primary breeding habitat for mountain plover in Montana is in the 
north-central portion of the State where mountain plover are highly 
dependent on black-tailed prairie dog colonies for habitat. Montana 
Fish, Wildlife and Parks modeled suitable mountain plover habitat in 
the State. Mapping indicated that the greatest area of highly suitable 
habitat occurs in Phillips, Blain, Valley, and Fergus Counties with 
patchy distribution though the central and southeast portions of the 
State. The total area of suitable habitat estimated was 18.5 million ac 
(7.5 million ha) (McDonald 2010).
    Childers and Dinsmore (2008, p. 706) reported an estimate of 1,028 
mountain plover in Phillips and Valley Counties in 2004 (95 percent CI 
(903 to 1,153)). In 2010, standardized census areas in southwest, 
central, and northeast Montana produced fewer sightings than previous 
surveys (1992-2000, 2004); however, McDonald (2010) stated that results 
were negatively influenced by above average rainfall, increased 
vegetation height, and limited private land access; therefore, results 
cannot be relied upon. Other than apparent confirmation of a previously 
documented decline in the southwest census area (FaunaWest Wildlife 
Consultants 2004, pp. 4-5), no trends could be inferred from the 2010 
survey.
    Andres and Stone (2009, p. 8) used the above estimate by Childers 
and Dinsmore (2008, p. 706) and previous estimates of about 600 
mountain plover elsewhere in Montana and provided a Statewide estimate 
of approximately 1,600 mountain plover. BBS observations of mountain 
plover on routes in Montana were insufficient to provide estimates of 
population trend.
New Mexico
    Most breeding season reports of mountain plover in New Mexico have 
come from the northeast and western counties. Sager (1996, pp. 8-9) 
found 152 presumed breeding adults at 35 sites in 11 counties in 
northern New Mexico. Marguilies et al. (2004, p. 3) estimated 200 
mountain plover in Union County alone throughout the summer and located 
46 nests. In a limited effort, they also found 22 mountain plover and 
six nests on public lands in Taos and Colfax Counties.
    At BLM's North Unit, Taos County, point counts in 2005 through 2007 
estimated 176 mountain plover on 8,400 ac (3,400 ha) of the 50,000-ac 
(20,000-ha) unit considered to be favorable mountain plover breeding 
habitat, based on past observation of mountain plover (Hawks Aloft 
2007, pp. 9-11). If the entire unit was occupied at the same density, 
an estimated 1,000 mountain plover might have been present on the North 
Unit. Manderson (2010, pers. comm.) inspected habitat away from survey 
routes in 2010, and suggested that, based on habitat quality, 500 or 
more mountain plover could be present on the entire unit. Mountain 
plover numbers seen on the same survey routes in 2010 were comparable 
to those in earlier (2005 through 2007) surveys (Hawks Aloft 2010, p. 
13), suggesting this population may be stable.
    Goguen (2010, pers. comm.) estimated a minimum of 40 to 50 breeding 
mountain plover on the Vermejo Ranch, Colfax and Taos Counties. 
Mountain plover were also recently reported present in El Malpais 
National Conservation Area, Cibola County (Hawks Aloft 2008, entire).
    We found no Statewide breeding surveys or estimates of Statewide 
breeding populations for mountain plover in New Mexico, other than 
Andres and Stone's (2009, p. 8) conservative estimate of 500. Given the 
above data from Union County, the BLM's North Unit in Taos County, the 
Vermejo Ranch in Colfax and Taos Counties, and likely mountain plover 
occurrence in several other counties, we believe that at least 1,000 
and potentially significantly more mountain plover breed in New Mexico.
    BBS data from New Mexico (Sauer 2010a), 1966 through 2009 (-5.0 
percent decline annually, 95 percent CI (-8.6 to -1.2)) and 1999 
through 2009 (-4.8 decline annually, 95 percent CI (-12.1 to 2.7)), 
demonstrate a long-term decline and also suggest a short-term decline 
in breeding mountain plover numbers in New Mexico. New Mexico is the 
only State for which the long-term BBS trend statistically differs from 
zero.
Nebraska
    In our December 5, 2002, proposal to list the mountain plover we 
estimated 200 mountain plover in Nebraska (67 FR 72399). Recent studies 
attempted to identify the extent of breeding distribution and 
population size in Nebraska (Bly et al. 2008, entire). Most nests were 
found on agricultural fields in Kimball County, in extreme southwestern 
Nebraska, but mountain plover were also found in nearby Cheyenne and 
Blain Counties. The minimum breeding population was estimated to be 80 
adults in 2007, based on nests found, and the total estimate of 
breeding birds ranged upward to 360 (Bly et al. 2008, p. 127). Van der 
Burg et al. (2010, pp. 50-53) reported on monitoring in the same three 
counties (Kimball, Cheyenne, and Blain) in southwestern Nebraska and 
estimated that mountain plover breeding numbers of 1,650, 1,617, and 
1,558 over 3 years of the study (2005, 2006, and 2007, respectively). 
The authors attributed past low estimates in Nebraska to: (1) Low 
detection probabilities; (2) clumped spatial distribution of mountain 
plover, which their estimation methodology corrected for; and (3) 
``chronic undersampling.'' Given the above estimates from Van der Burg 
et al. (2010, pp. 50-53), an estimate by Andres and Stone (2009, p. 8) 
of 500 breeding mountain plover in Nebraska appears low.
    Nebraska is the only State that has regulatory mechanisms in place 
to conserve the mountain plover and its habitat, which likely protect 
relatively few individuals. The Nebraska Game and Parks Commission 
lists the mountain plover as a ``threatened'' species. Listing of 
endangered and threatened species identifies those animals and plants 
whose continued existence in Nebraska is in jeopardy. Efforts can then 
be made to restore the species or to prevent extirpation or extinction. 
Once a species is listed, a State law, titled the Nebraska Nongame and 
Endangered Species Conservation Act, automatically prohibits take, 
exportation, and possession, and imposes severe penalties on violators 
(Nebraska Game and Parks Commission

[[Page 27766]]

2011). Proposed projects that would be authorized, funded, or carried 
out by Nebraska State agencies are reviewed as part of a mandatory 
consultation process designed to prevent a State action from 
jeopardizing the existence of an endangered or threatened species. 
Recovery plans for endangered or threatened species are developed; 
these recovery plans identify, describe, and schedule the actions 
necessary to restore populations of these animals and plants to a more 
secure status. Given that most mountain plover in Nebraska occur on 
private agricultural lands, there are not many State projects that are 
reviewed under the law. It is generally implemented only 4 or 5 times 
per year, primarily on transportation, transmission, and energy 
development projects (Lackey 2011, pers. comm.). While this law may 
provide protection for some individual mountain plover in Nebraska, we 
believe that it would only have minimal positive effects on the entire 
population in Nebraska, or on the rangewide population.
Oklahoma
    Recent studies to determine the breeding distribution and 
population size in Oklahoma detected mountain plover in Cimarron and 
Texas Counties in the Oklahoma panhandle, mostly on fallow or barren 
agricultural fields (McConnell et al. 2009, pp. 30-33). Randomized 
point counts were used to derive a Statewide population estimate of 68 
to 91 birds (McConnell et al. 2009, pp. 32-33). Andres and Stone (2009, 
p. 8) estimated 200 mountain plover breeding in Oklahoma. Given results 
of McConnell et al. (2009, pp. 32-33), we believe that Andres and 
Stone's (2009, p. 8) estimate may be slightly high. The range of the 
mountain plover in Oklahoma was described as stable over the past 100 
years, with the suggestion that populations may have changed little 
(Hatcher 2010).
Kansas
    The Kansas Department of Wildlife and Parks (2005) stated that 
mountain plover breed only on dry upland in the shortgrass prairie of 
western Kansas. While conversion to agriculture has left little native 
breeding habitat, Cable and Seltman (2010, pp. 50-51) reported mountain 
plover are an uncommon but regular breeding species in western Kansas 
and that they also use idle cropland. Morton County may also serve as a 
staging area for migration in late summer (Cable and Seltman 2010, p. 
51). Andres and Stone (2009, p. 8) estimated 200 breeding mountain 
plover in Kansas. No comprehensive surveys of breeding mountain plover 
in Kansas have been attempted; however, given their apparent use of 
both prairie and cropland, and a substantial population in nearby 
Colorado, the estimate may be appropriate.
Texas
    The mountain plover likely breeds in Texas, but there are no 
confirmed reports of breeding since 1993 (Andres and Stone 2009, p. 
16). Holliday (2010) described breeding season sight reports of 
mountain plover from the Texas Panhandle near known Oklahoma breeding 
sites. Holliday (2004) also mapped potential breeding habitat, much of 
it on private land that has not been surveyed. Andres and Stone (2010) 
did not provide an estimate of breeding mountain plover in Texas. We 
believe that at least minimal numbers of mountain plover breed in 
Texas.
Arizona
    The only known mountain plover nesting in Arizona is in Apache 
County in east-central portion of the State, with at maximum perhaps a 
dozen breeding birds (Gardner 2010, pers. comm.). Breeding has occurred 
on grasslands where cattle were concentrated and at Gunnison prairie 
dog (C. gunnisoni) colonies (Corman 2005, pp. 591-591; Gardner 2010). 
However, hundreds of square miles of potential breeding habitat in 
northern and western Arizona have never been surveyed, and there are 
reports of potential breeding mountain plover on Tribal lands in Navajo 
County (Corman 2005, pp. 591-591; Gardner 2010, pers. comm.). Andres 
and Stone (2009, p. 8) estimated 100 breeding mountain plover in 
Arizona. This estimate acknowledges potential for a more substantial 
breeding population than limited observations have documented.
Utah
    The mountain plover has been a historically rare breeder in shrub-
steppe habitat in the Uinta Basin of northeastern Utah. Manning and 
White (2001, p. 225) described a small breeding population that 
averaged about 15 adults yearly. Mountain plover breeding in the area 
subsequently declined, and no birds have been found during surveys of 
the area since 2003 (Maxfield 2010, pers. comm.). Andres and Stone 
(2009, p. 8) estimated fewer than 50 breeding mountain plover in Utah. 
Based on no recent records of breeding mountain plover, this estimate 
may be optimistic.
North Dakota and South Dakota
    The mountain plover once bred in these States, with higher numbers 
present in South Dakota, but there are no recent breeding records in 
either North Dakota or South Dakota (North Dakota Game and Fish 
Department 2010; South Dakota Game, Fish and Parks 2010).
Canada
    A review of breeding records for Canada (Knapton et al. 2006, p. 
33) concluded that the mountain plover is a peripheral species in 
Canada with no evidence that it was ever a common or regular breeder. 
The first breeding record was documented in 1979 and the most recent in 
2007 (Knapton et al. 2006, pp. 32-33; Holroyd 2010, pers. comm.). Most 
sightings and breeding records come from extreme southeastern Alberta, 
with at least one incidence of confirmed breeding in Saskatchewan. 
Holroyd (2010, pers. comm.) provided updated records of sightings 
through 2009, mostly from Alberta. Andres and Stone (2009, p. 8) 
estimated fewer than 100 mountain plover breeding in Canada. We are not 
aware of any attempts to systematically survey all potential breeding 
areas in the Canadian range. However, given the low number and limited 
distribution of reported recent sightings (Holroyd 2010, pers. comm.), 
we believe that actual breeding numbers are fewer than 100.
Mexico
    Breeding records of mountain plover in Mexico have been documented 
in southeastern Coahuila and Nuevo Leon, following a history of 
breeding season observations in Mexican prairie dog colonies (Desmond 
and Chavez-Ramirez 2002 entire; Gonzalez-Rojas 2006, pp. 81-84). 
Nesting is suspected in San Luis Potosi, 130 mi (200 km) south of the 
above records (Luevano et al. 2010, p. 123).
    The extent of mountain plover breeding in Mexico is largely 
unknown. Andres and Stone (2009, pp. 8, 15) estimated fewer than 300 
mountain plover breeding in Mexico (fewer than: 50 in Chihuahua, 100 in 
Cohuila, 100 in Nuevo Leon, and 50 in San Luis Potosi), but suspect 
that if there are major concentrations of breeding mountain plover not 
yet discovered anywhere in their range, they are likely in Mexico. The 
estimate of fewer than 300 birds is at best a guess, but is 
appropriately conservative given the lack of knowledge regarding 
breeding mountain plover occurrence and distribution in Mexico.
    In summary, we believe that the rangewide breeding population of 
mountain plover likely exceeds 20,000, with largest populations in 
Colorado, conservatively 11,000; Wyoming,

[[Page 27767]]

conservatively 3,400; Montana 1,600; Nebraska 1,600; New Mexico, at 
least 1,000 and potentially many more; and smaller populations 
elsewhere (Kansas, Oklahoma, Texas, Utah, Canada, and Mexico).
Wintering Range
California
    Mountain plover are found from north-central California to the 
Mexico border, mostly from September to mid-March, with peak numbers 
from December through February (Knopf and Wunder 2006; Hunting and 
Edson 2008, p. 181). Mountain plover were historically common on the 
coastal plain in southern California (coastal prairie, alkaline flats, 
agricultural fields) before being displaced by human development 
(Hunting and Edson 2008, p. 182; Wunder and Knopf 2003, p. 78). 
Historically, much of the mountain plover habitat in the Central Valley 
grasslands was lost following the decline of grazing elk (Cervus 
canadensis), pronghorn antelope, burrowing kangaroo rats, ground 
squirrels (Spermophilus spp.), and other mammals. The combined 
activities of these herbivores maintained suitable habitat conditions 
for mountain plover, conditions closely resembling habitat 
characteristics found on breeding habitats (Knopf and Rupert 1995, p. 
750). Farther south in California, desert scrub in the Imperial Valley 
was converted to agriculture beginning in the 1940s, creating important 
wintering habitat for the mountain plover. See Hunting and Edson (2008, 
p. 181) for details of the mountain plover's historical range and 
abundance in California.
    Mountain plover currently occur in the greatest numbers in two 
general areas in California: (1) The western Central Valley from 
southern Colusa and Yolo Counties in the north to Kern County in the 
south (especially the western San Joaquin Valley, the name by which the 
southern Central Valley is known); and (2) the Imperial Valley in 
Imperial County (Hunting and Edson 2008, p. 182). The Carrizo Plain, 
separated from the San Joaquin Valley by the Temblor Range, and the 
Panoche Valley are also regularly occupied wintering areas.
    Populations and trends in the Central Valley are difficult to 
determine due to the abundance of potential habitat, flock movements, 
and lack of systematic surveys (Knopf and Rupert 1995, p. 749; Edson 
and Hunting 1999, p. 17). In our December 5, 2002, proposal to list the 
mountain plover (67 FR 72396), we included Edson and Hunting's 1999 (p. 
27) comment that mountain plover were ``rare and local, exceedingly 
rare, or accidental'' within individual counties in the San Joaquin 
Valley. Wunder and Knopf (2003, p. 78) suggested that, as a result of 
habitat loss, many mountain plover had shifted from the Central Valley 
to the Imperial Valley. Hunting and Edson (2008, p. 182) considered 
reports of 200 to 300 birds in the San Joaquin Valley in winter of 
2004-2005, 100 to 200 in Madera County in 2005-2006, 645 in Tulare 
County in December 2005, and about 300 in western Kings County in 
January 2006 to be ``exceptional.'' They also found noteworthy a survey 
total of 381 mountain plover at the Carrizo Plain in 2006 (Hunting and 
Edson 2008, p. 182). However, recent reports from the Central Valley 
also include 645 birds in Madera County in 2006 (McCaski and Garrett 
2006, p. 283), 426 in Tulare County in 2007 (McCaski and Garrett 2007, 
p. 326), 230 in San Joaquin County in 2008 (eBird 2010), 230 in Solano 
County in 2008 (Central Valley Bird Club 2010), and 223 in Kern County 
in 2010 (eBird 2010). These reports suggest that significant numbers of 
mountain plover continue to use widespread areas of the Central Valley 
annually. Nearby, a recent high count for the Carrizo Plain National 
Monument was 540 birds in 2009 (Sharum 2010).
    In the Imperial Valley, coordinated surveys by 26 observers over 2 
days in December 1999 sighted 3,758 mountain plover (Shuford et al. 
2004, p. 7). A survey of mountain plover and their use of cultivated 
fields in the Imperial Valley of California in 2001 found 4,037 birds 
(Wunder and Knopf 2003, p. 75), and 3,476 were counted from January 29 
through February 6, 2002, by four observers, with the largest flock 
consisting of 410 birds (AMEC Earth and Environment 2003, p. 9-10). 
Mountain plover wintering in the Imperial Valley were surveyed in 2003 
and 2004, in an attempt to develop a statistically reliable estimate of 
numbers (Knopf and Wunder 2004, entire). Flocking behavior, mobility, 
and weather were among factors found to limit the reliability of 
Imperial Valley estimates (Knopf and Wunder 2004, pp. 9-12). Results of 
more recent survey estimates in the Imperial Valley include more than 
4,500 mountain plover seen in January 2007, approximately 3,000 seen in 
January 2008, and 827 seen in January 2011 (Kelsey 2011, pers. comm.).
    Hunting et al. (2001 p. 40), Wunder and Knopf (2003, p. 76), and 
Hunting and Edson (2008, pp. 181-183) all suggested a significant 
decline in numbers of mountain plover wintering in California over 
previous decades. However, we found little evidence available to 
establish any trend in more recent (2000 to present) wintering numbers 
in California. The 4,500 mountain plover recorded in the Imperial 
Valley survey in 2007 (Kelsey 2011, pers. comm.) exceeded mountain 
plover observed in Statewide surveys from 1994, and 1998 through 2002 
(Knopf 1996, p. 12; 68 FR 53083). Most recently, a Statewide survey 
over 5 days in January 2011 found 1,235 mountain plover (Kelsey 2011, 
pers. comm.), considerably fewer than found in previous Statewide 
surveys or recent Imperial Valley surveys. However, it is not apparent 
how unusually wet weather or other factors contributed to the 
relatively low number of mountain plover reported in the 2011 survey. 
California experienced heavy rains in late 2010. December 2010 was the 
City of Los Angeles' wettest December in 121 years (Southern California 
Weather Notes 2010).
    While California remains the best documented wintering area for the 
mountain plover, it may winter less than 50 percent of the estimated 
breeding population (Andres and Stone, p. 9). Knopf (1996, p. 12) 
estimated 7,000 mountain plover wintering in California and 1,000 to 
3,000 wintering elsewhere. In our December 5, 2002, proposed rule to 
list the mountain plover as threatened, we suggested that few mountain 
plover wintered in Texas, Arizona, and Mexico (67 FR 72397). We do not 
know the actual number of mountain plover wintering in California or 
how the number varies from year to year; however, given no recent 
evidence that wintering birds in California number more than the 7,000 
estimate above (Knopf 1996, p. 12), and our current rangewide estimate 
of at least 20,000 breeding mountain plover, the previous contention 
that California winters the majority of all mountain plover appears 
incorrect. The fewer mountain plover that are wintering in California, 
on average or in any given winter, the more important that wintering 
areas outside California become. Unfortunately, we have little 
information to pinpoint where the majority of mountain plover are 
wintering.
Texas
    Holiday (2010), based on an examination of LandSat (satellite) 
photos, found that winter records of mountain plover in Texas 
correlated to the distribution of barren fields and grazed pastures. He 
also suggested that the northern limit of the wintering range

[[Page 27768]]

in Texas is related to the average number of frost-free days, which 
influences insect availability. Collins (2006, pp. 27-31) summarized 
mountain plover wintering status in Texas (with much of the compiled 
records and maps attributable to Holliday). Populations in Hondo County 
and Medina County areas were described as potentially the largest; 
Williamson County was characterized as a well-known wintering area, but 
with populations potentially small compared to other less known areas. 
Mountain plover were also present around Wharton, Wharton County, and 
surrounding counties, and the Corpus Christi area was said to 
potentially hold more mountain plover than reports indicate (Collins 
2006, p. 30). Estimates by knowledgeable local birders of wintering 
mountain plover in the coastal bend area (Nueces and San Patricio 
Counties) ranged from 200 up to 2,000 to 3,000 birds (Cobb 2009, pers. 
comm.). The higher numbers were characterized as speculative because 
the vast amount of available habitat where access is generally limited 
makes it difficult to draw any conclusions. Andres and Stone (2009, p. 
20) provided an estimate of 1,500 mountain plover wintering in Texas, 
with a note that abundance could be much greater.
Arizona
    Approximately 500 mountain plover are believed to winter in 
agricultural areas of southern and western Arizona, but numbers could 
be higher because private and Tribal lands are largely unsurveyed 
(Gardner 2010). Wintering numbers in La Paz and Pinal Counties appeared 
stable; numbers in Cochise County have significantly decreased in the 
last 10 to 15 years due to urban expansion; and Yuma County populations 
were characterized as increasing, with 150 to 300 birds annually 
(Gardner 2010; Robertson 2010, pp. 3-4). Wintering mountain plover are 
also reported from the Sulphur Springs Valley in Cochise County 
(Robertson 2010, p. 2). Andres and Stone (2009, p. 20) provided an 
estimate of 200 mountain plover wintering in Arizona. Given limited 
coverage of potential wintering habitat, we consider the above estimate 
of 500 birds wintering in Arizona the likely minimum.
Nevada
    Wintering mountain plover are rarely reported from Nevada, with the 
most recent reports of up to 17 mountain plover coming from the 
Armagosa Valley near the Nevada-California border northwest of Las 
Vegas (eBird 2010).
New Mexico
    While some mountain plover likely winter in southern New Mexico, we 
have no information regarding locations or numbers.
Mexico
    Mountain plover's winter distribution in Mexico has not been well 
studied, but the species is believed to winter from along the United 
States-Mexico border south into the border States of Baja California, 
Sonora, Chihuahua, Coahuila, Nuevo Leon, and Tamaulipas, and beyond 
into Durango, Zacatecas, and San Luis Potosi (Gonzales-Rojas et al. 
2006, p. 81; Knopf and Wuder 2006; Macias-Duarte and Punjabi 2010, p. 
4). While the Mexicali Valley, Baja California, located just south of 
the Imperial Valley, seems to have suitable wintering habitat (200,000 
ac (80,000 ha) of farmland), mountain plover have rarely been reported 
from the area (Macias-Duarte and Punjabi 2010, p. 3).
    Two primary concentration areas within the Chihuahuan Desert are 
believed to be most important for wintering mountain plover: (1) The 
Janos area in northwestern Chihuahua; and (2) the El Tokio grasslands 
in southern Coahuila, Nuevo Leon, northeastern Zacatecas, and northern 
San Luis Potosi (Macias-Duatre and Punjabi 2010, pp. 3-6). Mountain 
plover are most abundant in the La Soledad region of the El Tokio 
grasslands. The highest estimated density in Llano de la Soledad (based 
on data from the winter of 2005-2006) extrapolated over the area 
suggests that over 2,000 mountain plover were present. Extrapolation 
from Llano de la Soledad to all prairie dog colonies in the entire El 
Tokio region provided an estimate of 6,800 mountain plover (Macias-
Duarte and Punjabi 2010, p. 6). While this estimate is crude and may be 
optimistically high, it is not inconsistent with reports of mountain 
plover flocks in the area totaling 1,600 to 3,500 birds reported by 
Andres and Stone (2009, p. 18). In the winter of 2005-2006, surveys in 
Janos estimated 1,435 birds (Salinas 2006, p. 43).
    The reported sightings and the estimates presented above are 
maximums reported, and the numbers can vary greatly from year to year. 
However, these reports suggest that a substantial number of mountain 
plover may winter in Mexico. Andres and Stone (2009, p. 20) provided an 
estimate of 5,000 birds wintering in Mexico. Changes in sampling 
methodology, annual variability in mountain plover numbers, and the 
short duration covered by recent systematic surveys prevent any 
conclusions regarding trends (Macias-Duarte and Punjabi 2010, pp. 5-6, 
16, 17).

Summary of Comments and Recommendations

    We requested written comments from the public on the proposed 
listing of the mountain plover during the June 29, 2010, through August 
30, 2010, comment period that followed our June 29, 2010, document (75 
FR 37353) vacating our September 9, 2003, withdrawal (68 FR 53083) and 
reinstating our December 5, 2002, proposal to list the mountain plover 
(67 FR 72396). We contacted appropriate Federal, State, and local 
agencies; scientific organizations; and other interested parties, and 
invited them to comment on the proposed rule and supporting documents. 
Following an initial draft of our final determination we contacted 5 
peer reviewers and asked them to review selected portions of the draft.
    We received 53 comments in response to the December 5, 2002, 
proposed rule (67 FR 72396) during the June 29, 2010, to August 30, 
2010, comment period. These included comments from 3 Federal entities, 
10 States, 3 local governments, 28 organizations or groups (business, 
industry, environmental), and 8 private parties. WildEarth Guardians 
also forwarded us 302 similar comments from individuals, and the 
Colorado Farm Bureau forwarded us 8 similar comments from individuals. 
We received no requests for public hearings. We also reviewed comments 
received after our February 16, 1999, and December 5, 2002, proposals 
to list the mountain plover (64 FR 7587 and 67 FR 72396, respectively) 
for relevant issues not addressed in more recent comments. All 
substantive comments have either been incorporated into this final 
determination or are addressed below.

Peer Review

    In accordance with our policy published in the Federal Register on 
July 1, 1994 (59 FR 34270), we solicited expert opinions from five 
knowledgeable individuals with scientific expertise that included 
familiarity with the mountain plover, with other shorebird species, the 
geographic region and habitats in which the mountain plover occurs, and 
conservation biology principles. We provided reviewers with a partial 
draft of this document. We received responses from all five of the peer 
reviewers that we contacted. The peer reviewers generally agreed that 
we accurately described the species and its habitat requirements; that 
we provided accurate review and analysis of factors

[[Page 27769]]

affecting the species; that our assumptions and definitions of suitable 
habitat were logical and adequate; that there were few oversights, 
omissions, or inconsistencies in out draft document; and that we used 
pertinent literature to support our assumptions and conclusions. One 
reviewer was generally critical of the synthesis of information 
regarding threats to mountain plover habitat, especially our assessment 
of wintering habitat in the Imperial Valley. One reviewer limited 
comments primarily to population trends. The peer reviewers provided 
suggestions to improve this final document. Recommended editorial 
revisions, clarifications, and other changes have been incorporated 
into the final document as appropriate. We respond to all substantive 
comments below or through changes to the final document.

Comments From Peer Reviewers

    (1) Comment: Three reviewers questioned specific details of our 
range map.
    Our Response: Figure 1, depicting the mountain plover's range, was 
developed based on those in Knopf and Wunder 2006, and Andres and Stone 
2009, with modifications based on our review of recent information. Our 
map depicts generalized areas believed to support breeding and 
wintering mountain plover, and does not depict localized areas of 
presence or absence. We made some revisions to our range map based on 
reviewer comments.
    (2) Comment: One reviewer pointed out that while mountain plover 
are attracted to burned areas on their breeding ground, there is little 
evidence as to whether such burned areas benefit breeding mountain 
plover (for example, through higher nest success or fledging success) 
compared to habitats they may otherwise use.
    Our Response: Reduced vegetative cover resulting from burning 
appears more attractive to mountain plover than similar habitat left 
unburned. However, we agree that studies have not documented the 
specific relationship of burning to successful mountain plover nesting.
    (3) Comment: One reviewer stated that estimates of annual survival 
should be considered minimum estimates, because studies do not control 
for permanent migration of mountain plover (i.e., they assume birds not 
accounted for have died rather than moved away from the study area).
    Our Response: We agree and have acknowledged this in the text. 
Studies in Montana have produced the most complete information on 
juvenile (first year of life) and adult mountain plover annual survival 
rates, but the extent to which these studies underestimate survival 
rates due to emigration is not known.
    (4) Comment: One reviewer asserted that recent literature clearly 
identified adult survival as a vital importance to productivity and 
survival of shorebird populations.
    Our Response: We agree. In the limited studies that have estimated 
adult survival of mountain plover, adult mountain plover survival 
appears relatively high. The suggestion that management efforts to 
increase mountain plover populations might best be targeted at 
increased chick survival (hatching to fledging) result, in part, from 
data showing relatively low and highly variable survival of mountain 
plover chicks (see Survival, Lifespan, and Site Fidelity above).
    (5) Comment: Two reviewers noted that while the mountain plover may 
have a long lifespan compared to many other shorebirds, some shorebirds 
do live longer and other bird families, such as seabirds, live much 
longer.
    Our Response: Mountain plover in the wild have been known to live 
to over 10 years. We have qualified our description of the mountain 
plover as a ``relatively'' long-lived species.
    (6) Comment: One reviewer suggested that mountain plover fidelity 
to breeding sites is more regional than site-specific and that 
differences in habitat across the mountain plover breeding range may 
influence site fidelity.
    Our Response: Both may be correct. Lack of genetic differentiation 
found by Oyler-McCance et al. (2005, p. 359; 2008, pp. 496-497) suggest 
that mixing of mountain plover across regions is also occurring.
    (7) Comment: One reviewer suggested that we discuss spatial and 
temporal variation in long-term and recent BBS trend data for the 
mountain plover and cited a long-term (1966 through 2009), negative New 
Mexico trend as the only statistically significant population trend 
among the rangewide or Statewide BBS trend estimates we provide.
    Our Response: We have included data pertinent to spatial and 
temporal (by State and long-term versus short-term) trends in mountain 
plover populations in this document when available (see Conservation 
Status and Local Populations above). These statistics are based on 
fewer data and generally appear less reliable than rangewide trends. 
The long-term trend estimate in New Mexico is unique among those we 
cite, in that it reflects a statistically significant indication of at 
least some decline.
    (8) Comment: One peer reviewer stated that there is insufficient 
information about the distribution and status of the mountain plover in 
Mexico to evaluate whether past, present, or future loss of prairie 
dogs and the ecosystem they support in Mexico is a significant threat 
to the mountain plover.
    Our Response: We agree that information on the distribution and 
status of the mountain plover in Mexico is limited. Based on the 
information available, past loss of prairie dogs colonies in Mexico has 
decreased available mountain plover habitat and may have had some 
adverse impact on the mountain plover. Recent Mexican and international 
attention to conservation of prairie dogs and grassland complexes in 
Mexico improves prospects for maintaining existing mountain plover 
wintering habitat (see Factor A below). While future losses of prairie 
dog colonies in Mexico may occur, we do not believe that associated 
impacts to mountain plover's habitat present a significant threat to 
the mountain plover over its wintering range.
    (9) Comment: One reviewer stated that discussion of habitat loss to 
land use modification would be greatly improved by including specifics 
of how these losses fall within the precise breeding and wintering 
habitats of the mountain plover. Two reviewers contended that the 
relative threat posed by agricultural conversion (of grasslands) was 
difficult to assess unless analyzed at a fine spatial scale.
    Our Response: The mountain plover's breeding and wintering ranges 
extend across a large area and encompass a variety of habitat types. We 
have addressed habitats supporting the mountain plover, habitat losses, 
and threats to mountain plover habitat on a rangewide and regional 
level, and in some cases on a State or local level as well.
    (10) Comment: One reviewer offered that uncertainties regarding 
future agricultural practices on private lands emphasized the 
importance of managing for the mountain plover on State and Federal 
lands.
    Our Response: A great degree of uncertainty exists regarding future 
agricultural practices on private lands, but we believe that changes in 
agriculture are not likely to significantly threaten the mountain 
plover in the foreseeable future. Across the range of the mountain 
plover there are currently many initiatives, on both public and private 
lands, to manage habitat for wildlife including the mountain plover, 
bird species using similar habitats, and

[[Page 27770]]

prairie dogs (see Factor A discussion below). The mountain plover has 
been designated a bird of conservation concern by the Service (2008) 
and has special conservation status in many States (see Conservation 
Status and Local Populations above and Factor A discussion below). We 
anticipate and support continued emphasis on mountain plover 
conservation and management by our Federal and State partners.
    (11) Comment: One reviewer noted that, without synthesis of exactly 
what agricultural lands mountain plover require on their wintering 
areas and how those specific fields are threatened (for example, 
fallowing of crop fields in California's Imperial Valley), our 
conclusion that threats impacting only a small portion of agricultural 
lands would not affect mountain plover was problematic.
    Our Response: In Migration and Wintering Habitat above, we describe 
wintering habitats favored by the mountain plover. In Factor A below we 
discuss threats that may impact these habitats, including threats to 
certain crop types favored by the mountain plover. The level of 
analysis we provide is sufficient to evaluate threats to the mountain 
plover from changes on agricultural lands that provide wintering 
habitat and utilizes the best available information we have regarding 
this topic. Without specific information to suggest otherwise, we 
conclude that threats would not disproportionately impact those 
particular fields that presently receive, or in the future would 
receive, most use by the mountain plover.
    (12) Comment: One reviewer noted that the Imperial Valley, 
California, an area supporting significant numbers of wintering 
mountain plover, is one of the fastest growing areas of the United 
States.
    Our Response: From 1984 to 2008, urban area in the Imperial Valley 
increased by 6,000 ac (2,400 ha) (CDC 2010), much of it outside of 
croplands favored by the wintering mountain plover. About 381,000 ac 
(154,000 ha) of field crops are present in the Imperial Valley 
(Imperial Irrigation District (IID) 2009a). We concluded that 
population growth and urban expansion is having a modest impact on 
Imperial Valley croplands, but does not rise to the level of a threat 
to the species (see Factor A discussion below).
    (13) Comment: One reviewer stated that, over the wintering range of 
the mountain plover, increase in human population, associated land use 
changes, and reductions in available water for agriculture would impact 
areas currently used by mountain plover. The reviewer concluded that 
because there was ``lack of suitable habitat to move to,'' this would 
be detrimental to mountain plover.
    Our Response: Human development and changes in agriculture, 
including changes brought on by future water availability, are likely 
to impact some of the areas currently used by wintering mountain plover 
in California, in southern Arizona, and elsewhere in their wintering 
range. Based on the likely magnitude of such changes and the extensive 
wintering range of the mountain plover, we conclude that loss of 
wintering habitat is not likely to be a significant threat to the 
mountain plover in the foreseeable future (see our discussion in Factor 
A below).
    (14) Comment: One reviewer questioned whether mountain plover are 
impacted by pesticides and herbicides used on sod farms where they are 
often seen during migration or in winter.
    Our Response: We have found no documentation of effects to mountain 
plover from exposure to pesticides on sod farms. However, in the past, 
the use of diazinon, an organo-phosphate pesticide, on sod farms may 
have impacted the mountain plover. In 1988, after documented large die-
offs of birds of other species, the U.S. Environmental Protection 
Agency (EPA) cancelled the registration of diazinon for use on golf 
courses and sod farms (EPA 2006, p. vii). We have no information 
regarding significant harm of any bird species since 1988 that is 
attributable to use of pesticides on sod farms.
    (15) Comment: One reviewer suggested more discussion on invasive 
grasses and their impact on mountain plover.
    Our Response: Invasive plants, including nonnative grasses planted 
as forage for cattle, are widespread across the western United States. 
Many invasive plants grow to a density or height that can make habitat 
unsuitable for mountain plover. While perceived by some as a potential 
threat, the effects of nonnative grasses and invasive plants on the 
mountain plover have not been well documented. Within the ecosystems it 
inhabits, the mountain plover is best supported where native or 
domestic herbivores, fire, dry conditions, soil conditions, or 
disturbance create low, sparse vegetation. In general, this is true 
whether the vegetative community consists only of native vegetation or 
also supports a component of nonnative or invasive plants.

Public Comments

Process Issues
    (16) Comment: One commenter stated that e-mails, personal 
communications, and letters that the Service referenced in support of 
the December 5, 2002, listing proposal (67 FR 72396) do not meet the 
best information available standard as described in Service policy (59 
FR 34271, July 1, 1994).
    Our Response: Our policy, as cited above, requires that we evaluate 
all scientific and other information available, which includes both 
published and unpublished materials, in the development of a listing 
action. We review the information regardless of origin, and determine 
whether it is reliable, is credible, and represents the best 
information available regarding the species under review. We document 
our evaluation of any information we use in making our decision, 
whether it supports the decision or not.
    (17) Comment: Commenters believed that our analysis in our February 
16, 1999, and December 5, 2002, proposals to list the mountain plover 
(64 FR 7587 and 67 FR 72396, respectively) used ``selective science'' 
to defend our position, while ignoring information contrary to our 
conclusion.
    Our Response: We base our determinations on review of all pertinent 
information available. This final determination is further based on 
substantial new and additional information available since our previous 
actions.
    (18) Comment: One commenter stated that in the 1999 and 2002 
proposals to list the mountain plover (64 FR 7587 and 67 FR 72396, 
respectively) the Service did not identify or quantify actual threats, 
and therefore the Service has not shown that mountain plover have 
declined or are at risk.
    Our Response: In this final determination, we have evaluated the 
relative security of the species from present and foreseeable threats 
across its breeding, migratory, and wintering range. Where available 
information has allowed, we have identified and quantified actual 
threats to the mountain plover in this evaluation. While threats, 
especially future threats, may be difficult to quantify, we evaluate 
threats based on analysis of the best scientific and commercial 
information available.
    (19) Comment: One commenter stated that e-mails and faxes should be 
accepted as comment on the proposed listing.
    Our Response: Our policy requires submission of written comments 
through the Internet (via the Federal

[[Page 27771]]

eRulemaking Portal at http://www.regulations.gov), or by U.S. mail or 
hand-delivery, and we believe this provides the means for all 
interested parties to provide comments, information, and 
recommendations.
    (20) Comment: Various commenters suggested that there are either 
more or fewer reasons for listing the mountain plover now compared to 
2003 when our proposed listing was withdrawn (68 FR 53083, September 9, 
2003).
    Our Response: Our 2003 decision was vacated by the Court and is not 
relevant to this final determination regarding the mountain plover. We 
have based our determination on the current status of the mountain 
plover and current and future threats to the species, based on the best 
scientific and commercial information available to us at this time.
Issues Regarding Range, Numbers, and Populations Trends
    (21) Comment: One commenter questioned our emphasis on the PNG in 
Colorado and Charles M. Russell National Wildlife Refuge (NWR) in 
Montana in our proposals to list the mountain plover, as relatively few 
mountain plover breed in either site.
    Our Response: We agree that neither site currently supports a large 
percentage of the total mountain plover population. Both sites are 
Federally controlled and have supported mountain plover research and 
management efforts. The PNG once likely supported the highest density 
of mountain plover in the species' breeding range. The dramatic loss of 
this sizable population has relevance to the rangewide population trend 
and may provide insight to current and future threats to the mountain 
plover. Charles M. Russell NWR provides management opportunities on a 
Montana site representative of those where mountain plover is largely 
dependent on the black-tailed prairie dogs to create desirable habitat 
conditions.
    (22) Comment: One commenter stated that breeding habitat on public 
and private lands in the mountain plover's range has not been 
adequately surveyed and suggested that additional surveys will 
consistently find more mountain plover.
    Our Response: Knowledge of mountain plover populations varies 
greatly across the breeding range. Surveys vary in methodology and 
scope. In some cases, lack of access to conduct surveys on private 
lands limits the accuracy of population estimates. Based on information 
available since 2002, estimates of mountain plover breeding numbers in 
certain States and throughout the range have been modified. Former 
rangewide population estimates were based on surveys of mountain plover 
in California, where the vast majority of birds were thought to winter. 
Our current rangewide population estimate is based on minimum breeding 
range population estimates. However, no estimate currently exists that 
provides a precise estimate of rangewide numbers.
    (23) Comment: One commenter dismissed population estimates as 
``just a guess.''
    Our Response: We believe that some structured studies on the 
breeding range have produced population estimates that approximate the 
actual numbers of mountain plover that are present. In other cases, 
estimates may be limited to the minimum number of individuals known, or 
may suggest the likely population size based on limited data. While we 
summarize population estimates and seek to understand population 
trends, numbers alone are not the basis for listing determinations 
under the Act. Listing determinations are based on whether there are 
threats present or likely to occur that would result in the species 
being in danger of extinction or likely to become so within the 
foreseeable future.
    (24) Comment: Several commenters cited increased rangewide 
population estimates as a reason why the mountain plover does not merit 
listing. One commenter cited the recent status change by the IUCN 
(downlisting from ``vulnerable'' to ``nearly threatened'') as evidence 
of reduced threat to the species.
    Our Response: While greater abundance suggests less vulnerability, 
we have no basis to suggest that the increased estimate of mountain 
plover numbers reflects an actual, rangewide increase. The number of 
individuals of a species present is only one factor considered when 
assessing vulnerability to extinction. Current and future threats may 
be of greater significance. Downlisting by the IUCN was based on 
revised population estimates alone, and not on changed interpretation 
of threats present.
    (25) Comment: One commenter noted that all wintering areas in the 
United States and Mexico have not been located and opined that further 
searching is likely to yield more wintering sites.
    Our Response: While more information overall has been gathered 
since our 2002 proposal (67 FR 72396, December 5, 2002), much is still 
unknown regarding wintering habitat. Rangewide breeding population 
estimates and wintering estimates from California suggest that a 
substantial percentage of mountain plover winter elsewhere. Because the 
large flock sizes observed in California are not regularly encountered 
elsewhere, mountain plover numbers may occur at lower densities in 
other parts of their wintering range.
    (26) Comment: One commenter stated that the former estimate of 
20,000 breeding mountain plover at the PNG in the 1970s may have been 
off by an order of magnitude.
    Our Response: While the actual number present in the 1970s is 
unknown, it is well established that mountain plover populations on the 
PNG have greatly decreased since that time, with relatively few 
breeding mountain plover present since the mid-1990s.
    (27) Comment: One commenter questioned our estimates of up to 
10,000 mountain plover at Kern NWR in California during the 1960s.
    Our Response: Many mountain plover used Kern NWR in winter during 
the 1960s, but the 10,000 estimate is by far the largest recorded 
(Engler 1992). We believe estimates at Kern NWR approximate mountain 
plover numbers attracted to the refuge by favorable habitat conditions 
previously present.
    (28) Comment: Multiple commenters mentioned continued, significant 
declines across the breeding and wintering range of the mountain 
plover, as cited by researchers, as indicative of the species' 
imperiled status.
    Our Response: Documentation of historical range contraction and 
apparent decline in mountain plover populations is reflected in long-
term BBS and CBC trends. Despite more intensive study in recent years, 
it is not clear if, or to what extent, any declines in mountain plover 
populations continue. See our discussion of Population Size and Trends 
above.
    (29) Comment: A few commenters stated that BBS and CBC data and 
trends regarding mountain plover are unreliable. Others state that 
these data are a reason for concern.
    Our Response: The BBS is the best available long-term trend 
information for the mountain plover on its breeding range. It is an 
imprecise indicator of mountain plover population trends. These data 
appear to confirm a decline over the period 1966 through 2009, but 
results suggest that the rate of any continued (1999 through 2009) 
decline has moderated. The CBC data are more restricted in geographic 
scope than are the BBS data, but these data also suggest a long-term 
decline. Few CBC count circles regularly report mountain plover, and 
numbers are highly variable, likely reflecting mobility of wintering 
flocks.

[[Page 27772]]

See our discussion of Population Size and Trends above.
    (30) Comment: We received a comment that insufficient data are 
available to predict any trend toward extinction.
    Our Response: We agree that current trend data are limited and that 
the ability to project future population trends is difficult. However, 
we have reviewed the best population and trend data available as part 
of our analysis of the mountain plover's status. In making our final 
listing determination, we not only looked at population trends, but we 
have also evaluated the best available information on current and 
future threats to the species.
    (31) Comment: One commenter suggested that population trends at the 
PNG, where the birds have been closely studied, are indicative of the 
overall population trend for the mountain plover.
    Our Response: Knopf (2008, p. 61) summarized mountain plover 
studies on the PNG in Weld County, Colorado, and suggested reasons for 
that population's former abundance and more recent decline, including 
long-term changes in habitat since abandonment of agricultural fields 
following the ``Dust Bowl'' of the 1930s. We believe that this 
represents a unique history because long-term BBS data (Sauer 2010a) 
suggest a relatively stable population in Colorado despite the dramatic 
drop in numbers on the PNG. In 2008, Knopf expressed the opinion that 
similar numbers of mountain plover were breeding in Weld County as in 
1990, just not on the PNG (Knopf 2008, p. 54). We have no scientific 
information that would point to the precipitous decline in mountain 
plover historically at the PNG as indicative of the overall mountain 
plover population trend.
    (32) Comment: One commenter suggested that mountain plover numbers 
are dynamic, and that their current abundance is within the range of 
normal fluctuation due to annual variation in weather patterns.
    Our Response: Breeding numbers and nest success can vary locally 
based on a number of factors including weather. However, the historical 
reduction in rangewide mountain plover numbers seems well 
substantiated. Interpretation of recent trends is made more difficult 
by short-term variability in population numbers that may reflect annual 
weather variation. The effect of all factors, natural and human-caused, 
that may contribute to the survival of the mountain plover is 
considered in this determination, including variation in weather 
patterns and longer-term changes in climate.
Species Vulnerability
    (33) Comment: One commenter referenced the mountain plover's 
relatively short lifespan as contributing to the vulnerability of 
populations to extirpation if one or more years of unfavorable habitat 
on their breeding grounds prevent successful nesting.
    Our Response: As discussed above in our discussion of Population 
Size and Trends, and under Factor E below, our former conclusion that 
the lifespan of mountain plover contributed to its vulnerability has 
been refuted based on more recent information. The mountain plover is 
now considered a relatively long-lived species, with one individual 
documented living for 10 years (Dinsmore 2008, p. 52). We do not 
believe that mountain plover lifespan substantially influences the 
vulnerability of mountain plover to extinction.
    (34) Comment: One commenter stated that breeding mountain plover 
populations are often discontinuous, in part because of habitat 
fragmentation, and stated that local, isolated mountain plover 
populations have an increased vulnerability to random natural and 
human-caused events.
    Our Response: It is generally true that small and isolated 
populations are less secure than larger populations. While the mountain 
plover is a migratory, highly mobile species, it generally returns to 
the same breeding sites, which isolates local populations to a degree. 
Small mountain plover populations are vulnerable to ``blinking out'' if 
events destroy or degrade habitat. This vulnerability may be offset by 
the species' ability to colonize new habitat as it becomes available. 
Recent studies describe mountain plover dispersal from natal sites or 
former breeding sites, and suggest that the mountain plover has been 
able to disperse and exploit habitat nearby if former habitat is 
destroyed.
Prairie Dog Issues
    (35) Comment: We received numerous comments regarding mountain 
plover and prairie dogs. They included comments regarding the mountain 
plover's dependence on prairie dogs, and the distribution, abundance, 
and trends in prairie dog populations. One commenter contended that if 
the black-tailed prairie dog does not merit listing, then the mountain 
plover does not either.
    Our Response: It is well established that in parts of its range, 
Montana in particular, the mountain plover is largely dependent during 
breeding on the habitat that prairie dogs create and maintain. 
Elsewhere, mountain plover also breed in a variety of habitats, 
including prairie, semi-desert, and cropland. See our discussion 
regarding the status and threats to the black-tailed prairie dog and 
potential effect on the mountain plover in Factor A below. We recently 
determined that the black-tailed prairie dog does not warrant listing 
under the Act (74 FR 63343, December 3, 2009), but it does not follow 
that this would automatically lead to a similar conclusion for the 
mountain plover since the species could be subject to a variety of 
threats unrelated to the status of prairie dogs.
    (36) Comment: We received a comment that the Service in 1999 and 
2002 underestimated the presence of prairie dogs and therefore their 
habitat and the number of mountain plover that prairie dog colonies 
supported.
    Our Response: Our current analysis includes information developed 
since 2002. Under Factor A below, we discuss current estimates of 
prairie dog abundance and implications of prairie dog numbers to 
mountain plover.
    (37) Comment: Some commenters stated that black-tailed prairie dogs 
lack protection, are often poisoned or shot, and are often affected by 
sylvatic plague; therefore, prairie dog colonies and the mountain 
plover they support remain vulnerable.
    Our Response: We agree that there are few protections for the 
black-tailed prairie dog. However, despite the above factors, the 
black-tailed prairie dog has increased in number throughout all States 
in its range in the United States since the 1960s. In the United 
States, we do not foresee any significant decreases in black-tailed 
prairie dog populations or the habitats they create. On December 3, 
2009, the Service published a 12-month finding that the black-tailed 
prairie dog is not threatened with extinction and is not likely to 
become so in the foreseeable future (74 FR 63343). In Mexico, both the 
black-tailed prairie dog and the Mexican prairie dog continue to be 
reduced in number and distribution, and this likely impacts mountain 
plover habitat. See our discussion under Factor A below.
    (38) Comment: Other commenters cited conservation efforts that 
target prairie dogs, as well as efforts to conserve greater sage-grouse 
(Centrocercus urophasianus), lesser prairie-chicken (Tympanuchus 
pallidicinctus), and black-footed ferret (Mustela nigripes), and 
concluded that these existing efforts make mountain plover conservation 
efforts unnecessary.
    Our Response: Efforts to conserve these species are in response to 
declines in numbers and threats to their future existence. While the 
mountain plover

[[Page 27773]]

will benefit from conservation of prairie dogs, some other species 
require habitats unlike those favored by the mountain plover. To the 
extent that mountain plover benefit from conservation efforts for other 
species, these are addressed under Factor A, below.
    (39) Comment: One commenter contended that the presence of prairie 
dogs was only one of several factors that create mountain plover 
breeding habitat and that soil type, soil moisture, cattle grazing, 
fire, and incidence of drought all play a role in supplying suitable 
mountain plover breeding habitat.
    Our Response: While the literature on the mountain plover is 
replete with the association of mountain plover and prairie dog 
colonies, we agree that other factors, singly or in combination, can 
shape mountain plover breeding habitat, and we have taken this into 
consideration in this final listing determination.
Grassland Conversion and Agricultural Issues
    (40) Comment: Multiple commenters state that grassland conversion 
to cropland is a significant threat.
    Our Response: While grassland conversion contributed to past 
contraction in the mountain plover's range and reduction of the 
mountain plover's numbers, much of this took place on the eastern Great 
Plains where conversion to crops such as corn and soybeans was 
feasible. The rate of grassland conversion is now much reduced. We do 
not believe that the current or anticipated future conversion of 
grasslands to other uses is a significant threat. Dryland agriculture, 
found in the southern portions of the mountain plover's breeding range, 
supports significant numbers of breeding mountain plover. The extent to 
which the use of dryland agricultural habitat is beneficial to the 
mountain plover is largely undetermined. See our discussion under 
Factor A below.
    (41) Comment: One commenter contended that current farming 
practices benefit breeding mountain plover, that mountain plover are an 
adaptable species that have shifted from grasslands to cultivated lands 
on both their breeding and wintering areas, and that cultivated lands 
are now the most important habitat for the mountain plover. Other 
commenters raised the question of whether the choice to nest in 
cropland is detrimental to mountain plover.
    Our Response: Research findings from Colorado present a complex 
picture. Hatching success on some croplands is similar to that found on 
grasslands with or without prairie dogs. Chick survival appears to be 
lower on crop fields, but results of some studies differ, perhaps 
depending on variables such as annual weather conditions and site-
specific levels of predation. The influence of the agricultural 
landscape on mountain plover recruitment has not been fully determined. 
Wintering mountain plover favor crop fields at times, but habitat 
preference seems to vary greatly by region. Mountain plover use of crop 
fields in winter may reflect the loss of preferred native habitats.
    (42) Comment: One commenter stated that farming practices on the 
prairie have not changed in 50 years and questioned why they could 
suddenly be a threat.
    Our Response: Dryland farming practices in eastern Colorado and 
adjacent States have remained relatively stable, although market 
factors may favor one crop over another. Historically, conversion of 
prairies to crop fields likely contributed to the decline of mountain 
plover, especially in the eastern portion of its range. Farm operations 
can directly impact nesting, but the current relationship between 
dryland crop fields and breeding mountain plover is complex. However, 
the best available information indicates that current agricultural 
practices have remained largely unchanged in recent years and have not 
been shown to pose a threat to the mountain plover (see Factor A 
discussion below).
    (43) Comment: Several commenters stated that the Conservation 
Reserve Program is beneficial to the mountain plover, while other 
commenters thought the program was detrimental to the mountain plover.
    Our Response: The U.S. Department of Agriculture (USDA) administers 
the Conservation Reserve Program, which allows producers to retire 
agricultural lands for a 10-year period, thereby benefitting wildlife 
and other resources. Most of these lands are planted with nonnative 
grasses that support other wildlife species but often do not create 
mountain plover habitat. The program likely has little effect on 
overall mountain plover habitat because a relatively small portion of 
agricultural fields are retired at any one time and retired lands 
provide minimal benefit to mountain plover.
    (44) Comment: Commenters expressed concern that anticipated human 
population growth in South Park, Park County, Colorado, and the 
fragmentation of existing habitat there, will impact a significant 
mountain plover population.
    Our Response: We agree that buildout of private lands in South Park 
would adversely affect the mountain plover breeding population that is 
currently present. However, based on information from Park County, 
population growth is much slower than once predicted, and we do not 
anticipate substantial human development will occur in the area in the 
foreseeable future. See our discussion under Factor A below.
Livestock/Grazing/Range Management
    (45) Comment: One commenter stated that range management has 
contributed to the past decline of mountain plover and is a current 
threat, as practices vary little from those used previously.
    Our Response: Range management is often designed to maximize forage 
and diminish excessive disturbance to grass and soil. Such management, 
when employed, does not benefit the mountain plover. However, we do not 
see range management as representing a current or future threat to the 
mountain plover, as there is no information to suggest that current 
range management practices and the habitat conditions now present are 
likely to change substantially in the future.
    (46) Comment: One commenter cited recommendations by Knopf and 
Wunder (2006) to prioritize research regarding varied livestock grazing 
practices and their effects on mountain plover.
    Our Response: Research is ongoing as to how range management 
affects mountain plover and a variety of other grassland species. We 
have a basic understanding of how livestock grazing can enhance 
mountain plover habitat (Dechant et al. 2003, entire).
    (47) Comment: Commenters cited the decline in sheep (Ovis aries) 
numbers in the mountain plover's breeding range as detrimental to 
mountain plover.
    Our Response: Sheep grazing helps maintain low vegetation structure 
favored by the mountain plover. The U.S. sheep industry has been in 
decline since the 1940s. Past declines in sheep may have contributed to 
losses in mountain plover breeding habitat. The future of the sheep 
industry in the United States is difficult to predict. See our 
discussion under Factor A below.
    (48) Comment: One commenter stated that cattle do not replace the 
role of bison in the ecosystem, and that the role of cattle grazing as 
it relates to insect availability has not been adequately evaluated.
    Our Response: The historical loss of bison resulted in a number of 
changes to the prairie ecosystem. Current mountain plover numbers and 
distribution, and our evaluation of threats to the species, are based 
on an ecosystem largely devoid of bison.

[[Page 27774]]

Insect numbers and availability to mountain plover under various 
grazing regimes may be worthy of investigation.
Mineral Extraction/Energy Development
    (49) Comment: We received many comments on the threat to the 
mountain plover posed by oil and gas field development, and wind energy 
development. Commenters stated that effects of energy development on 
the mountain plover are largely unknown and that the mountain plover's 
response to oil, gas, and wind energy development should be 
investigated.
    Our Response: We discuss the potential impact of energy development 
on mountain plover under Factor A below. Wells, turbines, roadways, and 
related development constitute potential threats. While far from 
definitive, recent studies suggest mountain plover may be little 
affected by oil and gas development. Thus far, we have no data on the 
effect of wind energy development on wintering mountain plover.
    (50) Comment: One commenter recounted the history of mountain 
plover presence at the Antelope Coal Mine in Wyoming and suggested that 
mountain plover are tolerant of both ground disturbance and nearby 
industrial activity.
    Our Response: We agree that results of monitoring at this site 
confirm the mountain plover's preference for open ground created by 
disturbance and a general tolerance of human activity. While mining 
activity displaces mountain plover, reclamation following mining may 
restore habitat.
    (51) Comment: One commenter described new wind energy projects 
under development in southern Texas areas where mountain plover winter 
and thought that the species would be affected by the presence of 
turbines.
    Our Response: As stated earlier, thus far, we have no data on the 
effect of wind energy development on wintering mountain plover. The 
response of mountain plover to turbines on their breeding areas (which 
indicates some degree of tolerance) may not provide insight into how 
flocks respond in winter.
    (52) Comment: One commenter noted conservation efforts to limit 
energy development on State-designated greater sage-grouse Core 
Breeding Areas in Wyoming, which include 36 percent of likely mountain 
plover breeding habitat in the State. The commenter suggested that this 
will provide a significant measure of protection for the mountain 
plover.
    Our Response: While limitations on energy development in these 
areas may reduce potential for any associated adverse impacts on the 
mountain plover, there is uncertainty as to whether such measures will 
persist into the future. Designated greater sage-grouse Core Breeding 
Areas are broad and encompass habitats that support mountain plover, 
but from a habitat perspective, the needs of the two species differ. 
Measures to manage for the greater sage-grouse may not benefit the 
mountain plover.
    (53) Comment: One commenter suggested that the Service should base 
its analysis of the energy development threats on what is known 
regarding the impact of roads, habitat conversion, and fragmentation. 
Others raised the issue of roads and structures resulting in increases 
in mammalian and avian predators of mountain plover, which in turn 
could lead to higher mortality of mountain plover chicks and adults.
    Our Response: In general, while some other species have been shown 
to be adversely impacted by energy development, we have little evidence 
of similar impacts on the mountain plover. Changes in habitat brought 
on by energy development, including the potential that roads and 
structures may facilitate increased predation on the mountain plover, 
are addressed under Factor A and Factor C below. Some adverse impacts 
are likely, but there may also be offsetting benefits resulting from 
the increase in bare ground preferred by the mountain plover.
    (54) Comment: One commenter noted that the Western Governors 
Association, States, and the wind industry have been addressing 
concerns regarding construction of wind energy projects on sensitive 
wildlife areas.
    Our Response: The Service is engaged with the wind industry and 
other partners on issues regarding a range of wildlife including the 
endangered whooping crane (Grus americana), and candidates including 
the greater sage-grouse, lesser prairie chicken, and Sprague's pipit 
(Anthus spragueii), as well as the mountain plover. We anticipate that 
current emphasis on renewable energy projects will be accompanied by 
cooperative initiatives to minimize impacts to species of concern.
    (55) Comment: One commenter was concerned that mountain plover 
populations could decrease significantly while studies on impacts from 
energy development were ongoing and that precautionary measures should 
be enacted to preclude potential impacts.
    Our Response: The USFS and BLM have designated the mountain plover 
a sensitive species within portions of the range (see discussion under 
Factor D below). These agencies address potential impacts to the 
species when reviewing energy development. However, we will continue to 
work with these and other Federal agencies, States, and other partners 
to monitor the status of the mountain plover.
Wintering Habitat
    (56) Comment: We received many comments on actual or potential loss 
of wintering habitat in California and how this could affect rangewide 
populations of mountain plover. Commenters stated that the historical 
and ongoing conversion of grasslands in California is a threat to the 
mountain plover. Some commenters cited Andres and Stone (2009, p. 1), 
describing crucial threats facing the mountain plover, including ``* * 
* the inability to manage agricultural lands in the Imperial Valley, 
California, to provide consistent winter habitat, and the loss or 
inadequate management of other known wintering areas in California.''
    Our Response: Much of the native grassland that the mountain plover 
formerly used for wintering in California has been lost. While the 
mountain plover has shown a preference for native and nonnative 
grasslands in California, especially when heavily grazed, the mountain 
plover has successfully switched to using crop fields. Additional 
conversion of grasslands to various other lands uses may increase 
mountain plover dependence on these crop fields. Any resulting adverse 
effects of this change are largely speculative.
    Based on a variety of existing and projected trends in land use, 
the further reduction of grassland and crop fields used by mountain 
plover for wintering in California seems likely. However, as of 2007, 
California supported over 25 million ac (10 million ha) of land in 
farms, including 9.5 million ac (3.8 million ha) of cropland, 5.5 
million cattle, and 600,000 sheep (USDA 2010). The mountain plover is a 
highly mobile species that uses habitat opportunistically in winter. 
The mountain plover's preference for certain agricultural lands above 
others is well documented. However, the pervasive expanse of 
agriculture throughout the Central Valley and Imperial Valley suggests 
to us that, while current and foreseeable future changes may reduce 
favored wintering habitat, the quantity and variety of agricultural 
habitat remaining in California will continue to provide sufficient 
wintering areas for the mountain plover.
    (57) Comment: One commenter noted that in the Imperial Valley, an 
important wintering area for mountain plover, the

[[Page 27775]]

area of bermudagrass and alfalfa (crops favored by the mountain plover) 
has declined.
    Our Response: Both bermudagrass and alfalfa show recent declines in 
area from 2005 to 2009 (Imperial Irrigation District (IID) 2010). While 
area devoted to all hay (including bermudagrass and alfalfa) in the 
Imperial County varies yearly, 233,000 ac (90,000 ha) were present in 
both the 1997 and the 2007 (USDA Census of Agriculture (USDA) 2010). We 
do not have evidence indicating the likelihood of long-term future 
declines in acreage devoted to these two crops.
    (58) Comment: One commenter noted that the wintering range of the 
mountain plover in Texas is not well described and that the species' 
occurrence in Texas is variable. There was concern that habitat needs 
were not understood and that Texas populations were not receiving the 
attention they merited.
    Our Response: We agree that knowledge of mountain plover wintering 
in Texas has been scant (as described in Conservation Status and Local 
Populations above). Distribution is largely limited to private lands 
where land use has varied little and where few threats are known. New 
efforts to survey abundance and habitat use of mountain plover in Texas 
are currently under way.
Pesticides
    (59) Comment: Some commenters expressed concern that use of 
pesticides to control grasshoppers (family Acrididae) and the Mormon 
cricket (Anabrus simplex) reduces foods that sustain breeding mountain 
plover, especially chicks, in the mountain plover's breeding range.
    Our Response: Efforts to control grasshoppers and Mormon crickets 
are generally limited to suppressing populations in years and in areas 
where infestations occur, and have the goal of reducing densities to 
limit economic impacts. While at times local mountain plover 
populations could be affected by these activities, we do not believe 
that grasshopper and Mormon cricket control represents a significant 
threat to mountain plover populations. See our further discussion under 
Factor E below.
Climate
    (60) Comment: Some commenters suggested that climate change could 
bring warmer and drier conditions that may benefit mountain plover 
breeding.
    Our Response: Mountain plover breeding numbers and breeding success 
can vary greatly based on a number of factors, including annual weather 
variation. Anticipated changes in climate will alter annual norms of 
temperature and precipitation, but those changes will likely vary 
across the mountain plover's breeding and wintering range (see 
discussion under Factor E below). Overall, we believe it is speculative 
to conclude that these effects will be beneficial to the mountain 
plover.
Conservation Efforts and Effects of Listing
    (61) Comment: Several commenters noted that conservation 
partnerships between State agencies, landowners, and conservation 
groups have promoted conservation of mountain plover and that listing 
would negate some gains in cooperation.
    Our Response: We agree that partnerships are important to the 
conservation of the mountain plover, especially in those States where 
mountain plover occur mostly on private lands. The concern that such 
partnerships could be affected by listing is legitimate, but is not a 
factor evaluated when determining whether a species warrants listing 
under the Act.
    (62) Comment: One commenter suggested that traditional land uses on 
private land would continue even if listing occurred. Another commenter 
suggested listing under the Act would decrease the ability to 
effectively manage habitat, slowing management response to changing 
science and conditions on the ground. A third commenter suggested 
listing would provide impetus for needed research.
    Our Response: We agree that listing under the Act could lead to 
multiple outcomes, including those above. We considered all available 
scientific and commercial information in making our determination as to 
whether the mountain plover is currently, or may in the foreseeable 
future become, in danger of extinction.
    (63) Comment: Several commenters emphasized the importance of 
developing a special rule under section 4(d) of the Act to exempt 
certain activities from the take provisions of the Act should the 
mountain plover be listed.
    Our Response: In our June 29, 2010, document (75 FR 37353) we 
addressed the possible development of a special 4(d) rule if the 
mountain plover were listed as threatened. The intent was to develop a 
mechanism by which agricultural practices that might result in take, 
but were believed to have no net adverse impact on the mountain plover, 
could continue. Development of such a rule would allay some concerns 
associated with listing and would contribute to continued cooperation 
efforts with private landowners. Were we to determine that the mountain 
plover met the definition of a threatened species, we would consider 
developing a special rule under section 4(d) of the Act. However, 
because we determined that the species does not warrant listing, the 
consideration of a special 4(d) rule is not necessary.

Summary of Information Pertaining to Five Factors

    Section 4 of the Act (16 U.S.C. 1533) and implementing regulations 
(50 CFR 424) set forth procedures for adding species to the Federal 
Lists of Endangered and Threatened Wildlife and Plants. Under section 
4(a)(1) of the Act, a species may be determined to be endangered or 
threatened based on any of the following five factors:
    (A) The present or threatened destruction, modification, or 
curtailment of its habitat or range;
    (B) Overutilization for commercial, recreational, scientific, or 
educational purposes;
    (C) Disease or predation;
    (D) The inadequacy of existing regulatory mechanisms; or
    (E) Other natural or manmade factors affecting its continued 
existence.
    The February 16, 1999 (64 FR 7587), proposed listing rule provided 
a description of threats affecting the mountain plover under the five 
listing factors identified in section 4(a)(1) of the Act. The December 
5, 2002, proposal (67 FR 72396), which was described as a 
``supplemental proposal,'' provided pertinent new information. Both of 
the proposed rules concluded that the mountain plover was likely to 
become an endangered species in the foreseeable future unless measures 
were taken to reverse its decline. Conservation measures to reverse the 
decline were discussed in both of the proposals.
    In our February 16, 1999, proposed rule to list the species (64 FR 
7587) and our December 5, 2002, proposed rule to list the species (67 
FR 72396) we described a number of potential threats to the mountain 
plover. We cited historical decline in the black-tailed prairie dog (98 
percent range wide) and its effect on mountain plover habitat. We 
described effects of past rangeland loss to agricultural conversion (30 
percent of the Great Plains) and more recent conversion at specific 
mountain plover breeding sites. We addressed residential expansion into 
a mountain plover breeding area in South Park, Colorado, and stated 
that buildout of private lands would be detrimental. We hypothesized 
that cultivated areas used for breeding by mountain plover may

[[Page 27776]]

act as a ``population sink'' and that this could impact population 
viability. We expressed concern over the rising trend in oil, gas, and 
mineral exploration in mountain plover breeding habitat and, while we 
suggested habitat changes might not be detrimental, we cautioned that 
roads and human disturbance could impact mountain plover breeding. We 
cited potential impacts of both historical loss of grasslands and 
changing agricultural practices on mountain plover wintering areas in 
California. With the Imperial Valley growing in importance to wintering 
mountain plover, we suggested that water conservation, water transfer 
projects, burning restrictions, urbanization, and resulting 
modification of agricultural practices in the Imperial Valley could be 
detrimental to mountain plover populations. In our 1999 and 2002 
proposals we also expressed concerns regarding the mountain plover's 
average life span and breeding site fidelity as factors potentially 
impacting persistence of local breeding populations. We described a 
short average life span as limiting opportunities for mountain plover 
to reproduce. We also suggested that high site fidelity and the 
specific breeding habitat that mountain plover required limited 
opportunities to disperse to new breeding sites should former breeding 
areas turn inhospitable. We addressed concerns over mountain plover 
exposure to pesticides; however, we documented no deleterious effects.
    In the nine years since our 2002 proposal, substantial new 
information has been developed regarding the mountain plover and 
potential threats to its existence. Our December 3, 2009, 12-month 
finding on a petition to list the black-tailed prairie dog summarized 
new information on the species and provided a basis for us to assess 
whether threats to black-tailed prairie dog may, in turn, affect the 
mountain plover (74 FR 63343). We now believe that the black-tailed 
prairie dog is a resilient species and that, overall, populations in 
the mountain plover breeding range are not likely to decline. Recent 
data confirms that rangeland conversion to agriculture remains 
insignificant across the mountain plover's breeding range. Of the 
States where we previously documented rangeland declines, none have 
experienced significant decline in rangeland in recent years. Expanded 
human development of mountain plover breeding habitat in South Park, 
Colorado, did not proceed as previously anticipated, and is not 
expected to do so in the foreseeable future. Mountain plover use of 
cultivated lands has been further investigated, providing insight into 
the value of crop lands to breeding mountain plover. It now appears 
that perhaps one quarter of the rangewide mountain plover population 
breeds in crop fields and little evidence has surfaced to suggest that 
is problematic. Energy production in mountain plover habitat continues 
to expand, including increased development of oil and gas, and wind 
energy projects. Studies to date have not documented adverse impacts of 
oil and gas development, or wind energy projects. Effects of such 
projects on mountain plover merit continued study, largely because of 
their potential future scope. In California, land use changes continue 
in the Imperial Valley and elsewhere. However, based on current 
rangewide mountain plover population estimates (over 20,000 breeding 
birds) we now believe that the majority of mountain plover winter in 
areas other than California. We conclude that even with reduction of 
California wintering habitat, sufficient area of wintering habitat will 
remain, in California and elsewhere, to support current populations. 
Life span, site fidelity, and dispersal of both adult and juvenile 
mountain plovers have been further investigated. Contrary to our 
previous belief, the mountain plover is now considered a relatively 
long-lived species. Results of genetic research provide evidence that 
mixing among mountain plover breeding populations is occurring. 
Dispersal, especially by returning one year old mountain plover, 
appears significant. Site fidelity and the mountain plover's ability to 
seek out alternative sites for breeding are no longer of concern. While 
substantially more information has been developed regarding exposure of 
mountain plover to pesticides, no evidence of actual impacts to 
individuals, or suggestions that pesticides are having local or 
rangewide impacts to the species have surfaced.
    The following summary builds on scientific and commercial 
information presented in our 1999 and 2002 proposals and provides our 
current analysis based on all information currently available.

Factor A. The Present or Threatened Destruction, Modification, or 
Curtailment of Habitat or Range

    Recent summaries of the mountain plover's status (Dinsmore 2003; 
Knopf and Wunder 2006; Andres and Stone 2009) have highlighted the loss 
or degradation of mountain plover habitat as the greatest threat to the 
species. The primary issues that have been raised are potential loss of 
prairie dog populations and the mountain plover habitat they create; 
loss of native prairie and rangeland habitats; cropland breeding 
habitat as a potential reproductive sink; oil, gas, and mineral 
development; wind and solar energy development; loss and changes to 
wintering habitat in California; livestock grazing practices; and 
urbanization. We address these below.
Threats to Prairie Dogs and Associated Loss of Habitat
    Much of the mountain plover breeding range described above follows 
the range of the black-tailed prairie dog on grasslands of the Great 
Plains from Canada to Mexico. To a lesser extent, mountain plover also 
breed within the ranges of the white-tailed, Gunnison's, and Mexican 
prairie dogs. Mountain plover often nest in black-tailed prairie dog 
colonies at densities greater than in other habitats (Childers and 
Dinsmore 2008, p. 707; Tipton et al. 2009, p. 496), and mountain plover 
numbers have been shown to track changes in prairie dog abundance 
brought on by sylvatic plague (Dinsmore et al. 2005, pp. 1550-1551; 
Augustine et al. 2008, unpaginated; Dinsmore and Smith 2010, pp. 42-
44). A common recommendation regarding conservation of the mountain 
plover is to assure the maintenance or expansion of black-tailed 
prairie dog populations and the landscapes they create (Dinsmore et al. 
2005, p. 1552; Augustine et al. 2008; Knopf 2008, p. 61; Andres and 
Stone 2009, p. 35; Dinsmore et al. 2010). Current and future threats to 
the distribution and abundance of prairie dogs, especially the black-
tailed prairie dog, may in turn be threats to the mountain plover.
    On December 3, 2009, the Service published a 12-month finding on a 
petition to list the black-tailed prairie dog as endangered or 
threatened under the Act (74 FR 63343). We found listing to be not 
warranted. Here, we rely heavily on the analysis and results of that 
finding to assess the potential threat to the mountain plover from 
current or future loss of breeding habitat in the United States that is 
created and maintained by the black-tailed prairie dog.
    In our December 5, 2002, proposal to list the mountain plover we 
discussed historical reduction of the black-tailed prairie dog numbers, 
but not current populations or recent population trends (67 FR 72402). 
In our 2009 finding regarding the black-tailed prairie dog, we 
estimated that 2.4 million ac (1 million ha) of occupied black-tailed 
prairie dog habitat exists in a shifting mosaic over time, throughout 
an estimated 283 million ac (115 million ha) of suitable habitat. We 
evaluated

[[Page 27777]]

recent trends in occupied habitat and considered occupied habitat an 
appropriate surrogate for the status of the species. Rangewide, we 
estimated historical occupied area of black-tailed prairie dog colonies 
to be between 80 million ac and 104 million ac (32 to 42 million ha), 
almost all in the United States. Occupied area in the United States had 
decreased to a low of 364,000 ac (147,000 ha) by 1961 (largely because 
of eradication efforts), and subsequently increased to the 2.4 million 
ac (1 million ha) cited above. Throughout the United States, this 
represents a 600 percent increase in estimated black-tailed prairie dog 
numbers from 1961. See our December 3, 2009, finding (74 FR 63343) for 
the methods used to arrive at these estimates and cautions regarding 
their accuracy.
    The following evaluation of black-tailed prairie dog status 
highlights the three States, Colorado, Montana, and Wyoming, which have 
the greatest number of breeding mountain plover associated with black-
tailed prairie dog colonies. In Colorado, occupied black-tailed prairie 
dog habitat historically existed in the eastern half of the State, east 
of the Front Range Mountains (Hall and Kelson 1959, p. 365). Currently, 
the distribution of the black-tailed prairie dog is scattered in 
remnant populations throughout at least 75 percent of the historical 
range (Van Pelt 2009, p. 14). The most recent estimate of occupied 
habitat is 788,657 ac (319,158 ha) (Odell et al. 2008, p. 1311). This 
is approximately one-third of all currently occupied black-tailed 
prairie dog habitat in the United States, and is an eight-fold increase 
over occupied habitat thought to be present in Colorado in 1961.
    The Conservation Plan for Grassland Species in Colorado 
(Conservation Plan) (Colorado Division of Wildlife 2003, p. 1) has a 
goal ``to ensure, at a minimum, the viability of the black-tailed 
prairie dog and associated species (mountain plover, burrowing owl, 
swift fox, and ferruginous hawk (Buteo regalis)) and provide mechanisms 
to manage for populations beyond minimum levels, where possible, while 
addressing the interests and rights of private landowners.'' The 
Conservation Plan includes a species account for mountain plover, but 
does not provide any regulatory protections for the species or its 
habitat.
    In Montana, where mountain plover are strongly associated with 
prairie dog colonies (Childers and Dinsmore 2008, p. 701), black-tailed 
prairie dog occupied habitat historically existed in the eastern two-
thirds of the State, with the exception of the northeastern corner of 
the State (Hall and Kelson 1959, p. 365). Current prairie dog 
distribution is scattered in remnant populations over 90 percent of the 
historical range (Van Pelt 2009, p. 20). Currently, 193,862 ac (78,453 
ha) of occupied habitat are estimated to occur in Montana (Hanauska-
Brown 2009). This represents nearly a seven-fold increase over occupied 
habitat thought to be present in Montana in 1961.
    In Wyoming, the black-tailed prairie dog historically occupied 
habitat in the eastern half of the State, east of the Rocky Mountains 
(Hall and Kelson 1959, p. 365). Currently, distribution is scattered in 
remnant populations throughout at least 75 percent of the historical 
range (Van Pelt 2009, p. 40). A 2006 study estimated the amount of 
occupied habitat to be 229,607 ac (92,919 ha) (Grenier et al. 2007, p. 
125) and these results suggested that black-tailed prairie dog 
populations in Wyoming remain stable (Emmerich 2010, pers. comm.). This 
represents nearly a five-fold increase over occupied habitat thought to 
be present in Wyoming since in 1961.
    In the past, the conversion of native prairie habitat or rangeland 
to cropland reduced black-tailed prairie dog colonies, and thereby 
impacted the mountain plover's most productive breeding habitat in the 
grassland ecosystem. Conversion of native prairie to cropland 
historically progressed across the Great Plains from east to west. The 
most intensive farming activity remains in the east, in portions of 
North Dakota, South Dakota, Nebraska, Kansas, Oklahoma, and Texas, 
where higher rainfall amounts and generally better soils result in 
greater agricultural production, and the land supports crops such as 
corn and soybeans. This land conversion resulted in the historical 
reduction in black-tailed prairie dog populations; as well as 
reductions in mountain plover populations in Nebraska, Kansas, 
Oklahoma, and Texas; it also resulted in the extirpation of the 
mountain plover populations in North Dakota and South Dakota. Land with 
the highest potential for traditional farming uses was converted many 
years ago. The threat of future destruction of both prairie dog and 
mountain plover habitat through cropland conversion is minimal, much 
less than in the early days of agricultural development in the Great 
Plains (see Loss of Breeding Habitat to Land Conversion and 
Development, below).
    The present or threatened alteration of habitat due to oil, gas, 
coalbed methane, and mineral extraction, and wind energy development, 
affects portions of black-tailed prairie dog occupied habitat; however, 
we have no information regarding the extent of potential impacts. 
Nevertheless, prairie dog occupancy has apparently increased within oil 
and gas development areas in Wyoming (Sorensen et al. 2009, pp. 5-6). 
We have no evidence that present or threatened curtailment of habitat 
due to oil, gas, coalbed methane, and mineral extraction, and wind 
energy development, is a limiting factor for the black-tailed prairie 
dog in Wyoming or elsewhere throughout its range.
    Approximately 110 million ac (45 million ha) of cropland and 283 
million ac (115 million ha) of rangeland occur within the black-tailed 
prairie dog's range at present (Ernst 2008, pp. 10-19). In our December 
3, 2009, finding for the black-tailed prairie dog (74 FR 63343), we 
contrasted the 2.4 million ac (1 million ha) of currently occupied 
habitat with the 283 million ac (115 million ha) of rangeland and 
concluded that sufficient potential habitat still occurs within the 
range of the species in the United States to accommodate large 
expansions of prairie dog populations (which in turn would benefit the 
mountain plover) if the landowners and public sentiment allow. We 
concluded that the present or threatened destruction, modification, or 
curtailment of habitat or range is not a limiting factor for the black-
tailed prairie dog and that we do not anticipate that impacts from 
habitat loss are likely to negatively impact the status of the species 
in the foreseeable future. Because of the association between the 
mountain plover and the black-tailed prairie dog, we believe that 
appropriate habitat to support prairie dog colonies is not a limiting 
factor within the breeding range of the mountain plover.
    Sylvatic plague is an exotic disease foreign to the evolutionary 
history of North American prairie dogs. It is caused by the bacterium 
Yersinia pestis. Black-tailed prairie dogs are very sensitive to 
sylvatic plague, and mortality in colonies affected frequently reaches 
100 percent. Sylvatic plague has expanded its range to all States 
within the range of the black-tailed prairie dog in recent years and 
has caused local population declines at several sites. These declines 
are typically followed by partial or complete recovery. Rangewide and 
Statewide estimates of prairie dog occupied area did not include 
unoccupied prairie dog colonies where sylvatic plague (or poisoning) 
had at least temporarily eliminated prairie dogs. Over all prairie dog 
colonies, unoccupied area was found to total 12 percent in Colorado, 15 
percent in Montana, and 13 percent in Wyoming. The BLM mapped prairie 
dog colonies

[[Page 27778]]

in Phillips County, Montana in 2004 and 2005, and returned to 50 
randomly selected prairie dog colonies in 2010. Of the 50 colonies 
selected for sampling, 48 were still active in 2010 (McDonald 2010). In 
the changing mosaic, colonies lost or temporarily inactive may be 
offset by colonies reoccupied or newly established.
    We documented in our 12-month finding on a petition to list the 
black-tailed prairie dog that, since the early 1960s, occupied black-
tailed prairie dog habitat has increased in every State, even in those 
States where sylvatic plague has been present for over 50 years (74 FR 
63355-63356). This increase has occurred despite continued impacts from 
sylvatic plague and other threats. In our 2009 finding, we concluded 
that the status of the black-tailed prairie dog, as indicated by 
increased occupied habitat since the early 1960s, indicates that 
sylvatic plague is not a limiting factor for the species (74 FR 63357).
    Similarly, the increase in black-tailed prairie dog numbers in the 
United States has occurred despite conflicting Federal and State 
regulations and policies that encourage conservation of prairie dogs 
through development of State and rangewide management plans, yet in 
many cases continue to allow shooting and poisoning of prairie dogs. 
Nevertheless, affected Federal and State agencies are engaged in black-
tailed prairie dog management and monitoring to a much greater extent 
than they were 10 years ago.
    Efforts to conserve the black-tailed prairie dog will likely be 
beneficial to the mountain plover. Our December 3, 2009, finding for 
the black-tailed prairie dog (74 FR 63343) described the 1998 
establishment of the Black-tailed Prairie Dog Conservation Team, with 
representatives from each State within the historical range of the 
species, and the development of ``The Black-tailed Prairie Dog 
Conservation Assessment and Strategy'' (Van Pelt 1999, entire), which 
initiated development of ``A Multi-State Conservation Plan for the 
Black-tailed Prairie Dog, Cynomys ludovicianus, in the United States'' 
(Multi-State Plan) (Luce 2002). The purpose of the Multi-State Plan was 
to provide adaptive management goals for future prairie dog management 
in the 11 States within the species' range. The plan identified 10-year 
target objectives including maintaining and increasing occupied acreage 
of black-tailed prairie dog habitat, and increasing the number of large 
prairie dog complexes. The States also agreed to draft Statewide 
management plans for the black-tailed prairie dog. The States approve 
their own Statewide management plans. Colorado and Wyoming have 
finalized grassland conservation plans that support and meet the 
objectives of the Multi-State Plan. However, Montana is among the 
States that have finalized management plans that do not support or meet 
all of the objectives of the Multi-State Plan. These and other efforts 
give promise that the trend of increasing black-tailed prairie dogs 
populations since 1961 can be sustained.
    Climate change will likely affect black-tailed prairie dogs and 
their habitat; however, at this time we have no information on the 
direct relationship between climate change and black-tailed prairie dog 
population trends, and we cannot quantify the potential magnitude or 
extent of impact that climate change may have on the species. While 
climate change may potentially impact the species in future decades, 
particularly through its effects on sylvatic plague, it is not apparent 
that a net loss in occupied habitat will result. The current status of 
the black-tailed prairie dog does not suggest that the combined effects 
of sylvatic plague and climate change are currently limiting factors 
for the species or that they will become so within the foreseeable 
future, and we do not believe climate change will result in significant 
population-level impacts to the black-tailed prairie dog.
    In summary, we believe that the black-tailed prairie dog is a 
resilient species and that overall United States populations are not 
expected to be significantly affected by habitat loss due to conversion 
to cropland, sylvatic plague, shooting, poisoning, or climate change 
(74 FR 63364, December 3, 2009).
    Mountain plover populations in Montana, and to a lesser extent 
other breeding areas, are dependent on the prairie dog for breeding 
habitat. Given our conclusion that habitat created or enhanced by 
black-tailed prairie dogs is unlikely to decrease, we conclude that 
threats to the black-tailed prairie dog in the United States do not 
represent a threat to the continued existence of the mountain plover.
    Potential dependence of both wintering and breeding mountain plover 
populations on remaining prairie dog colonies in Mexico is of concern 
(Macias-Duarte and Panjabi 2010, pp. 9-10). In Mexico, decline of 
native grasslands supporting the black-tailed prairie dog and the 
Federally endangered Mexican prairie dog have been extensive, despite 
some environmental regulations designed to protect prairie dogs and 
their habitats. The large black-tailed prairie dog complex at Janos has 
been reduced by 73 percent since 1988, to approximately 38,000 ac 
(16,000 ha), while Mexican prairie dog colonies within the El Tokio 
region have also been reduced to approximately 79,000 ac (32,000 ha) 
(Andres and Stone 2009, p. 28; Ceballos et al. 2010, pp, 7-8; Macias-
Duarte and Punjabi 2010, p. 9-10). Both areas, at least in some years, 
support significant numbers of wintering mountain plover (see 
Conservation Status and Local Populations above). Destruction and 
fragmentation of prairie dog colonies has occurred through poisoning 
and shooting of prairie dogs, conversion to cattle ranching or farming, 
overgrazing, and drought. Mexico experienced a prolonged drought in the 
Janos area in recent years, which resulted in dramatic loss of 
vegetation, followed by a reduction in black-tailed prairie dog 
occupied habitat (Larson 2008, p. 87).
    These losses in prairie dog habitat in Mexico have degraded or 
eliminated the extent of wintering plover habitat in these areas. 
Recent efforts to protect prairie dogs and grasslands also benefit 
wintering mountain plover and may help stop or reverse recent trends. 
Government designation of protected areas in Chihuahua and Nuevo Leon, 
and efforts by Pronatura Noreste, The Nature Conservancy, and other 
institutions, hold promise (Andres and Stone 2009, pp. 33, 40; Macias-
Duarte and Punjabi 2010, p. 10). In 2009, the 1.3-million-ac (526,000-
ha) Janos Biosphere Reserve was established to protect some of the best 
remaining shortgrass prairie in Mexico and thereby benefit the black-
tailed prairie dog. This conservation initiative is led by Mexico's 
National Protected Areas Commission and the Chihuahuan State government 
(The Nature Conservancy 2010). The Llano de la Soledad, which 
encompasses the major Mexican prairie dog complexes of the El Tokio 
area, a 26,000-ac (10,500-ha) area, has been designated a State Natural 
Area for Ecological Conservation administered by the Agency of 
Environmental Protection and Natural Resources of Nuevo Leon. 
Neotropical migratory bird grants from the Service have supported 
efforts led by Pronatura Noreste to protect and manage key lands 
through purchase and easement. While past habitat loss for the mountain 
plover at Janos and El Tokio has been significant, international 
attention to these and to other important grassland complexes in Mexico 
improves prospects for future conservation and maintenance of mountain 
plover wintering habitat.
    Knowledge of mountain plover breeding on prairie dog colonies in 
Mexico is limited. The primary known

[[Page 27779]]

value of black-tailed and Mexican prairie dog colonies to the mountain 
plover is as wintering habitat; yet use varies greatly from year to 
year. Mountain plover use of croplands and rangelands present in Mexico 
for wintering is largely unstudied. For example, agricultural areas in 
northern Baja California, the coastal plains of Sonora and Sinaloa, and 
throughout the northern Chihuahuan Desert States may potentially 
support substantial wintering populations (Macias-Duarte and Punjabi 
2010, p. 10). The net effect of reduction in prairie dog colonies in 
Mexico to mountain plover is largely unknown. However, given that 
mountain plover winter extensively in cropland habitats in California 
and Texas, we believe that cropland habitats in Mexico are likely 
available as alternative wintering habitat. There is no available 
information to indicate that the past, current, or potential future 
loss of black-tailed and Mexican prairie dog colonies and the 
ecosystems they support in Mexico is a significant threat to the 
mountain plover.
    Despite the ongoing effects of habitat conversion, sylvatic plague, 
shooting and poisoning, and lack of regulatory mechanisms that provide 
protection, black-tailed prairie dog habitats have increased in the 
United States over the last 50 years (74 FR 63343, December 3, 2009). 
Although there is significant concern about the status of black-tailed 
and Mexican prairie dogs and their habitats in Mexico, there is no 
information available to indicate that further reductions in prairie 
dogs in Mexico are threatening the mountain plover. At this time, the 
best available scientific information does not indicate that the loss 
of prairie dog habitat is likely to threaten the mountain plover now or 
in the foreseeable future.
Loss of Breeding Habitat to Land Conversion and Development
    As described above, losses of native grasslands in the Great Plains 
have been severe since European settlement. Losses of these native 
grasslands have been greatest in the eastern Great Plains and have 
impacted the mountain plover mainly from conversion of prairie 
grasslands to crop fields incompatible with mountain plover breeding, 
including those planted to corn and soybeans. These losses are likely 
the reason why the mountain plover no longer breeds in the Dakotas, has 
a limited range in Nebraska, and is now a rare breeder in Kansas (Graul 
and Webster 1976, p. 266; Knopf and Wunder 2006). Land conversion to 
agriculture continues, primarily in the northern Great Plains, but at a 
much slower rate. Over the 15-year period from 1982 to 1997, in 
Montana, Wyoming, and Colorado, there were no decreases in the amount 
of rangeland or pastureland present (USDA 2010). Conversion to cropland 
may be locally affecting mountain plover in some areas of Montana. 
Approximately 47,000 ac (19,000 ha) of native grassland was converted 
to agriculture in Montana from 2005 to 2009 (Ducks Unlimited, cited in 
McDonald 2010). Statewide, the amount of cropland in Montana increased 
by about 3 percent from 1997 to 2007 (USDA 2010). In the four Montana 
counties with the most mountain plover habitat (Blain, Fergus, 
Phillips, and Valley Counties), cropland increased over the same period 
by about 6 percent, with most of the increase attributable to Valley 
County (USDA 2010). However, the cited conversion from 2005 to 2009 
represents less than 0.2 percent of the 30 million ac (12 million ha) 
of ``grassland/herbaceous'' cover present in Montana in 2001 (USGS 
2001). Cropland is used by breeding mountain plover elsewhere, but its 
potential for use in Montana is unknown. Conversion of grasslands to 
cropland in Montana may locally impact mountain plover; however, we 
believe this low rate of conversion would have negligible rangewide 
effect.
    The best information available does not allow us to estimate the 
specific amount of occupied grassland breeding habitat for mountain 
plover that has been converted to other uses in recent years. However, 
given the apparent low rate of grassland conversion in Montana and 
rangewide, and the mountain plover's ability to use grassland that has 
been converted to other uses such as certain agricultural crops 
including wheat, sorghum, and millet, we believe that grassland 
conversion does not pose a substantial threat to the mountain plover in 
Montana, or elsewhere in its breeding range, now or in the foreseeable 
future.
    In our 1999 and 2002 proposals to list the mountain plover as a 
threatened species (64 FR 7587 and 67 FR 72396, respectively), we also 
addressed the concern that grassland breeding habitat may be lost to 
human development. Since the mountain plover's breeding range is 
extensive, there are undoubtedly instances where human development is 
and will locally displace the mountain plover. We agree with the 
conclusion of Andres and Stone (2009, p. 22) that habitat in the 
mountain plover breeding range is subject to little overall threat from 
residential and commercial development, because human development is 
not expected to be very extensive in the largely rural areas of the 
species' breeding habitat.
    An area that generated past concern in our 1999 and 2002 proposals 
is South Park, Park County, Colorado, an approximately 480,000 ac 
(200,000 ha) grassland basin where the mountain plover breeding 
population is estimated to be about 2,300 birds. Much of the mountain 
plover habitat in South Park is privately owned, and 32 percent of this 
area has been subdivided (Granau and Wunder 2001, pp. 8-9). Substantial 
build-out of those properties currently subdivided would be detrimental 
to mountain plover; however, human population growth in South Park is 
modest (Nichols 2010, pers. comm.). Many of the subdivisions occurred 
in the 1960s and 1970s, and have not been developed. Earlier forecasts 
suggested South Park would have a human population of 10,000 by 2010, 
but the current human population stands at approximately 3,500 (Nichols 
2010, pers. comm.). Issuance of building permits countywide have 
decreased steadily in recent years, from 297 in 2002 to 70 in 2009 
(Carrington 2010, pers. comm.). In addition, land protection and 
conservation efforts by the BLM, Park County, Colorado Open Lands, and 
The Nature Conservancy are ongoing in South Park. The BLM (2009a, p. 2) 
amended their Royal Gorge Resource Area Management Plan for the South 
Park Subregion in light of new resource goals, including the protection 
of mountain plover breeding habitat. Their Land Tenure Designation Plan 
for South Park was modified to keep a greater portion of the BLM's 
approximately 63,000 ac (26,000 ha) of South Park lands in Federal 
ownership and make less sensitive BLM lands available for exchange to 
consolidate Federal lands of highest resource value. Primary goals of 
Park County's Master Plan include protection of environmentally 
sensitive areas, and managing the location and pace of residential 
growth (Park County 2001, p. 13). In addition, Colorado Open Lands and 
their partners have preserved approximately 17,000 ac (7,000 ha) of 
lands in South Park to minimize development in and around significant 
conservation areas (Colorado Open Lands 2011).
    The current level of residential development in South Park is not 
currently a threat to the mountain plover and, given recent development 
trends and conservation initiatives, we do not consider residential 
development in South Park to be a threat in the foreseeable future. 
Elsewhere, threats from human development are largely limited to 
wintering habitat.

[[Page 27780]]

    In summary, we do not believe that conversion of the mountain 
plover's grassland breeding habitat to cropland, or to human 
residential and commercial development, represents a threat to the 
mountain plover now or in the foreseeable future.
Range Management
    Breeding mountain plover in grasslands are strongly associated with 
heavy grazing and soil disturbance (Knopf and Wunder 2006). In the 
absence of prairie dogs, activities such as heavy cattle grazing, the 
concentration of cattle at loafing areas and at water, and burning of 
rangeland provide habitat for mountain plover. However, typical range 
management practices such as fencing, rotational grazing, decreased 
stocking rates, and planting nonnative grasses to improve soil moisture 
promote uniform vegetative cover and taller grasses, which are less 
beneficial to breeding mountain plover. In addition, human efforts to 
suppress wildfire are generally detrimental to mountain plover.
    Specific range management options for mountain plover are somewhat 
limited. Cattle grazing provides benefits to mountain plover, but this 
is especially true when it maintains low vegetation and patches of bare 
ground. Heavy cattle grazing may not be a financially justifiable 
option for ranchers and can create conditions unfavorable to many other 
species of wildlife. Aside from grazing, specific range management 
options for mountain plover are somewhat limited. Mountain plover use 
burned areas for breeding, and prescribed burning can be used as a 
habitat management tool (Knopf 2008, p. 61; Andres and Stone 2009, p. 
29). Ongoing USFS burning programs on the PNG and the Comanche National 
Grasslands in Colorado to attract breeding mountain plover have had 
some success (Augustine 2010a, pers. comm.). However, primary benefits 
of burning a site are generally of short duration, i.e., 1 or 2 years 
(Augustine 2010b, pers. comm.). The value of burning is dependent on 
the extent and the frequency of burns. Augustine and Malchunas (2009, 
p. 89) suggested that late winter shortgrass burns may have neutral or 
positive consequences for livestock, but burning is not a management 
practice generally employed within the mountain plover's breeding 
range.
    Even without rangeland management that specifically benefits the 
mountain plover, soil type, site history, or drought may create habitat 
conditions that are beneficial to breeding mountain plover. Rocky or 
clay pan substrate may suppress vegetation and provide breeding habitat 
(Knopf and Wunder 2006). In years of low precipitation, grazing at 
relatively low intensity has a greater impact on grassland vegetation 
and can produce habitat conditions favorable for mountain plover 
breeding.
    Knopf (2008, entire) provided an historical account of mountain 
plover populations on the PNG, Weld County, Colorado, and discussed the 
future of mountain plover in the area. He suggested that mountain 
plover numbers in the area had been in decline since the post-dust bowl 
days of the late 1930s and early 1940s, and that the dramatic decline 
in the mid-1990s was the abrupt end point of a process of deteriorating 
mountain plover habitat (recovery of grassland habitat), which was 
exacerbated by other factors such as wet spring weather and predation 
(Knopf 2008, p. 60). Given current range management practices, Knopf 
suggested that short-term benefits from prescribed burning and, more 
significantly, the maintenance of prairie dog colonies were the only 
viable means to enhance mountain plover habitat on the PNG.
    Sheep grazing can maintain the low vegetation structure that is 
beneficial to breeding mountain plover. However, the current level of 
sheep grazing does not maintain significant amounts of mountain plover 
breeding habitat rangewide. The sheep industry in the United States has 
been in decline for more than 60 years and now supports about one-tenth 
of the number of sheep present in the 1940s. Decreases in sheep grazing 
may have been a contributing factor to loss of favorable grassland 
breeding habitat for the mountain plover in the past. The future of the 
industry is uncertain; continued declines in the industry are likely in 
some areas, but changes in the industry also present opportunities for 
its growth (National Academy of Sciences 2008, p. 4). For the 
foreseeable future, it appears likely that sheep grazing will remain a 
minor rangewide contributor to maintenance of favorable mountain plover 
breeding habitat, but that potential for any further decline in 
breeding habitat due to additional loss of acreage grazed by sheep is 
minimal.
    A number of conservation efforts target the conservation of 
grasslands, prairie ecosystems, and prairie birds: The Great Plains 
Landscape Conservation Cooperative (a public/private initiative to 
proactively conserve declining habitats on private lands); The Nature 
Conservancy's ecoregional plan for the Central Shortgrass Prairie; the 
Colorado Division of Wildlife's Conservation Plan for Grassland Species 
and similar efforts in other States; Natural Resources Conservation 
Service conservation efforts under the Farm Bill; preservation of 
grasslands via conservation easements, including more than 350,000 ac 
(140,000 ha) in easements reported by the Colorado Cattleman's 
Agricultural Land Trust (2010); the Rocky Mountain Bird Observatory's 
Prairie Partners; and The Nature Conservancy's ``Prairie Wings'' 
effort. Many of these initiatives include conservation of the mountain 
plover, the black-tailed prairie dog, and other species supported by 
the prairie dog ecosystem.
    In summary, the extent to which mountain plover are benefitted by 
cattle grazing on any given site is determined by the range management 
practices employed. While some current management practices result in 
habitat conditions that are not optimal for mountain plover breeding, a 
large number of mountain plover nest on rangeland. We do not anticipate 
future changes to the current pattern of range management across the 
breeding range of the mountain plover that would prove detrimental to 
the mountain plover and its habitat. The extent to which range 
management practices could benefit the mountain plover in the future is 
dependent on conservation of black-tailed prairie dog colonies and, to 
a lesser extent, on willingness to employ prescribed burning as a range 
management tool. Grazing by sheep can create favorable breeding habitat 
for mountain plover. The sheep industry in the western United States 
has declined over time, but we do not anticipate that future changes in 
the sheep industry will have a net negative impact on existing mountain 
plover habitat or be a threat to existing mountain plover habitat in 
the future.
Cultivated Areas in the Mountain Plover Breeding Range Acting as a 
Potential Population Sink
    Agricultural practices can destroy mountain plover nests and eggs 
from mechanical treatment (tilling, planting, application of 
fertilizers and pesticides), and crops growing beyond a certain height 
may cause nest abandonment (Knopf and Rupert 1999, p. 85; Dinsmore 
2003, p. 27). In our 1999 and 2002 proposals to list the mountain 
plover as a threatened species (64 FR 7587 and 67 FR 72396, 
respectively), we raised the concern that these activities could create 
a reproductive ``sink,'' or in other words a situation in which 
mountain plover are drawn to crop fields for nesting but do not produce 
viable young at a rate that would sustain the population.

[[Page 27781]]

    Knopf and Rupert (1999, p. 84) suggested that breeding mountain 
plover having the opportunity to nest on either agricultural or prairie 
areas chose both equally. In the eastern Colorado shortgrass prairie 
ecosystem, mountain plover breeding densities on crop fields were twice 
as high as the densities found on grasslands without prairie dogs, 
although only one-fifth as high as the densities found on prairie dog 
colonies (Tipton et al. 2009, p. 496). Based on the area of habitats 
surveyed and densities of mountain plover estimated, approximately 40 
percent of mountain plover may use crop fields for nesting in eastern 
Colorado. Nebraska studies (Van der Burg et al. 2010, pp. 48, 50) 
suggested a similar percentage of the mountain plover in Nebraska 
utilize crop fields for nesting. The small, seemingly stable, breeding 
mountain plover population in Oklahoma was primarily found in plowed or 
fallow fields, although again the potential of a reproductive sink was 
raised (MacConnell et al. 2009, pp. 31-33). Based on estimates of 
mountain plover using crop fields in Colorado and Nebraska, together 
with known use of crop fields in Wyoming, Oklahoma, and Kansas, we 
conclude that up to one quarter of all mountain plover may utilize crop 
fields for breeding. Given the significance of crop fields to breeding 
mountain plover and questions regarding a possible reproductive sink, 
research is ongoing to better understand the role that crop fields play 
in support of breeding mountain plover populations (Dreitz et al. 
2010).
    In Colorado, mountain plover hatching success was found to be 
similar in native grasslands and crop fields, although causes of nest 
mortality differed between the two habitats (Dreitz and Knopf 2007, pp. 
684-685). Use of crop fields was not determined to be detrimental to 
mountain plover hatching success. However, a subsequent eastern 
Colorado study found chick survival to be similar on crop fields (23 
percent) to shortgrass habitat without prairie dogs (24 percent), but 
lower than chick survival on shortgrass habitat occupied by black-
tailed prairie dogs (75 percent), and the author again suggested that 
crop fields may represent a reproductive sink or ``ecological trap'' 
(Dreitz 2009, pp. 875-877). Given the study results, the same concern 
could be raised regarding shortgrass habitat lacking prairie dogs. In 
contrast to the study above, recent research on crop fields in Nebraska 
found 95 percent survival of chicks of adult mountain plover tracked 
for 35 days (Blakesley and Jorgensen 2010, pers. comm.), although loss 
of contact with other adult mountain plover suggests that actual chick 
survival was somewhat lower (Blakesley 2010, pers. comm.). Preliminary 
data from studies of radio-tracked chicks in Montana and Colorado in 
2010 (Dreitz et al. 2010) did not show chick survival in crop fields to 
be lower than in other habitats. While results reported by Dreitz 
(2009, pp. 875-877) above come from the most comprehensive study of 
chick survival in crop fields, other studies indicate that mountain 
plover chick survival rates on crop fields and among other prairie 
habitats vary greatly in time and place.
    Shackford et al. (1999, p. 119) suggested that decreasing nest loss 
from mechanical treatment of fields would benefit mountain plover. Nest 
marking efforts that allow farmers to avoid nests and reduce nest 
mortality from agricultural operations have been conducted with 
cooperating farmers in Colorado and Nebraska (Dreitz and Knopf 2007, p. 
685; Lock and VerCauteren 2008, entire; Bly 2010a). The Colorado 
Division of Wildlife and the Nebraska Game and Parks Commission, along 
with the Rocky Mountain Bird Observatory, initiated nest marking 
programs. In Nebraska, a reported 80 percent of 246 nests marked in 
crop fields over 3 years successfully hatched young (Bly 2010a). As a 
comparison, an experiment using dummy nests suggested a 35 percent 
success rate was likely in crop fields if nests were not marked (Bly 
2010a).
    While recent analysis of mountain plover populations suggests that 
efforts targeting chick survival may hold more conservation value than 
those efforts to enhance nest success, management techniques to achieve 
higher chick survival may be difficult to employ. In addition, nest 
marking programs have helped establish ties between the agricultural 
community and wildlife managers (Dreitz and Knopf 2007, pp. 685-686; 
VerCauteren 2010). Outreach efforts to farmers continue, including 
education regarding mountain plover and transition from nest marking to 
landowners' taking the lead in finding and avoiding mountain plover 
nests in the course of their field operations. Community efforts, such 
as the annual Mountain Plover Festival sponsored by the Karval 
Community Alliance in Lincoln County, Colorado, promote stewardship of 
the mountain plover and other wildlife as an integral part of both 
farming and ranching practices.
    Studies documenting numbers and reproductive success of mountain 
plover breeding on crop fields in eastern Colorado and Nebraska do not 
entirely resolve the issue of the relative value of this habitat to the 
mountain plover. However, in studies from eastern Colorado, nest 
success in crop fields (Dreitz and Knopf 2007, pp. 684-685) and chick 
survival in crop fields (Dreitz 2009, pp. 875-877; Dreitz et al. 2010) 
appear similar to nest success and chick survival in native shortgrass 
without prairie dogs. We conclude that crop fields support breeding 
mountain plover as well as shortgrass without prairie dogs, although 
likely not as well as shortgrass with prairie dogs. If the crop fields 
in eastern Colorado that are regularly occupied by breeding mountain 
plover are a reproductive sink, their continued occupancy by mountain 
plover is dependent on a net influx of birds dispersing from other 
breeding habitats. We have no evidence to suggest whether or not this 
is occurring. Further, unless mountain plover prefer and choose crop 
fields for breeding over available (unoccupied) habitat where 
reproductive success is higher, breeding in crop fields, even if less 
successful, would not seem detrimental. We conclude that, based on the 
information available, the mountain plover's use of crop fields for 
breeding does not represent a threat to the species.
    Another concern is the potential that change in current 
agricultural practices will result in future loss of the types of crop 
fields that currently provide breeding habitat for mountain plover. 
Dryland agriculture is the type of agriculture that most frequently 
supports breeding mountain plover, and it is dominated by wheat, but 
also includes crops of sorghum, millet, and sunflowers. Annual 
variation in the use of dryland agriculture fields is dictated by a 
number of factors including weather, government programs, crop prices, 
and preferences of individual farmers. It is not known whether any 
significant future changes to dryland agriculture that the mountain 
plover uses for breeding are likely to occur or how they would affect 
mountain plover (Andres and Stone 2009, p. 23).
    In recent years, ethanol production from corn has expanded in the 
United States; however, most corn is cultivated east of the range of 
the mountain plover (Westcott 2007, pp. 1-3). Additionally, the 
increase in corn production largely occurs by adjusting crop rotations 
between corn and soybeans (Westcott 2007, p. 7); neither crop regularly 
supports mountain plover. We do not anticipate that increased ethanol 
production will result in a substantial loss in the species' occupied 
or potential habitat because the majority of this activity lies outside 
the range of the mountain plover.

[[Page 27782]]

    In conclusion, we believe that approximately one quarter of the 
rangewide mountain plover population breeds in crop fields in Colorado, 
Nebraska, or elsewhere, but there is no evidence that this represents a 
reproductive sink detrimental to the rangewide population. Dryland 
agriculture has changed little over recent decades, and we have little 
evidence to suggest that crop fields now, or in the future, represent a 
significant threat to the mountain plover.
Energy and Mineral Development
    Development targeting oil and gas, coal bed methane, wind energy, 
and other mineral resources is extensive within the breeding range of 
the mountain plover. Energy development is a national priority as 
mandated by Executive Orders 13212 (Actions to Expedite Energy-Related 
Projects) (66 FR 28357, May 22, 2001) and 13514 (Federal Leadership in 
Environmental, Energy, and Economic Performance) (74 FR 52117, October 
8, 2009), and the Energy Independence and Security Act of 2007 (42 
U.S.C. 17001 et seq.). Current permitting and construction of new 
energy projects on Federal and non-Federal lands reflects this 
priority. The development of energy resources requires construction at 
well or wind turbine sites, as well as access roads, pipelines, power 
lines, and other support facilities. These projects could have an 
immediate effect on breeding mountain plover due to disturbance and 
habitat conversion, and secondary effects associated with operation and 
maintenance.
    The magnitude of the issue is best exemplified by energy 
development in Wyoming, where the Wyoming Natural Diversity Database 
(WYNDD) (2010) has used habitat mapping and mountain plover observation 
records to map the probability of mountain plover presence. In Wyoming, 
WYNDD (2010) predicts a high probability of mountain plover occurrence 
over about 7 million ac (3 million ha) and a medium probability of 
occurrence over about 14 million ac (6 million ha). We evaluated 
overlap between predicted mountain plover presence and energy 
development (Lindstom 2010).
    As of February 2010, 5,043 wells, approximately 12 percent of 
operating oil and gas wells in Wyoming (Wyoming Oil and Gas Commission 
2010), occurred in areas of high probability of mountain plover 
occurrence, while 13,266 wells, about 32 percent of wells, occurred in 
areas with medium probability of mountain plover occurrence. While 
wells are clustered in well fields, this would equate to one well per 
about 1,400 ac (560 ha) in areas of high probability of mountain plover 
occurrence and one well per 1,080 ac (430 ha) in areas medium 
probability of occurrence. We believe that this represents a relatively 
low overall potential impact to mountain plover habitat.
    Of 13 million ac (6 million ha) of authorized (both developed and 
undeveloped) BLM oil and gas leases in Wyoming (BLM 2009b), we 
estimated that 52 percent were in areas of high or medium probability 
of mountain plover occurrence (or about one-third of all areas of high 
or medium probability of mountain plover occurrence were under BLM 
lease).
    Areas in Wyoming of wind classes 4 through 7 (a measure of wind 
resource potential) account for about 6 million ac (2.4 million ha), or 
about 30 percent, of those areas of high or medium probability of 
mountain plover occurrence (National Renewable Energy Laboratory 2002). 
Since additional factors determine development potential, only a 
portion of these areas would likely see future wind energy development.
    Future energy development will depend on whether oil and gas 
resources are actually present, the location of wind resources relative 
to consumers, future demand, economic considerations, and environmental 
regulations. Therefore, it is uncertain to what degree energy projects 
will be developed in mountain plover breeding habitat in Wyoming, or 
other portions of the range, in the foreseeable future. However, given 
our evaluation above, we believe that current and future energy 
development in mountain plover habitat may be substantial in Wyoming. 
Existing and proposed oil and gas development and wind energy projects 
also occur in mountain plover habitat in Montana and the plains of 
Colorado, as well as in other States within the mountain plover's 
breeding, migratory, and wintering range. The cumulative total of 
current and future energy development elsewhere in the mountain 
plover's breeding range may not approach that likely to occur in 
Wyoming, but energy development is likely to occur within many breeding 
areas used by the species. For example, oil and gas development 
continues in Weld County, Colorado, and renewed exploration is 
occurring on and near the PNG (Philbrook 2010, pers. comm.), formerly 
an important breeding area for the mountain plover.
    Concerns over impacts of oil and gas development to landscapes and 
to various wildlife species have prompted environmental review 
standards (BLM 2010c), and may lead to more widespread use of 
development practices that minimize impacts. For example, directional 
drilling, where feasible, has the potential to decrease habitat 
impacts. Increased piping, product storage in central locations, and 
remote sensing of wells may reduce vehicular traffic and the impact of 
roads.
    Despite the prevalence of energy development activities throughout 
the range of the mountain plover, there is little evidence as to 
whether, or to what extent, the overall effects of energy development 
are detrimental to mountain plover (Andres and Stone 2009, p. 25). 
Although oil and gas field development modifies and fragments nesting, 
brood rearing, and foraging habitats, mountain plover continue to use 
these areas (Smith and Keinath 2004, p. 36; Carr, in review). For many 
wildlife species, the principal impact of energy development is 
fragmentation rather than habitat loss. Energy development, even when 
extensive, may directly impact only a small percentage of an area. In a 
study of the Big Piney-LaBarge oil and gas field in the Upper Green 
River Valley of Wyoming, where well density averaged about one well per 
64 ac (26 ha), 97 percent of the landscape was within 0.25 mile (0.40 
kilometer) of infrastructure (roads, pipelines, well pads, waste pits), 
but only 4 percent of the area was directly impacted by oil and gas 
infrastructure (Morton et al. 2004, pp. 10-11). Carr (in review) found 
that mountain plover located nests in relation to habitat available, 
rather than avoiding locations of energy development. We have no data 
to suggest that the mountain plover is impacted by habitat 
fragmentation, as opposed to habitat loss.
    Because the mountain plover generally favors disturbance that 
reduces vegetative cover and exposes bare ground (e.g., prairie dogs, 
grazing, fire), it may tolerate surface disturbance from energy 
development (Andres and Stone 2009, p. 25; Carr, in review). In Utah, 
disturbed areas around oil well pads reportedly created open habitat 
with bare ground suitable for the mountain plover (Day 1994, pp. 298-
299). Manning and White (2001, p. 226) found all mountain plover nests 
in Utah to be situated near roadways or oil well pads, and saw adults 
and chicks using these areas for foraging both day and night. However, 
they suggested that while mountain plover tended to choose nest sites 
near surface disturbance, the overall impact of oil and gas expansion 
could be negative (Manning and White 2001, p. 226). This small, 
apparently isolated Utah population subsequently

[[Page 27783]]

declined, and no birds have been found during surveys of the area since 
2003 (Maxfield 2010, pers. comm.). Decline of the population occurred 
subsequent to oil and gas development, but no direct tie was 
established. Severe drought and cessation of sheep grazing that 
provided mountain plover breeding habitat may have been more 
significant to the apparent loss of this local population (Maxfield 
2010, pers. comm.).
    Carr (in review) provides the only targeted study of mountain 
plover response to oil and gas development. The USGS study evaluated 
the effects of oil and gas development on mountain plover population 
density and nesting success in mixed desert shrublands in Wyoming. 
Results suggested that the presence of wells, roads, and associated 
infrastructure at densities studied (up to 8 wells per square mile (3 
per square kilometer)) did not have detectable negative effects on 
breeding mountain plover (Carr, in review). Carr (in review) concluded 
that energy development at low to moderate levels may be compatible 
with nesting mountain plover, although the author suggested the need 
for additional studies of potential effects of energy development on 
chick survival and potential for impacts at higher well densities.
    Tolerance to disturbance from energy development by mountain plover 
could result in nesting or foraging in areas where continued human 
disturbance and vehicular traffic could pose threats to adults and 
chicks. Carr (in review) cautioned that human activities at well sites 
might keep mountain plover from their nests, subjecting eggs to 
possible overheating. In Oklahoma, mountain plover appeared unaffected 
by the presence of roads (MacConnell et al. 2009, p. 33). Manning and 
White (2001, p. 226) indicated that vehicular traffic did not influence 
incubation or foraging behavior, and, while vehicular collisions with 
mountain plover might be a concern, no such mortalities were noted. 
Andres and Stone (2009, pp. 26, 27) noted that mountain plover are 
tolerant of vehicles, and while there is potential that vehicles could 
kill adult or juvenile birds, such mortality would not likely have a 
population-level impact. In addition, collisions with stationary 
structures such as power lines have been discounted as not likely a 
significant cause of mortality (Knopf and Wunder 2006; Andres and Stone 
2009, p. 26).
    Other impacts of energy development on the mountain plover and its 
habitat could occur. These include a potential for increase in 
predators, increased opportunity for spread of invasive plants, and 
potential changes in human land use such as cessation of grazing. 
Despite these concerns, to date, impacts of oil and gas development at 
levels typically seen in mountain plover breeding habitat have not been 
shown to decrease mountain plover populations.
    Coalbed methane extraction is a process in which: (1) Wells are 
drilled into the coal seam; (2) the seam is dewatered; and (3) the 
methane is then extracted from the seam, compressed, and piped to 
market. In Wyoming, some water from coalbed methane operations is used 
for surface or subsurface irrigation of agriculture fields and 
rangeland. There is concern that plover habitat, including prairie dog 
colonies, have been and could be lost to these practices, thereby 
altering or eliminating important mountain plover habitat (Rogers 2010, 
pers. comm.). In the Powder River Basin, about 2,000 ac (800 ha) of 
such irrigation is occurring and more than 7,000 ac (3,000 ha) is 
permitted (Fischer 2010, pers. comm.). We have no information as to 
whether or not mountain plover have been displaced. While changes in 
habitat caused by this irrigation may alter habitat and cause a local 
impact to mountain plover, we do not believe that the relatively small 
area involved represents a threat to overall mountain plover 
populations in this region.
    Like oil and gas development, wind energy development presents a 
range of habitat changes and disturbance factors that could affect the 
mountain plover. In addition, there is concern that the mountain 
plover's use of areas may decline during and after construction due to 
avoidance of wind turbines or increased mortality attributable to 
collisions, primarily with moving rotor blades. Lock (2010) highlighted 
the potential for wind energy projects to displace breeding mountain 
plover, but described the potential threat of mortality from collisions 
as being of ``low certainty.''
    The most comprehensive study conducted on potential effects of wind 
power development on the mountain plover came from the facility on 
Foote Creek Rim in Carbon County, Wyoming, where mountain plover were 
studied from 1994 (prior to construction) through 2007 (Young et al. 
2007, entire). The authors suggested that mountain plover habituated 
over time to the presence of turbines, as evidenced by nesting within 
60 feet (ft) (20 meters (m)) of the base of a tower in one instance 
(Young et al. 2007, p. 18).
    Wind towers, rotors, and associated meteorological towers pose an 
added risk that mountain plover may be struck by blades or fly into 
stationary structures. However, carcass searches at Foote Creek Rim 
documented no mountain plover mortalities attributable to collisions 
over the 3 years the studies were conducted. On breeding grounds, 
mountain plover fly at low heights. In a common courtship display, a 
male flies only to a height of approximately 16 to 33 ft (5 to 10 m) 
(Knopf and Wunder 2006). The lowest point of rotor sweep on the Foote 
Creek Rim site (57 ft (17 m)) was above the typical heights flown by 
mountain plover during courtship and breeding (Young et al. 2007, p. 
18). Research at the Judith Gap Wind Farm in Montana found no evidence 
of mountain plover displacement or fatalities (MacDonald 2010). 
However, recently we became aware of two mountain plover mortalities 
from searches of Wyoming wind energy projects (Sweanor 2010, pers. 
comm.). Because sources of mortality could not be confirmed for either 
carcass, we do not know whether the birds were struck by rotor blades, 
collided with towers, or died from other causes. Rotor sweep was 126 ft 
(41 m) above the ground in both cases, well above heights that breeding 
mountain plover are thought to regularly fly. At Glenrock Rolling 
Hills, one of the two sites reporting a mortality, no mountain plover 
were observed prior to construction of the wind energy project, but 
nesting occurred after construction, suggesting that nesting habitat 
may have been created through project disturbance (Sweanor 2010, pers. 
comm.).
    Wind energy development could present a greater potential issue for 
post-breeding congregations of mountain plover, because hundreds of 
birds may flock in a single area. However, we have no information 
regarding behavior of post-breeding flocks that could be applied to the 
potential threat of bird strikes from wind turbines. Little is known 
regarding their potential to strike moving blades or stationary 
structures, although based on mortality studies, shorebirds (plovers, 
sandpipers, and similar species) do not seem to be at great risk of 
colliding with turbines or communication towers (Kerlinger 2011, pers. 
comm.). Wind energy projects have reportedly been constructed and are 
proposed in South Texas agricultural fields that may overlap with areas 
used by wintering mountain plover (Cobb 2010, pers. comm.). The 
potential for mountain plover displacement or collisions in Texas is 
unknown. In California, wind energy development projects tend to be 
located on mountain ridges where wind speeds are greater and, 
therefore, are less likely to impact wintering mountain plover.

[[Page 27784]]

One exception is in Antelope Valley, Kern County (California), an area 
where mountain plover are known to winter. Several wind energy projects 
have been permitted on a mosaic of desert and agricultural lands. 
Overall, evidence available does not suggest that wind energy 
development is likely to displace mountain plover from breeding or 
wintering areas, or cause direct mortality through collisions to the 
extent that it would pose a threat to the species.
    Surface mining for coal and other minerals can displace mountain 
plover within the footprint of the work for the duration of the active 
mining. Whether or not this would result in permanent displacement is 
dependent on whether and how restoration occurs. We have little site-
specific data on impacts of surface mining to nearby mountain plover. 
Surveys over 28 years at Cloud Peak Energy's Antelope Mine in Campbell 
and Converse Counties, Wyoming, documented mountain plover's use of the 
mine permit area and adjacent lands (Green 2010). Mountain plover 
numbers declined as mining and the footprint of surface disturbance 
progressed, but in general they showed tolerance to mining activities 
nearby (Green 2010). In 2010, adult mountain plover and chicks were, 
for the first time, seen using a reclaimed mine area at the Antelope 
Mine (Green 2010). Mountain plover can be directly affected by surface 
mining through temporary or permanent loss of their habitat. However, 
we do not believe that surface mining, currently or in the future, will 
impact a significant amount of the mountain plover's breeding range or 
represent a threat to the species.
    The BLM considers the mountain plover, among other species, when 
evaluating the impacts of energy development on the environment. The 
BLM, through its Special Status Species program, has developed various 
management scenarios for the protection of the mountain plover 
throughout its range. In 2005, the BLM analyzed the potential effects 
to the mountain plover from management actions approved in Resource 
Management Plans for the various BLM field offices in Wyoming (BLM 
2005). At the time, we concluded that BLM's proactive conservation 
measures should aid in protecting the species from further decline 
(Kelly 2007). The conservation measures committed to by the BLM 
included habitat screening (determining whether habitat might support 
the mountain plover) and, as appropriate, subsequent surveys for the 
possible presence of mountain plover prior to approval of ground-
disturbing activities; designation of a 0.25-mi (0.40-km) buffer around 
occupied nests during the nesting season, with restrictions on 
activities to protect nesting plover; and continued research and census 
activities targeting the mountain plover on BLM-administered land in 
Wyoming (BLM 2005). A number of best management practices were also 
provided, to be considered on a case-by-case basis, to help protect the 
mountain plover and expand suitable nesting habitat. While these 
measures are not binding, and on-the-ground conservation efforts likely 
vary by BLM field office, a proactive cooperative approach between the 
BLM and the Service in Wyoming has heightened recognition of mountain 
plover conservation on BLM-administered lands and provides a basis for 
future cooperation to safeguard the species.
    Solar energy projects are likely to displace mountain plover when 
situated in breeding or wintering habitat. Unlike oil and gas wells or 
wind turbines, solar collectors are placed so close together that they 
effectively eliminate the ability of mountain plover to use the 
habitat. Solar energy development potential is greatest in southwestern 
States and California and, except for Colorado's San Luis Valley and 
Northern New Mexico, occurs in areas used mostly by wintering rather 
than breeding mountain plover. See Changes in Land Use in Mountain 
Plover Wintering Range below for a discussion of solar energy 
development.
    In summary, potential effects to the mountain plover from energy 
and mineral development are largely uncertain. Ground disturbance from 
oil and gas development and wind energy development may, in some cases, 
enhance or create mountain plover habitat, but whether the net effect 
of such activity is beneficial or detrimental has not been determined. 
The risk of significant mortality through mountain plover being struck 
by rotors of wind turbines appears low. Whether, or to what extent, 
construction of wind energy projects displaces breeding or wintering 
mountain plover has not been clearly established. Surface mining 
displaces mountain plover, at least until an area is restored, and 
development of solar fields likely results in habitat loss. Overall, 
more information regarding possible impacts of energy and mineral 
development to mountain plover is needed. However, the information 
currently available does not indicate that energy and mineral 
development threatens the mountain plover now or is likely to do so 
within the foreseeable future.
Changes in Land Use in Mountain Plover Wintering Range
    In our December 5, 2002, proposal to list the mountain plover (67 
FR 72396), we emphasized the potential impact to mountain plover 
populations from changes to wintering habitat in California, including 
changes stemming from human population growth, changes in agriculture, 
water availability, and burning restrictions. It now appears that the 
proportion of the rangewide population of mountain plover that winter 
in California is far less than previously believed (see Conservation 
Status and Local Populations above). However, the importance of 
mountain plover wintering habitat in California has been a continued 
topic of investigation and interest (Kopft and Rupert 1995; Hunting et 
al. 2001; Wunder and Knopf 2003; Hunting and Edson 2008). Knopf and 
Rupert (1995, p. 750) cited a high overwinter survival rate of mountain 
plover in California and their use of agricultural fields, and 
concluded that long-term population declines were likely attributable 
to processes on their breeding grounds. Dinsmore et al. (2010) 
concluded that adult survival in winter was high and suggested that 
conservation and management efforts be directed toward chick survival 
on breeding grounds and habitat during migration. In contrast, Hunting 
and Edson (2008, p. 184) attributed both past declines and potential 
future declines in rangewide plover populations to loss of traditional 
wintering sites in California. Andres and Stone (2009, pp. 21, 22) 
stated that effects to the mountain plover from changes to wintering 
habitat in California's Central Valley were unknown, but also expressed 
concerns regarding maintenance of quality wintering habitat in the 
Imperial Valley, where a majority of mountain plover in California are 
now thought to winter. Below we address current trends and potential 
changes to the future extent and quality of mountain plover wintering 
habitat in California.
    Concern continues to center on land use trends, conversion of 
agricultural lands to other uses, and changes in agriculture (Andres 
and Stone 2009, pp. 22-24; Hunting and Edson 2008, p. 184). Due to 
population growth in California, more rural and agricultural land is 
being urbanized. Between 1982 and 2007, approximately 8 percent of 
California's croplands, 11 percent of the State's pasturelands, and 6 
percent of State's rangelands were lost (USDA 2010). However, as of 
2007, California still supported approximately 9.5 million ac (3.8 
million ha) of cropland,

[[Page 27785]]

1.1 million ac (0.4 million ha) of pastureland, and 17.5 million ac 
(7.0 million ha) of rangeland (USDA 2010).
    The dynamic, market-driven nature of agricultural production and 
changes in cultivation practices in California could affect the 
availability and quality of wintering habitat for the mountain plover. 
Another issue is the dependence of California agriculture on irrigation 
water, some of which is imported from other areas, and its future 
availability. Future changes in the availability of irrigation water 
might result from competition with other water uses, the effects of 
global climate change (see discussion under Factor E below), and 
changes in the characteristics of agricultural lands as a result of 
improved or more broadly implemented water conservation techniques.
    Development of energy projects, especially solar energy, in 
mountain plover wintering habitat is also a concern in California. 
California's electric utility companies were required by California 
statute (Chapter 464, Statutes of 2006) to use renewable energy to 
produce 20 percent of their power by 2010. Governor Schwarzenegger's 
Executive Order of November 2008 (S-13-08) set a higher, more 
ambitious goal of 33 percent by 2020 (California Energy Commission 
2010). On April 12, 2011, Governor Jerry Brown signed Senate Bill 2X 
into law, requiring that 33 percent of the State's electric generation 
come from renewable sources by 2020 (Los Angeles Times 2011). A main 
source of renewable power will be solar energy. A Statewide list of 
solar energy projects includes over 400 proposals (Brickley 2011, pers. 
comm.). Many large solar energy projects are being proposed on BLM 
land, often in desert areas. The BLM, along with the Department of 
Energy (DOE), is currently in the process of developing a Programmatic 
Environmental Impact Statement (PEIS) for solar energy development in 
six southwestern States, including California. The document assesses 
development of a new solar energy program for siting utility-scale 
solar energy projects on BLM lands. Any program adopted will have 
implications for solar energy project siting in mountain plover 
wintering habitat. A draft of the PEIS was made available for public 
comment December 17, 2010 (75 FR 78980). Mountain plover are not 
specifically addressed in the PEIS, but potential impacts to wildlife 
and appropriate mitigation measures are provided (DOE 2010, pp. 5-73 to 
5-96).
    As described in Conservation Status and Local Populations above, 
the California winter range of the mountain plover is primarily in the 
Central Valley (including the Sacramento and San Joaquin valleys) and 
the Imperial Valley. The Carrizo Plain in San Luis Obispo County is 
also recognized as an important wintering site. Other areas where 
mountain plover are regularly observed include the Panoche and Antelope 
valleys.
The Central Valley (Sacramento Valley and San Joaquin Valley), Carrizo 
Plain, Panoche Valley, and Antelope Valley
    In the Central Valley, human population growth over the last 20 
years has resulted in a declining trend in agricultural area, with a 
smaller, but corresponding, trend of conversion to urban uses 
(California Department of Conservation (CDC) 2010). The rate of land 
conversion to urban uses in the Central Valley increased beginning in 
1990. With the exception of Solano County, the human populations of 
Central Valley counties within the wintering range of the mountain 
plover all grew faster than the Statewide average between 2000 and 2009 
(U.S. Census Bureau 2010).
    In the Sacramento Valley, urbanization in Yolo and Solano Counties, 
the two principal counties supporting wintering mountain plover, has 
not adversely impacted the mountain plover to date, because known 
wintering locations are located outside city planning boundaries. 
However, continued population growth beyond the current planning 
horizon could potentially threaten individual wintering localities that 
are close to urban areas, particularly those in areas most proximate to 
Sacramento.
    In the San Joaquin Valley, human population growth has been 
approximately 17 percent over the period from 1997 through 2010. To 
date, most of the resulting urban growth has occurred adjacent to, and 
in the general vicinity of, the towns, such as Modesto, Fresno, and 
Bakersfield, that developed along Highway 99 in the eastern portion of 
the San Joaquin Valley (Teitz et al. 2005, p. 27). These urban areas 
are located to the east and outside of the mountain plover's wintering 
range. To date, urbanization in the western San Joaquin Valley is 
restricted to the Interstate 5 corridor, which supports few mountain 
plover. Therefore, we expect it to have little effect on wintering 
mountain plover. Scenarios developed to gauge effects of future 
population growth and urbanization suggest that the San Joaquin Valley 
will experience significant urban growth within the next 35 years; 
increasing populations will result in scattered urbanization within the 
plover's wintering range, but the pattern of development will depend on 
land use planning goals, and potential development of high speed rail 
(Teitz et al. 2005, pp. 45-67).
    In the San Joaquin Valley counties (Fresno, Kern, Kings, Madera, 
Merced, San Joaquin, Stanislaus, Tulare), cropland declined by about 3 
percent from 1997 to 2007, to about 5.2 million ac (2.1 million ha) 
(USDA 2010). Crop fields in alfalfa and other hay, favored by mountain 
plover, were relatively stable and accounted for about one-third of all 
cropland in the San Joaquin Valley in 2007 (USDA 2010).
    While relatively little agricultural land is being lost, conversion 
from annual agricultural crops to permanent crops that do not provide 
mountain plover with habitat is significant within the San Joaquin 
Valley. For example, in the San Luis Unit of the Central Valley Project 
(CVP), in Fresno, Kings, and Merced Counties, agricultural acreage has 
increasingly been converted to permanent crops of orchards or 
vineyards. We estimate the percentage of land in permanent crops at 
somewhere between 16 percent and 24 percent of the San Luis Unit, 
compared with 10 percent in 2000. General field observations and land 
value reports (California Society of Farm Managers and Rural Appraisers 
2009, pp. 31-64) suggest that this is a continuing trend, with new 
orchards displacing cotton and tomato crops in many areas of the 
Central Valley. In Madera County, some locations formerly utilized by 
wintering mountain plover have been converted from rangeland to annual 
crops or to permanent crops such as pistachio trees (Woods 2009, pers. 
comm.).
    Outside of the Central Valley, orchard land in San Luis Obispo 
County, which includes the Carrizo Plain, a known mountain plover 
wintering area, rose from 29,000 ac (12,000 ha) to 54,000 ac (22,000 
ha) from 2007 to 2009, to about 18 percent of cropland in the county. 
Conversion to orchard crops in the nearby Maricopa and Cuyama valleys 
near the Carrizo Plain area have resulted in loss of wintering mountain 
plover habitat (Sharum 2010). Overall, conversion of annual cropping 
systems to permanent crops is expected to continue and poses an 
additional, but unquantified, source of habitat loss for the mountain 
plover.
    As a result of the large-scale irrigation efforts in the western 
San Joaquin Valley, approximately 1,750,000 ac (710,000 ha) of 
agricultural lands with shallow groundwater tables have become impaired 
due to accumulated concentrations of naturally occurring toxic 
elements, including selenium.

[[Page 27786]]

With the passage of the Central Valley Project Improvement Act (CVPIA) 
in 1992, Federal and State acquisition programs enabled owners to stop 
farming, or ``retire'' their privately owned, drainage-impaired 
agricultural lands as a strategy to reduce drainage problems and 
address selenium accumulations (Service 1998; USDI 2005). Lands 
targeted for retirement lie primarily within the San Luis Unit of the 
CVP along the west side of the San Joaquin Valley where approximately 
379,000 ac (152,000 ha) of agricultural land have been identified as 
contributing to poor water quality. Of these lands, nearly 200,000 ac 
(80,000 ha) have been proposed for land retirement (USBR 2007), and, to 
date, more than 100,000 ac (40,000 ha) of agricultural land have been 
retired within the San Luis Unit. We have no estimate of what 
proportion of this area may have supported acceptable wintering habitat 
for the mountain plover or the extent to which it was used by the 
mountain plover.
    A portion of the lands proposed for retirement are expected to be 
used for drainage reclamation; between 1,280 and 3,300 ac (5,170 and 
1,340 ha) of existing irrigated cropland will be converted to treatment 
facilities and evaporation basins, while 12,500 ac (5,100 ha) of either 
existing or fallowed cropland will be converted to reuse areas in which 
crops will be irrigated with selenium-contaminated, agricultural 
drainwater in order to reduce selenium loads in the agricultural run-
off (Service 2006). These areas might threaten some mountain plover 
with selenium toxicity, as described below in the discussion under 
Factor E. Numerous retired parcels are characterized by dense weedy 
growth (Cypher et al. 2007, p. 28; Service 2006), and are not expected 
to provide suitable habitat for the plover. Substantial retired acreage 
has been converted to permanent crops utilizing alternate sources of 
water. Other retired lands that support grazing or farming may remain 
suitable for wintering mountain plover.
    Due to the historical importance of agriculture in the Central 
Valley, the valley has the highest percentage of privately owned land 
in the State. Only 4 percent of Sacramento Valley land and 7 percent of 
San Joaquin Valley land is public open space. In the Central Valley, a 
variety of conservation and restoration projects have been implemented 
to protect natural resources, although 57 percent of such conservation 
projects report a focus on riparian habitat enhancement (Great Valley 
Center 2005, p. 30). Twenty-three local and regional land trusts 
operate in the Central Valley to protect valley wildlife, farmland, 
habitat, rivers, and native vegetation (Great Valley Center 2005, pp. 
30-31). The Service does not have information on the area of specific 
habitat types that have been protected within the range of the mountain 
plover or whether these efforts have produced substantial benefits to 
the species.
    In the Sacramento Valley, we have found no planned solar energy 
development likely to threaten the mountain plover's habitat. However, 
the legislation cited above (Chapter 464, Statutes of 2006, and 
Governor Schwarzenegger's Executive Order of November 2008 (S-
13-08)) has initiated a significant increase in the planning for solar 
development in and adjacent to the San Joaquin Valley. Solar 
developments proposed thus far vary greatly in size: small projects of 
100 to 200 ac (40 to 80 ha), to projects of potentially to 30,000 ac 
(12,000 ha) in size. The Service does not have specific information on 
mountain plover use of many of these sites, but we conclude that sites 
will be unsuitable for mountain plover after development.
    To date, small projects are proposed for scattered locations across 
the southern San Joaquin Valley, while large projects have been 
proposed both within the San Joaquin Valley, and in the Carrizo Plain 
and Panoche Valley areas. The solar projects proposed on the valley 
floor are typically situated on active or recently cultivated 
agricultural lands and several larger projects have been proposed for 
lands that have been used for livestock grazing.
    The Service is currently aware of up to six small solar projects, 
each approximately 200 ac (80 ha) in size, which are expected within 
the mountain plover's general wintering range in the southern San 
Joaquin Valley. The projects will be constructed by Pacific Gas and 
Electric, a major California utility company. In the San Joaquin 
Valley, the solar projects proposed on the valley floor are typically 
situated on active or recently cultivated agricultural lands and 
several larger projects have been proposed for lands that have been 
used for livestock grazing. The Service concludes that sites will be 
unsuitable for mountain plover after development.
    Several large proposals are located within the mountain plover's 
general wintering range. A large 32,000-ac (13,000-ha) park, the 
Westlands Solar Park, has been proposed for western Fresno and Kings 
Counties, with an initial phase of approximately 10,000 ac (4,000 ha). 
It will be constructed on agricultural land that the Westlands Water 
District has slated for land retirement (Woody 2010). We expect that 
additional proposals for retired farmland are likely due to the general 
perception that such lands have few environmental issues.
    The Maricopa Sun Solar Complex (approximately 9,000 ac (3,600 ha)) 
is proposed for agricultural lands in western Kern County near the edge 
of the plover's winter range. We do not know whether the mountain 
plover uses the site. Development of the project includes cancellation 
of a contract to preserve agricultural land. The Draft Environmental 
Impact Report identifies mountain plover as a potential winter migrant 
(Kern County Planning and Community Development Department 2010, pp. 1, 
4.4-8).
    In the Carrizo Plain, San Luis Obispo County, two solar projects 
have been proposed, including the 4,000-ac (1,619-ha) California Valley 
Solar Ranch (CVSR) and the 4,500-ac (1,800-ha) Topaz Solar Farm. Both 
facilities would be located approximately 6 miles north of the Carrizo 
Plains National Monument, an important natural area for the plover, on 
a mixture of natural lands, grazing lands, and cropped lands (Aspen 
Environmental Group 2010, pp. C3-2-C3-3, C6-4). Suitable foraging and 
roosting habitat for the mountain plover occurs on sites under 
consideration (Aspen Environmental Group 2010, pp. C6-4-C6-5, C6-11). 
Mountain plover have been observed on the CVSR site but likely occur 
sporadically and in low numbers (Boroski 2011, pers. comm.).
    The Panoche Valley, an area of about 12,000 ac (5,000 ha) in San 
Benito County, receives annual use by wintering mountain plovers. A 
solar project is currently proposed on 3,200 ac (1,300 ha) of potential 
mountain plover wintering habitat, or about one-third of the potential 
mountain plover habitat present in the Panoche Valley. Proposed 
mitigation would preserve and manage other nearby habitat.
    The Antelope Valley, an area of approximately 900,000 ac (360,000 
ha) in Los Angeles and Kern Counties, supports wintering mountain 
plover annually, with numbers estimated in the low 100s using crop 
fields and grasslands (eBird 2010). How much of the valley's area is 
mountain plover habitat is unclear. The valley is primarily privately 
owned land, and its proximity to human population centers has generated 
high interest in renewable energy (solar and wind) development that 
could reduce mountain plover wintering habitat.
    Solar energy projects currently planned in the San Joaquin Valley, 
the

[[Page 27787]]

adjacent Carrizo Plain, and the Panoche and Antelope valleys are 
likely, over time, to reduce existing mountain plover wintering 
habitat. A variety of siting considerations, including presence of 
other wildlife species of concern, and potential mitigation 
requirements, will dictate the extent to which mountain plover are 
affected. The Sacramento Valley and Imperial Valley lands used by the 
mountain plover are less likely to be developed for solar projects. We 
know of no solar projects are currently planned for agricultural lands 
known to support mountain plover in the Imperial Valley, discussed 
below.
    As future solar projects are proposed and implemented, we conclude 
that they will cause some continued loss of mountain plover wintering 
habitat in California. While cumulative impacts of these projects, and 
other factors such as urbanization and changes in agriculture, are 
likely to reduce the total area of wintering habitat available, 
substantial acreage of appropriate wintering habitat will persist in 
the Central Valley, Carrizo Plain, Panoche Valley, and Antelope Valley.
The Imperial Valley
    As of 2009, about 381,000 ac (154,000 ha) of field crops existed in 
the Imperial Valley (Imperial Irrigation District (IID) 2009a). The 
Imperial County has witnessed a decline in annual area used for 
agricultural purposes from 1984 through 2008 of about 21,000 ac (8,000 
ha) or 4 percent (CDC 2010), while the county saw an increase in area 
used for urban areas in the same period of about 6,000 ac (2,400 ha) or 
29 percent (CDC 2010). Urban expansion has accounted for only a 
relatively small portion of the 4 percent decline in agricultural lands 
over a period of 24 years. At this rate, conversion of agricultural 
lands to urban lands in Imperial County has a modest impact.
    Habitat in the Imperial Valley believed most important for mountain 
plover includes alfalfa fields, especially those harvested then grazed 
by sheep, and bermudagrass fields burned following harvest (Wunder and 
Knopf 2002, pp. 75-76). Both alfalfa and bermudagrass acreages have 
declined in recent years (2005-2009) (IID 2009a). However, in 2009, 
these crops occupied 195,000 ac (79,000 ha) or approximately 51 percent 
of total field crop acreage in the Imperial Valley (IID 2009a). Area 
devoted to all hay (including alfalfa and bermudagrass), 233,000 ac 
(90,000 ha), was the same in Imperial County in both 1997 and the 2007 
(USDA 2010). Data available also suggest the number of sheep in the 
Imperial Valley have declined recently as well but that numbers 
fluctuate over time. It is not known whether these short-term declines 
are indicative of future trends.
    The continued success of agricultural habitats used by the mountain 
plover in the Imperial Valley depends on a reliable water supply. The 
Imperial Valley depends on Colorado River water to irrigate its crops, 
but there has been increasing pressure for more water to be diverted to 
urban areas. In 2003, the State of California and water agencies across 
the State signed the Quantification Settlement Agreement (QSA) to 
dictate distribution of water from the Colorado River. The settlement 
allocated 370,000 acre-feet (ac-ft) (456 million cubic meters (cu-m)) 
of water to urban areas in Southern California and Tribal areas (IID 
2010a, p. 2). Most of the 370,000 ac-ft (456 million cu-m) will come 
from improvements in on-farm water efficiency and improved irrigation 
technology (IID 2010a, p. 2; Delfino 2006, p. 161).
    Under the QSA, Imperial County must also fallow agricultural land, 
some of which will be transferred to the San Diego Water Authority, and 
some of which will go to mitigation to restore the Salton Sea (IID 
2010a, p. 1). The area of land fallowed depends on the intensity of 
water use, not farm size (IID 2010b, p. 1). Fallowing will be conducted 
on a sliding scale. The program began in 2003 with lands fallowed that 
had been irrigated by under 10,000 ac-ft (1.2 million cu-m) of water, 
and peaked in 2010 to lands fallowed that had been irrigated by over 
80,000 ac-ft (9.9 million cu-m) of water. The program will slowly 
decline before agricultural fallowing ends in 2017 (IID 2009b). The 
area of land fallowed in 2009-2010 was about 10,500 ac (4,300 ha) or 
about 2 percent of agricultural land in the valley. Overall, lands 
fallowed will reduce the area of crop fields in the Imperial Valley but 
we have no specific information as to extent to which those fields 
fallowed provide wintering habitat to the mountain plover.
    The future of the QSA is in question. On January 13, 2010, the 
Superior Court of California found that funding provisions of the QSA 
were unconstitutional, and officially invalidated the QSA on January 
19, 2010 (QSA Coordinated Cases, Case No.: JC4353). IID asked for, and 
received, a stay that temporarily allowed the terms of the QSA to 
remain in effect (Case No.: JC4353). As of April 2011, a ruling was 
anticipated before the end of the year (Imperial Valley Press 2011, p. 
1). It is unclear what effect the cancellation of the QSA will have on 
water use and fallowing, given the extreme contention and difficulty in 
negotiating the 2003 settlement. If the stay does not remain in place, 
the IID may halt fallowing, as it has been strongly opposed to 
fallowing as a conservation measure (IID 2010c, p. 1). If the fallowing 
program remains in place, it could continue as an immediate, but 
relatively insignificant, threat to mountain plover habitat, as it 
would only affect a small portion of agricultural fields, with no 
definitive data indicating if (or how much) fallowing will occur on 
those croplands that mountain plover frequent.
    The yield from alfalfa crops is related to the amount of irrigation 
the land receives (Hanson et al. 2007, p. 1). Alfalfa could thus be 
more significantly impacted by water use restrictions. In California, 
revenue for alfalfa is expected to decrease slightly by 2050, 
decreasing 11 percent Statewide (Howitt et al. 2008, p. 11). These 
statistics take water use into consideration (California Department of 
Finance 2007, p. 5). In contrast, Bermudagrass is drought-tolerant, and 
one study showed little decrease in crop yield under drought conditions 
(Kneebone 1966, p. 96; George et al. 1992, pp. 23-24).
    Yield and acreage of bermudagrass could be affected by restrictions 
on burning in the Imperial Valley due to pollution concerns. To comply 
with California's air pollution restrictions (California Code of 
Regulations 2001, pp. 80100-80170), the Imperial County Air Pollution 
Control District (ICAPCD) has set forth rules and regulations (ICAPCD 
2010b, pp. 701.1-702.1) governing implementation of a smoke management 
program (ICAPCD 2010a, pp. 1-37) for agricultural burning. These rules 
and regulations allow for agricultural burning after the ICAPCD has 
analyzed several factors: (1) Quantitative and qualitative analysis of 
meteorological conditions; (2) current smoke complaints; (3) source/
receptor consideration; and (4) current air quality levels (ICAPCD 
2010b, p. 8). The number of burn days permissible in the areas of 
Imperial County has declined (California Air Resources Board 2010) 
since 2003, but the amount of bermudagrass acreage burned in the same 
period (2003 to 2009) shows little trend and averages about 18,000 ac 
(7,000 ha) (Lancero, pers. comm.; Cavazos 2010, pers. comm.). Any 
concern that current burning restrictions limit bermudagrass 
cultivation appears unsupported by these data.
    Future trends in alfalfa and Bermudagrass may largely determine the 
extent and quality of mountain plover wintering habitat available in 
the Imperial Valley. While no predictions of

[[Page 27788]]

future area devoted to these two crops is available, we do not have any 
information that would lead us to conclude that their occurrence will 
significantly decline. Therefore, we anticipate that in the future 
substantial areas of alfalfa and Bermudagrass fields will remain 
available to support wintering mountain plover in the Imperial Valley.
    Currently, there is no habitat conservation plan (HCP) implemented 
in the Imperial County. The Imperial Irrigation District is currently 
working on an HCP, but they have not yet finalized the plan or been 
issued a section 10(a)(1)(b) permit under the Act (Roberts 2010, pers. 
comm.); however, in the current draft of the HCP, mountain plover is a 
covered species.
    Individually, urbanization, water restrictions, and trends in 
agriculture do not appear to pose significant threats to the acreage or 
quality of wintering habitat available or to the mountain plover's use 
of the Imperial Valley. However, in the foreseeable future, their 
combined effects, along with climate change, could appreciably reduce 
habitat available to mountain plover and potentially affect the nature 
or extent of wintering mountain plover use of the Imperial Valley.
    Mountain plover winter over a large range and in diverse habitats. 
In our February 16, 1999, proposed rule to list the species we cited 
sources suggesting that most mountain plover, an estimated 7,000 of a 
rangewide population of 8,000 to 10,000 birds, wintered in California 
(64 FR 7587). However, we now believe that less than half of the 
rangewide population, estimated at over 20,000 birds, winter in 
California (see Population Size and Trends above). As of 2007, over 18 
million ac (7 million ha) in California (about 18 percent of the State) 
supported cropland, pastureland, or rangeland (USDA 2010). While only a 
portion of this area provides habitat for the mountain plover in any 
given winter, the total includes 1.7 million ac (0.7 million ha) of 
alfalfa, Bemudagrass, and other hay crops that the mountain plover 
utilizes, including 230,000 ac (90,000 ha) in Imperial County alone. 
The total also includes 1.1 million ac (0.4 million ha) of pastureland, 
often used by mountain plover. To exploit these and other wintering 
habitats, mountain plover are able to move long distances and use 
various sites as conditions become favorable within a given winter 
(Knopf and Wunder 2006). Mountain plover appear annually at some 
favored wintering sites, but site fidelity by individual birds appears 
low. Birds may also alternate between wintering areas in California and 
elsewhere in different years. Cumulatively, the potential changes in 
land uses in California described above will likely result in a 
reduction of mountain plover wintering habitat in the State. However, 
given the available agricultural acreage cited above, it is not 
apparent that even a reduction in California wintering habitat 
substantially larger than that which we anticipate would significantly 
affect California's ability to support mountain plover numbers 
currently wintering in the State. We conclude that any likely reduction 
of mountain plover wintering habitat in California will not threaten 
the mountain plover plover's ability to maintain a wintering population 
in California or threaten the species range wide in the foreseeable 
future.
Wintering Outside of California
    Elsewhere, in the Phoenix area, Maricopa County, and some other 
wintering sites in southern Arizona, mountain plover have been 
displaced by growth of human populations (Gardner 2010; Robertson 2010, 
pers. comm.). Declines are likely to occur in the Tucson area, Pinal 
County, and perhaps in Yuma County as well, due to increased human 
populations and, more directly, due to an accompanying reduction in 
agriculture. Wintering mountain plover populations in Cochise County, 
where there is less urban development and where the amount of cropland 
increased from 1997 to 2007 (USDA 2010), will likely remain more 
stable. Solar energy development is occurring in areas of southern 
Arizona, but the extent to which projects may overlap mountain plover 
wintering habitat has not yet been determined.
    Both increases in human population and expansion of agriculture are 
occurring in areas of southern Arizona (Council for Agricultural 
Science and Technology 2009, pp. 8-12). Rather than the total area 
urbanized, the extent and nature of future agriculture that is present 
in southern Arizona and available for mountain plover use will likely 
dictate the future value of this area to wintering mountain plover. 
However, water resources are limited, and urban uses may compete with 
agriculture for available water. Southern Arizona is thought to winter 
a relatively small portion of the rangewide mountain plover population. 
We believe that any net future decreases in agricultural lands in 
southern Arizona will be limited and that these potential future 
decreases in agricultural lands in southern Arizona will not markedly 
affect the ability of the area to support these wintering mountain 
plover.
    Other than potential impacts from wind energy development described 
in Energy and Mineral Development above, we have no information 
regarding threats to wintering mountain plover from habitat changes in 
Texas.
    Outside of the trends in wintering areas in Mexico described in 
Threats to Prairie Dogs and Associated Loss of Habitat above, we have 
little information regarding threats to the mountain plover from 
wintering habitat changes in Mexico. Based on their wintering habitat 
preferences in the United States, significant numbers of mountain 
plover may winter in agricultural areas in Mexico. Possible areas of 
concentration and the types of agriculture utilized remain 
undocumented.
Summary of Factor A
    The mountain plover occupies a wide geographic range across the 
breeding, migration, and wintering seasons. The extensive and diverse 
habitats it utilizes are subject to a number of changes that represent 
potential threats.
    Black-tailed prairie dogs create favorable breeding habitat for the 
mountain plover in States including Colorado, Montana, and Wyoming. 
Black-tailed prairie dog numbers have increased by a factor of six 
since 1981 in States where they are present, and associated mountain 
plover habitat has likewise increased. We do not anticipate loss of 
black-tailed prairie dog numbers or the mountain plover habitat they 
maintain in the foreseeable future.
    Current conversion of prairie and grasslands to other land uses 
within mountain plover breeding habitat appears negligible when viewed 
from a rangewide perspective. Formerly expressed concerns regarding 
human development in South Park, Colorado, where a high density of 
mountain plover breeds, now seem unfounded.
    Cattle grazing generally benefits mountain plover breeding habitat, 
but some range management practices do not create favorable conditions 
for mountain plover breeding. Specific range management to benefit 
mountain plover could be employed, but overall we expect current cattle 
grazing to continue relatively unchanged in the foreseeable future.
    Suggestions that cropland use by breeding mountain plover may be 
detrimental to populations have not been substantiated.
    Energy and mineral development alters landscapes, and some 
activities can adversely impact mountain plover habitat, at least 
locally and temporally. The mountain plover often benefits from ground 
disturbance and may tolerate or

[[Page 27789]]

benefit from certain development activities. Mountain plover collisions 
with wind turbines are likely to occur infrequently. Overall, oil and 
gas extraction, wind power projects, and mineral extraction have not 
been shown to have significant adverse impacts to the mountain plover.
    Wintering mountain plover are wide-ranging, and seek out a variety 
of grassland, rangeland, crop field, and semi-desert landscapes, from 
the Gulf Coast to the Pacific Ocean, to meet their needs. Habitat in 
California and across the mountain plover's wintering range is dynamic, 
based on yearly weather patterns, grazing levels, crops present, and 
timing of planting or harvest. Currently available wintering habitat 
can not be easily quantified, nor can its projected quantity and 
quality in the foreseeable future be easily predicted. A future net 
loss of wintering habitat in California appears likely, based on solar 
development projects and other factors described above, but given the 
expanse of wintering habitat currently present, it is not apparent that 
this will have any affect on the number of wintering mountain plover 
California will support.
    Dinsmore et al. (2010) assessed factors affecting population growth 
in the mountain plover in order to target conservation and management 
efforts. They cited mountain plover adult survival as high in winter 
and suggested conservation efforts should target increased chick 
survival on breeding grounds. This is consistent with Knopf and Rupert 
(1995, p. 750), who concluded that past declines in the mountain plover 
were attributable to events taking place on the breeding grounds not 
during winter. We believe that rather than changes in wintering 
habitat, future changes on the mountain plover's breeding grounds that 
influence reproductive success will dictate rangewide mountain plover 
numbers and population trends. The quantity and quality of breeding 
habitat, and the ability of the mountain plover to successfully 
reproduce will depend largely on future human land uses, rangeland and 
cropland management practices, the potential effects of energy 
development, and the abundance and distribution of prairie dogs. We 
have no credible evidence to show that future changes in the extent and 
quality of mountain plover rangewide wintering habitat, of the 
magnitude likely to occur, would significantly influence their total 
population or population trend, or that they endanger the species now 
or would be likely to endanger the species in the foreseeable future.
    We conclude that the best information available indicates that the 
mountain plover is not now, or in the foreseeable future, threatened by 
the present or threatened destruction, modification, or curtailment of 
its habitat or range to the extent that listing under the Act as an 
endangered or threatened species is warranted at this time.

Factor B. Overutilization for Commercial, Recreational, Scientific, or 
Educational Purposes

    Mountain plover were historically hunted for human consumption on 
the Great Plains (Knopf and Wunder 2006). Under the Migratory Bird 
Treaty Act (MBTA) (16 U.S.C. 703-712), mountain plover are not legally 
hunted in the United States, Canada, or Mexico, although Andres and 
Stone (2009, p. 27) note that some illegal shooting may occur in some 
areas of Mexico. The extent or significance of any such activity is 
unknown, but, because we have no information that such illegal hunting 
activity is widespread, we believe it is unlikely to be a significant 
threat to the mountain plover's continued existence.
    Birders (bird watchers) may seek out mountain plover for viewing. 
This activity is most likely to occur on a few publicized sites and 
often takes place from, on, or near roadways. Mountain plover are 
relatively tolerant of disturbance and often ignore humans in vehicles. 
If approached on foot they quickly retreat (Knopf and Wunder 2006). We 
believe that observation by birders does not represent a threat to the 
mountain plover because it is limited in extent and most birders 
attempt to minimize disturbance to birds as they pursue their 
activities.
    Most research conducted on mountain plover relies on passive 
sampling (e.g., point counts) rather than active handling. Passive 
sampling is not likely to substantially affect the mountain plover. The 
studies that involve handling of adults, chicks, and eggs may impact 
individuals, but these studies are small enough in scale that they are 
not likely to affect populations as a whole. Knopf and Wunder (2006) 
cautioned mountain plover eggs could become overheated if exposed to 
direct sun on hot days. However, we do not have any information to 
indicate that this has caused decreased nest success in areas where 
research occurs.
Summary of Factor B
    We do not have any evidence of risks to mountain plover from 
overutilization for commercial, recreational, scientific, or 
educational purposes, and we have no reason to believe that that this 
factor will become a threat to the species in the foreseeable future. 
We conclude that the best scientific and commercial information 
available indicates that the mountain plover is not now, nor in the 
foreseeable future, threatened by overutilization for commercial, 
recreational, scientific, or educational purposes.

Factor C. Disease or Predation

Disease
    We are not aware of any diseases or parasites that pose a threat to 
the mountain plover at this time. West Nile virus, which has been 
documented to cause deaths in many bird species, has not been found in 
mountain plover (Andres and Stone 2009, p. 29). Since 2007, 4,888 dead 
birds have been identified throughout California as deaths attributed 
to the West Nile virus (California Department of Public Health (CDPH) 
2010). Within this time span, West Nile virus has been reported from a 
number of Central Valley counties, but to date no mountain plover 
deaths have been attributed to the virus (CDPH 2010). Over the same 
time period, there have been no bird deaths associated with West Nile 
virus in Imperial County.
    Dreitz et al. (2010) investigated causes of mortality in mountain 
plover chicks and reported preliminary analysis of blood samples from 
chicks in Colorado and Montana. Blood parasitism was low in Colorado, 
and none was detected in Montana.
    The Intergovernmental Panel on Climate Change (IPCC) (2007, p. 51) 
suggests that the distribution of some disease vectors may change as a 
result of climate change. However, we have no information to suggest 
any specific disease may become problematic to the mountain plover as a 
result of climate change.
Predation
    The list of predators on mountain plover, their nests, and young is 
extensive, and includes the American badger (Taxidea taxus), skunks 
(Spilogale spp. and Mephitis spp.), ground squirrels, swift fox (Vulpes 
velox), coyote (Canis latrans), bullsnake (Pituophis catenifer), 
Swainson's hawk (Buteo swainsoni), prairie falcon (Falco mexicanus), 
common raven (Corvus corax), great-horned owl (Bubo virginianus), 
burrowing owl (Athene cunicularia), and loggerhead shrike (Lanius 
ludovicianus) (Smith and Keinath 2004, p. 20; Andres and Stone 2009, p. 
28).
    Survival rates of adult mountain plover are thought to be quite 
high on

[[Page 27790]]

both breeding and wintering grounds, and it is unlikely that predation 
of adult mountain plover constitutes a significant concern to mountain 
plover populations overall (Smith and Keinath 2006, p. 19). Emphasis 
has been largely placed on predation of nests and chicks (Kopf and 
Wunder 2006; Andres and Stone 2009, p. 28; Dreitz et al. 2010, entire). 
Survival of nests to hatching is similar to or greater than that found 
in other ground-nesting prairie shorebirds in the Great Plains, and 
nest success does not appear to be a limiting factor to population 
growth of the species (Dinsmore et al. 2010). Survival of chicks from 
hatching to fledging has been highlighted as a potentially important 
life stage that could be targeted for management to support the 
conservation and expansion of mountain plover populations, for example, 
from habitat improvements that may reduce predation rate (Dinsmore et 
al. 2010).
    Knopf (2008, p. 50) cited the swift fox as the major predator on 
eggs and the primary predator on chicks on the PNG in Colorado, and 
suggested that reduced predator control and subsequent increase in 
predators was a contributing factor in the dramatic decline in mountain 
plover the area experienced. Thirteen-lined ground squirrels 
(Spermophilus tridecemlineatus) have been the greatest source of nest 
predation in South Park, Colorado (Wunder 2010b, pers. comm.). Chick 
monitoring in Colorado in 2010 confirmed 38 mortalities, including 13 
from avian predation (most on less than 16-day old chicks by burrowing 
owls) and 8 by mammalian predators including swift fox and American 
badger (Dreitz et al. 2010, pp. 3-4). Predation by unknown species was 
suspected in some other deaths (Dreitz et al. 2010, pp. 3-4). Similar 
research in Montana in 2010 implicated black-billed magpies (Pica 
hudsonia) as a possible cause of disappearances of chicks whose fate 
was not confirmed.
    Knopf and Wunder (2006) suggested mountain plover nest visits by 
researchers could lead to predation by ravens (Corvus spp.). Similarly, 
nest marking to avoid nest destruction during agricultural operations 
may alert predators to nest locations.
    We do not believe that natural levels of predation present a threat 
to the mountain plover, although the risk could be increased through 
human development and habitat fragmentation. This may result where 
predators concentrate their foraging activities and movements along 
habitat edges. However, Mettenbrink et al. (2006, p. 195) looked at 
mountain plover nesting in a prairie landscape fragmented by crop 
fields and found little relationship between nest predation and 
distance to habitat edges. The authors concluded that predators of 
mountain plover in the shortgrass prairie apparently do not hunt 
selectively along anthropogenic (human-created) edges. Roads may serve 
as travel routes for predators (Pitman et al. 2005, p. 1267), and 
natural gas development has been shown to increase the occupancy of the 
common raven, a potential predator of mountain plover nests and chicks, 
in sage brush habitat (Bui et al. 2010, pp. 73-74). Increases in roads 
and structures associated with energy development could result in 
increased predation on mountain plover nests or chicks. However, Carr 
(in review) found no relationship between mountain plover nest success 
and road or well density.
    While predation accounts for a major portion of chick mortality, we 
have no information that would lead us to conclude that predation on 
mountain plover chicks differs from levels experienced by other upland 
nesting shorebirds or that, across the range of the mountain plover, it 
is a current or future threat to the survival of the species.
Summary of Factor C
    We do not find evidence that disease is currently impacting the 
mountain plover, nor do we have information to indicate that disease 
outbreaks will increase in the future. While the level of predation on 
mountain plover nests and chicks is high, it is not inconsistent with 
that found in other ground-nesting bird species. Fragmentation of 
habitats, including that associated with energy development, could 
increase predation, but evidence to date does not suggest any increase 
is occurring. We do not have information at this time to indicate that 
predation is impacting the mountain plover at a level that threatens 
the species. We conclude that the best scientific and commercial 
information available indicates that the mountain plover is not now, or 
in the foreseeable future, threatened by disease or predation to the 
extent that listing under the Act as an endangered or threatened 
species is warranted at this time.

Factor D. The Inadequacy of Existing Regulatory Mechanisms

    Under this factor, we examine whether existing regulatory 
mechanisms are inadequate to address the threats to the mountain plover 
discussed in Factors A, B, C and E. The Service considers regulatory 
mechanisms to mean all mechanisms that are related to a comprehensive 
regime designed to maintain a conserved wildlife population. In 
addition to the five factors that section 4(a)(1) of the Act directs 
the Service to consider, section 4(b)(1)(A) of the Act requires the 
Service to take into account, ``those efforts, if any, being made by 
any State or foreign nation, or any political subdivision of a State or 
foreign nation, to protect such species. * * *'' We consider these 
efforts when developing our threat analyses under all five factors and 
in particular under Factor D. Therefore, under Factor D we consider not 
only laws and regulations, but other mechanisms that are part of a 
regulatory process such as management plans and agreements, 
conservation practices, and so forth.
    In analyzing whether the existing regulatory mechanisms are 
inadequate, the Service reviews relevant Federal, State, and Tribal 
laws, plans, regulations, Memoranda of Understandings (MOUs), 
Cooperative Agreements, and other such mechanisms that influence 
conservation. We give strongest weight to statutes and their 
implementing regulations, and management direction that stems from 
those laws and regulations. An example would be the terms and 
conditions attached to a grazing permit that describe how a permittee 
will manage livestock on a BLM allotment. They are non-discretionary 
and enforceable, and are considered a regulatory mechanism under this 
analysis. Other examples include State governmental actions enforced 
under a State statute or constitution, or Federal action under statute. 
Some other agreements (MOUs and others) are more voluntary in nature; 
in those cases we analyze the specific facts for that mechanism to 
determine the extent to which it can be relied on in the future. We 
consider all pertinent information, including the efforts and 
conservation practices of State governments, whether or not these are 
enforceable by law. Regulatory mechanisms, if they exist, may preclude 
the need for listing if such mechanisms are judged to adequately 
address the threat to the species such that listing is not warranted.
    Conversely, threats on the landscape are not ameliorated when not 
addressed by existing applicable regulatory mechanisms, or when the 
existing mechanisms are not adequate (or not adequately implemented or 
enforced). We cannot predict when or how State and Federal laws, 
regulations, and policies will change; however, most Federal land use 
plans are valid for at least 20 years. In this section, we review 
actions undertaken by State and Federal

[[Page 27791]]

entities designed to reduce or remove threats to mountain plover and 
its habitat.
Federal Laws and Regulations
    The mountain plover is covered under the provisions of the 
Migratory Bird Treaty Act (MBTA), which provides regulatory protection 
for mountain plover by prohibiting actions causing direct mortality and 
destruction of nests. In addition, the mountain plover is listed as a 
Bird of Conservation Concern by the Service in all 12 Bird Conservation 
Regions encompassing the species' breeding and wintering ranges. Birds 
of Conservation Concern represent the highest conservation priorities 
under the MBTA for the Service's Migratory Bird Program (Service 2008, 
p. iii). The goals of the Service's Migratory Bird Program include the 
protection, restoration, and management of migratory bird populations 
to ensure long-term ecological sustainability (Service 2011). The 
Service's goal is to prevent or remove the need for additional bird 
listings under the Act by implementing proactive management and 
conservation actions. The list is to be used to develop research, 
monitoring, and conservation actions to stimulate coordinated and 
collaborative proactive conservation actions among Federal, State, 
Tribal, and private partners (Service 2008, p. iii). However, the 
designation as a Bird of Conservation Concern does not in and of itself 
provide any extra protections for the mountain plover or its habitat.
    The BLM and the USFS are the primary Federal agencies that manage 
lands that provide breeding or wintering habitat for the mountain 
plover. The BLM's lands and USFS-managed National Grasslands provide 
important breeding habitat in Montana, Wyoming, Colorado, and New 
Mexico. The BLM's lands in California and southern Arizona may provide 
habitat for wintering mountain plover.
    The Federal Land Policy and Management Act of 1976 (FLPMA) (43 
U.S.C. 1701 et seq.) is the primary Federal law governing most land 
uses on BLM-administered lands. Section 102(a)(8) of FLPMA (43 U.S.C. 
1701(a)(8)) specifically recognizes wildlife and fish resources as 
being among the uses for which these lands are to be managed. 
Regulations pursuant to FLPMA and the Mineral Leasing Act (30 U.S.C. 
181 et seq.) that address wildlife habitat protection on BLM-
administered land include 43 CFR 3162.3-1 (Drilling applications and 
plans) and 43 CFR 3162.5-1 (Environmental obligations); subpart 4120 
(Grazing Management) of Title 43 of the Code of Federal Regulations 
(CFR); and subpart 4180 (Fundamentals of Rangeland Health and Standards 
and Guidelines for Grazing Administration) of Title 43 of the CFR.
    Mountain plover have been designated as a BLM Sensitive Species in 
Colorado (BLM 2000a), California (BLM 2006), and Wyoming (BLM 2010a). 
The management guidance afforded sensitive species under BLM Manual 
6840--Special Status Species Management (BLM 2008, entire) states that 
``Bureau sensitive species will be managed consistent with species and 
habitat management objectives in land use and implementation plans to 
promote their conservation and to minimize the likelihood and need for 
listing under the [Act]'' (BLM 2008, p. 05V). The BLM Manual 6840 
further requires that Resource Management Plans (RMPs) should address 
sensitive species, and that implementation ``should consider all site-
specific methods and procedures needed to bring species and their 
habitats to the condition under which management under the Bureau 
sensitive species policies would no longer be necessary'' (BLM 2008, p. 
2A1). See our discussion above under Factor A, Energy and Mineral 
Development, for more on measures the BLM has taken in Wyoming to 
conserve the mountain plover as a sensitive species.
    The BLM in Montana has designated a Mountain Plover Area of 
Critical Environmental Concern (ACEC), which contains 24,730 ac (9,892 
ha) of habitat suitable for breeding mountain plover (BLM 2000b, p.1). 
Management prescriptions apply within the ACEC to protect breeding 
mountain plover during its nesting period. All construction activity 
and surface disturbance are prohibited from April 1 to July 31, road 
construction is minimized within the ACEC, and seasonal restrictions 
also apply to off-highway travel (BLM 2000b, pp. 8-9). While the ACEC 
is a focus of BLM's efforts to conserve the mountain plover, the area 
covers only a small fraction of all mountain plover habitat in Montana.
    As a designated sensitive species under BLM Manual 6840, mountain 
plover conservation must be addressed in the development and 
implementation of RMPs on BLM lands. RMPs are the basis for all actions 
and authorizations involving BLM-administered lands and resources. They 
establish allowable resource uses, resource condition goals and 
objectives to be attained, program constraints and general management 
practices needed to attain the goals and objectives, general 
implementation sequences, and intervals and standards for monitoring 
and evaluating the plan to determine effectiveness and the need for 
amendment or revision (43 CFR 1601.0-5(n)). The RMPs provide a 
framework and programmatic guidance for activity plans, which are site-
specific plans written to implement decisions made in an RMP. Examples 
include Allotment Management Plans that address livestock grazing, oil 
and gas field development, travel management (motorized and mechanized 
road and trail use), and wildlife habitat management. Activity plan 
decisions normally require additional planning and National 
Environmental Policy Act (NEPA; 42 U.S.C. 4321 et seq.) analysis. If an 
RMP contains specific direction regarding mountain plover habitat, 
conservation, or management, it represents an enforceable regulatory 
mechanism to ensure that the species and its habitats are considered 
during permitting and other decision-making on BLM lands.
    The BLM has regulatory authority for oil and gas leasing on Federal 
lands and on private lands with a severed Federal mineral estate, as 
provided at subpart 3100 (Onshore Oil and Gas Leasing; General) of 
Title 43 of the CFR, and they are authorized to require stipulations as 
a condition of issuing a lease. They can condition ``Application for 
Permit to Drill'' authorizations, conducted under a lease that does not 
contain specific mountain plover conservation stipulations, but 
utilization of conditions is discretionary, and we are uncertain as to 
how this authority is applied.
    Management of National Forest System lands is guided principally by 
the National Forest Management Act (NFMA) (16 U.S.C. 1600-1614, August 
17, 1974, as amended). The NFMA specifies that all National Forests 
must have a Land and Resource Management Plan (LRMP) (16 U.S.C. 1604) 
to guide and set standards for all natural resource management 
activities on each National Forest or National Grassland. The NFMA 
requires USFS to incorporate standards and guidelines into LRMPs (16 
U.S.C. 1604(c)). The USFS conducts NEPA analyses on its LRMPs, which 
include provisions to manage plant and animal communities for 
diversity, based on the suitability and capability of the specific land 
area in order to meet overall multiple-use objectives. The USFS 
planning process is similar to that of the BLM. The mountain plover is 
a USFS sensitive species in Region 2, which includes all of Colorado 
and portions of Wyoming and Nebraska.
    The USFS policy provides direction to analyze potential impacts of 
proposed

[[Page 27792]]

management activities to sensitive species in a biological evaluation. 
The LRMPs for grassland units within USFS Region 2 (PNG, Nebraska 
National Forest, and Thunder Basin National Grassland in Wyoming) 
contain management direction for the mountain plover (USFS 2001). Some 
examples of the LRMP standards (required measures) for the three areas 
include: (1) Prohibiting development of new facilities within 0.25 mi 
(0.40 km) of known mountain plover nests or nesting areas; (2) limiting 
vehicle speeds in occupied mountain plover habitat to 25 miles per hour 
(mph) (40 kilometers per hour (kph)) on resource roads and 35 mph (56 
kph) on local roads; (3) designing vegetation management projects in 
suitable mountain plover habitat to maintain or improve mountain plover 
habitat; and (4) maintaining occupied nesting and brooding habitat on 
black-tailed prairie dog colonies by limiting new oil and gas 
development to one well per 80 ac (32 ha) within occupied habitat. 
Cumulatively, structure and facility development will not occur on more 
than 2 percent of the occupied mountain plover nesting habitat in each 
prairie dog colony on the Thunder Basin National Grasslands (USFS 
2001). As described above in the discussion under Factor A, the PNG has 
been conducting prescribed burning for many years to improve breeding 
habitat for mountain plover (Knopf 2008, pp. 25-26). Numerous research 
projects on mountain plover have also been conducted on the PNG and the 
adjacent USDA Research Area (Augustine 2010a, pers. comm.; Augustine 
2010b, pers. comm.).
    In Colorado and Wyoming, a multi-agency team, consisting of 
biologists from the Service, BLM, USFS, and National Park Service, 
developed a non-regulatory screening tool to allow for proactive and 
consistent management and conservation of the mountain plover on public 
lands and to provide a tool for streamlining agency review and 
implementation of activities (BLM 2004). The screening tool allows 
agency personnel to evaluate the impacts of projects (such as energy 
development, rangeland management, and recreation) that would occur 
within or adjacent to mountain plover habitat to determine whether the 
project would result in an impact to the species at the local or 
rangewide scale. Use of the screening tool would not stop any projects 
from occurring, but rather would alert agency personnel to possible 
project impacts so that the project could be modified if possible. 
While the screening tool provides a good non-regulatory mechanism for 
Federal biologists in Colorado and Wyoming to evaluate the effects of 
their proposed actions, it does not require that projects ultimately 
have no effect on mountain plover. However, this screening tool 
provides for advanced notice of actions and facilitates coordination 
between the multi-state agency team.
    The Federal laws, regulations, and actions cited above are designed 
to reduce or remove threats to the mountain plover and its habitat. 
There is no information available to indicate that the species is 
threatened by the inadequacy of existing Federal laws and regulations.
State and International Laws and Regulations
    The Nebraska Game and Parks Commission lists the mountain plover as 
``threatened.'' But, this regulatory mechanism likely protects 
relatively few individuals (see Conservation Status and Local 
Populations above). While some States, such as Colorado, have specific 
management plans that address mountain plover conservation, and all 
States within the range of the species include it within their State 
Wildlife Conservation Strategies (see Conservation Status and Local 
Populations above), there is no rangewide or intrastate coordinated 
management effort and no requirement to implement specific management 
actions. However, there is no information available to indicate that 
the species is threatened by the inadequacy of existing State 
regulatory mechanisms.
Canada
    The mountain plover has been listed as endangered in Canada since 
1987. Knapton et al. (2006, p. i) noted that listing was in part due to 
a perceived decline from 1980 to 1986. The Species At Risk Act (SARA), 
passed December 12, 2002, is a commitment by the Canadian government to 
prevent the extinction of wildlife and provide the necessary actions 
for the recovery of species deemed endangered. These at-risk wildlife 
species are provided with legal protection under SARA, and their 
biological diversity is thereby conserved (Environment Canada 2010). As 
noted in the Background section above, the mountain plover population 
in Canada is very small, and efforts there to improve habitat will not 
likely have a significant impact on this species' conservation 
rangewide. There is no information available to indicate that the 
species is threatened by the inadequacy of existing regulatory 
mechanisms in Canada.
Mexico
    In 2001, Mexico established a list of species classified as 
endangered, threatened, under special protection, or probably extinct 
in the wild (Commission for Environmental Cooperation (CEC) 2011). The 
mountain plover was listed as threatened (Andres and Stone 2009, p. 
14). Under the General Wildlife Law, the use of at-risk species may be 
authorized only for the collection and capture for restoration, 
repopulation, and reintroduction activities (CEC 2011). However, 
regulatory powers and wildlife management prerogatives reside largely 
with the Federal government with States taking a more minor role. 
Shifting Federal agency responsibility and lack of agency funding 
results in inadequate protection and management of wildlife resources 
(Valdez et al. 2006, p. 277). Although regulatory mechanisms in Mexico 
appear to be minimal or are not adequately enforced, Mexico constitutes 
a small portion of the overall species' breeding range. Mountain plover 
appear to winter in significant numbers in Mexico, but at that time of 
year, they are highly mobile and less vulnerable to human activity than 
when nesting, and they therefore may require few regulatory 
protections. There is no information available to indicate that the 
species is threatened by the inadequacy of existing regulatory 
mechanisms in Mexico.
Summary
    While mountain plover conservation has been addressed in some 
State, Federal, and international plans, laws, regulations, and 
policies, none of these have applicability throughout the range of the 
mountain plover sufficient to provide effective population-level 
conservation. However, we have found in the analysis of the other four 
factors (A, B, C, and E) that there are no activities that currently 
rise to the level of a significant threat to the mountain plover. 
Therefore, we conclude that the best scientific and commercial 
information available indicates that the mountain plover is not now, 
and is not expected to become within the foreseeable future, threatened 
by the inadequacy of existing regulatory mechanisms to the extent that 
listing under the Act as an endangered or threatened species is 
warranted at this time.

[[Page 27793]]

Factor E. Other Natural or Manmade Factors Affecting the Species' 
Continued Existence

Genetic Diversity
    The loss of local populations may impact a species because local 
populations may possess unique genetic characteristics that are 
important to the species' genetic diversity and its ability to adapt to 
future environmental changes. However, for mountain plover, genetic 
studies using nuclear microsatellites have concluded that mountain 
plover across sampled breeding locations in Colorado and Montana 
comprise a single, relatively homogenous gene pool (Oyler-McCance 2005, 
p. 359; Oyler-McCance et al. 2008, pp. 496-497). These results suggest 
that there is sufficient gene flow among breeding areas to offset 
reported adult fidelity to breeding areas and genetic effects of small 
populations (genetic drift, loss of genetic diversity) (Oyler-McCance 
et al. 2005, p. 360; Oyler-McCance et al. 2008, pp. 496-497). While 
this seems unusual for a species with relatively high reported site 
fidelity, it suggests pair formation in mixed winter flocks from 
different breeding areas. Widespread mixing of mountain plover 
populations in winter has been documented (Wunder 2007, p. 118). From a 
genetic perspective, this information suggests that no single breeding 
population requires special conservation or protection (Oyler-McCance 
et al. 2005, p. 360). However, not all populations have received 
genetic analysis, including potentially non-migratory breeding 
populations in Mexico. We conclude that there is no known restriction 
of gene flow within the species, and that the loss of any given local 
population will not substantially impact the genetic diversity of the 
mountain plover or the species' ability to adapt to future stressors.
Longevity, Site Fidelity, and Sex Ratio
    In our December 5, 2002, proposed listing rule (67 FR 72396), we 
stated, ``* * * that because the average lifespan of a mountain plover 
is less than 2 years, and breeding does not occur until 1 year of age, 
an individual mountain plover will likely have only one breeding season 
to contribute to population recruitment.'' Previous study results 
underestimated adult survival and, more importantly, our proposed rule 
erroneously concluded that average lifespan reflected typical adult 
survival. In the best available estimate of adult mountain plover 
survival, the annual survival rate of adult mountain plover of both 
sexes in Phillips County, Montana, ranged from 0.74 to 0.96 yearly 
(Dinsmore 2008, p. 50). Based on this study, a mountain plover 
returning to its breeding ground would likely return multiple 
additional years. Dinsmore et al. (2010) characterized the mountain 
plover as typical of relatively long-lived bird species, documented to 
live over 10 years, where repeated reproductive attempts throughout 
life are less important to population growth than adult survival. On 
the basis of our review of the best available information, we now 
believe that a short average lifespan and resulting limited 
reproductive opportunities, as suggested in our 2002 proposal, do not 
constitute a threat to the mountain plover.
    In our February 16, 1999 (64 FR 7587), and December 5, 2002 (67 FR 
72396), proposals to list the mountain plover as a threatened species, 
we considered the plover to have high fidelity to breeding sites. In 
patchy habitat, when nesting habitat is destroyed or unavailable, it 
may be difficult for the mountain plover to find a new place to breed, 
thus resulting in the decline of populations. Dispersal ability may be 
important to the use of available habitat and conservation of the 
mountain plover given the patchiness of desirable breeding habitat. 
Altered or fragmented landscapes may force mountain plover to disperse 
greater distances. For example, in Montana, where the mountain plover 
is highly dependent on black-tailed prairie dog colonies for breeding 
habitat, sylvatic plague outbreaks often make previously used breeding 
habitat undesirable. As discussed above, Skrade and Dinsmore (2010, pp. 
671-672) demonstrated the mountain plover's ability to disperse at 
least locally to exploit favorable breeding habitats nearby, and in at 
least one instance, an adult mountain plover returned to breed at a 
site about 25 mi (40 km) from a site where it was banded during the 
previous season. We conclude that while the mountain plover generally 
exhibits fidelity to breeding sites, it is capable, at least locally, 
of seeking out and exploiting new habitat through both juvenile 
dispersal and through adult birds returning to different breeding sites 
in subsequent years. On a local scale (several mi/km), loss or 
fragmentation of breeding habitat is unlikely to have an inordinate 
effect on mountain plover survival and reproduction (i.e., effects are 
likely to be proportional to, but not in excess of the amount of 
habitat loss).
    Previously, concern arose as to whether a preponderance of male 
mountain plover among those birds handled by researchers in California 
suggested a skewed sex ratio (more males than females) range wide and 
whether this might adversely affect reproductive potential. Knopf 
(2003, pers. comm.) speculated that a slightly unbalanced sex ratio in 
California might result from slightly higher overall mortality in 
females or from differential wintering, with females wintering further 
south, in Mexico. Rangewide sex ratios for mountain plover are still 
unknown (Knopf and Wunder 2006) and we have no evidence that relative 
number of males and females in mountain plover populations represents a 
threat to the species.
Exposure to Pesticides
    Potential exposure of mountain plover to pesticides and 
agrochemicals on wintering areas in California, and resulting impacts 
to mountain plover health and reproduction, have been cited as a 
potential threat (Knopf and Wunder 2006). Exposure of mountain plover 
to direct pesticide application is likely minimized because most 
pesticide application occurs on growing crops, and less frequently on 
harvested and fallow fields, or grazed pastures that mountain plover 
frequent.
    The organochlorine agricultural pesticide DDT, and its byproduct 
DDE, can cause thinning of eggshells and decreased reproductive success 
in birds (Longcore et al. 1971, pp. 486, 489). DDT has not been in use 
in California since the 1970s, and in many cases, DDE levels that 
remain in the environment will decrease slowly over several decades 
(Thomas et al. 2008, pp. 55, 65). Organochloride levels in mountain 
plover collected from three California counties (Imperial, San Luis 
Obispo, and Tulare) in 1991-1992 ranged from 1.0 to 10.0 parts per 
million (ppm) (dry weight); although these levels are considered high 
for an upland bird, no subsequent issues with bird behavior or eggshell 
thickness in mountain plover were noted (Knopf and Wunder 2006). Levels 
of DDE of 43 ppm (wet weight) were found in eggs collected from 
abandoned mountain plover nests in Park County, Colorado, in 2001 
(Knopf and Wunder 2006). No effects on eggs, chicks, or adult mountain 
plover were established.
    Historically, soils in the Imperial Valley are known to be high in 
DDE (California Department of Food and Agriculture (CDFA) 1985, p. 27). 
Studies have shown unchanging levels of the chemical in the past 
decades; this suggests a persistent, local source of the chemical 
(Gervais and Catlin 2004, pp. 509-510). The Imperial Valley is the 
suspected source for high DDE concentrations and decreased reproductive 
success in white-faced

[[Page 27794]]

ibises (Plegadis chihi) (Yates et al. 2010, p. 159). Levels of DDE in 
resident burrowing owls are suspected to act as a stressor, but 
reproductive effects have not been documented (Gervais and Anthony 
2003, p. 1259).
    Service biologists recently collected and analyzed mountain plover 
eggs, soils, and soil invertebrates from breeding areas in Colorado, 
Wyoming, and Montana, and soils and soil invertebrates from wintering 
areas in the Imperial Valley (Zeeman 2011, pers. comm.). Chemical 
analyses of eggs showed measurable, and in some cases high, levels of 
persistent organic pollutants, most notably DDE. Much lower 
concentrations of polychlorinated biphenyls (PPBs), hexachlorobenzene, 
tetrachlorobenzenes, alpha chlordane, oxychlordane (chlordane 
metabolite), heptachlor epoxide, and dieldrin were found. Contaminants 
detected in mountain plover eggs were also detected in soil and 
invertebrate samples from fields in Imperial Valley, but no measurable 
levels were found in soil and invertebrates at the breeding grounds.
    The upper concentrations of DDE detected, 50 ppm (wet weight) in 
two eggs, was within the range of values (which can range from as low 
as 3 ppm in sensitive species to 30 ppm in less sensitive species) 
associated with eggshell thinning and reproductive impairments in wild 
birds (Blus 1996). Conspicuous signs of impacts associated with DDE 
exposure, such as eggshell cracking and embryo malformation, were not 
detected in mountain plover (Zeeman 2011, pers. comm.). Based on 
concentrations found in eggs, DDE from wintering areas, including the 
Imperial Valley, could potentially affect mountain plover (Zeeman 2011, 
pers. comm.). The potential for the other contaminants detected in 
eggs, both individually or in combination, to affect the mountain 
plover is being evaluated by the Service (Zeeman 2011, pers. comm.). 
The results cited above suggest that exposure varies by individual and 
that few mountain plover have DDE levels that raise a concern. In 
addition, no effects of DDE to adult mountain plover, their eggs, or 
chicks have been established. At this time, we believe that if an 
effect occurs, it would probably be localized, and would affect 
individual birds or eggs and not have an effect at a population or 
species level.
    Certain organophosphate insecticides are still used to control 
insect pests on crops in California's Central Valley within the range 
of the mountain plover. Iko et al. (2003, p. 119) measured 
cholinesterase levels in mountain plover, a measure of exposure to 
organophosphorus and carbamate insecticides, and found that they varied 
widely between mountain plover collected in California from the Central 
Valley where pesticide use is widespread and from the Carrizo Plain 
where there is minimal pesticide use, but no differences were observed 
in mountain plover body condition.
    The Central Valley is one of the State's primary growing regions 
for alfalfa. Sixty percent of the State's hay crop is grown here, with 
over 600,000 ac (240,000 ha) planted to alfalfa within the Central 
Valley (Godfrey 2002, p. 4). Insecticides used on alfalfa pests include 
chlorpyrifos, malathion, and pyrethroids. Insecticide applications in 
alfalfa usually occur once insects reach damaging levels, typically in 
March or later in the growing season (Godfrey 2002, pp. 4-10), 
suggesting that exposure of wintering mountain plover to treatments 
would be limited, if any. Because early spring insecticide treatments 
in alfalfa have been found to largely eliminate nontarget insect 
species complexes (Godfrey 2002, pp. 4-6), an unknown but potential 
residual effect to mountain plover prey availability may exist in 
specific areas the following winter. If present, such an effect could 
locally reduce desirability of certain alfalfa fields to wintering 
mountain plover, but would not have a rangewide impact to the species.
    Malathion, a broad-spectrum organophosphate insecticide, has been 
used to control the beet leaf-hopper (Circulifer tenellus) in rangeland 
habitat, fallow fields, oil fields, and cultivated areas on both public 
and private lands in the San Joaquin Valley (BLM 2002, pp. 1-2; CDFA 
2007, p. 8; CDFA 2008, pp. 1-4). The beet leaf-hopper is a vector for 
curly top virus, which negatively affects crops. In the western and 
southern portions of the San Joaquin Valley, aerial spraying may occur 
fall through spring, and may include treatment of approximately 200,000 
ac (80,000 ha) in years with high beet leaf-hopper populations. 
Treatment usually results in a target population decline of over 90 
percent (CDFA 2008, pp. 1-4). Potential impacts to the mountain plover 
from the control treatments could result from both direct exposure and 
indirectly from the reduction of insect prey (CDFA 2007, p. 79).
    Although beet leaf-hopper control is potentially immense in scale, 
in the 10 years up to 2002, an average of only about 4,400 ac (1,800 
ha) per year were treated in the bird's wintering range within the San 
Joaquin Valley, primarily in sloped terrain that is not thought to be 
desired by the mountain plover (CDFA 2007, p. 79). The limited area and 
quality of mountain plover habitat treated, coupled with the species' 
large wintering range in California, led the CDFA to determine that the 
curly top treatment program would not be likely to significantly impact 
the mountain plover (CDFA 2007, p. 80). On public lands managed by the 
BLM, prescribed usage avoids malathion spraying on wintering mountain 
plover areas when the plover is present (BLM 2002, p. 1).
    Chemical exposure in Mexico where regulations and enforcement may 
be less stringent could be of concern (Andres and Stone 2009, p. 30). 
DDE levels in mountain plover eggs reported by Zeeman (2011, pers. 
comm.) may have resulted from exposure in Mexico, where DDT is still 
used. While we believe that crop fields in Mexico have potential to 
support large numbers of wintering mountain plover, significant 
mountain plover use of crop fields in Mexico has not been reported 
(Macias-Duarte and Punjabi 2010, pp. 3, 7), nor have specific issues 
regarding pesticide use and impact to mountain plover been identified. 
While changing agricultural practices regarding pesticide application 
or evolution of new chemicals for use in the United States or Mexico 
could prove a future threat, we have no basis for predicting the 
potential of such an occurrence.
    We have no evidence that pesticides are significantly impacting 
mountain plover populations either locally or rangewide. However, given 
the information summarized above, additional evaluation of any possible 
effects to mountain plover from former and ongoing pesticide use within 
the mountain plover's range appears prudent.

Selenium Toxicity

    Within the western San Joaquin Valley, selenium is present in the 
soil and has the potential to occur in ponded irrigation water in 
fields and drainages. Irrigation with drainwater used to flood wetlands 
has resulted in biological accumulation of selenium sufficient to harm 
reproduction of shorebirds and other wildlife (Ohlendorf et al. 1987, 
pp. 169-171, 174-181). Potential effects of selenium poisoning on birds 
can include gross embryo deformities, winter stress syndrome, depressed 
resistance to disease due to depressed immune system function, reduced 
reproductive success, reduced juvenile growth and survival rates, mass 
wasting, loss of feathers (alopecia), embryo death, altered enzyme 
function, and mortality (Ohlendorf 1996, pp. 131-139; O'Toole and 
Raisbeck 1998, pp. 361-380). Species exposed to multiple

[[Page 27795]]

stressors can become more vulnerable to exposure to selenium.
    Because the mountain plover is an upland bird feeding primarily on 
terrestrial insects, its habits may limit its exposure to selenium. 
Still, selenium bioaccumulation in the food chain could create a 
contaminant hazard for mountain plover feeding on insects in alkaline 
flats, grazed pastures, and plowed fields in this area. Specific 
exposure of the mountain plover to selenium, or any adverse effects of 
such exposure have not been documented.
    In summary, it has been documented that mountain plover have been 
exposed to various levels of potentially harmful pesticides and 
chemical toxins in various portions of its range. However, we have no 
information to indicate that the mountain plover is responding 
negatively to this exposure or that it is likely to respond negatively 
in the future. Exposure levels that elicit negative responses in other 
bird species do not appear to elicit a similar negative response in 
mountain plover. Therefore, we do not believe that mountain plover are 
threatened by exposure to pesticides and chemical toxins.
Grasshopper and Cricket Control
    Efforts to control grasshoppers and Mormon crickets, especially 
Federal control programs on BLM lands, have been cited as potentially 
detrimental to breeding mountain plover. Grasshoppers occur throughout 
the breeding range of the mountain plover and can reach population 
levels considered to be a threat to agriculture. The USDA's Animal and 
Plant Health Inspection Service (APHIS) conducts rangeland grasshopper 
and Mormon cricket control, including areas occupied by breeding 
mountain plover. Logically, a significant reduction in these mountain 
plover foods could affect mountain plover fecundity and survival. 
However, efforts to control grasshoppers and Mormon crickets on Federal 
lands are generally limited to suppressing populations in years and 
areas where infestations occur, and do not have the goal of 
eradication, but rather the goal of reducing densities to levels that 
limit economic impacts (BLM 2010b). Numbers of these insects present 
after treatment may remain greater than those present in a normal year. 
The BLM currently is pursuing a strategy of ``reduced area and agent 
treatments,'' with the majority of treatments through aerial spraying 
of a pesticide (diflubenzuron, a chiton inhibitor) with limited impacts 
to non-target species (BLM 2010b). Broad spectrum insecticides 
(carbaryl and in limited cases malathion) are used more sparingly, and 
as a secondary treatment.
    Control on private lands can be undertaken by State or local 
government agencies, or private landowners without participation or 
oversight by APHIS. Treatment on private lands likely varies depending 
on resources available and the economic implications of infestations. 
Where treatment occurs, it likely has the similar goal of reducing 
insect densities to acceptable levels. Grasshopper and cricket control 
can have an impact on mountain plover prey and could, in some years and 
at some locations, adversely affect mountain plover breeding. However, 
since the scope and impact of these control efforts appear minimal 
relative to the mountain plover breeding range, we conclude that 
grasshopper and Morman cricket control does not represent a significant 
threat to rangewide mountain plover populations.
Weather
    Annual weather variation influences mountain plover habitat and 
breeding success. Inclement weather may hinder egg laying (Knopf and 
Wunder 2006). Cold, rain, and hail can result in loss of nests and 
decreased chick survival. Dreitz et al. (2010, pp. 3-4) identified 
weather as a significant cause of chick mortality. Mammalian predators 
of mountain plover eggs and chicks are scent-driven, and wet conditions 
enhance predation (Knopf and Wunder 2006; Wunder 2007, p. 121).
    Wunder (2007, pp. 119-121) presented evidence that recruitment may 
be linked to regional patterns of weather, with highest recruitment 
coming from breeding areas with low precipitation and a subsequent 1- 
to 2-year lag observed in increased populations of adults (Wunder 2007, 
pp. 119-121). Productivity may be influenced by drought cycles, with 
dry years reducing predation from mammals and suppressing vegetative 
growth, thus providing increased accessibility to insects. Annual 
survival of mountain plover in Montana proved higher during periods of 
drought, although prolonged drought eventually decreases abundance of 
insect foods (Dinsmore 2008, p. 52). Weather variation affects mountain 
plover productivity across its breeding range, but we have no evidence 
that normal weather fluctuations represent a threat to the mountain 
plover.
Climate Change
    There is no information available on the direct relationship 
between the environmental changes associated with climate change and 
mountain plover population trends. However, climate change could 
potentially impact the species. According to the IPCC (2007, p. 6), 
``warming of the climate system is unequivocal, as is now evident from 
observations of increases in global average air and ocean temperatures, 
widespread melting of snow and ice, and rising global average sea 
level.'' Average Northern Hemisphere temperatures during the second 
half of the 20th century were very likely higher than during any other 
50-year period in the last 500 years and likely the highest in at least 
the past 1,300 years (IPCC 2007, p. 30). It is very likely that over 
the past 50 years cold days, cold nights, and frosts have become less 
frequent over most land areas, and hot days and hot nights have become 
more frequent (IPCC 2007, p. 6). It is likely that heat waves have 
become more frequent over most land areas, and the frequency of heavy 
precipitation events has increased over most areas (IPCC 2007, p. 30).
    Changes in the global climate system during the 21st century are 
likely to be larger than those observed during the 20th century (IPCC 
2007, p. 19). For the next 2 decades, a warming of about 0.2 degrees 
Celsius ([deg]C) (0.4 degrees Fahrenheit ([deg]F)) per decade is 
projected (IPCC 2007, p. 19). Afterward, temperature projections 
increasingly depend on specific emission scenarios (IPCC 2007, p. 19). 
Various emissions scenarios suggest that by the end of the 21st 
century, average global temperatures are expected to increase 0.6 to 
4.0 [deg]C (1.1 to 7.2 [deg]F), with the greatest warming expected over 
land and at most high northern latitudes (IPCC 2007, p. 46).
    The IPCC (2007, p. 48) predicts that the resiliency of many 
ecosystems is likely to be exceeded this century by an unprecedented 
combination of climate change associated disturbances (e.g., flooding, 
drought, wildfire, and insects), and other global drivers. Current 
climate change predictions for terrestrial areas in the Northern 
Hemisphere indicate intense precipitation events, warmer air 
temperatures, and increased summer continental winds (Field et al. 
1999, pp. 5-10; Cayan et al. 2005, pp. 6-28). With medium confidence, 
IPCC predicts that approximately 20 to 30 percent of plant and animal 
species assessed so far are likely to be at an increased risk of 
extinction if increases in global average temperature exceed 1.5 to 2.5 
[deg]C (3 to 5 [deg]F).
    The mountain plover is primarily a species of grasslands and semi-
desert. Grasslands in the Great Plains of the United States and 
southern Canada are predicted to get warmer and drier with climate 
change (North American Bird

[[Page 27796]]

Conservation Initiative 2010, p.18). Southwestern grasslands are 
expected to become drier because of declining precipitation and higher 
temperatures, especially the Chihuahuan Desert grasslands of the 
southwestern United States and northern Mexico, which are critical 
wintering areas for many grassland birds, including the mountain plover 
(North American Bird Conservation Initiative 2010, p.18). In northern 
grasslands, additional precipitation is expected, but they will still 
become drier because warmer temperatures will cause increased 
evaporation (North American Bird Conservation Initiative 2010, p. 18). 
Variability in precipitation is also expected to increase; droughts, 
flooding, and extreme storms (such as hailstorms) are all expected to 
become more common (North American Bird Conservation Initiative 2010, 
p.18). Increased atmospheric carbon dioxide will probably contribute to 
invasions of woody shrubs into grasslands (North American Bird 
Conservation Initiative 2010, p. 18), which could make certain habitats 
unusable for the mountain plover.
    Climate Wizard (TNC 2007) predicts an average temperature increase 
of approximately 4 to 6 [deg]F by the 2050s for the majority of 
mountain plover breeding and wintering habitat within the United 
States. Precipitation is projected to decline slightly in the southwest 
portion of the range, and to increase by 10 to 15 percent in the more 
northern portions of the range in the same time period. However, as 
stated above, warmer temperatures and evaporation may offset any gains 
in precipitation. By the 2080s, temperatures are predicted to increase 
by as much as 7.5 [deg]F within the species' breeding range, and 
precipitation to decline from 2050s levels throughout the range (TNC 
2007). Weather data in the Imperial Valley recorded by the Desert 
Research Institute of the Western Regional Climate Center (WRCC) 
between 1927 and 2010 show an increasing trend in average temperature 
during the months of September through March, when mountain plover are 
present in the area (WRCC 2010a, Figure 1). Projected temperature 
change for the Imperial Valley was obtained through the Climate Wizard, 
in which an average of all models was used to display change in 
temperature. These data indicate a 3.9 [deg]F increase in temperature 
for the 2050s and a 5.7 [deg]F increase for the 2080s (TNC 2007). The 
WRCC also documented in Imperial, California, a slight increasing trend 
in average precipitation (inches) from 1925-2010 (WRCC 2010b). 
Projected change in precipitation values for the Imperial Valley was 
also obtained through the Climate Wizard in which an average of all 
models was used to display percent change in precipitation. These data 
indicate a 1.1 percent increase in precipitation for the 2050s and an 
increase of 0.3 percent by the 2080s (TNC 2007).
    Change in plant phenology (timing of life cycle events such as 
vegetative growth and reproduction) may be one of the earliest observed 
responses to rapid global climate change and could potentially have 
serious consequences both for plants and animals that depend on 
periodically available resources (Moza and Batnegar 2005, p. 243). A 
change in the timing of availability of insects that mountain plover 
and their chicks rely on as a food source could occur as a result in 
changes in plant phenology.
    Because they are often highly competitive, invasive plant species 
are altering the plant composition of ecosystems and changing their 
structure and function over large landscape areas. Addition of fine 
fuels from these species often increases fire frequency, which can lead 
to increased dominance by invasive species and further habitat 
degradation. Climate change is exacerbating these changes by altering 
the amount and seasonal distribution of precipitation and seasonal 
temperature patterns in ways that often favor the invasive species 
(Tausch 2008). This could potentially result in changes in the amount 
of ground cover in mountain plover habitat, which could discourage 
mountain plover nesting. Nonnative wildlife species that could compete 
with the mountain plover for resources or prey on the species could 
potentially move into their habitats.
    Although the mountain plover was not included in ``The State of the 
Birds--2010 Report on Climate Change'' (North American Bird 
Conservation Initiative), it was assessed using the sensitivity traits 
analysis used in that report (Sauer 2010b, pers. comm.). The threat of 
climate change impacts to the plover was considered low, as it was only 
considered sensitive to one of the five main traits (it was considered 
a breeding obligate to a single habitat type) (Sauer 2010b, pers. 
comm.). Species that occupy only a single habitat for breeding are 
vulnerable should climate change reduce or eliminate that habitat. 
While the mountain plover has been often described as a grassland 
obligate (i.e., is dependent on grasslands for breeding), it also 
breeds in agricultural fields, and in semi-desert habitat. As such, we 
believe it is less likely to be threatened by climate change impacting 
grassland, or any one of its favored breeding habitats, than is 
suggested by its classification as a breeding obligate to a single 
habitat type. The mountain plover was not considered sensitive to 
potential climate change impacts based on the other four traits (its 
migratory habits, dispersal ability, niche specificity, and 
reproductive potential) (Sauer 2010b, pers. comm.). In general, the 
mountain plover seems to possess characteristics that would allow it to 
adapt to changing environmental and climate conditions. See the North 
American Bird Conservation Initiative (2010, p. 28) for definitions of 
these traits.
    Specific information on mountain plover suggests that the species 
might be adapted to drought, and that climate change predictions of the 
Great Plains becoming warmer and drier might benefit the species 
(Dinsmore 2008, p. 52). Andres and Stone (2009, p. 31) predicted 
increased summer temperatures and decreased precipitation could benefit 
mountain plover breeding. Recruitment of juvenile mountain plover into 
the population appears linked to regional patterns of precipitation, 
with highest recruitment coming from areas with lowest precipitation 
every year, and a subsequent increase in populations of adults observed 
from the same areas after a 1- to 2-year lag (Wunder 2007, pp. 119-
121). Annual survival of mountain plover in Montana proved higher 
during periods of drought, despite potential reduction in insect foods 
(Dinsmore 2008, p. 52). Peterson (2003, pp. 291-292) concluded that 
there have been subtle shifts northward in ranges of grassland birds, 
including mountain plover, potentially due to climate change.
    Climate change predictions are based on models with assumptions, 
and there are uncertainties regarding the magnitude of associated 
climate change parameters, such as the amount and timing of 
precipitation and seasonal temperature changes. There is also 
uncertainty as to the magnitude of effects of predicted climate 
parameters. The mountain plover, along with its habitat, will likely be 
affected in some manner by climate change. A shift in the species' 
geographic range may occur due to an increase in temperature and 
drought, although climate change would likely not pose as great a risk 
to mountain plover habitat as it may to species in polar, coastal, or 
montane ecosystems. Nonnative and invasive species, both plants and 
animals, could move into plover habitat as a result of

[[Page 27797]]

changes in temperature or precipitation patterns and degrade nesting 
habitat or compete with the mountain plover for resources. A change in 
the timing of availability of insects that mountain plover and their 
chicks rely on as a food source could occur as a result of changes in 
plant phenology. There is no information available to suggest that any 
of these factors are impacting mountain plover now or that they will 
likely impact the species in the foreseeable future.
    Based on all the potential climate change factors, a shift in range 
of the species could be possible, but there is no information available 
to suggest that a net loss in occupied breeding habitat or a 
significant impact to the status of the species will result. Although 
currently difficult to quantify, changes in climate, including higher 
temperatures, increasing stochastic precipitation events, high winds, 
and increasing soil dryness, will likely lead to a loss of agricultural 
production in the Imperial Valley; however, wintering habitat seems 
adequate to support the species. The species is adaptable to a wide 
array of climes, as evidenced by a geographic range that includes 12 
States, Canada, and Mexico. Based on the best available information on 
climate change projections modeled over the next 40 to 70 years, we do 
not consider climate change to be a significant threat to the mountain 
plover at this time.
Human Disturbance
    Knopf and Wunder (2006) stated that mountain plover on nests are 
extremely tolerant of human disturbance from vehicles, tractors, and 
aircraft, but quickly moved away when approached by a human on foot. 
While adult mountain plover would not likely be affected by humans on 
foot, eggs left unprotected for a period of time could become 
overheated if exposed to direct sun on hot days.
    It seems likely that heavy construction activities nearby could 
impact nesting mountain plover. Such activities are limited in scope 
across mountain plover breeding habitat at any one time. In addition, 
timing stipulations that restrict construction related to oil and gas 
development, wind-power development, and some other activities in the 
vicinity of mountain plover during the nesting season exist for some 
Federal lands (Knopf and Wunder 2006).
    Mountain plover are only one of a number of breeding bird species 
found in the habitats and locations where they nest. While prohibitions 
under the MBTA govern direct mortality and the destruction of mountain 
plover nests, general awareness of MBTA protections and of efforts to 
protect nesting birds, their nests, and their eggs may help limit human 
disturbance to nesting mountain plover.
    Andres and Stone (2009, p. 27) suggested population-level effects 
from human disturbance were unlikely. We conclude that while human-
caused disturbance may impact mountain plover, such impacts are 
generally of limited scope, and human disturbance is not likely a 
significant threat to the species.
Cumulative Impacts
    Some of the threats discussed in this finding could work in concert 
with one another to cumulatively create situations that potentially 
impact the mountain plover beyond the scope of each individual threat. 
For example, as discussed under Factor C, habitat fragmentation, 
including energy development that both alters habitat and provides 
structure on which predators could perch, could lead to increase in 
predation on the mountain plover. We have no data to determine if, or 
to what extent, such a scenario is likely to occur. We conclude, at 
this time, that it does not present a threat to the future existence of 
the mountain plover.
    Similarly, under Factor A, we alluded to the potential that in the 
Imperial Valley and other areas of California, human development, solar 
development, changing agricultural practices, water availability, and 
climate change could interact to heighten potential loss of mountain 
plover wintering habitat. In the future, warming climate may 
necessitate use of more irrigation water for crops at the same time 
that water availability decreases due to expansion of human population 
and related water demand. In our best judgment, agriculture in the 
Imperial Valley, and in other areas of California that support the 
mountain plover, are likely to be affected by some variation of the 
above scenario. However, specific changes in agriculture are uncertain. 
Seasonal change in timing of crops, potential change toward those crops 
needing less water, and changes in irrigation practices may or may not 
detract from available wintering habitat for mountain plover. While 
cumulatively, these factors will likely reduce the total area of 
wintering habitat available, we believe that sufficient area of 
appropriate agricultural habitat will persist to support wintering 
mountain plover.
    We have not identified other likely scenarios where the potential 
threats discussed in the five factors above have potential to work in 
concert to synergistically produce threats to the mountain plover above 
those which we have analyzed. We conclude that, at this time, there are 
no identifiable cumulative impacts likely to threaten the existence of 
the mountain plover in the foreseeable future.
Summary of Factor E
    We conclude that the best scientific and commercial information 
available indicates that the mountain plover is not now, or likely in 
the future, threatened by genetic stochasticity, its typical lifespan, 
its site fidelity, exposure to pesticides, selenium toxicity, 
grasshopper and cricket control, weather, climate change, or human 
disturbance, or cumulative impacts of potential threats such that the 
species is in danger of extinction or likely to become so within the 
foreseeable future.

Finding

    As required by the Act, we considered the five factors in assessing 
whether the mountain plover is endangered or threatened throughout all, 
or a significant portion of its range. We have carefully examined the 
best scientific and commercial information available regarding the 
status and past and present and future threats faced by the mountain 
plover. We reviewed information in our files, other available published 
and unpublished information, and information provided by interested 
parties following our February 16, 1999, and December 5, 2002, 
proposals to list the mountain plover (64 FR 7587 and 67 FR 72396, 
respectively), and following our June 29, 2010, document (75 FR 37353) 
vacating our September 9, 2003, withdrawal (68 FR 53083) and 
reinstating our 2002 proposal. We also consulted with Federal and State 
land managers.
    There have been historical impacts to the mountain plover, in 
particular the loss of much of the native prairie ecosystem, including 
bison, prairie dog colonies, other native grazers, and wildfires that 
produced extensive mountain plover habitat on the Great Plains. 
However, past concerns regarding continuing and future loss of breeding 
habitat provided by black-tailed prairie dog colonies appears 
unfounded. Conversion to agriculture remains insignificant across the 
mountain plover's breeding range. Human development and resultant 
impact to mountain plover breeding habitat in South Park, Colorado, has 
not occurred as previously anticipated, and is not expected to do so in 
the foreseeable future. Little evidence has

[[Page 27798]]

surfaced to suggest that the mountain plover's substantial use of 
cultivated lands for breeding is problematic. The potential for future 
energy development to adversely affect mountain plover and their 
habitat on their breeding or wintering ranges is not fully known and 
requires continued research. However, studies to date do not lead us to 
conclude that these activities currently pose substantial threats to 
the mountain plover or will in the foreseeable future. Climate change 
may impact the mountain plover, positively or negatively, in ways not 
yet envisioned.
    In the past, we were concerned that mountain plover life span was 
short compared to other plovers and that this, in combination with high 
breeding site fidelity, presented a threat to breeding populations. 
Contrary to our previous belief, the mountain plover is now considered 
a relatively long-lived species. Site fidelity and ability to seek out 
alternative sites for breeding does not appear to be a concern. Based 
on new information regarding life span, site fidelity, and dispersal, 
we no longer believe that these aspects of the mountain plover's life 
history represent any threat to the species. Lastly, recent information 
confirms that some mountain plover are exposed to pesticides, but no 
evidence of impacts to individuals, local populations, or rangewide 
impacts to the species have been demonstrated.
    The current status of the mountain plover does not suggest that 
future habitat changes, or the combination of climate change and 
habitat changes will result in significant population-level impacts in 
the foreseeable future. Their geographically widespread breeding and 
wintering locations, and ability to use a variety of habitats, 
contribute to their security. During breeding, they utilize short- and 
mixed-grass prairie, prairie dog colonies, agricultural lands, and 
semi-desert (Dinsmore 2003, pp. 14-17). The variety of habitats in 
which they successfully breed suggests that threats affecting one 
habitat type would not greatly increase the mountain plover's 
vulnerability to extinction. Mountain plover have proven to be 
adaptable to many human activities, such as using crop fields for 
breeding and wintering, and benefitting from some cattle grazing 
practices. Over time, the extent of wintering habitat in California is 
likely to decline, but wintering mountain plover exploit a variety of 
grassland, rangeland, crop fields, and semi-desert landscapes from the 
Gulf Coast to the Pacific Ocean. We conclude that any foreseeable 
future declines in wintering habitat, in California or elsewhere, are 
unlikely to imperil the mountain plover.
    We estimate the current rangewide mountain plover breeding 
population to be over 20,000 birds. This is more than double the 
estimate of 8,000 to 10,000 mountain plover that we cited in our 
December 5, 2002, proposal to list the mountain plover as a threatened 
species (67 FR 72396). While we have no evidence that an actual 
population increase has occurred, a larger known population provides 
added security from current and future potential influences and 
threats.
    Based on our review of the best available scientific and commercial 
information pertaining to the five factors, we find that the threats, 
alone or cumulatively, are not of sufficient imminence, severity, or 
magnitude to indicate that the mountain plover is in danger of 
extinction, or likely to become endangered within the foreseeable 
future, throughout all or a significant portion of it range. The 
mountain plover has experienced historical losses of native habitat 
resulting in a significant decline in the rangewide population. 
However, BBS survey results suggest that the recent (1999 through 2009) 
rate of decline has moderated (see Population Size and Trends above). 
We have no evidence that potential threats (as discussed in Factors A, 
B, C, D, and E) are acting on the species or its habitat in a way that 
would reverse this positive trend or result in an increased rate of 
population decline within the foreseeable future. The currently 
estimated rangewide mountain plover population, more than 20,000 
breeding birds, is more than double that estimated in 2002, providing 
the species with added security should increased threats to its 
wellbeing arise. As stated above, the mountain plover's geographically 
widespread breeding and wintering ranges, and ability to exploit a 
variety of habitats, contribute to its security. According to the Act, 
the term ``endangered species'' means any species which is in danger of 
extinction throughout all or a significant portion of its range; the 
term ``threatened species'' means any species which is likely to become 
an endangered species within the foreseeable future throughout all or a 
significant portion of its range. We conclude that the mountain plover 
does not meet the definition of endangered, because there is an 
apparent trend toward stability of the species' rangewide population, 
it remains widespread over both its breeding and wintering ranges, and 
it can exploit a variety of habitats including areas of human 
disturbance. In addition, we have found no threats acting on the 
mountain plover in a way that would drive the species towards being 
endangered in the foreseeable future; therefore, the species does not 
meet the definition of threatened. Therefore, we find that listing the 
mountain plover as an endangered or threatened species is not warranted 
throughout all or a significant portion of its range at this time (see 
the Significant Portion of the Range discussion below). As such, we 
withdraw our December 5, 2002, proposed rule (67 FR 72396) to list the 
mountain plover as a threatened species.

Distinct Vertebrate Population Segments/Significant Portion of the 
Range

    After assessing whether the species is endangered or threatened 
throughout its range, we next consider whether a distinct vertebrate 
population segment (DPS) or whether any significant portion of the 
mountain plover range meets the definition of endangered or is likely 
to become endangered in the foreseeable future (threatened).

Distinct Vertebrate Population Segment

    Under the Service's Policy Regarding the Recognition of Distinct 
Vertebrate Population Segments Under the Endangered Species Act (61 FR 
4722, February 7, 1996), three elements are considered in the decision 
concerning the establishment and classification of a possible DPS. 
These are applied similarly for additions to or removal from the 
Federal List of Endangered and Threatened Wildlife. These elements 
include:
    (1) The discreteness of a population in relation to the remainder 
of the species to which it belongs;
    (2) The significance of the population segment to the species to 
which it belongs; and
    (3) The population segment's conservation status in relation to the 
Act's standards for listing, delisting, or reclassification (i.e., is 
the population segment endangered or threatened).
Discreteness
    Under the DPS policy a population segment of a vertebrate taxon may 
be considered discrete if it satisfies either one of the following 
conditions:
    (1) It is markedly separated from other populations of the same 
taxon as a consequence of physical, physiological, ecological, or 
behavioral factors. Quantitative measures of genetic or morphological 
discontinuity may provide evidence of this separation.
    (2) It is delimited by international governmental boundaries within 
which differences in control of exploitation, management of habitat, 
conservation

[[Page 27799]]

status, or regulatory mechanisms exist that are significant in light of 
section 4(a)(1)(D) of the Act.
    We do not consider any population segment of mountain plover to be 
markedly separated from other populations of the same taxon as a 
consequence of physical, physiological, ecological, or behavioral 
factors. Mountain plover are naturally distributed across a large 
landscape in a discontinuous fashion. Available breeding and wintering 
habitats exist in a constantly shifting mosaic of suitable habitat 
throughout the western Great Plains and Rocky Mountain States from 
Canada to Mexico. As an avian species, mountain plover are able to move 
long distances during migration, and to return to different 
geographical areas for breeding or wintering.
    Although there is some evidence that mountain plover exhibit some 
site fidelity to their breeding areas (Graul 1973, p. 71; Skrade and 
Dinsmore 2010, p. 672), other studies have shown that the species can 
disperse over relatively long distances (Knopf and Wunder 2006; Bly 
2010b, pers. comm.). There are no known barriers to movement throughout 
the geographic range of the species. Wunder (2007, p. 118) concluded 
that there is widespread mixing of mountain plover populations in 
winter and that birds may use alternate wintering sites in different 
years. A genetic study using nuclear microsatellites concluded that 
mountain plover across sampled breeding locations in Colorado and 
Montana comprised a single, relatively homogenous gene pool (Oyler-
McCance et al. 2008, pp. 496-497). Results suggested that there was 
sufficient gene flow among breeding areas to offset genetic effects of 
small populations and reported adult fidelity to breeding areas (Oyler-
McCance et al. 2008, pp. 496-497).
    The mountain plover spans international boundaries between the 
United States, Canada, and Mexico; however, the vast majority of 
occupied breeding habitat occurs in the United States with few breeding 
records in Canada and Mexico. Mexico likely winters a substantial 
number of mountain plover that breed in the United States. The known 
relative distribution of mountain plover between the three countries 
has remained fairly constant in recent years. Additionally, we are not 
aware of any differences in control of exploitation, management of 
habitat, conservation status, or regulatory mechanisms that exist in 
Canada or Mexico that are significant in light of section 4(a)(1)(D) of 
the Act (the inadequacy of existing regulatory mechanisms). Therefore, 
we do not believe that international boundaries provide evidence of 
discrete mountain plover populations.
    We determine, based on a review of the best available information, 
that no mountain plover population segments meet the discreteness 
conditions of the 1996 DPS policy. Therefore, no mountain plover 
population segment qualifies as a DPS under our policy, and no DPS is a 
listable entity under the Act.
    The DPS policy is clear that significance is analyzed only when a 
population segment has been identified as discrete. Because we found 
that no mountain plover populations meet the discreteness element and, 
therefore, do not qualify as a DPS under the Service's DPS policy, we 
will not conduct an evaluation of significance.

Significant Portion of the Range

    The Act defines an endangered species as one ``in danger of 
extinction throughout all or a significant portion of its range,'' and 
a threatened species as one ``likely to become an endangered species 
within the foreseeable future throughout all or a significant portion 
of its range.'' The term ``significant portion of its range'' is not 
defined by the statute. For the purposes of this finding, a significant 
portion of a species' range is an area that is important to the 
conservation of the species because it contributes meaningfully to the 
representation, resiliency, or redundancy of the species. The 
contribution must be at a level such that its loss would result in a 
significant decrease in the viability of the species.
    If an analysis of whether a species is endangered or threatened in 
a significant portion of its range is appropriate, we engage in a 
systematic process that begins with identifying any portions of the 
range of the species that warrant further consideration. The range of a 
species can theoretically be divided into portions in an infinite 
number of ways. However, there is no purpose in analyzing portions of 
the range that are not reasonably likely to be significant and 
endangered or threatened. To identify only those portions that warrant 
further consideration, we determine whether there is substantial 
information indicating that (i) the portions may be significant and 
(ii) the species may be in danger of extinction there or likely to 
become so within the foreseeable future. In practice, a key part of 
this analysis is whether the threats are geographically concentrated in 
some way. If the threats to the species are essentially uniform 
throughout its range, no portion is likely to warrant further 
consideration. Moreover, if any concentration of threats applies only 
to portions of the range that are unimportant to the viability of the 
species, such portions will not warrant further consideration.
    We next address whether any portions of the mountain plover's range 
warrant further consideration. On the basis of our review, we found no 
geographic concentration of threats on breeding or wintering habitat 
such that the subspecies may be in danger of extinction in that 
portion. Although the mountain plover's wintering habitat in California 
is likely to decrease in the future because of changes in land use and 
agriculture, we have determined that the likely extent of change will 
not result in a significant threat to the species' ability to maintain 
a wintering population in California. Similarly, we found that there is 
no area within the breeding range of the mountain plover where the 
potential threat of changes to habitat are concentrated or may be 
substantially greater than in other portions of the range. The factors 
affecting the species are essentially uniform throughout its range, 
indicating that no portion of the mountain plover's range warrants 
further consideration of possible endangered or threatened status.
    We request that you submit any new information concerning the 
status of, or threats to, the mountain plover to our Colorado 
Ecological Services Office (see ADDRESSES) whenever it becomes 
available. New information will help us monitor the mountain plover and 
encourage its conservation. If an emergency situation develops for the 
mountain plover or any other species, we will act to provide immediate 
protection.

References Cited

    A complete list of references cited is available on the Internet at 
http://www.regulations.gov and upon request from the Colorado 
Ecological Services Office (see ADDRESSES).

Authors

    The primary authors of this document are the staff members of the 
Colorado Ecological Services Office (see ADDRESSES).

Authority

    The authority for this section is section 4 of the Endangered 
Species Act of 1973, as amended (16 U.S.C. 1531 et seq.).

    Dated: April 29, 2011.
Rowan W. Gould,
Acting Director, Fish and Wildlife Service.
[FR Doc. 2011-11056 Filed 5-11-11; 8:45 am]
BILLING CODE 4310-55-P