[Federal Register Volume 68, Number 174 (Tuesday, September 9, 2003)]
[Proposed Rules]
[Pages 53083-53101]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 03-22860]


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DEPARTMENT OF THE INTERIOR

Fish and Wildlife Service

50 CFR Part 17

RIN 1018-AI45


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 Fish and Wildlife Service (Service), determine that 
the action of listing the mountain plover (Charadrius montanus) as 
threatened, pursuant to the Endangered Species Act of 1973, as amended 
(Act), is not warranted, and we consequently withdraw our proposed rule 
and our proposed special rule. We make this determination because 
threats to the species as identified in the proposed rule are not as 
significant as earlier believed, and current 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.

ADDRESSES: The supporting documentation for this rulemaking is 
available for public inspection, by appointment, during normal business 
hours, at the U.S. Fish and Wildlife Service Field Office, 764 Horizon 
Drive, Building B, Grand Junction, Colorado 81506-3946, telephone; 970-
243-2778, facsimile 970-245-6933, or e-mail [email protected]. 
Pertinent information also is available at the Web site http://www.r6.fws.gov/mtnplover/.

FOR FURTHER INFORMATION CONTACT: Allan Pfister, Assistant Field 
Supervisor, Grand Junction, Colorado (see ADDRESSES), telephone 970-
243-2778; facsimile 970-245-6933.

SUPPLEMENTARY INFORMATION:

Background

    The mountain plover (Charadrius montanus) is a small bird averaging 
21 centimeters (8 inches) in body length and is similar in size and 
appearance to a killdeer (Charadrius vociferus). It is light brown 
above with a lighter colored breast, but lacks the contrasting dark 
breastbelt common to most other plovers, including the killdeer. 
Mountain plovers are insectivores; beetles, grasshoppers, crickets, and 
ants are its principal food items (Stoner 1941, Baldwin 1971, Rosenberg 
et al. 1991, Knopf 1998).
    The mountain plover is associated with shortgrass and shrub-steppe 
landscapes throughout its breeding and wintering range. Historically, 
on the breeding range, the plover occurred on nearly denuded prairie 
dog colonies (Knowles et al. 1982, Olson-Edge and Edge 1987) and in 
areas of major bison concentrations where vegetation was clipped short 
(Knopf 1997). Currently, the mountain plover also is found on human-
made landscapes (e.g., sod farms and cultivated fields) that may mimic 
their natural habitat associations, and on other sites with little 
vegetative cover (e.g., alkali flats). As mountain plovers are usually 
associated with sites that are modified by grazing and digging mammals 
(kangaroo rat (Dipodomys sp.) precincts and California ground squirrel 
(Spermophilus beecheyi) colonies on wintering grounds in California, as 
well as prairie dog colonies on the breeding grounds), Knopf and Miller 
(1994) suggested classifying the mountain plover as a species more 
closely associated with disturbed prairie sites, rather than pristine 
prairie landscapes.
    Mountain plovers nest in the Rocky Mountain and Great Plains States 
from Montana south to Nuevo Leon, Mexico. Most mountain plovers breed 
in Montana, Wyoming, and Colorado, with substantially fewer breeding 
birds occurring in Arizona, Kansas, Nebraska, New Mexico, Oklahoma, 
Texas, and Utah. Breeding was confirmed in 1999 in Mexico on a Mexican 
prairie dog (Cynomys mexicanus) colony in the State of Nuevo Leon 
(Desmond and Ramirez 2002). Nesting habitat in Canada is restricted to 
southeastern Alberta and southwestern Saskatchewan. Nesting has not 
been documented in Canada since 1990.
    Breeding adults, nests, and chicks have been observed on cultivated 
lands in Colorado, Kansas, Nebraska, Oklahoma, and Wyoming (Shackford 
and Leslie 1995; Shackford et al. 1999; V. Dreitz, Colorado Natural 
Heritage Program, in litt. 2003; Young and Good 2000). The majority of 
mountain plovers winter in California, where they are found mostly on 
cultivated fields. However, they also can be found on grasslands or 
landscapes resembling grasslands (Edson and Hunting 1999, Knopf and 
Rupert 1995, Wunder and Knopf 2003). Wintering mountain plovers also 
are reported in Arizona, Texas, and Mexico, but fewer have been 
documented at these locations than in California.
    Historically, the mountain plover has been found in a variety of 
habitats during winter, including grasslands and agricultural fields in 
California (Belding 1879 in Grinnell et al. 1918; Tyler 1916; Grinnell 
et al. 1918; Preston 1981 in Moore et al. 1990; Werschkull et al. 1984 
in Moore et al. 1990). Irrigated farmlands--burned Bermuda grass fields 
and grazed alfalfa fields--in the Imperial Valley of California, where 
desert scrub has been converted to agriculture within the past 100 
years, have become the predominant winter habitat for mountain plovers 
(Wunder and Knopf 2003, AMEC Earth and Environmental 2003). There, 
plovers move onto fields for short periods following harvest, 
especially where the fields are turned over, burned, or grazed by 
sheep. Insect availability, furrow depth, size of dirt clods, and the 
vegetation of contiguous land parcels are believed to influence the 
suitability of individual cultivated fields (E. Marquis-Brong, in litt. 
1999). Therefore, while cultivated lands are abundant throughout the 
Central and Imperial Valleys, not all of them are suitable wintering 
habitat. Because annual climatic changes in the Central Valley can 
greatly influence vegetative structure within a given year, mountain 
plover observations at traditionally occupied sites decline in years 
when abundant rainfall causes vegetation to become too tall (E. 
Marquis-Brong, Bureau of Land Management (BLM), in litt. 1999).
    Historically, breeding mountain plovers were reported as locally 
rare to abundant, and widely distributed in the Great Plains region 
from Canada south

[[Page 53084]]

to Texas (Coues 1878, Knight 1902, McCafferty 1930, Bailey and Neidrach 
1965). Knopf (1996b) estimated the North American mountain plover 
population to be between 8,000 to 10,000 birds. His estimate is based 
on a 1994 count of mountain plovers on their winter habitat in 
California. Applying the same assumptions using the more recent 1998-
2002 winter counts ranging from 1,372 to 4,037 individuals would yield 
an estimate ranging from 5,000 to 11,000 (Hunting et al., 2001; Shuford 
et al. 2000; Wunder and Knopf 2003, S. Myers, pers. comm. 2002). The 
search efforts among years are not comparable, but represent the best 
available information. We believe the estimates provided are a 
reasonable approximation of mountain plover total abundance, given 
recent survey efforts directed at mountain plovers on their winter 
habitat, the dedicated efforts to locate them in California's Central 
and Imperial valleys, and their winter flocking behavior that enhances 
detection.
    As discussed by Knopf (1996b), the continental breeding range of 
the mountain plover has been reduced from its historical extent, 
especially in the eastern portion of the range. The mountain plover was 
formerly common in western and central Kansas (Goss 1891), and reported 
as numerous between Fort Supply, Oklahoma, and Dodge City, Kansas 
(McCauley 1877). The species was historically numerous in Colorado 
(Bailey and Niedrach 1965) and Wyoming (Knight 1902). Lower numbers of 
mountain plovers formerly occupied western South Dakota (South Dakota 
Ornithologist's Union 1991) and Nebraska (Knopf 1996b), and there is 
one known breeding reference from North Dakota (Roosevelt 1885). There 
was a single report of breeding mountain plovers in northern Mexico in 
1901 (Sanford et al. 1924), and breeding was confirmed in the State of 
Nuevo Leon in 1999 (Desmond and Ramirez 2002).
    Colorado--The Colorado Bird Atlas Partnership estimated a 
population of 7,200 (range from 3,652 to 12,168) mountain plovers in 
Colorado, with perhaps 22 percent of these in Weld County (H. Kingery, 
in litt. 1997; Kingery 1998). However, this population estimate should 
be considered a ``first approximation'' and used with caution (Kingery 
1998). A more recent effort to estimate mountain plover abundance is 
the Rocky Mountain Bird Observatory's estimate of 4,850 individual 
mountain plovers in eastern Colorado (S. Gillihan, in litt. 2003).
    Mountain plovers have been studied intensively in Weld County, 
Colorado, from the late 1960s to the present. Graul and Webster (1976) 
considered Weld County in northeastern Colorado the breeding stronghold 
for the mountain plover, a conclusion widely referenced by subsequent 
authors (e.g., Knopf and Rupert 1996). However, inventories completed 
by the Colorado Bird Atlas Partnership from 1987 through 1995 found 
mountain plovers more widely distributed than previously known in many 
other eastern Colorado counties (Kingery 1998). Based on their 
inventories, the Bird Atlas Partnership concluded that 75 percent of 
Colorado's mountain plovers occurred south of Weld County (H. Kingery, 
Colorado Bird Atlas Partnership, pers. comm. 1994, in litt. 1998).
    Breeding mountain plovers also have been reported from southeastern 
Colorado by others (Chase and Loeffler 1978; Nelson 1993; R. Estelle, 
Colorado Bird Observatory, in litt. 1994; M. Scott, BLM, in litt. 2000; 
K. Giesen, Colorado Division of Wildlife (CDOW), in litt. 2001). During 
a 1996 inventory, Carter et al. (1996) concluded that mountain plovers 
occur at very low densities in 10 eastern Colorado counties, and are 
most numerous in Kiowa and Park Counties. Mountain plovers also have 
been seen in Moffat County in northwestern Colorado (Behrends and 
Atkinson 2000). The Colorado Natural Heritage Program conducted 
mountain plover surveys in Park County in central Colorado from 1994 
through 2002, and currently estimate 2,300 mountain plovers at this 
location (Pague and Pague 1994, Sherman et al. 1996, Hanson 1997, 
Granau and Wunder 2001, Wunder et al. in prep.). South Park appears to 
currently be the most productive breeding location in Colorado, and 
probably throughout the entire breeding range. This is clearly the 
largest breeding population of mountain plovers in Colorado, and 
perhaps throughout the breeding range.
    In Weld County, 60 to 70 percent of the mountain plover habitat 
occurs on the Pawnee National Grassland, a historically recognized 
breeding stronghold (F. Knopf, in litt. 1991). Today, nearly all 
mountain plovers have abandoned the Pawnee National Grassland. During 
the late 1960s, Graul and Webster (1976) estimated about 69,000 
hectares (171,000 acres) of good habitat on the Pawnee National 
Grassland, with mountain plover densities of at least 10/
kilometer2 (26/mile2). Based on these estimates, 
we calculate that at least 7,000 mountain plovers likely occupied the 
Pawnee in the early 1970s. Knopf (in litt. 1991) estimated about 1,280 
individuals in 1991, while presently the Grassland population is about 
78 individuals (F. Knopf, pers. comm. 2002).
    Graul (1973) hypothesized that mountain plover productivity on the 
Pawnee is influenced by drought and its corresponding effects on food 
supply. In 1995, the Pawnee received above-average spring rainfall 
resulting in lush vegetation growth not suitable as mountain plover 
nesting habitat. As a result, few birds were found there during the 
breeding season; conditions continued through 1996 and 1997, with few 
adult birds and very little reproduction observed through 2002 (Knopf 
1996; F. Knopf, in litt. 2003).
    Although mountain plovers nest on cultivated fields in southeast 
Colorado and adjacent States, 1 study (Shackford et al.1999) found that 
of 46 nests monitored on cultivated fields, 31 nests failed and the 
fate of the remaining 15 nests was unknown. Of the 31 failed nests, 22 
nests (48 percent of total nests) were destroyed by farm machinery. 
Giesen (in litt. 2000) reported a higher nest success on agricultural 
fields than on native rangeland. As a result of these conflicting 
findings, research was initiated in five eastern Colorado counties to 
better describe nest success and productivity, and the implications of 
cultivated field nesting to mountain plover population recruitment (T. 
McCoy, Colorado Natural Heritage Program, in litt. 2001). In 2001 and 
2002 within the study area, nests on croplands numbered 45 and 85, 
respectively, with the increase due to a 40 percent increase in area 
surveyed (V. Dreitz, in litt. 2002). Nest success on cropland and 
rangeland was equal in 2001, but was about 10 percent higher on range 
in 2002 (V. Dreitz, in litt. 2002). Predation was the major cause of 
nest failure on rangelands in 2001 and 2002. Predation and tillage 
losses were the cause of nest failure on cropland, but the combined 
losses on cropland were fewer than predation losses on rangeland in 
either year.
    Based on the data presented above, we estimate over 7,000 breeding 
mountain plovers in Colorado.
    Montana--The largest known number of breeding mountain plovers in 
Montana is found on a large complex of black-tailed prairie dog 
colonies in the contiguous Phillips and Blaine Counties (Knowles and 
Knowles 2001, Dinsmore 2001). In Phillips County, nearly all mountain 
plovers are found on active prairie dog colonies that also are grazed 
by cattle (Dinsmore 2001).
    Although Phillips and Blaine Counties contain a major breeding 
concentration for the species (Knopf and

[[Page 53085]]

Miller 1994, Knowles and Knowles 2001, Dinsmore 2001), small numbers of 
mountain plovers also breed on BLM lands in Valley County (Little 
Beaver Creek), and on private land in Wheatland and Golden Valley 
Counties near the Little Belt and Big Snowy Mountains (Knowles and 
Knowles 1998). Surveys through 2003 also report mountain plovers in Big 
Horn, Broadwater, Carbon, Fergus, Jefferson, Hill, Madison, 
Musselshell, Petroleum, Rosebud, and Treasure Counties (L. Hanebury, 
Service, pers. comm. 2003; Knowles and Knowles 1996, 1998; J. Grensten, 
BLM, pers. comm. 1998).
    The most recent information documents that the mountain plover 
population in southern Phillips County increased from about 100 
individuals in 1995, to 175 individuals in 2001 (Dinsmore 2001). In 
2003, over 150 nests were found on the study site (Dinsmore, pers. 
comm. 2003). This increase is likely due to the recovery of black-
tailed prairie dogs from a recent sylvatic plague epizootic. Mountain 
plovers at the Fort Belknap Indian Reservation increased from 0 to 20 
from 1993 to 1998 following an increase in black-tailed prairie dogs 
and the introduction of bison grazing, and there may presently be as 
many as 100 individuals, although the change may be due to more 
rigorous inventory (Knowles and Knowles 2001; S. Dinsmore, pers. comm. 
2003). Mountain plover densities on black-tailed prairie dog colonies 
at the Charles M. Russell National Wildlife Refuge declined by more 
than half from 1980 to 1996. Prairie dog numbers at Charles M. Russell 
National Wildlife Refuge have increased since 1996, and plover numbers 
have gone up slightly. Knowles and Knowles (2001) report that between 
1992 and 2000 mountain plovers declined at their Central and 
Southwestern study areas, but increased slightly at their Northeastern 
study area.
    Dinsmore (2001) concluded that mountain plovers in southern 
Phillips County are entirely dependent on an active black-tailed 
prairie dog population, and that the mountain plover abundance at his 
study site will likely parallel the population trends of black-tailed 
prairie dogs.
    Knowles and Knowles (1996) estimated less than 2,000 mountain 
plovers in Phillips and Blaine Counties, and less than 800 additional 
individuals at the other occupied locations in the State. Based on his 
6 years of research, Dinsmore (pers. comm. 2002) provided a rough 
estimate of 700 mountain plovers throughout all of Phillips and Blaine 
Counties, and noted that Knowles and Knowles (1996) estimate of 800 
mountain plovers at other areas is reasonable. Therefore, we believe 
the best information currently available indicates the total population 
in Montana is approximately 1,500 mountain plovers (Knowles and Knowles 
1996, Knowles and Knowles 1998, Dinsmore 2001, Dinsmore, pers. comm. 
2002).
    Wyoming--The mountain plover is classified as common in Wyoming, 
with breeding known or suspected in 20 of 28 latitude/longitude blocks 
(latilong blocks) occurring across the entire State (Wyoming Game and 
Fish Department 1997). The latilong records reviewed included sightings 
from 1969 to 1996, with the highest number of individual records 
occurring in the Saratoga, Wapiti, Powell, Casper, Bill, and Laramie 
blocks. Because the search effort among the blocks is not equal, the 
number of records reported for each block is not a good indicator of 
mountain plover abundance within each block. Further, while latilong 
records may note evidence of breeding, they do not provide information 
regarding nesting success. Based on these latilong records, the Wyoming 
Game and Fish Department reports the mountain plover as common in the 
State, but acknowledges that information is lacking to make any 
estimate of total population or determine whether it is increasing, 
stable, or declining (Oakleaf et al. 1996).
    Additional inventories have been conducted in Wyoming that confirm 
the presence of mountain plovers at many of the previously reported 
locations. For example, surveys conducted in the Powder River Basin 
(Campbell, Converse, Sheridan, Crook, and Weston Counties) in 2001, in 
preparation for the Powder River Basin Oil and Gas Project, found 15 
mountain plovers (Good et al. 2002, Keinath and Ehle 2002). Most of the 
Powder River Basin is private land, and the surveys were conducted from 
public roads only. Consequently, these surveys may not be a good 
representation of mountain plover abundance in the Powder River Basin. 
From 1992 to 2002, nesting was confirmed on the Thunder Basin National 
Grassland (Thunder Basin) (within the Powder River Basin) in northeast 
Wyoming in most years (Bartosiak 1992; M. Edwards, Forest Service, in 
litt. 1994; T. Byer, in litt. 1997; T. Thompson, Forest Service, in 
litt. 2003).
    Knopf (in litt. 2001b) reported that mountain plovers may be more 
common in Wyoming than previously believed, particularly in Carbon 
County. In 1999 and 2000, a total of 159 and 105 mountain plover adults 
were reported from Sweetwater and Carbon Counties, respectively, with 
many fewer individuals reported from Albany, Bighorn, Fremont, Lincoln, 
Natrona, Park, Sublette, and Washakie Counties (P. Deibert, in litt. 
2002). Surveys near Lysite in Fremont County found 39 mountain plovers 
on about 530 ha (1,300 ac) of suitable habitat (L. Hayden-Wing, Hayden-
Wing Associates, in litt. 2003). Surveys for mountain plovers in south-
central Wyoming in 2002 found a total of 50 adults and 11 nests 
(Hayden-Wing Consultants 2002). As many as 51 mountain plovers likely 
occurred on Foote Creek Rim in Carbon County in 1994, but the number 
declined to 26 in 2002 (Young and Erickson 2003). Most plovers have 
vacated habitat near the wind turbines and congregated on a prairie dog 
colony on the northern end of the Rim (Young and Erickson 2003). Nine 
nests were located on Foote Creek Rim in 2000 (Young and Good 2000).
    The total number of mountain plovers observed on Thunder Basin 
National Grasslands declined from 53 to 37 from 1993 to 2002, while the 
area surveyed during this time quadrupled (T. Thompson, in litt 2003). 
Black-tailed prairie dog colonies in the area were affected by a 
significant plague event in 2001 and 2002. Mountain plovers on Thunder 
Basin nest almost entirely on black-tailed prairie dog colonies 
(Keinath and Ehlen 2002).
    From 1979 to 2002, nesting was confirmed on and near the Antelope 
Coal Mine in the southern Powder River Basin, and breeding densities 
were reported to range from 0.9 to 2.4 birds/km2 (2.3 to 
6.2/mi2) (Oelklaus 1989, Thunderbird Wildlife Consulting, 
Inc. 2003). From 1982 to 1991, a total of 26 broods were reported on 
mine permit areas, while only 6 broods have been reported on the same 
permit areas from 1992 to 2002 (Thunderbird Wildlife Consulting, Inc. 
2003). Parrish (1988) inventoried mountain plovers over an extensive 
area of the southern Powder River Basin, and reported an overall 
density of about 0.1 mountain plover/km2 (0.3/
mi2). Mountain plovers throughout the southern Powder River 
Basin are generally thought to be widely scattered at low densities, 
with a few areas of local concentrations (Oelklaus 1989). Inventories 
from the Laramie Plains and Cheyenne Plains in the late 1950s report 
densities ranging from 0.3 to 23.8 mountain plovers/km2 (0.9 
to 61.9/mi2) (Laun 1957, Finzel 1964). Therefore, densities 
reported from the southern Powder River Basin in the 1980s are less 
than those reported from the Laramie and Cheyenne Plains in the 1950s, 
but it is unknown whether the difference is due to a decline in

[[Page 53086]]

mountain plover abundance, inherent differences in habitat quality, or 
both.
    Knopf (in litt. 1991, 2001b) found mountain plovers on the Laramie 
Plains, in the vicinity of Shirley Basin, on the Chapman Bench (Park 
County) north of Cody, and on Mexican Flats (Carbon County) northwest 
of Baggs. Specific surveys of Chapman Bench between 1988 and 1999 found 
between 7 to 14 adult mountain plovers and some juveniles (P. Deibert, 
pers. comm. 1999a).
    Mountain plovers also breed in shrub-steppe habitat in southwest 
Wyoming (Oakleaf et al. 1982). The BLM estimates 10 to 15 breeding 
pairs in the Jack Morrow Hills north of Rock Springs in Sweetwater 
County (L. Keith, BLM, pers. comm. 1999). Mountain plovers reported 
from Morton Pass in Albany County have declined from about 30 in 1997 
to about 5 in 2000 (Young and Erickson 2003).
    Based on the best information available from Wyoming, mountain 
plovers may number from 2,000 to 5,000 individuals (P. Deibert, pers. 
comm. 2003; F. Knopf, in litt. 2003).
    Nebraska--A nesting mountain plover was found in Kimball County in 
western Nebraska in 1990 (F. Knopf, in litt. 1990), and two mountain 
plover nests were found in a fallow field in the same vicinity in 1997 
(W. Jobman, Service, in litt. 1997). Seventeen mountain plovers were 
counted on 10 cultivated fields in western Nebraska in 1992 and 1995 
(Shackford and Leslie 1995), and 1 nest was found in summer fallow in 
Kimball County in 1999 (W. Jobman, in litt. 1999).
    No mountain plovers were found in 2001, following inventories of 92 
sites, including black-tailed prairie dogs colonies, in 8 western 
Nebraska counties (K. Nelson, Nebraska Game and Parks Commission, in 
litt. 2003). The lack of mountain plovers may have been due to the 
survey occurring late in the breeding season. In 2002, a survey 
occurred in Kimball County exclusively, which is dominated by dry land 
wheat farming with very little shortgrass prairie. A total of 118 
mountain plovers were found at the 66 locations surveyed, and all but 1 
individual were in wheat fields. A total of 27 juvenile mountain 
plovers also were seen, with most of these in tilled, fallow ground. We 
have no information to assess trends in Nebraska, but the Nebraska Game 
and Parks Commission is concerned about the bird's viability in the 
State (K. Nelson, in litt. 2003).
    New Mexico--Sager (1996) noted that the mountain plover was 
reported as ``fairly common'' in New Mexico in 1928, and recognized 
that the 152 mountain plovers he surveyed in 1995 would not likely be 
construed as ``fairly common'' today. However, he cautioned that 
mountain plovers may be more numerous than he reports because of their 
difficulty in detection and clumped distribution. Sager (1996) also 
reported that New Mexico is likely on the fringe of acceptable mountain 
plover habitat. We are not aware of a total population estimate or 
population trend for New Mexico.
    Oklahoma--Historic records of mountain plovers east of Cimarron 
County do not mention breeding behavior, so it is unclear whether the 
mountain plovers reported were nesting or migrating to other locations. 
Hence, both the historic and current distribution may be confined to 
Cimarron County in the panhandle of Oklahoma. In Cimarron County during 
the nesting seasons of 1986-1990, Shackford (1991) observed 15 mountain 
plovers in native grassland and 10 in cultivated fields. Ten of the 15 
birds observed in native grassland were on prairie dog colonies. The 
few plovers found, combined with the discovery of one mountain plover 
nest on a maize field, stimulated searches of cultivated fields in 
Oklahoma in 1992, 1993, and 1994. Using approximately the same search 
method and effort each year, 408, 428, and 108 individual mountain 
plovers were found on cultivated fields in each of these years, 
respectively, and up to 13 nests were found on the cultivated fields 
from 1986 through 1995 (Shackford et al. 1999, Shackford and Leslie 
1995). The plovers reported include both plovers seen during the 
breeding season as well as mountain plovers in premigratory flocks. The 
decline in 1994 is attributed to a decline in mountain plovers seen 
during the nonbreeding season, not necessarily a decline in breeding 
birds. No other surveys have been completed in Oklahoma, and estimates 
of the total Statewide population have not been made (S. Harmon, 
Service, pers. comm. 2002).
    Kansas--Counts of breeding mountain plovers on cultivated lands in 
western Kansas from 1992 through 1995 ranged from 52 (6 counties 
searched) to 114 (4 counties searched) (Shackford and Leslie 1995). 
Surveys of cultivated fields and rangelands within the boundary of the 
Cimarron National Grassland (Cimarron) in Kansas also have been 
conducted. Counts on the Cimarron in 1994, 1996, and 1997 ranged from 1 
to 13, with most of the sightings on plowed fields (J. Chynoweth, 
Forest Service, in litt. 1997).
    Other Breeding Areas--In Utah, the only site known to have breeding 
mountain plovers is in Duchesne County, south of Myton, in the Uinta 
Basin. Counts of breeding mountain plovers in this area from 1992 
through 2001 ranged from 6 to 29. From 1992 to 2001, broods were found 
in all years except 1992, 1999, and 2001; six adults and no broods were 
found in 2001; and no mountain plovers were seen in 2002 (T. Dabbs, 
BLM, in litt. 1997; F. Knopf, in litt. 1999; B. Stroh, Forest Service, 
pers. comm. 2002).
    Three pairs of nesting mountain plovers were reported near Fort 
Davis, Texas, in 1992 (K. Brian, Davis Mountain State Park, pers. comm. 
1992). More recent breeding in Texas has not been reported due to lack 
of access to private land (P. Horner, Texas Parks and Wildlife 
Department, in litt. 1997).
    From 1914 to the present, mountain plovers in Arizona have been 
reported during the breeding season from Apache, LaPaz, Maricopa, and 
Navajo Counties. A pair was found on Navajo Nation land near Winslow in 
June 1995, and an adult incubating three eggs was found near 
Springerville, Apache County, Arizona, in May 1996 (T. Cordery, 
Service, pers. comm. 1998; D. Shroufe, Arizona Game and Fish 
Department, in litt. 1999). In May 2002 breeding behavior was observed 
in three birds west of Springerville, in Apache County (Ted Cordery, 
BLM, pers. comm. 2003).
    The most recent nesting record in Canada was one nest in 
southeastern Alberta in 1989 (S. Jewell, Service, in litt. 2000). No 
mountain plovers were found during searches conducted in Alberta and 
Saskatchewan in 2001 (C. Wershler, Sweetgrass Consultants, pers. comm. 
2002).
    Mountain plover breeding behavior was observed in 1998 in Nuevo 
Leon, Mexico, and one nest was found on a Mexican prairie dog colony in 
1999 (Knopf and Rupert 1999a, Desmond and Ramirez 2002).
    We believe that Montana, Wyoming, and Colorado represent the 
historic and current core mountain plover breeding range, although 
additional peripheral locations in Oklahoma and New Mexico may play an 
important role in the species' conservation.
    Historically, mountain plovers have been observed during the winter 
in California, Arizona, Texas, Nevada, and on the California coastal 
islands of San Clemente Island, Santa Rosa Island, and the Farallon 
Islands (Strecker 1912; Swarth 1914; Alcorn 1946; Jurek 1973; Garrett 
and Dunn 1981; Jorgensen and Ferguson 1984; B. Deuel, American Birds 
Editor, in litt. 1992; D. Shroufe, in litt. 1999). In Mexico, wintering 
mountain plovers have been sighted in

[[Page 53087]]

Baja California, as well as north-central and north-eastern Mexico, in 
Sonora, Chihuahua, Coahuila, Durango, Nuevo Leon, and San Luis Potosi 
(Russell and Lamm 1978; A. Garza de Leon, The Bird Galley, in litt. 
1990; L. Stenzel, Point Reyes Bird Observatory, in litt. 1992; Gomez de 
Silva et al.1996; Knopf and Rupert 1999a; Dieni et al. 2003, J. Taylor, 
pers. comm. 2003).
    All information we have reviewed indicates that California is the 
primary wintering ground for mountain plovers, supporting up to 95 
percent of the United States' population of mountain plovers (Morey, in 
litt. 2003). However, recent isotope studies indicate that there may be 
a disproportionate number of males in the wintering flocks. Seventy-
five percent of the feathers sampled from the Imperial Valley in the 
winter of 2002 were from males, and sixty-two percent were from males 
in the winter of 2003. This could indicate a slightly higher female 
mortality, or perhaps differential migration patterns between male and 
female plovers (e.g. females wintering farther south into Mexico). More 
stable isotope work in the next two years may help answer this question 
(Knopf, pers. comm. 2003).
    Mountain plovers are most frequently reported and found in the 
greatest numbers in two general locations in California--(1) The 
western Central Valley from Solano and Yolo Counties to Kern County 
(primarily the western San Joaquin Valley), and (2) the Imperial Valley 
in Imperial County. Throughout these areas, sightings occur on 
agricultural fields and noncultivated sites. Research conducted in the 
San Joaquin Valley concluded that the noncultivated sites are the 
preferred habitat there, while cultivated sites are the exclusive 
habitat in the Imperial Valley (Knopf and Rupert 1995, Wunder and Knopf 
2003).
    From 1961 to 1968 anywhere from 25 to 10,000 mountain plovers were 
counted in winter on Kern National Wildlife Refuge in the San Joaquin 
Valley (J. Engler, Service, in litt. 1992). In January 1994, 
researchers counted 3,346 mountain plovers during a simultaneous 1-day 
survey of 25 sites throughout California (B. Barnes, National Audubon 
Society, in litt. 1994). A similar coordinated survey at 31 sites in 
the Central and Imperial valleys in January 1998 estimated 2,663 
mountain plovers (Hunting et al. 2001). In December 1999, two skilled 
observers were unable to find any mountain plovers in the entire San 
Joaquin Valley after 2 days searching traditionally occupied sites 
(Dinsmore, in litt. 2000b), which may have been due to degraded habitat 
conditions following heavy rains (F. Knopf, pers. comm. 2000). On 
February 2, 2002, 536 mountain plovers were counted in the entire San 
Joaquin Valley, which may indicate some recovery of habitat conditions 
since 1999 (S. Fitton, in litt. 2002). Within the San Joaquin Valley, 
premigratory flocks of up to 1,100 birds have been seen in Tulare 
County (Knopf and Rupert 1995). The Carrizo Plain (separated from the 
San Joaquin Valley by the Tremblor Range) also is recognized as a 
predictable wintering site, with wintering birds reliably reported from 
the west side from 1971 to 1998 (S. Fitton, in litt. 1992, 
www.birdsource.org 2000). Solano and Yolo Counties in the Central 
Valley near Sacramento also provide wintering habitat for mountain 
plovers, with about 200 being seen in these counties in recent years 
(K. Hunting, California Department of Fish and Game, in litt. 1998; C. 
Conard, Sacramento Audubon, in litt. 2003).
    Wunder and Knopf (2003) suggested that many mountain plovers have 
apparently shifted from the Central Valley as a result of habitat loss 
to southern California and the Imperial Valley. Recent search efforts 
and records for the Central Valley classify the mountain plover as rare 
and local, exceedingly rare, or accidental, within individual counties 
in the San Joaquin Valley (Edson and Hunting 1999; K. Hunting, 
California Fish and Game, pers. comm. 2003).
    In the Imperial Valley, coordinated surveys occurred in February, 
November, and December 1999. The maximum effort of 26 observers in 15 
parties over 2 days located 3,758 mountain plovers in December (Shuford 
et al. 2000). From January 9-19, 2001, 4,037 mountain plovers were 
counted by 2 observers in the Imperial Valley (Wunder and Knopf 2003), 
and 3,421 were counted there from January 29 to February 6, 2002, by 4 
observers (S. Myers, AMEC Earth and Environmental, pers. comm., 2002). 
In the 2002 Christmas Bird Count (CBC) for that area only 12 were 
counted; surveys were abandoned in January 2003 when the birds could 
not be found following heavy rains (Knopf, pers. comm, 2003).
    The only consistently collected information available to judge a 
population trend are the CBC data. The CBC data from 1955-1999 from all 
count circles in California reporting mountain plovers indicated a 
decline in mountain plovers of about 1 percent annually (J. Sauer, U.S. 
Geological Survey--Biological Resource Division (USGS-BRD), in litt. 
2000; Wunder and Knopf 2003). This equates to a 35 percent decline in 
the population from 1955 to 1999 (J. Sauer, pers. comm. 2003). The CBC 
numbers fluctuate greatly from year to year based on observer 
variability, survey intensity, and the spatial and temporal 
distribution of mountain plovers (AMEC Earth and Environmental 2003).
    Arizona, Texas, Nevada, and Mexico--Wintering mountain plovers also 
are reported from other areas, but in much lower numbers than are 
reported from California. From 1914 to the present, up to 340 mountain 
plovers have been reported during the winter from Cochise, Maricopa, 
Pima, Pinal, and Yuma Counties in Arizona (D. Shroufe, in litt. 1999). 
In Texas, up to146 mountain plovers were reported from Guadalupe, San 
Patricio, and Williamson Counties (J. Maresh, no affiliation, pers. 
comm. 1999; G. Lasley, American Birds, pers. comm. 1992). Mountain 
plovers also have been sighted throughout the year in Aransas, Concho, 
Kleberg, Nueces, Schleicher, Tom Green, and Val Verde Counties in Texas 
(P. Horner, in litt. 1997), and at Laguna Atascosa National Wildlife 
Refuge on the Texas coast (L. Laack, Service, in litt. 1992). About 400 
wintering mountain plovers were reported in west Texas in 2003 (T. 
Fennell, unaffiliated, in litt. 2003). In Nevada, several mountain 
plovers were collected in the Lahontan Valley in 1940, and a few have 
been reported in the Fallon CBC circle in the 1990s (Alcorn 1946, 
www.birdsource.org 2000). In January 1992, researchers counted 148 
mountain plovers at the north end of Laguna Figueroa, Baja California, 
Mexico (L. Stenzel, in litt. 1992). In 1994, mountain plovers were seen 
on a Mexican prairie dog colony in San Luis Potosi, Mexico (Gomez de 
Silva et al. 1996). In January 2000, 110 mountain plovers were found on 
black-tailed prairie dog colonies in Chihuahua, Mexico (S. Gillihan, in 
litt. 2003). Winter surveys for mountain plovers in Mexico completed 
during the past several years have failed to find any populations that 
approach the numbers found in California (R. Estelle, pers. comm. 
1998).
    In summary, with the heightened awareness to wintering mountain 
plovers during the past decade (including black-footed ferret recovery 
planning on prairie dog colonies in Mexico), and the mountain plover's 
winter flocking behavior, we believe it is unlikely that significant 
numbers of mountain plovers are not being detected. The widespread 
distribution of the species makes it difficult to obtain comprehensive 
population counts.

[[Page 53088]]

Previous Federal Action

    On December 30, 1982, we designated the mountain plover as a 
category 2 candidate species, meaning that more information was 
necessary to determine whether the species status was declining, 
stable, or improving (47 FR 58458). In 1990, we prepared a status 
report on the mountain plover indicating that Federal listing may be 
warranted (Leachman and Osmundson 1990). We elevated the mountain 
plover to a category 1 candidate species in the November 15, 1994, 
Animal Candidate Notice of Review (59 FR 58982). At that time, category 
1 candidate species were defined as those species for which we had 
sufficient information on biological vulnerability and threats to 
support issuance of a proposed rule to list. In 1996, we redefined 
candidate species and eliminated category 2 and 3 candidate 
designations (61 FR 64481). Candidate species were defined using the 
old category 1 definition. The mountain plover retained its candidate 
species designation as reported in the September 19, 1997, Review of 
Plant and Animal Taxa (62 FR 49398). On July 7, 1997, we received a 
petition to list the mountain plover as threatened from the 
Biodiversity Legal Foundation. The Service responded by notifying the 
petitioner that petitions for candidate species are considered second 
petitions, because candidate species are species for which we have 
already decided that listing may be warranted. Therefore, no 90-day 
finding was required for the Biodiversity Legal Foundation's petition. 
We published a proposed rule to list the mountain plover as threatened 
on February 16, 1999 (64 FR 7587), and requested that comments be 
provided by April 19, 1999. We announced public hearings for the 
proposal on April 19, 1999, and concurrently extended the comment 
period to June 21, 1999 (64 FR 19108).
    Higher priority listing actions precluded listing work on the 
mountain plover during Fiscal Years 2000 and 2001. On October 16, 2001, 
Earthjustice (representing the Biodiversity Legal Foundation, 
Biodiversity Associates, and Center for Native Ecosystems) submitted a 
60-day Notice of Intent to sue to the Secretary of the Department of 
the Interior and the Service Regional Director for failure to meet 
listing deadlines for the mountain plover, as required by section 
4(b)(6)(A) of the Act. The Service responded to Earthjustice on 
December 21, 2001, with a commitment to submit an amended listing 
proposal for the mountain plover by September 30, 2002. On October 7, 
2002, we agreed to prepare a document to reopen the public comment 
period for this listing decision by November 30, 2002; hence, the 
December 5, 2002, notice to reopen the comment period (67 FR 72396). On 
February 21, 2003, we extended the comment period to March 21, 2003 (68 
FR 8487).

Summary of Comments Received on the Proposed Rules

    In both the February 16, 1999, proposed rule (64 FR 7587) and the 
December 5, 2002, proposed rule (67 FR 72396), all interested parties 
were requested to submit factual reports or information that might 
contribute to the development of a final determination. Federal and 
State agencies, county governments, scientific organizations, and other 
interested parties were contacted and requested to comment. Several 
newspaper articles appeared in Montana, Wyoming, and Colorado following 
our distribution of background materials to print media. We also 
solicited and received the expert opinions of three independent 
specialists regarding pertinent scientific or commercial data and 
issues relating to the biological and ecological information for the 
mountain plover. We received a total of 194 written comments on the 
1999 proposed rule.
    We distributed a press release to announce the 2002 proposed rule. 
We again solicited peer review of independent specialists regarding the 
listing proposal and special rule. We received a total of 65 written, 
e-mail, or telephone comments on the 2002 proposed rule.
    In response to the 1999 proposed rule, public hearings were 
requested in Nebraska by the Forest Service; in Montana by the Phillips 
County Prairie Ecosystem Action Council, the Phillips County Board of 
County Commissioners, and Erin Crowder; and in Wyoming by the Park 
County Board of County Commissioners, Wheatland Irrigation District, 
Wyoming Farm Bureau Federation, Laramie County Conservation District, 
Platte County Resource District, Antelope Grange, Mountain Valley 
Livestock, Inc., Ultra Resources, and John and Phyllis Thalken.
    Public hearings were held at the following locations and dates:
    [sbull] Billings, Montana, May 26, 1999.
    [sbull] Malta, Montana, May 25, 1999.
    [sbull] Greeley, Colorado, May 25, 1999.
    [sbull] Lamar, Colorado, May 26, 1999.
    [sbull] Casper, Wyoming, June 2, 1999.
    We received written and verbal comments from State and Federal 
elected officials, State and Federal agencies, nongovernmental 
organizations, and private citizens. We received a total of 52 comments 
at the 5 public hearings. Of the total 246 written and verbal comments 
received on the 1999 proposed rule, 136 opposed, 41 supported, 53 
expressed concern about the proposal, and 16 sought a list of the 
references or requested public hearings.
    Following release of the December 5, 2002, proposed rule, we 
received requests for public meetings from Congressman Bob Filner 
representing the 50th District of California, the Oklahoma Farm Bureau, 
the Kansas Farm Bureau, and the Nebraska Farm Bureau. Following 
discussions with each of these individuals, we held public meetings at 
the following locations:
    [sbull] El Centro, California, January 23, 2003.
    [sbull] Elkhart, Kansas, February 5, 2003.
    The Service distributed news releases announcing the meetings in El 
Centro, California, and Elkhart, Kansas, on January 16, 2003, and 
January 29, 2003, respectively. Notification of the Elkhart meeting 
also appeared on the local access television station within the 
Elkhart, Kansas, viewing area.
    We received a total of 11 verbal comments from the 2 public 
meetings held in 2003. Of the total of 75 verbal and written comments 
received on the December 5, 2002, proposed rule, 25 comments opposed 
the listing proposal, 15 supported the proposal, 24 expressed concern, 
and 11 requested an extension of time or public hearing.
    All written and verbal comments presented at the public hearings 
and received during the public comment period, including peer review 
comments, were considered in preparing this final determination. Most 
of the comments opposing the action criticized the quality of the 
science used to support the proposal, stated that we did not thoroughly 
address each listing factor, noted the potential for the Federal 
listing to restrict activities on both public and private lands, and 
suggested that listing should be delayed to allow other alternatives to 
work to conserve the species (e.g., conservation agreements). Some 
comments also challenged the value of listing the species, and argued 
that listing the mountain plover will conflict with other species' 
conservation efforts and the implementation of other Federal programs. 
Other respondents supported listing because of the decline in the 
distribution and numbers of mountain plovers and the potential future 
natural or man-caused actions to result in further decline of the 
species, and also asked that critical habitat be designated. Each of 
the five peer reviewers (three in

[[Page 53089]]

1999, two in 2002) indicated that the proposed rule contained 
sufficient scientific information to support proposed listing. We have 
consolidated similar comments, organized them by central themes, and 
provide our responses below.

Listing Decision Statute Issues

    Comment 1: The Service has violated statutory intent by not 
complying with `the best information available' standard, has 
inappropriately `piggybacked' a new proposal on the `stale' 1999 
proposal, and has shown deferential treatment to environmental 
organizations, evidenced by the settlement agreement with Earthjustice.
    Response 1: This final determination presents a significant amount 
of new information that has become available since the 1999 proposed 
rule, including new information that caused us to discount Breeding 
Bird Survey (BBS) trends as statistically insignificant, and to 
reconsider what we earlier proposed as threats on agricultural lands on 
the breeding grounds. The settlement agreement does not reflect 
preferential treatment, but rather an appropriate means to resolve 
litigation where the final determination was overdue.
    Comment 2: E-mails, personal communications, and letters do not 
meet the `best information available' standard as described in Service 
policy (59 FR 34271).
    Response 2: Our policy, as cited above, requires that we evaluate 
all scientific and other information available, which may include 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, credible, and represents the best information 
available regarding the species under review. We must document our 
evaluation of any information we use in reaching our decision, whether 
it supports or refutes that decision.

Biased Decision Issues

    Comment 3: Several commenters stated that our analysis of the 
mountain plover population trend data, grassland conversion statistics, 
oil and gas development projections, prairie dog population data, and 
other issues, are specific examples of the Service's use of `selective 
science.' The commenter believe the Service has `selected science' to 
defend a listing position in the proposed rules, while ignoring 
information that defends the withdrawal of the listing proposal.
    Response 3: During the two public comment periods in 2002 and 2003, 
we received numerous comments from affected States and other interested 
parties. We have based our decision on our review of all the pertinent 
information we received. This determination includes new and additional 
information, including research results, that was not available for the 
proposed rule.
    Comment 4: The multiple-clutch breeding system of the mountain 
plover influences the annual fluctuation in the population, and 
prepares the mountain plover for a changing environment.
    Response 4: Multiple-clutching is believed to be a strategy that 
allows the mountain plover to respond to abundant prey (Graul 1973) 
which can, therefore, result in annual fluctuations in mountain plover 
numbers at individual breeding locations. We agree that annual 
fluctuations in mountain plovers may be in response to prey, but the 
affect of multi-clutching on population trends is unknown.
    Comment 5: The Service understated the effects of predation on 
mountain plovers, did not consider the invasion by red fox (Vulpes 
vulpes), and did not describe what is going to be done to reduce 
predation effects on mountain plovers. Predation has a much greater 
effect on the mountain plover population than losses on croplands.
    Response 5: We have revised the section on predation to include red 
fox as a potential predator, and assess the implications of predation 
to mountain plover conservation. However, red fox are not typically 
associated with habitats occupied by mountain plovers.
    Comment 6: The Service has not identified or quantified actual 
threats and, therefore, has not shown that mountain plovers have 
declined or are at risk.
    Response 6: The commenter is correct that we have not quantified 
the threats to the mountain plover or the number of individuals lost as 
a result of each threat. We have based our determination to withdraw on 
the wide distribution of the mountain plover and the relative security 
of the species from present or foreseeable threats across its current 
range.

Habitat Characteristics Issues

    Comment 7: Mountain plovers are not at risk when nesting on 
croplands. Current agricultural practices are beneficial to the 
mountain plover.
    Response 7: In the 1999 proposed rule, we stated that agricultural 
practices on cultivated lands may contribute to the decline of mountain 
plovers. Research has confirmed that some nests are lost to some 
cultivation practices (Dreitz and Knopf, in litt. 2003). As reported in 
this final determination, preliminary research findings from Colorado 
suggest that nesting success on cultivated lands does not differ 
significantly from nesting success on grassland nesting sites (Dreitz 
and Knopf, in litt. 2003). We agree that nesting success on some 
croplands is similar to that found on grasslands, but the relative 
influence of each landscape on mountain plover population recruitment 
has not been determined.
    Comment 8: Cultivated lands provide habitat where none existed 
before.
    Response 8: Cultivated lands have replaced grasslands within the 
historic breeding and wintering range of the mountain plover. Hatching 
success on cultivated lands and grasslands appears to be similar in the 
southern portion of the breeding range.
    Comment 9: Mountain plovers are an adaptable species, and have 
effectively shifted from grasslands to cultivated lands in many 
breeding and wintering areas. Cultivated lands, not grasslands, are now 
the most important habitat for mountain plovers at both breeding and 
wintering locales.
    Response 9: See response to Comments 7, 8, and 21.
    Comment 10: The role of insect availability has not been thoroughly 
evaluated, particularly given that livestock dung is less abundant than 
bison dung, and the prevalence of dung influences insect abundance. 
Also, systemic insecticides are used on cattle, which reduces insect 
availability.
    Response 10: We agree that the role of insect availability has not 
been thoroughly evaluated. However, no information has been provided to 
show that insect abundance or diversity have been significantly 
modified by the replacement of bison with domesticated livestock, or 
that the use of systemic pesticides influences insect abundance or 
composition.
    Comment 11: Mountain plover habitat is provided by several factors 
such as low moisture, drought, herbivory, fire, and grazing. In 
Montana, unique soil types are the key element in defining suitable 
mountain plover habitat. Prairie dog colonies are not the only suitable 
habitat.
    Response 11: We agree that numerous factors can provide suitable 
mountain plover habitat. We agree that soils are important to providing 
the vegetation and bare ground required by nesting mountain plovers. 
For example, Beauvais and Smith (2003) stated that poor soil, low 
precipitation, and wind scour help provide the proportion of bare 
ground needed by nesting mountain plovers in the Jack Morrow

[[Page 53090]]

Hills area of southwest Wyoming. However, the literature also is 
replete with examples documenting the association of mountain plovers 
with prairie dogs (e.g., Dinsmore 2001, Knowles 1999, Kotliar et al. 
1999).
    Comment 12: Habitat fragmentation and isolation increase the 
mountain plovers vulnerability to random natural and human-caused 
events.
    Response 12: No scientific information specifically discusses the 
influence of fragmentation or isolation on the persistence of mountain 
plovers at currently occupied breeding and wintering sites.
    Comment 13: The anticipated growth at South Park will impact 
mountain plovers and their habitat.
    Response 13: Complete development of South Park into private homes 
would probably adversely impact mountain plover. However, the 
anticipated growth at South Park will be low-density residential 
development, and full build-out is not anticipated in the foreseeable 
future since the current human population in Park County is small 
(16,000 people). It also is likely that conservation efforts ongoing in 
South Park will preserve important mountain plover habitat. 
Consequently, we believe potential threats to mountain plovers that 
might result with development will be offset by conservation measures 
implemented at the State and county levels.

Mountain Plover Distribution Issues

    Comment 14: All suitable habitat on private and public lands 
throughout the breeding range of the mountain plover has not been 
thoroughly inventoried. Additional searching in the breeding range has 
consistently found more mountain plovers.
    Response 14: We have revised the population estimates for 
individual States based on new information from commenters and 
literature. We agree that surveys on all private lands in the breeding 
range could reveal additional birds. For that reason, in addition to 
the birds' flocking tendencies in winter, and 44 years of CBC data, we 
base our total population estimate on counts from wintering habitat in 
California, not on a summation of counts from breeding locales. 
Mountain plovers occurring at undetected breeding locations would be 
expected on the winter habitat from October through mid-March. This 
estimate assumes that most of the birds winter in California.
    Comment 15: All wintering areas in the United States or Mexico have 
not been located. Further searching will yield more wintering sites and 
more mountain plovers.
    Response 15: All historic and current information we have reviewed 
support California as the key wintering location for mountain plovers, 
with many fewer numbers occurring elsewhere. Searches for mountain 
plovers on wintering grounds in Mexico have been ongoing for the past 
several years. We agree that additional searching is likely to find 
other sites used by mountain plovers, but we believe that finding large 
numbers of wintering mountain plovers will be highly unlikely, given 
the level of effort dedicated in the United States and Mexico over the 
past decade to locating mountain plovers. We have revised this section 
of our determination to cite new information provided during the 
comment period.

Mountain Plover Total Population and Trends Issues

    Comment 16: The mountain plover is declining throughout its range, 
and its current abundance is low compared to other bird species.
    Response 16: The CBC data from wintering grounds in California 
identify a slow decline in mountain plover abundance the last 44 years. 
However, the numbers vary widely from year to year, and their accuracy 
cannot be determined with any certainty.
    Comment 17: The population estimate in the 1999 and 2002 proposed 
rules is just ``a guess'' and is not reliable.
    Response 17: The majority of wildlife population numbers are 
estimates, because it is rarely possible to count all the individuals 
of a species to develop a precise population number. We have relied on 
practices accepted in conservation science, using the best information 
available to us, to provide the public with a total population 
estimate. The total population estimate of 8,000 to 10,000 individuals 
was made by Dr. Fritz Knopf, a Senior Scientist with USGS-BRD in Fort 
Collins, Colorado. Dr. Knopf has been studying mountain plovers since 
1986, and has published widely on the mountain plover throughout its 
range. We believe he is well qualified to make a population estimate. 
Dr. Stephen Dinsmore, who recently completed his doctoral research on 
mountain plovers in Montana, agrees with the population estimate. The 
only other estimates available are those we have developed for 
individual States in the breeding range based on other sources of 
information.
    The estimate is based on a 1-day coordinated survey on the winter 
habitat in 1994, which was conducted by 95 observers covering 25 sites 
in 9 counties. In addition, both planned and incidental searches to 
locate and report mountain plovers in California have been ongoing for 
decades.
    Many respondents challenged the reliability of the population 
estimate because of its reliance on a 1-day winter survey, and its 
failure to include the numerous mountain plovers that they believe 
occur on private lands throughout the nesting range. Counting animals 
on their winter habitat is an accepted technique for estimating the 
abundance of many species, with migratory waterfowl and big game being 
two examples. The survey coordinated by the National Audubon Society in 
California was a legitimate approach to monitor a wintering species, 
and represented a new effort to count mountain plovers.
    The commenters are correct in stating that the population estimate 
alone cannot be used as a basis for listing. We have provided the 
abundance and distribution information to give the public a better 
sense of the status of the mountain plover.
    Comment 18: How can the Pawnee National Grassland and Charles M. 
Russell National Wildlife Refuge be important when so few mountain 
plovers occupy these sites?
    Response 18: We emphasized the significance of the Pawnee National 
Grassland because of its historic importance to the mountain plover, 
its Federal ownership and management, and its potential contribution to 
mountain plover conservation. We identified the Charles M. Russell 
National Wildlife Refuge because of its location in Phillips County, 
Montana, an area with suitable and potentially suitable habitat and 
currently one of the largest breeding mountain plover populations. We 
believe each of these properties, with proper management, can make 
significant contributions to mountain plover conservation on public 
lands.
    Comment 19: The Service did not acknowledge that Dr. Walter Graul's 
1976 population estimate for the Pawnee National Grassland is now 
considered inaccurate.
    Response 19: We discussed this issue with Dr. Graul in preparing 
this final determination. The commenter correctly notes that subsequent 
to Dr. Graul's 1976 estimate of 20,000 mountain plovers on the Pawnee 
National Grassland, he stated that it may have been off by an order of 
magnitude. Dr. Graul provided the 1976 estimate to satisfy a request of 
the American Ornithological Union to establish a relative magnitude of 
abundance for the mountain plover. However, Dr. Graul believes that 
mountain plovers were much more numerous during his

[[Page 53091]]

research than have been noted in recent years by himself or Dr. Fritz 
Knopf. Consequently, while our use of historic numbers to show a 
declining trend at the Pawnee National Grassland can be challenged, Dr. 
Graul and Dr. Knopf both agree that a significant decline has been 
evident since the late 1960s. We have revised the appropriate section 
of the final determination.
    Comment 20: The present and future change in winter habitat in 
California is a significant range-wide threat to mountain plovers.
    Response 20: As described in this final decision, we do not believe 
the anticipated conversions of cultivated and noncultivated habitats in 
California will have an immediate significant impact on wintering 
mountain plovers throughout California. We discussed this issue with 
Dr. Fritz Knopf for preparation of this final determination (F. Knopf, 
pers. comm. 2003). Dr. Knopf agreed that winter habitat does not appear 
to be limited, but acknowledged that habitat quality may not be similar 
among all cultivated and noncultivated lands. Mountain plovers are 
opportunistic foragers while they occupy winter habitat, and have the 
ability to seek suitable habitats available over a wide area. Knopf and 
Rupert (1995) determined that mountain plovers prefer noncultivated 
sites to cultivated lands, and others have observed that mountain 
plovers appear to select unique characteristics (E. Marquis-Brong, BLM, 
in litt. 1999). However, given that cultivated habitat is pervasive 
throughout the Imperial and Central Valleys, we do not believe the 
current rate of conversion represents an imminent threat to mountain 
plovers.
    Comment 21: Mountain plover numbers are very dynamic, and their 
current abundance merely reflects a normal fluctuation.
    Response 21: We agree that mountain plover abundance at local 
breeding areas can fluctuate annually based on local environmental 
conditions.
    Comment 22: Population fluctuations due to climatic events should 
be considered temporary and not a justification for listing.
    Response 22: The Service must consider all factors, natural or 
human-caused, that may contribute to a species' survival and recovery. 
We agree that climatic events may affect localized populations, either 
positively or negatively, on a temporary basis. Presently, it is 
believed that climatic events on the Pawnee National Grassland have 
negatively influenced mountain plover abundance there.
    Comment 23: The BBS data are not reliable. The 2002 proposed rule 
stated that new BBS information was available, but new BBS information 
could not be found.
    Response 23: The 1999 proposed rule cited literature published by 
Dr. Fritz Knopf, which used published BBS trend analyses reporting the 
mountain plover declining throughout its range, and declining more 
rapidly than other grassland endemic birds. His conclusions were based 
on the BBS data for the periods from 1966 to 1993. The 1999 proposed 
rule also cited an analysis by Dr. John Sauer with the USGS-BRD, 
showing that for the period 1966 to1996, the BBS trend analysis yielded 
a statistically significant estimated annual rate of decline of 2.7 
percent. Because of the numerous comments we received on the 1999 
proposed rule regarding the BBS data, we requested a review of the data 
by the USGS-BRD, which is the Federal agency responsible for 
administering the BBS program.
    According to Sauer (in litt. 1999), the survey-wide trend analysis 
lacked statistical confidence due to the wide variability in mountain 
plovers reported from individual routes in each of the years from 1967 
to 1998. We concluded that, although the BBS is the only long-term 
trend information available in the breeding range, it is not a 
statistically reliable indicator of mountain plover population trends.
    Comment 24: A commenter criticized the 30-year-old National 
Wildlife Refuge records because of a lack of information, the 
variability in observer experience, and inconsistency in survey routes 
followed.
    Response 24: In 1992, we received a report from the Kern National 
Wildlife Refuge that consolidated mountain plover observations and 
discussed their historic and current status on the Kern and Pixley 
National Wildlife Refuges in California (J. Engler, Service, in litt. 
1992). The report included observation records from 1961 to 1991, and 
lacked data for many years during that period. The records of mountain 
plover sightings from the refuges were collected during inventories for 
waterfowl, which included observations of migrating shorebirds and 
other species. It is common for annual waterfowl surveys to be 
conducted by different people, given staff turnover and personnel 
availability. However, refuge biologists are thoroughly trained in bird 
identification, and, more importantly, because the mountain plover was 
known as a regular resident of these refuges, we are confident that the 
biologists completing the survey were able to correctly identify 
mountain plovers when encountered. We agree that the refuge data 
provide an approximate estimate rather than a precise number of 
mountain plovers wintering on the refuge.
    Comment 25: The CBC data are unreliable because count circles are 
not always the same over time, errors have been published by American 
Birds, the number of individuals reported could be wrong, and the wrong 
species can be reported.
    Response 25: We agree that CBC numbers fluctuate greatly from year 
to year based on observer variability, survey, intensity, and the 
spatial and temporal distribution of mountain plovers. We contacted Mr. 
Geoff LeBaron of the National Audubon Society, who is in charge of the 
CBC surveys and is responsible for analyzing the data; he is familiar 
with the suggested limitations (G. LeBaron, National Audubon Society, 
pers. comm. 1999). Mr. LeBaron agreed that some count circle centers 
may change over time, due to encroachment of development within the 
count circle and, therefore, may not be completely ``static'' over the 
entire period of record. However, he did not believe this seriously 
compromises the quality of the data for the geographic area over the 
long term. He also agreed that the other limitations cited by the 
commenter can occur when field data are being evaluated for species 
that occupy similar habitats, or are similar taxonomically. However, 
because the mountain plover is unique in these respects and, therefore, 
unlikely to be confused with any other species by experienced 
observers, he does not believe any of these limitations apply to the 
mountain plover. The Anadarko Petroleum Corporation retained Dr. Mark 
Boyce to analyze the CBC data (M. Boyce, University of Alberta, in 
litt. 2003). Dr. Boyce's analysis did not refute the conclusions of Dr. 
John Sauer with USGS-BRD (in litt. 2000). We have revised the section 
in this final determination to report additional information regarding 
the CBC.
    Comment 26: Population trends of the mountain plover at the Pawnee 
National Grassland are indicative of the total population trend.
    Response 26: There is no scientific evidence to support the claim 
that the precipitous decline documented at the Pawnee National 
Grassland has influenced the total mountain plover population.
    Comment 27: The mountain plover's short lifespan makes the species 
vulnerable to decline.
    Response 27: There is no scientific evidence to support the 
commenter's claim that the mountain plover's risk of

[[Page 53092]]

extinction is exacerbated by a short lifespan.

Grassland Conversion Issues

    Comment 28: Grassland conversion has destroyed mountain plover 
habitat and resulted in a decline in mountain plovers.
    Response 28: We are unable to precisely quantify the amount of 
mountain plover habitat that has been lost due to agricultural 
conversions and, therefore, are unable to precisely quantify the impact 
to mountain plovers. We do not believe the present or future conversion 
of grasslands is an imminent threat to all mountain plover breeding 
locations, throughout the species' range.
    Comment 29: The Service overstated the loss of grasslands as an 
impact on breeding mountain plovers, because the rangeland loss 
reported in the 2002 proposed rule is minuscule relative to total 
rangeland available. This means that the impact to mountain plover 
habitat is even smaller and, therefore, of no consequence.
    Response 29: We agree that most grassland conversion occurred prior 
to 1982, and that the proportion of rangeland lost to total rangeland 
from 1992 to 1997 is small. We have revised the section of the final 
determination addressing grassland conversion.
    Comment 30: The Service inappropriately analyzed the National 
Resource Inventory database in its description of rangeland conversion 
loss, and the implications to mountain plover habitat.
    Response 30: Because we are unable to precisely differentiate 
mountain plover habitat from among the NRI cover types, the NRI data 
are of little value in clearly and concisely assessing the degree of 
threat to mountain plovers or their habitat. We have revised the 
section of the final determination.
    Comment 31: Some commenter stated that the presence of thousands of 
acres of Conservation Reserve Program (CRP) lands represents a threat 
to mountain plover habitat. Other commenter complained that the Service 
has not given credit to the thousands of acres of grassland created by 
the CRP.
    Response 31: The CRP administered by the Department of Agriculture 
allows producers to retire lands for 10-year periods to remove highly 
erodible soils from production, thereby benefitting wildlife and other 
resources. As of 1992, 2,002,000 ha (4,946,000 ac) of land were 
enrolled in the program in Colorado, Montana, and Wyoming, and most of 
these lands were planted to grass (Berlinger and Knapp 1991, Lesica 
1995). The wildlife that benefit most from these practices (such as 
ring-necked pheasant, northern bobwhite, and western meadowlarks) are 
those associated with tall vegetation (Schenck and Williamson 1991), 
although within each State, the Department of Agriculture has the 
ability to plant a variety of grass species, including short grasses 
that benefit mountain plover.
    Comment 32: Wintering habitat is becoming a limiting factor. The 
historic conversion of grassland in California impacted mountain 
plovers, and future modifications of crop types, agricultural 
practices, or urbanization will have additional impact.
    Response 32: Mountain plovers demonstrate some flexibility on 
winter habitat. Wunder and Knopf (2003) reported that agricultural 
practices on croplands in the Imperial Valley are critical to wintering 
mountain plovers, although Knopf and Rupert (1995) concluded that 
grasslands were preferred by wintering mountain plovers to agricultural 
fields in the Central Valley. While not all of the croplands are 
suitable foraging habitat, and modification of practices on croplands 
used for foraging could be detrimental to some mountain plovers, we do 
not believe the rate of conversion occurring now is having a 
significant influence on the total abundance of mountain plovers 
throughout California.

Livestock Grazing, Range Management, and Farming Issues

    Comment 33: Range management is a factor in the historic decline of 
mountain plovers, and represents a current threat to existing mountain 
plover populations. Grazing practices now are very similar to those 
that were adopted decades ago.
    Response 33: The prevailing grazing management standards adopted by 
Federal agencies and grazing associations tend to maximize forage 
production and diminish excessive disturbance to grass and soil. Such 
practices can be detrimental to mountain plovers, although we have no 
information to indicate this is happening on a broad scale across the 
species' range.
    Comment 34: The Service incorrectly stated that the Forest Service 
has no schedule for revising grazing management prescriptions on the 
Pawnee National Grassland.
    Response 34: This final determination has been corrected to report 
our recent coordination with the Forest Service regarding their planned 
revisions to range allotment management plans on the Pawnee National 
Grassland, which are designed in part to enhance mountain plover 
breeding habitat.
    Comment 35: Since farming practices have not changed in 50 years 
how can there be any impact to mountain plovers?
    Response 35: We recognize there are numerous small farming and 
ranching operations that have retained historic practices that may 
benefit mountain plovers. As a result of a variety of factors, 
including more advanced technology and more effective agricultural 
chemicals, the average farm size has increased. As the farms have 
gotten larger, it is no longer feasible to till and plant a field 
within a short period of time. Consequently the lands are tilled in 
early spring when suitable habitat for mountain plover nesting is 
present. Therefore, some nests are at risk from spring tilling if 
measures are not taken to avoid nests. This final determination 
describes the implications of current farming practices to mountain 
plover conservation.

Issues Related to Prairie Dogs

    Comment 36: We received numerous comments on the Service's 
discussion of mountain plovers and prairie dogs, the abundance and 
distribution of prairie dogs, and the role of prairie dogs in the 
historic and current status of the mountain plover.
    Response 36: This final determination cites published literature, 
expert opinion, and other sources of available information to describe 
the association of mountain plovers and prairie dogs. Of the many 
comments received addressing prairie dogs, only one provided detailed 
information to challenge our discussion regarding the distribution of 
mountain plovers on prairie dog colonies in Montana. Recently, research 
completed in southern Phillips County, Montana, affirmed a strong 
association of mountain plovers with prairie dogs (Dinsmore 2001). 
Therefore, based on our review of the information available, we 
continue to believe breeding mountain plovers are strongly associated 
with prairie dogs in Montana. We have revised the section on prairie 
dogs to report new information.
    Comment 37: The Service grossly underestimated the abundance of 
prairie dogs and, therefore, grossly underestimated the abundance of 
mountain plovers.
    Response 37: The Wyoming Department of Agriculture is correct that 
the current estimate of black-tailed prairie dogs in Wyoming is greater 
than earlier Service estimates. However, it does not follow that the 
mountain plover population is proportionately underestimated. As stated 
above, we base our total mountain plover

[[Page 53093]]

population estimate on winter counts, not availability of breeding 
habitat. We have revised the final determination to acknowledge the new 
estimates for prairie dogs, and discuss the implications of prairie dog 
abundance to mountain plover viability.
    Comment 38: Prairie dog poisoning has increased.
    Response 38: The Service has new information to suggest that 
poisoning of black-tailed prairie dogs may have increased in some 
States in the mountain plover's range (Service 2002.). We have revised 
this section of the final determination to conclude that while prairie 
dog poisoning may have increased locally, it does not represent an 
imminent threat to mountain plovers throughout their breeding range.
    Comment 39: Prairie dog shooting is a threat to mountain plovers.
    Response 39: We agree that shooting black-tailed prairie dogs has 
been shown to reduce prairie dog abundance at some locations. However, 
it has not been shown to be a significant threat to maintenance of 
black-tailed prairie dog colonies (Service 2002.). While it has the 
potential to degrade or prevent recovery of habitat and impact mountain 
plover breeding success, we believe those instances are localized and 
infrequent. We have no information to indicate that the incidental 
shooting of mountain plovers is significant.

Mineral Development Issues

    Comment 40: Oil and gas development, including coalbed methane, is 
a potential significant threat to mountain plovers.
    Response 40: This final determination provides information 
describing the potential effects to mountain plovers from oil and gas 
development. The degree of effect depends on the density of mountain 
plovers and level of oil and gas development within a project area.
    Comment 41: The presence of mountain plovers at the Antelope Coal 
Mine in Wyoming is evidence that mining does not impact mountain 
plovers.
    Response 41: We have revised the final determination to report new 
information from the Antelope Coal Mine, including its potential 
effects on mountain plovers.

Pesticide Issues

    Comment 42: Inclusion of grasshopper control as a potential threat 
is not valid because the rule admits that Federal grasshopper control 
programs have been abandoned.
    Response 42: The Animal and Plant Health Inspection Service (APHIS) 
has recently authorized rangeland grasshopper control, and control of 
grasshoppers can occur when they reach economic thresholds. We have 
revised the final rule to report new information regarding pesticide 
exposure from grasshopper control and from California wintering 
habitat.

Regulatory Mechanisms

    Comment 43: Existing regulatory mechanisms are inadequate to 
protect the mountain plover.
    Response 43: We have no evidence that the existing regulatory 
mechanisms have contributed to the decline of the mountain plovers 
throughout a significant portion of their range. The Forest Service and 
the BLM routinely include the mountain plover in their planning 
documents to ensure that activities they authorize do not contribute to 
the further decline of the species. The NRCS has prepared a fact sheet 
for the mountain plover to encourage farmland practices beneficial to 
the mountain plover. The Service is developing a dialogue with all 
Federal agencies to ensure that measures are included in land 
management plans to protect and promote the conservation of the 
mountain plover. Federal listing would not add significant conservation 
benefit above those efforts presently adopted by Federal agencies.

Peer Review

    In compliance with the July 1, 1994, Service Peer Review Policy (59 
FR 34270), peer reviews were provided by five specialists. The peer 
reviewers in 1999 were Dr. Marshall Howe with USGS-Patuxent Wildlife 
Research Center, Dr. C.R. Preston with the Draper Museum of Natural 
History in Cody, Wyoming, and Dr. James Dinsmore with Iowa State 
University in Ames, Iowa. Each of these peer reviewers concluded that 
there was sufficient information to list the mountain plover as 
threatened. The reasons cited by the peer reviewers included small 
population and declining trend of the species, prairie dog distribution 
and decline, habitat loss to grassland conversion, the influence of 
cropland nesting efforts on mountain plover conservation, and pesticide 
exposure.
    Two peer reviewers provided comments to the 2002 listing proposal. 
One peer review was provided by Dr. Peter Paton with the University of 
Rhode Island in Kingston, and the second peer review was provided by 
Mr. Steve Forrest with Hyalite Consulting in Bozeman, Montana. Mr. 
Forrest was selected by Earthjustice following the settlement agreement 
reached between the Service and Earthjustice to expedite a listing 
decision for the mountain plover. Both of these peer reviewers also 
supported the proposal to list the mountain plover. The issues 
identified by each of them were similar to those received from the peer 
reviewers in 1999, but also included attention to other specific issues 
such as declines in Weld County, Colorado, Montana, and Thunder Basin 
National Grassland in Wyoming, as well as habitat fragmentation, 
prairie dog shooting, and the proposed special rule.
    Since the 1999 listing proposal and following the 2002 re-opening 
of the comment period, we have acquired additional information 
regarding the concerns identified by each of the peer reviewers, as 
disclosed in this final determination.

Summary of Factors Affecting the Species

    Section 4 of the Act (16 U.S.C. 1531 et seq.) and the regulations 
(50 CFR part 424) that implement the listing provisions of the Act set 
forth the procedures for adding species to the Federal list of 
endangered and threatened species. A species may be determined to be 
endangered or threatened due to one or more of the five factors 
described in section 4(a)(1) of the Act. These factors and their 
application to the mountain plover rangewide are discussed below.

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

Historical and Current Conversion of Grassland in Breeding Range
    As described in the 1999 and 2002 proposed rules, the historic 
conversion of grassland to cropland likely contributed to the decline 
of mountain plovers and their habitat (e.g., Graul and Webster 1976, 
FaunaWest 1991, Knopf and Rupert 1999b). To assess more recent 
grassland conversion, we reviewed information available from the 
National Resources Inventory (NRI) of the U.S. Department of 
Agriculture Natural Resources Conservation Service (NRCS) between 1982 
and 1997. We selected the ``rangeland'' cover type because ``native 
grassland'' is not a type category within the data base specifically, 
but is represented under the rangeland category. Comprehensive NRI data 
is only available from 1982 through 1997 (NRCS 1998; K. Musser, NRCS, 
in litt. 2000; K. Musser, pers. comm 2002). We used only areas occupied 
by mountain plovers in their breeding range to compare the rangeland 
conversion statistics (Knowles and Knowles 1998, Shackford and Leslie 
1995).

[[Page 53094]]

    From 1982 to 1997, rangeland decreased in Colorado by 217,200 ha 
(536,700 ac), in Kansas by 14,852 ha (36,700 ac), in Nebraska by 14,326 
ha (35,400 ac), in Oklahoma by 16,512 ha (40,800 ac), in Montana by 
59,894 ha (148,000 ac), and in Wyoming by 18,090 ha (44,700 ac). More 
acres were converted prior to 1992 in all States except Nebraska and 
Montana, where acres converted after 1992 were about the same or more 
than doubled, respectively. The total lands converted are a small 
fraction of the total rangeland. While the best information available 
does not allow us to quantify the acres of occupied mountain plover 
habitat converted, using the rate of rangeland conversion, we believe 
native grassland conversion is small and does not pose a substantial 
threat to mountain plovers.
    The Montana Fish, Wildlife and Parks expressed concern over 
conversion of native habitat in Montana (P. Graham, Montana Fish, 
Wildlife and Parks, in litt. 1999). For example, Knowles and Knowles 
(2001) reported that a total of 13 percent of the land area in their 
central Montana study area has been converted from native grass from 
1991 to 1999, and that mountain plovers have abandoned all but one of 
the sites that were converted. Mountain plovers in the central Montana 
study area declined from more than 100 in 1992 to about 70 individuals 
in 2000, as a result of grassland conversion (Knowles and Knowles 2001; 
C. Knowles, pers. comm. 2003).
    Mountain plovers nest successfully on croplands in Colorado and 
perhaps contiguous States (V. Dreitz and F. Knopf, in litt. 2003; 
Shackford et al. 1999). While the findings are preliminary and 
represent a small percentage of total croplands in eastern Colorado, 
they suggest that existing croplands and grasslands in the southern 
portion of the breeding range may be of equivalent value to nesting 
mountain plovers (V. Dreitz and F. Knopf, in litt. 2002). In Montana 
and northern Wyoming, nesting on cultivated land has not been observed 
(Knowles and Knowles 2001; Shackford et al. 1999). However, since the 
amount of rangeland converted is small (NRCS 1998), we conclude that 
the impact to mountain plovers in Montana and northern Wyoming is 
comparably small, regardless of how cultivated land is used by mountain 
plovers in those states.
    In some areas in the mountain plover breeding range, grasslands are 
being converted to housing subdivisions. Of some concern is development 
of nesting habitat in South Park, Park County, Colorado, where the 
mountain plover population is now estimated to be about 2,300 
individuals, which is the largest known remaining concentration of 
mountain plovers in the breeding range (Wunder et al. in prep.). The 
known breeding sites in South Park are vulnerable to ongoing and 
proposed future residential development. Full build-out of those sites 
currently subdivided would be detrimental to mountain plovers (Sherman 
et al. 1996, Granau and Wunder 2001). However, it is unknown how 
extensive future development will actually be or how fast it will 
proceed, such that while it is a potential threat we have no reason to 
believe that it means the species is likely to be in danger of 
extinction in the foreseeable future. It also is likely that private 
conservation efforts ongoing in South Park will preserve important 
mountain plover habitat.
Cultivated Areas in Breeding Range as Potential Population Sinks
    In the 1999 proposed rule, we stated that we believed cultivated 
lands in the southern portion of the breeding range created population 
sinks for the mountain plover, contributing to species decline. In an 
effort to better define the implications to mountain plover survival, 
research was initiated on cultivated fields and rangelands in five 
counties in eastern Colorado in 2001 (T. McCoy, in litt. 2001). 
Preliminary data analysis indicates that nest success is comparable 
between cropland and rangeland (V. Dreitz and F. Knopf, in litt. 2003). 
Nest failure was attributed principally to tillage and predation on 
cropland, and to predation on rangeland (V. Dreitz and F. Knopf, in 
litt. 2002). However, while hatching success on croplands and 
grasslands is similar in the southern portion of the breeding range, 
comparable data on juvenile survivorship are not available so mountain 
plover reproductive success on cropland relative to grasslands is not 
fully known (V. Dreitz and F. Knopf, in litt. 2002; Knopf, in litt. 
2003).
Historical Conversion of Grassland in Wintering Range
    Historically, mountain plover habitat in the Central Valley was 
lost following the decline of grazing elk, pronghorn, burrowing 
kangaroo rats, ground squirrels, and other mammals. The combined 
activities of these herbivores maintained suitable habitat conditions 
for mountain plovers, closely mimicking habitat characteristics found 
on breeding habitats (Knopf and Rupert 1995). Elk are now extirpated 
from the Central Valley, and pronghorns, once extirpated, have recently 
been reintroduced into the Carrizo Plains (BLM et al. 1995). The 
federally-listed giant kangaroo rat (Dipodomys ingens) and Tipton 
kangaroo rat (Dipodomys nitratoides nitratoides) have declined to about 
2 percent and 1 percent of their former range, respectively, due 
primarily to conversion of grassland habitat to agriculture and 
urbanization, and secondarily due to other incidental human activities 
and control of California ground squirrels (W. White, Service, in litt. 
2001a; 52 FR 283; S. Jones, Service, pers. comm. 2003). The occupied 
range of each of these species in the San Joaquin Valley overlaps the 
described wintering range of the mountain plover. Currently, it is 
estimated that giant kangaroo rats may occupy about 11,145 ha (27,540 
ac) and the Tipton kangaroo rat may occupy about 25,000 ha (63,000 ac) 
(Service 1998). While we cannot measure the degree of impact to 
mountain plovers resulting from the loss of these mammals, we believe 
any further loss would be detrimental to the species by further 
reducing natural habitats.
    Native grasslands in the San Joaquin Valley have been nearly 
eliminated. Of nearly 1,800,000 ha (4,400,000 ac) of native grasslands 
present prior to extensive settlement, no more than 600 ha (1,500 ac) 
remained in 1972 (Moore et al. 1990). This loss of grasslands has been 
paralleled by a loss of other natural habitats, with the total of all 
uncultivated lands in the San Joaquin Valley now occupying less than 
61,000 ha (150,000 ac) (Service 1998).
    Mountain plovers wintering in the San Joaquin Valley prefer native 
Valley sink scrub and nonnative grasslands over any of the more 
commonly cultivated land types (Anderson et al. 1991; Knopf and Rupert 
1995) when the grasslands are grazed or burned (Knopf and Rupert 1995). 
These preferred habitats occupy less than 26,000 ha (66,000 ac) of the 
San Joaquin Valley (Anderson et al. 1991). Mountain plovers in the San 
Joaquin Valley depend on these core areas of uncultivated lands in 
October and November (Engler, in litt. 1992; Knopf and Rupert 1995), 
and further loss of these areas would be detrimental to the species 
(Knopf and Rupert 1995).
    Mountain plovers use cultivated croplands in the Imperial Valley of 
California, where in recent years (except the winter of 2002-03 when 
excessive rain prevented it) greater than 50 percent of all individuals 
of the species wintered (Wunder and Knopf 2003). Until agricultural 
development began in the 1940s, this historically desert region was not 
known to support the species. Here, 37 percent of the mountain

[[Page 53095]]

plovers forage and roost on grazed or sprouting alfalfa fields; 34 
percent roost on short-term fallowed fields; and 13 percent forage on 
burned bermuda grass fields, while ungrazed alfalfa, unburned bermuda 
grass, melon and vegetable fields are rarely or never used (Wunder and 
Knopf 2003).
    Other habitats within the historic wintering range of the mountain 
plover have been modified by modern livestock grazing practices that 
maintain grass height that is higher than what mountain plovers can 
use. This is the situation in the Carrizo Plain, which is recognized as 
a predictable wintering area and historically may have provided up to 
50 percent of suitable plover wintering habitat. No more than 10 
percent of the Carrizo Plain's 103,000 ha (254,000 ac) was suitable for 
mountain plovers in the early 1990s (S. Fitton, in litt. 1992; BLM et 
al. 1995), but that figure has increased in recent years due to lower 
precipitation (S. Fitton, pers. comm. 2003). Habitat availability there 
appears to be linked to a combination of livestock grazing management 
and precipitation.
    We were unable to precisely quantify the acres of mountain plover 
wintering habitat converted to other uses annually because a data base 
quantifying mountain plover habitat does not exist. However, 
information from the California Department of Conservation confirms the 
routine conversion of existing croplands to vineyards, orchards, and 
other uses. For example, from 1990 to 2000, the acreage of vineyards in 
California nearly doubled to a total of 230,000 ha (570,000 ac) (M. 
Penberth, California Department of Conservation, in litt. 2003). In 
nine counties in the Central Valley where mountain plovers are now 
reported as ``rare and local,'' the acres in vineyards increased by 
about 25 percent (31,000 ha (76,000 ac)) from 1990 to 2000 (Edson and 
Hunting 1999; M. Penberth, California Department of Conservation, in 
litt. 2003). Conversion to vineyards represents a loss of potential 
habitat, although the extent of use by plovers prior to conversion is 
unknown.
    Urban development destroyed most noncultivated, historic coastal 
mountain plover winter habitat (Wunder and Knopf 2003), and anticipated 
urbanization and water transfers from rural to urban areas may impact 
the remaining natural habitats, as well as to existing cropland 
habitats in both the Central and Imperial Valleys. In California, the 
U.S. Census Bureau (2003) projected a 52 percent (17 million) 
population increase from 2000 to 2025. Based on past trends, 
considerable population growth is expected to occur in the Central 
Valley (American Farmland Trust 2003, Hunting et al. 2001). The 
Imperial County population is expected to nearly double by 2020 
(American Farmland Trust 2003). In the Imperial Valley, the North 
American Free Trade Agreement is expected to generate increased trade 
growth, and highway projects are now being planned to improve 
transportation efficiency (California Department of Transportation 
2001). As a result of the anticipated population growth, the American 
Farmland Trust (2003) designated the Imperial and Central Valleys 2 of 
the top 20 threatened farming regions in the Nation. However, between 
1982 and 1992, only 8,000 ha (19,000 ac) of land in Imperial County 
were converted to urban uses. The present impacts to farm land in 
Imperial County have had no measurable impact on wintering mountain 
plovers. For example, the Service completed a draft biological opinion 
for a proposed transfer of water from the Imperial Valley to southern 
California coastal communities (P. Sorensen, Service, in litt. 2003). 
It is presently estimated that if the water transfer occurs, 12,000 to 
32,600 ha (30,000 to 80,500 ac) of bermuda grass sod farms and alfalfa 
could be fallowed each year (C. Roberts, Service, pers. comm. 2002; P. 
Sorensen, in litt. 2002), which we calculate would be from 15 to 39 
percent of the available foraging habitat described by Wunder and Knopf 
(2003). However, because of the mild winter climate in the Imperial 
Valley, crops are not fallowed for long periods of time. Land that is 
fallow 1 month may be tilled the next, presenting a shifting mosaic of 
foraging habitat for plovers. Because it is unclear whether the water 
transfer will occur and whether it will reduce foraging habitat for 
mountain plovers in the Imperial Valley, we cannot conclude that loss 
of cropland or modification of current practices threatens the species 
in the foreseeable future.
    In summary, although most natural habitat used by mountain plovers 
in California has been destroyed, some crops that have replaced it 
provide foraging and roosting habitat (Knopf and Rupert 1995, Wunder 
and Knopf 2003). Given a high over-wintering survival rate in the San 
Joaquin Valley and Carrizo Plain and the ability of the plovers to use 
croplands successfully, Knopf and Rupert (1995) concluded that a loss 
of a major proportion of native habitats in the wintering range has not 
limited plover populations.
    Mountain plovers have been reported in winter in other States in 
the United States and Mexico, but in comparison to California their 
numbers are few, and the threat of habitat destruction, modification, 
or curtailment is unknown with one exception. In the 1990s, the Ejido 
San Pedro CBC was initiated on a black-tailed prairie dog complex in 
northwestern Chihuahua, Mexico (birdsource.org 1992-2002). Mountain 
plovers have been reported in low numbers in most years, with no birds 
reported in some years (birdsource.org 1993-2002). Vegetation has been 
modified by livestock grazing to include woody shrubs, and prairie dog 
densities are low, which allows for increased vegetation height.
    In conclusion, after reviewing the current and anticipated impacts 
to wintering habitat, we find that they do not pose significant threats 
to the mountain plover.
Effects of Range Management on Mountain Plover Habitat
    Domestic livestock grazing is pervasive throughout the breeding 
range of the mountain plover. Currently accepted domestic livestock 
grazing management emphasizes a uniform grass cover to minimize 
grassland and soil disturbance, whereas the landscape created 
historically by native herbivores was a mosaic of grasses, forbs, and 
bare ground that changed frequently in time and location (Knopf 1996a, 
Knopf and Rupert 1999b). The shift to livestock grazing strategies that 
favor uniform cover is believed to be partly responsible for the 
decline of mountain plovers in the peripheral breeding areas of 
Oklahoma and Canada (Flowers 1985, Wershler 1989), but has only been 
assessed in limited, localized instances elsewhere within the major 
portion of the breeding range. Mountain plovers are no longer reported 
from the Lewis Ranch in central Montana since elimination of grazing 
there in 1993 (Knowles and Knowles 2001). The decline of mountain 
plovers on the Pawnee National Grassland in Colorado is due to multiple 
years of wet spring weather, persistent grazing systems, the apparent 
difficulty of adjusting domestic livestock stocking rates to 
accommodate years of increased forage, the lack of infrastructure to 
modify grazing systems, and the sparse application of grassland burning 
and mineral block placement to restore nesting habitat (Forest Service 
1994; S. Currey, Forest Service, in litt. 2002; F. Knopf, in litt. 
2002; R. George, in litt. 2002; E. Humphrey, Forest Service, in litt. 
2003). These examples are localized and do not appear to exemplify 
practices in a substantial portion of the breeding range. If the 
impacts were significant, we would anticipate being able to detect a 
declining trend in

[[Page 53096]]

abundance on the BBS, which shows a statistically significant decline 
from 1966 to 2002 only in the extreme southern portion of the breeding 
range where plover abundance is low and the number of routes detecting 
the species are few (BBS, http://www.mbr-pwrc.usgs.gov/bbs/bbs.html).
    Several range management practices conducted throughout the range 
of the mountain plover enhance the development of taller vegetation, 
thereby eliminating nesting opportunities (Graul and Webster 1976, 
Knowles and Knowles 1993). Examples of these practices include 
``pitting'' to increase moisture retention in the soil, introduction of 
exotic grass species such as crested wheatgrass, watershed improvement 
projects to retain water, and, in Montana, fire suppression (Graul 
1980, FaunaWest 1991, Knowles and Knowles 1993).
    Localized range management activities on private and public lands 
also destroy mountain plover habitat. In 2001, for example, two known 
mountain plover breeding sites were destroyed in Valley County, 
Montana, by the construction of stock tanks in an area designated by 
the BLM as an Area of Critical Environmental Concern for mountain 
plover (C. Knowles, in litt. 2001).
    Although range management activities may adversely affect some 
habitat for the mountain plover in specific instances, the complete 
absence of grazing causes mountain plover habitat to deteriorate. 
Therefore, we see grazing as necessary for the species, and not a 
threat to the species throughout its range.
Effects of the Decline of Burrowing Mammals on Mountain Plover Habitat
    The historic decline in abundance and distribution of prairie dogs 
likely contributed to the historic decline of the mountain plover 
(Knowles et al. 1982; S. Fitton, in litt. 1992; Knopf 1994). The 
mountain plover nests on active prairie dog colonies, principally those 
of the black-tailed prairie dog (Cynomys ludovicianus), throughout its 
breeding range, as prairie dogs maintain their preferred nesting 
habitat of low vegetation structure and a high percent of bare ground. 
Preliminary findings from Colorado suggest that mountain plover nesting 
success is higher on black-tailed prairie dog colonies than sites 
without prairie dogs (V. Dreitz and F. Knopf, in litt. 2002). Prairie 
dogs were widespread and numerous throughout the mountain plover's 
historic breeding range (Service 2002). Mountain plovers presently 
occupy prairie dog colonies in Colorado, Montana, Wyoming, Oklahoma, 
and New Mexico (Shackford 1991; Godbey 1992; Nelson 1993; Hawks Aloft 
2001b; M. Edwards, in litt. 1994; T. Thompson, in litt. 2003; Dinsmore 
2001). Montana, Wyoming, and Colorado likely comprised most of the core 
mountain plover breeding areas historically, and currently there are 
more mountain plovers associated with prairie dogs in those States. The 
suitability of prairie dog colonies as mountain plover habitat appears 
to be influenced by the individual colony size and prairie dog density 
(Knowles et al. 1982, Olson-Edge and Edge 1987, Dinsmore 2001). 
Therefore, total prairie dog acres is not a measure of total suitable 
mountain plover habitat available.
    Black-tailed prairie dogs have been reported to currently occupy 
about 256,000 ha (631,000 ac) in Colorado (Pusateri, CDOW, in litt. 
2002), 36,000 ha (90,000 ac) in Montana, and an estimated 50,000 ha 
(125,000 ac) in Wyoming (Luce 2003). In Phillips County, Montana, 99 
percent of the mountain plover nests found on survey transects were 
located on active prairie dog colonies (Dinsmore 2001). The largest 
population of mountain plovers in Montana (about 700 individuals) 
occurs on black-tailed prairie dog colonies in Phillips County, and 
mountain plover and prairie dog abundance are closely related there 
(Dinsmore 2001). Mountain plovers seem closely tied to active prairie 
dog colonies in Wyoming in the Powder River Basin, including Thunder 
Basin, particularly the Thunder Basin National Grassland. Mountain 
plovers are associated with black-tailed prairie dog colonies on the 
Pawnee National Grassland in northern Colorado (Nelson 1993; F. Knopf, 
in litt. 1999), in the Arkansas River Valley, and on the Comanche 
National Grassland in southeastern Colorado (K. Geisen, CDOW, in litt 
2001). A large population of mountain plovers nest in montane 
grasslands without prairie dogs in South Park in central Colorado 
(Wunder et al. in prep.). About 50 percent of the black-tailed prairie 
dog colonies in Colorado occur in nine southeastern counties, which 
also report numerous mountain plover sightings (Kingery 1998; L. 
Nelson, CDOW, in litt. 2002).
    Mountain plovers sometimes nest on white-tailed prairie dog 
colonies in Colorado, Wyoming, and Montana (P. Deibert, pers. comm. 
2003). Gunnison's prairie dogs occur at the periphery of the mountain 
plover breeding range in northern New Mexico and southern Colorado, and 
mountain plovers have been documented to nest on their colonies (5 out 
of 19 confirmed breeding sites on BLM lands in Taos County were on 
Gunnison prairie dog colonies (Hawks Aloft 2001b)). The geographic 
extent of mountain plover use of Gunnison colonies appears to be small, 
and limited information suggests no close dependence.
    Because mountain plovers have no ability to modify their 
environment to create suitable nesting conditions, the decline of 
prairie dogs can result in the loss of suitable nesting characteristics 
in only a few weeks (Dinsmore 2001).
    Outbreaks of sylvatic plague occur frequently throughout Montana, 
Wyoming, and Colorado on prairie dog colonies in the breeding range of 
the mountain plover. Sylvatic plague is an exotic disease to which 
prairie dogs have almost no immunity, although recent laboratory 
research indicates some isolated resistance to plague in black-tailed 
prairie dogs (Rocke, USGS, pers. comm. 2002). However, recently 
available population data across a majority of the species' range, that 
include many smaller populations (which represents the majority of all 
occupied habitat), indicate that occupied prairie dog habitat is more 
abundant and more stable than previously thought. The majority of 
black-tailed prairie dog populations occur in small, isolated complexes 
where the dynamics of disease appear to be fundamentally different than 
in larger populations. The reproductive and dispersal capabilities of 
the species, as indicated by the distribution, abundance, and trends 
data for the species, may be sufficient to counteract, at least 
partially, the impacts of a disease that occurs only sporadically in 
time and space (Service 2002).
    Prairie dog control, principally by poisoning, continues to occur 
on private and public lands throughout the mountain plover's breeding 
range, although the likelihood of control on public lands is minimized 
by Federal agency policies (Service 2002). Black-tailed prairie dog 
populations are capable of recovering rapidly from chemical control 
efforts that temporarily reduce their numbers (or from other depressant 
factors such as disease (Knowles 1986) or drought (Hoogland 1995)).
    Mountain plovers may vacate prairie dog colonies following plague 
or poisoning because of the rapid deterioration of habitat conditions 
(Dinsmore 2001), but we consider plague or prairie dog control to be a 
temporary impact on mountain plovers. For example, between 1992 and 
1996, prairie dog occupation of colonies in Montana's area of greatest 
prairie dog abundance was reduced by as much as

[[Page 53097]]

80 percent as a result of sylvatic plague (J. Grensten, pers. comm. 
1998). Mountain plover numbers along prairie dog transects in these 
colonies declined from 80 in 1991 to 7 in 1999, but have slowly 
increased since 1996 as prairie dog abundance has increased (S. 
Dinsmore, in litt. 2000a).
    Prairie dog shooting is popular throughout the breeding range of 
the mountain plover, and intense, persistent shooting of black-tailed 
prairie dogs has been shown to reduce prairie dog abundance, and 
perhaps prevent or retard recovery of colonies low in abundance due to 
sylvatic plague or poisoning (Vosburgh and Irby 1998; Knowles and 
Vosburgh 2001; L. Hanebury, pers. comm. 2003). We believe prairie dog 
shooting will continue to occur in areas occupied by mountain plovers. 
While it has the potential to degrade or prevent recovery of habitat 
and impact mountain plover breeding success, we believe those instances 
are localized and infrequent.
    New information made available this year from many State and 
Federal agencies indicates the quantity of occupied black-tailed 
prairie dog habitat has increased in the last several decades (Luce 
2003). Given the above summary of prairie dog habitat abundance, 
distribution, and threats and the subsequent impact on the mountain 
plover, we believe modification of prairie dog habitat is not a 
substantial threat to the mountain plover.
Oil, Gas, and Mineral Development in Mountain Plover Breeding Habitat
    The development of oil, gas, coalbed methane, and other mineral 
resources commonly occurs throughout the breeding range of the mountain 
plover. Expedited oil and gas development is a national priority, and a 
new interagency task force has been assembled to assist Federal 
agencies in their efforts to expedite review and completion of energy-
related projects on Federal lands (Executive Order 13212). However, we 
were able to find little documentation that this mineral resource 
development poses a current or future threat to mountain plovers.
    Numerous current BLM planning documents detail the number of wells, 
roads, and other facilities required to accommodate development of 
these mineral resources. A summary of these planning documents for 
Wyoming shows at least 10 authorized or proposed active natural gas and 
coalbed methane projects in known or potential mountain plover nesting 
habitat (e.g., Continental Divide/Wamsutter II Natural Gas Project, 
Seminoe Road Coal Bed Methane (CBM); Powder River Basin CBM) (P. 
Deibert, Service, in litt. 2003). Full build-out of these projects 
would result in over 50,000 individual wells, impacting up to 63,000 ha 
(155,000 ac), and creating nearly 32,000 km (20,000 mi) of new roads 
and 37,000 km (23,000 mi) of new pipelines (P. Deibert, in litt. 2002). 
Of these statistics, development of the Powder River Basin CBM alone 
will include nearly 40,000 wells and 27,000 km (17,000 mi) of new 
roads, affecting about 48,000 ha (118,000 ac) of lands (P. Deibert, 
Service, in litt. 2003). The Powder River Basin CBM project covers much 
of the black-tailed prairie dog habitat in Wyoming (K. Henke, pers. 
comm. 2003). In addition, there are about 14,000 coalbed methane wells 
proposed for the Powder River Basin in Montana (P. Deibert, in litt. 
2003). Numerous other projects (e.g., Bighorn Basin bentonite mine, 
Carbon Basin coal) are proposed or ongoing in Wyoming in areas occupied 
by mountain plovers (P. Deibert, in litt. 2003). In Wyoming, over 
12,000 coalbed methane wells were drilled by 2001, and the current 
development schedule established will result in nearly 40,000 
additional wells by 2011.
    Another example of increased energy development is Phase I of the 
SeaWest Wind Power Project in Wyoming. This wind farm is now 
operational and has disturbed 30 ha (70 ac) on the Foote Creek Rim 
Mesa, but final build-out calls for 667 to 1,000 wind turbines, that 
would permanently occupy 208 ha (515 ac) when complete.
    The development of oil, gas, and other energy resources requires 
construction of individual project pads, access roads, travel 
corridors, pipelines, power lines, and other facilities (Brockway 
1992). The degree of impact on mountain plovers from these activities 
depends on project size, density, frequency of maintenance and 
operation, and proximity to mountain plovers. However, the actual 
impact of this development on mountain plovers is unknown.
    Energy development has the potential to modify specific nesting, 
brood rearing, and foraging habitat characteristics, such as vegetation 
height, proportion of bare ground, prey density, and predator regimes 
(S. Dinsmore, Mississippi State University, in litt. 2003). Mountain 
plovers nest on nearly level ground and often near roads, adults and 
chicks often feed on or near roads, and roads may be used as travel 
corridors by mountain plovers, all of which make plovers susceptible to 
being killed by vehicles (McCafferty 1930, Laun 1957, Godbey 1992, 
Knowles and Knowles 2001), although we have no evidence that this has 
had an impact on mountain plover population levels.
    Energy development also results in soil disturbance, and because 
the mountain plover has been described as a ``disturbed prairie'' 
species (Knopf and Miller 1994), this disturbance could be inferred as 
benign or even beneficial to the species. The BLM has standards for 
revegetation of disturbed sites, and for control of invasive weed 
species along roads, well pads, and other disturbed sites. In the 
Powder River Basin of Wyoming, anticipated problems with invasive 
species induced by coalbed methane mining have not materialized to any 
significant extent (J. Carroll, pers comm. 2003).
    About 150 ha (370 ac) of mountain plover habitat at the Antelope 
Coal Mine in Converse County, Wyoming, have been affected by mining 
disturbance since 1982 (P. Deibert, pers. comm. 1999b). Mountain plover 
inventories conducted from 1982 to 2001 have documented the presence of 
mountain plovers and broods within and contiguous to the mine permit 
area. Although the number of broods on the mine permit area has 
declined since 1993, broods are still reported adjacent to the mine 
permit area (Thunderbird Wildlife Consulting, Inc. 2003). In Montana, a 
mountain plover nesting area near the Pryor Mountains in Carbon County 
was recently lost to bentonite mining (C. Knowles pers. comm. 2003). As 
many as 51 mountain plovers likely occurred on the Foote Creek Rim wind 
power project in Carbon County in southeastern Wyoming in 1994. The 
population there has now declined to about 26 (Johnson et al. 2000, 
Young and Erickson 2003). While we do not believe that mineral resource 
and wind farm development can be considered beneficial to mountain 
plovers, their combined impacts do not appear to pose a major threat.
    Our consideration of energy development as a listing factor in the 
proposed rules contributing to the potential decline of the mountain 
plover was based on the magnitude of anticipated development, as well 
as on information that existing projects have resulted, or are likely 
to result, in the modification of habitat required by nesting mountain 
plovers, and on enhanced opportunities for avian and terrestrial 
predators. However, because coalbed methane development, although 
widespread, has not been demonstrated to be detrimental to mountain 
plovers and because other types of energy development are more limited, 
we believe the current and anticipated mineral resource development in 
the

[[Page 53098]]

breeding range of the mountain plover is not a major threat to their 
continued existence.

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

    Prior to the passage of the Migratory Bird Treaty Act in 1918, 
mountain plovers were commercially hunted for food. However, this no 
longer occurs. Mountain plovers reside on some prairie dog colonies 
where recreational prairie dog shooting occurs. Although a few mountain 
plover mortalities have been attributed to shooting, this loss is not 
thought to be significant. There is no recent evidence that 
overutilization is a current threat.

Factor C. Disease or Predation

    Disease-related factors are not known to be a direct threat to the 
species. However, plovers that breed on prairie dog colonies are 
indirectly affected through a modification of habitat when an epidemic 
of sylvatic plague reduces numbers of prairie dogs in a colony (see 
discussion under Factor A).
    Mountain plovers eggs and chicks are the most vulnerable life 
stages to terrestrial and avian predation. Potential avian and 
terrestrial predators include the prairie falcon (Falco mexicanus), 
loggerhead shrike (Lanius ludovicianus), ravens (Corvus corax), swift 
fox (Vulpes velox), red fox, ground squirrels (Spermophilus spp.), and 
coyote (Canis latrans) (Graul 1975). Predation influences the 
productivity of all ground-nesting birds, and nesting success of less 
than 50 percent is not unusual. Predation on plover nests on the Pawnee 
National Grassland has ranged between 15 and 74 percent from 1969 to 
1994 (Graul 1975, Miller and Knopf 1993, Knopf and Rupert 1996). A high 
rate of nest predation by swift fox at the Pawnee National Grassland in 
1993 and 1994 may have been due to temporarily reduced alternate prey 
resources (Knopf and Rupert 1996).
    From 1994 to 2003, grasslands on the Pawnee National Grassland have 
been burned each year to enhance mountain plover nesting habitat (E. 
Humphrey, in litt. 2003). All eight nests monitored on the burn sites 
in 1996 were destroyed by swift fox (F. Knopf, in litt. 1996). 
Increased predation following burning, as indicated on the Pawnee 
National Grasslands, may affect nesting success locally in some years, 
but is not a persistent factor throughout the species' range. Nest 
predation also occurs in Phillips County, Montana, but is probably not 
a significant influence on nesting success at this location (Dinsmore 
2001).
    On December 17, 2002, we completed conferencing under the Act with 
the BLM for proposals to develop oil and gas resources in the Powder 
River Basin (M. Long, Service, in litt. 2003). We concluded that 
predation by mammalian and avian predators would increase with the 
development as proposed, and we recommended conservation measures to 
minimize adverse effects. Predation on the small number of nests in the 
Powder River Basin will not have an impact on the species rangewide.
    There is no evidence to indicate at this time that mountain plovers 
are affected by West Nile virus (Knopf pers. comm.).

Factor D. The Inadequacy of Existing Regulatory Mechanisms

    Protecting the mountain plover and its habitat is complicated by 
its wide geographic range, which includes private and public land, and 
numerous State, Federal, and Tribal Land authorities.

Federal Regulations

    One regulatory mechanism that currently protects the mountain 
plover is the Migratory Bird Treaty Act (MBTA), which prohibits direct 
mortality or the destruction of active nests. Other Federal laws that 
currently provide for conservation of mountain plovers include the 
Federal Land Policy and Management Act of 1976; National Forest 
Management Act of 1976; Federal Onshore Oil and Gas Leasing Reform Act; 
Federal Insecticide, Fungicide, and Rodenticide Act; and Federal 
Agriculture Improvement and Reform Act. Some Federal agencies such as 
the BLM or the Forest Service also have adopted policies to require 
that their actions not contribute to the declining status of a species.
    While Federal land ownership is not a guarantee of species 
conservation, Federal jurisdiction over surface resources can make 
application of conservation practices easier to implement. The BLM 
administers 13 percent of the mountain plover habitat (13,000 ha 
(27,000 ac)) in South Park, Park County, Colorado, where 20 percent or 
more of the entire mountain plover breeding population is estimated to 
occur. The BLM recently produced a conservation assessment to help 
guide implementation of future conservation measures for the mountain 
plover, including land exchange and consolidation (Granau and Wunder 
2001). In that assessment, the Reinecker Ridge State Wildlife Area in 
the central part of the county was identified as having excellent 
mountain plover breeding habitat and good conservation potential. It is 
already under public ownership, primarily through the BLM and Colorado 
State Land Board (Granau and Wunder 2001).
    The National Forest Management Act requires the Forest Service to 
manage habitats for native species. The Service has coordinated with 
the Forest Service for over a decade regarding the conservation needs 
of the mountain plover on the Pawnee National Grassland in Colorado. 
Mountain plovers are now nearly extirpated from this historic 
stronghold due to climatic events and changes in grazing management, 
and restoration of habitat has not been immediately forthcoming. 
Recently, the Forest Service initiated efforts to improve nesting 
habitat conditions on the Pawnee (Bedwell, in litt. 2003), although 
some recovery plans and recovery objectives will not be fully realized 
for several years (S. Currey, in litt. 2002).
    The Forest Service has closed the shooting season for black-tailed 
prairie dogs on the Thunder Basin National Grassland in Wyoming. While 
the reason for the closure was recovery of the endangered black-footed 
ferret, the mountain plover stands to gain habitat as prairie dogs 
there recover from an epizootic of sylvatic plague.
    Two small National Wildlife Refuges (Kern and Pixley) in The San 
Joaquin Valley and Carrizo Plain provide some natural and cropland 
habitat for wintering mountain plovers (J. Engler, in litt. 1992, 2003; 
Knopf and Rupert 1995), although they are not managed specifically for 
mountain plovers and some of the former potentially suitable grassland 
and shrubland on Kern National Wildlife Refuge has been overwhelmed 
with exotic grasses and saltcedar (J. Engler, in litt. 2003). The BLM, 
California Department of Fish and Game, and The Nature Conservancy have 
developed a management plan for the Carrizo Plain Natural Area that 
calls for grazing a 1,850-ha (4,640-ac) BLM allotment by sheep in a 
manner that would encourage use by mountain plover (BLM et al. 1995). 
Prescribed burning also is called for in the plan and has been 
demonstrated to encourage use by mountain plovers (Knopf and Rupert 
1995).

International Mechanisms

    The mountain plover is designated as a threatened species by Mexico 
(S. Jewell, Service, in litt. 2000) a designation that has begun to 
provide some awareness of the need for the species' conservation. 
Mexico currently has no regulations to protect the habitat of the 
mountain plover. The species also

[[Page 53099]]

was designated as endangered by Canada in 1987, a status that was 
confirmed in 2000 (Committee on the Status of Endangered Wildlife in 
Canada 2000).
    A Memorandum of Understanding between Canada, Mexico, and the 
United States was established to enhance coordination and partnerships 
regarding conservation of wildlife, plants, biological diversity, and 
ecosystems of mutual interest. The Memorandum of Understanding 
established the Trilateral Committee for Wildlife and Ecosystem 
Conservation and Management to develop and implement cooperative 
conservation projects within the three countries. This Committee has 
evaluated opportunities for shared conservation efforts on many 
species, including the mountain plover.

State Regulations

    The mountain plover is now classified as threatened in Nebraska, a 
``species of special interest or concern'' in California, Montana, and 
Oklahoma, a ``species in need of conservation'' in Kansas, and a ``high 
priority species of concern'' in New Mexico (Flath 1984; Sager 1996; E. 
Hunt, California Department of Fish and Game, in litt. 1990; Nebraska 
Game and Parks Commission 1992; Oklahoma Department of Wildlife 
Conservation 1992; Kansas Department of Wildlife and Parks 1992). 
States other than those identified above have not given the mountain 
plover any special designation. State listing can encourage State 
agencies to use existing authorities to conserve species and habitats, 
stimulate research, and allow redirection of priorities within State 
natural resource departments.
    State agencies within the range of the mountain plover have 
recently completed ``A Multi-State Conservation Strategy for the Black-
tailed Prairie Dog in the U.S.'' (Luce 2003) to pursue conservation of 
the black-tailed prairie dog through regulations or provision of 
incentives to landowners for maintaining prairie dog colonies. The sale 
of rodenticide within the mountain plover's breeding range has 
increased in recent years and prairie dog shooting also is popular 
throughout the range of the mountain plover. No State regulations limit 
prairie dog poisoning, but prairie dog shooting is regulated in some 
areas. Colorado has banned prairie dog sport shooting on all public 
lands and under most circumstances on private lands; Montana has 
adopted a seasonal closure of prairie dog shooting on public lands, and 
there are no restrictions on shooting prairie dogs in Wyoming, except 
on the Thunder Basin National Grassland where shooting is banned.
    The State of Colorado, in which a majority of the species' breeding 
range occurs, has initiated a program to conserve the mountain plover 
and its habitat, by reducing their vulnerability while they occupy 
cultivated lands, educating the public, and conserving grasslands that 
are known or potential breeding habitat (T. Blickensderfer, Colorado 
Department of Natural Resources, in litt. 2003). In 2003, the CDOW 
spent $263,000 to conduct research and monitoring on public and private 
lands occupied by mountain plovers, create an educational video, and 
implement a ``1-877-4PLOVER'' number to help reduce the ``take'' of 
mountain plovers on cultivated lands in Colorado and contiguous States. 
The CDOW also has created the Colorado Species Conservation Partnership 
program. The purpose of the program is to implement conservation 
actions on private and public lands throughout Colorado to ensure that 
the status of declining and at-risk species is improved to a level that 
will prevent their listing under the Act. The CDOW is pursuing mountain 
plover conservation under this program by recommending that $2 million 
be dedicated to long-term conservation agreements on private lands that 
may be occupied by mountain plovers. The initial sign-up for this 
effort resulted in applications for conservation easements for over 
60,704 ha (150,000 ac) of private shortgrass prairie in eastern 
Colorado that would cost $14,600,000. The CDOW is pursuing partnerships 
to implement these conservation easements, and is optimistic that more 
funding will be provided in future years (R. George, in litt. 2003).
    The Nebraska Game and Parks Commission working with the Rocky 
Mountain Bird Observatory has initiated a similar landowner incentive 
program called the Shortgrass Prairie Partnership (Holliday 2003) and 
funded in 2003 for over $500,000. It is in the first stages of 
implementation. While both the Colorado and Nebraska programs are 
voluntary habitat conservation programs, both wildlife agencies have 
the authority to initiate, fund, and implement them. These conservation 
efforts are new but have shown some initial successes and are likely to 
provide a significant level of protection for the mountain plover, 
especially in eastern Colorado.
    In California, the species is listed as a species of special 
concern. In the following discussion, we describe the regulatory 
mechanisms in California on a county-level basis.
    Three counties in California are drafting Habitat Conservation 
Plans (HCPs) with the Service to protect listed and declining species, 
including the mountain plover. With the development of the Western 
Riverside County Multiple Species HCP (MSHCP), the County of Riverside 
and other jurisdictions within Riverside County and California have 
requested an incidental take permit under section 10(a)(1)(B) under the 
Act for up to 164 covered species, including the mountain plover. The 
permit is needed to authorize take of listed species during urban and 
rural development, and agricultural activities in the approximately 
509,904-ha (1.26 million-ac) study area in western Riverside County. 
The county and other jurisdictions propose in their conservation 
strategy to conserve, monitor, and manage 85 percent of the potential 
plover wintering habitat (i.e., 2,715 of 3,185 ha (6,710 of 7,870 ac)) 
in the county. The Service is now assessing the effect of the MSHCP and 
the associated incidental take permit on the mountain plover and other 
species proposed for coverage.
    Similarly, a San Joaquin County HCP finalized in November 2000 
targets the protection of over 40,469 ha (100,000 ac) of habitat for 92 
species, including the mountain plover, following adoption of enabling 
ordinances and/or resolutions by local agencies. A similar HCP for 
Solano County, which includes protection of potential mountain plover 
habitat, is being drafted, but is not yet finalized.
    In summary, Federal, State, and county agencies and governments 
have taken significant proactive steps, in the absence of listing, and 
have shown progress in the conservation of mountain plovers and their 
habitat.

Factor E. Other Natural or Manmade Factors Affecting Its Continued 
Existence

Natural Factors
    Because mountain plovers congregate in large flocks on the 
wintering grounds, they may be more vulnerable to local catastrophic 
events there. For example, winter surveys in the Imperial Valley in 
February 2003 were cut short when heavy rains fell and the flocks of 
mountain plovers disappeared. It is speculated that the birds left 
their wintering grounds early or moved to less suitable habitats in the 
Central Valley (F. Knopf, in litt., 2003). The former appears more 
likely since the CBC for the area (Salton Sea South) had a record low 
number of plovers, while the Panoche Valley count to the north

[[Page 53100]]

had far greater numbers than usual (birdsource.org 2003).

Pesticide Application and Exposure

    Grasshoppers occur throughout the breeding range of the mountain 
plover and can reach population levels considered a threat to 
agriculture. The APHIS (2002) has authorized rangeland grasshopper and 
Mormon cricket control in areas occupied by mountain plovers. Dimilin, 
malathion, and carbaryl are the identified chemicals when grasshoppers 
reach economic thresholds (APHIS 2002). Control on private lands can be 
undertaken by State agencies or private landowners without 
participation or oversight by APHIS.
    The emphasis of the rangeland grasshopper control program is to 
reduce rather than eliminate grasshoppers, but effects to nontarget 
insects also occur. The effects of treatment are immediate, and some 
treatments can depress insect populations into the second year (APHIS 
2003). Grasshoppers and other insects are major prey items of mountain 
plovers, and control may influence mountain plover productivity (Graul 
1973, Knopf 1996b, Knopf and Rupert 1996). In conferring under section 
7 of the Act on the effects of treatments on mountain plover, we 
concluded that the application of rangeland grasshopper control as 
described by APHIS (2002) on mountain plover breeding habitat could 
result in reduced prey, greater foraging distances, increased chick 
predation, and reduced survival (W. Knapp, Service, in litt. 2002; R. 
Williams, Service, in litt. 2003).
    In Montana, grasshopper control is authorized to occur in 2003 on 
both public and private lands (APHIS 2003). Because APHIS, in 
conference with the Service, has agreed to treatments that will avoid 
active black-tailed prairie dog colonies and because mountain plovers 
in Montana are closely associated with black-tailed prairie dog 
colonies, we believe that treatments are not likely to threaten the 
plover there. Similarly, in Wyoming, planning is underway to authorize 
grasshopper control on BLM lands throughout Wyoming. After conferring 
with the Service, APHIS has agreed to avoid prairie dog colonies and to 
avoid known mountain plover nesting sites not associated with prairie 
dog colonies (K. Dickerson, Service, pers. comm. 2003). Control on 
private lands can be undertaken by State agencies or private landowners 
without participation or oversight by APHIS or the Service. While 
control of grasshoppers and other pests on private lands may pose a 
threat, we do not believe that it is of a magnitude or immediacy that 
warrants listing the species.
    Mountain plovers may be exposed to pesticides while they occupy 
winter habitat in California (Knopf 1996). In conferring under section 
7 of the Act, we concluded that malathion application to control curly-
top virus in the Imperial and San Joaquin Valleys would harass some 
wintering mountain plovers, but the timing and location of treatment 
was not likely to result in direct exposure, or significant impacts to 
mountain plover prey (W. White, Service, in litt. 2001b). More 
recently, the California Department of Fish and Game conducted an 
assessment of exposure risk in Imperial County, specifically, by 
comparing mountain plover presence in the Valley with crop types 
predominately used by them, and the pesticides typically applied to 
these crops (B. Hosea, California Department of Fish and Game, in litt. 
2003; Wunder and Knopf 2003). This information suggests that direct 
exposure to mountain plovers is reduced because application of 
pesticides occurs when plovers are not using the fields. For example, 
insecticides are usually applied to alfalfa fields when the alfalfa is 
too high to be attractive to mountain plovers. Also, insecticides are 
not applied while livestock are grazing fields to minimize pesticide 
exposure to livestock, and pre-planting herbicides are usually 
incorporated into the soil as a granular form, thus reducing exposure 
risk. Potential impacts to the mountain plover prey base on the 
wintering grounds are not known, but also appear to be minimal for 
reasons cited above (B. Hosea, in litt. 2003). Pesticide exposure by 
aerial drift is likely due to mosaic cropping patterns, but effects to 
mountain plovers are unknown.
    A review of exposure to organochlorines, selenium, and heavy metals 
showed that concentrations in mountain plovers were below thresholds 
that cause population-level effects (A. Archuleta, Service, in litt. 
1997). More recently, the Service analyzed pesticide levels in 20 
mountain plover eggs collected from Colorado and 4 from Montana. 
Dichlorodiphenyldichloroethylene (DDE) levels were detected in all 
eggs; in four eggs levels were above those known to be detrimental to 
other bird species (K. Dickerson, Service, in litt. 2002). While the 
levels detected in the mountain plover eggs may have been influenced by 
prolonged storage prior to analysis, the results nonetheless suggest 
that mountain plovers may be at risk from organochlorine pesticide 
exposure (K. Dickerson, Service, pers. comm. 2003). The DDE is a 
metabolite of dichlorodiphenyltrichloroethane (DDT), known to be 
responsible for eggshell thinning, and is extremely persistent in the 
environment. In addition, a recent investigation found a wide disparity 
in cholinesterase levels between mountain plovers collected in the 
Central Valley (pesticide use widespread) compared to those from the 
Carrizo Plain (pesticide use minimal), but no differences in mountain 
plover body condition (Iko, et al. 2003).

Status Summary

    The species was proposed in 1999 and 2002 as threatened because the 
best information available at that time indicated breeding population 
declines and loss of habitat due to a variety of factors, including 
agricultural practices, prairie dog declines, and grassland conversion. 
Research on some of these issues, reanalysis of old data, and new 
information obtained in the last year lead us to conclude that the 
threats to the species are such that listing is not warranted.
    There is no information to document that the mountain plover 
population is declining or will be in danger of extinction in the 
foreseeable future. The declines apparent in the BBS data turned out to 
be statistically insignificant. The CBC data in California are 
tremendously variable, but suggest a slow downward trend, whereas 
surveys on the wintering grounds by researchers do not demonstrate 
declines. Although there are many specific instances of grassland 
conversion destroying plover nesting habitat, nesting habitat does not 
appear to be limiting. Occupied prairie dog habitat is more abundant 
and more stable than previously thought, providing breeding and nesting 
habitat for plovers. Nesting appears to be equally successful on 
croplands as on native grassland. Distribution of plovers across the 
wintering range appears to depend more on annual farming practices and 
weather rather than on permanent habitat destruction.
    In the last few years, Federal land management agencies and State 
and county governments have become more actively involved in mountain 
plover management. In 1994, the Forest Service developed a ``Mountain 
Plover Management Strategy'' for the Pawnee National Grassland in 
Colorado. We believe formalized conservation efforts by the CDOW will 
improve the status of the mountain plover in Colorado. Other new 
conservation efforts within the breeding range include the recently-
established Federal, State, and private High Plains Partnership; the 
Department of Defense's Integrated Natural Resource Management Plan for 
Fort Carson,

[[Page 53101]]

Colorado; the Rocky Mountain Bird Observatory's ``Prairie Partners''; 
The Nature Conservancy's ``Prairie Wings''; and private land 
conservation easement efforts in South Park, Colorado.
    Other potential conservation measures for this species include--
implementing grazing plans that encourage high grazing intensity in 
plover nesting areas, revising county bulletins to include specific 
protective measures for the mountain plover during pesticide 
application, conducting haying and grazing on existing CRP tracts to 
manage for the grass height and density required by nesting plovers, 
providing seeding criteria for new CRP tracts that would encourage 
establishment of native shortgrass prairie species in preference to 
taller grasses, and providing incentives to landowners to leave 
cultivated areas unplanted until plover eggs have hatched and chicks 
are able to escape from machinery. We have initiated discussions with 
the NRCS to explore ways, such as through the Conservation Reserve 
Enhancement Program, that these measures might be implemented on 
private land.
    Following our above analysis and discussion, we have determined 
that the action of listing the mountain plover as threatened throughout 
its range as proposed in 1999 and 2002 is not warranted. We have made 
this determination because the threats to the species, as identified in 
the previous proposed rules, are not as significant as earlier 
believed, and current available information does not indicate that the 
threats to the species and its habitat are likely to endanger the 
species in the foreseeable future throughout all or a significant 
portion of its range. Consequently, we withdraw our 1999 and 2002 
proposed rules and our 2002 proposed special rule for the mountain 
plover.

References Cited

    You may request a complete list of all references cited in this 
document, as well as others, from the Assistant Field Supervisor at the 
Grand Junction, Colorado, Field Office (see ADDRESSES).

    Dated: September 3, 2003.
Marshall P. Jones, Jr.,
Acting Director, Fish and Wildlife Service.
[FR Doc. 03-22860 Filed 9-8-03; 8:45 am]
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