[Federal Register Volume 75, Number 169 (Wednesday, September 1, 2010)]
[Proposed Rules]
[Pages 53615-53629]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2010-21774]


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DEPARTMENT OF THE INTERIOR

Fish and Wildlife Service

50 CFR Part 17

[FWS-R2-ES-2009-0039]
[MO 92210-0-0008]


Endangered and Threatened Wildlife and Plants; 12-Month Finding 
on a Petition to List the White-Sided Jackrabbit as Threatened or 
Endangered

AGENCY: Fish and Wildlife Service, Interior.

ACTION: Notice of 12-month petition finding.

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SUMMARY: We, the U.S. Fish and Wildlife Service (Service), announce a 
12-month finding on a petition to list the white-sided jackrabbit as 
endangered and to designate critical habitat under the Endangered 
Species Act of 1973, as amended. After review of all available 
scientific and commercial information, we find that listing the full 
species, Lepus callotis, is not warranted at this time. We further find 
that listing one or both of the subspecies, Lepus callotis callotis and 
Lepus callotis gaillardi, is not warranted at this time. We find that 
listing the northern populations of the subspecies L. c. gaillardi as a 
Distinct Population Segment is not warranted at this time. However, we 
ask the public to submit to us any new information that becomes 
available concerning the threats to the full species of the white-sided 
jackrabbit, or to either of the two currently recognized subspecies, or 
the species' habitat at any time.

DATES: The finding announced in this document was made on September 1, 
2010.

ADDRESSES: This finding is available on the Internet at http://www.regulations.gov at Docket Number FWS-R2-ES-2009-0039. Supporting 
documentation we used in preparing this finding is available for public 
inspection, by appointment, during normal business hours at the U.S. 
Fish and Wildlife Service, New Mexico Ecological Services Field Office, 
2105 Osuna NE, Albuquerque, NM 87113. Please submit any new 
information, materials, comments, or questions concerning this finding 
to the above address.

FOR FURTHER INFORMATION CONTACT: Wally Murphy, Field Supervisor, New 
Mexico Ecological Services Field Office, 2105 Osuna NE, Albuquerque, NM 
87113; by telephone at 505-346-4781; or by facsimile at 505-346-2542. 
If you use a telecommunications device for the deaf (TDD), please call 
the Federal Information Relay Service (FIRS) at 800-877-8339.

SUPPLEMENTARY INFORMATION:

Background

    Section 4(b)(3)(B) of the Endangered Species Act of 1973, as 
amended (Act) (16 U.S.C. 1531 et seq.), requires that, for any petition 
to revise the Federal Lists of Endangered and Threatened Species that 
contains substantial scientific or commercial information that listing 
the species may be warranted, we make a finding within 12 months of the 
date of receipt of the petition. In this finding, we will determine 
that the petitioned action is: (1) Not warranted, (2) warranted, or (3) 
warranted, but the immediate proposal of a regulation implementing the 
petitioned action is precluded by other pending proposals to determine 
whether species are threatened or endangered, and expeditious progress 
is being made to add or remove qualified species from the Federal Lists 
of Endangered and Threatened Species. We must publish this 12-month 
finding in the Federal Register.

Previous Federal Action

    On October 15, 2008, we received a petition dated October 9, 2008, 
from WildEarth Guardians requesting that the white-sided jackrabbit 
(Lepus callotis) be emergency listed as endangered under the Act and 
critical habitat be designated. Included in the petition was supporting 
information regarding the species' taxonomy and ecology, historical and 
current distribution, present status, and actual and potential causes 
of decline. We acknowledged the receipt of the petition in a letter to 
WildEarth Guardians, dated November 26, 2008. However, emergency 
listing a species is not a petitionable action under the Act or the 
Administrative Procedure Act (APA; 5 U.S.C. Subchapter II), and is 
treated solely as a petition to list. In our letter we also stated that 
we had reviewed the petition and determined that available information 
did not indicate that the species was at significant risk of well-
being, thereby necessitating the need to provide the temporary 
protections under section 4(b)(7)the Act (i.e., emergency listing). In 
our letter, we advised the petitioner that, to the maximum extent 
practicable, we would address the petition within 90 days. During our 
review of the petition, we found that the majority of information cited 
in the petition was not readily available to us. Therefore, on January 
13, 2009, we requested that the petitioner provide additional 
references. On February 13, 2009, the petitioner provided references. 
We received a 60-day notice of intent to sue from the petitioner dated 
January 28, 2009, and on April 15, 2009, the petitioner brought a 
lawsuit against us for failure to respond to the petition within 90 
days of its receipt. On July 22, 2009, we published a 90-day finding 
indicating that the petition presented substantial information that 
listing the jackrabbit may be warranted, and initiated a status review 
(74 FR 36152). This notice constitutes the 12-month finding on the 
October 9, 2008, petition to list the white-sided jackrabbit as 
endangered.
    The white-sided jackrabbit was first listed as a candidate 
(Category 2) for Federal listing as either a threatened or endangered 
species under the Act in the 1982 Candidate Notice of Review (47 FR 
58454, December 30, 1982). Category 2 status included those taxa for 
which information in the Service's possession indicated that a proposed 
listing rule was possibly appropriate, but for which sufficient data on 
biological vulnerability and threats were not available to support a 
proposed rule. In the Candidate Notice of Review published on February 
28, 1996, we announced a revised list of animal and plant taxa that 
were regarded as candidates for possible addition to the

[[Page 53616]]

Lists of Endangered and Threatened Wildlife and Plants (61 FR 7595). 
The revised candidate list included only former Category 1 species. All 
former Category 2 species were dropped from the list to reduce 
confusion about the conservation status of these species and to clarify 
that the Service no longer regarded these species as candidates for 
listing. Because the white-sided jackrabbit was a Category 2 species, 
it was no longer recognized as a candidate species.
    The petition requests that we list the full species of the white-
sided jackrabbit, Lepus callotis, as threatened or endangered. The 
petition also requests that we list each of the recognized subspecies 
of the white-sided jackrabbit, Lepus callotis callotis and Lepus 
callotis gaillardi as threatened or endangered, should we conclude that 
the full species does not warrant listing, and the petition states that 
these recognized subspecies are taxonomically valid. The petition 
further requests that we list the northern populations of the 
subspecies currently recognized as L. c. gaillardi as a distinct 
population segment under the Act. We will examine each of these 
requests separately below.

Species Information: Lepus callotis

Taxonomy and Species Description

    There has been some dispute and inconsistency regarding the 
taxonomy of the species and its subspecies, and much of the literature 
remains inconclusive. In his book, Wildlife of Mexico: The Game Birds 
and Mammals, Leopold (1959, p. 345) included four species of 
jackrabbits under his description of the common name ``white-sided 
jackrabbits'': Lepus alleni, Lepus gaillardia, Lepus callotis, and 
Lepus flavigularis. In their 1962 paper, A Classification of the White-
sided Jackrabbits of Mexico, Anderson and Gaunt concurred with Leopold 
and others in the existence of four species, with non-overlapping 
geographic ranges, assigned the common name ``white-sided jackrabbit'' 
(Anderson and Guant 1962, p. 1). The authors later state that they 
regard each of the previously recognized species, Lepus callotis and 
Lepus gaillardi, as conspecific, or separate subspecies of the same 
species (that is, Lepus callotis callotis and Lepus callotis gaillardi) 
(Anderson and Guant 1962, p. 1). There are no recognized common names 
for these subspecies.
    The white-sided jackrabbit, Lepus callotis, occurs in New Mexico 
and in Mexico (see Figure 1 below). It is one of four species of hares 
(family Leporidae) that occurs in New Mexico (Findley et al. 1975), and 
one of 15 species occurring throughout the states of Mexico (Lorenzo et 
al. 2003, p. 11). The white-sided jackrabbit can be distinguished from 
other hares by its extensive white sides and inconspicuous or absent 
black ear tips, as well as differences in features of the skull 
(Findley et al. 1975, pp. 92, 96; Best and Henry 1993, p. 1; Anderson 
and Guant 1962, pp. 1-2). The species has black on the upper parts of 
its tail and the back and flanks are white (Lorenzo et al. 2003, p. 
11).
BILLING CODE 4310-55-S

[[Page 53617]]



 
   Figure 1. Map of the range of the white-sided jackrabbit. (Based on
                        Anderson and Gaunt 1962.)
 
 
 

[GRAPHIC] [TIFF OMITTED] TP01SE10.001

BILLING CODE 4310-55-C
    There is limited discussion in the literature regarding the 
distinctions between the two subspecies, Lepus callotis callotis and 
Lepus callotis gaillardi. Anderson and Gaunt (1962, pp. 2-5) compared 
specimens from each of the subspecies and recorded the following 
differences: L. c. gaillardi has paler and coarser coat, including the 
fringe of hair along the inner margin of the ear, the throat patch, and 
the hue of dorsal cover hairs. Specimens of this subspecies also have 
paler rump patches that contrast less with the whitish flanks and paler 
patches on the shoulders that tend to contrast with (rather than match 
or blend with) the darker middorsal pelage (fur). The authors also 
observed differences between the two subspecies in skull structure.
    Studies have been conducted to determine the genetic relationship 
between species within the genus Lepus (Lorenzo et al. 2003); however, 
we are not aware of any information that establishes the genetic 
distinctiveness of the two subspecies Lepus callotis callotis and Lepus 
callotis gaillardi. Although the literature is inconclusive, we have 
not encountered any information which indicates that the

[[Page 53618]]

subspecies L. c. callotis and L. c. gailllardi are not taxonomically 
valid. Therefore, we consider L. c. callotis and L. c. gaillardi to be 
valid subspecies of the species L. callotis.

Biology

    In the white-sided jackrabbit, females are generally larger than 
males (Bednarz 1977, pp. 13, 15). In New Mexico, white-sided 
jackrabbits are observed almost unvaryingly in pairs (Bednarz 1977, p. 
9), suggesting that mated animals remain together on a long-term basis. 
Pair bonds may serve to ensure adequate reproduction, in the context of 
generally low population density (Bednarz 1977, p. 12). The members of 
the pair are usually near each other and run together when approached 
by intruders (Bednarz 1977). Several litters are probably produced each 
year, with litter size appearing to average 2.2 young (Bednarz 1977, p. 
12). The young tend to have a soft, woolly coat in early life and 
attain sexual maturity at a rapid rate. Daytime observations of white-
sided jackrabbits are uncommon, as the species is primarily nocturnal 
(Bednarz 1977, pp. 6-11; Best and Henry 1993, p. 5). Although many 
species of jackrabbit and hare are considered pests because they may 
damage crops, fields, and orchards, the white-sided jackrabbit is not 
known to depredate crops.

Distribution

    The core distribution of the white-sided jackrabbit lies within 
Mexico (New Mexico Department of Game and Fish (NMDGF) 2006a, p. 114). 
The species historically occurred from southern New Mexico to northern 
Oaxaca, Mexico, within two distinct geographic areas (Best and Henry 
1993, p. 2). These two distinct geographic areas are occupied by each 
of the two subspecies. The historical range of the subspecies Lepus 
callotis gaillardia includes the southern Animas and Playas valleys of 
Hidalgo County, New Mexico, south into west-central Chihuahua and 
north-central Durango, Mexico (Bednarz and Cook 1984, p. 358; Reynolds 
1988, p. 1), although it is now likely extirpated from the Playas 
Valley as no observations of the species have been made in this area 
during more recent surveys (Traphagen 2002, p. 5; Frey 2004, p. 22; 
NMDGF 2006a, p. 115; Traphagen 2010, p. 1). The other subspecies, Lepus 
callotis callotis, ranges from central Durango south across the open 
plains of the Mexican Plateau to the State of Oaxaca, Mexico (Hall 
1981, p. 330). The geographic separation of the two areas occurs on 
either side of the Rio Nazas in Durango, Mexico. This river has been 
observed to act as a barrier and a catalyst for subspeciation in many 
mammal species, isolating one subspecies to the north of the river from 
the other to the south (Peterson 1976, pp. 496-498).
    The jackrabbit's historical range in the Animas and Playas Valleys 
of New Mexico occurs entirely within the Diamond A Ranch (Traphagen 
2010, p. 3) and was estimated to be about 121 square kilometers (sq km) 
(47 square miles (sq mi)), or approximately 12,000 hectares (ha) 
(30,000 acres (ac)) (Bednarz 1977, p. 6; Bednarz and Cook 1984, p. 
359). We are unaware of any similar estimates for the jackrabbit's 
range in Mexico. However, utilizing Geographic Information System (GIS) 
techniques and assessing the range maps of Anderson and Gaunt (1962, p. 
4) and Hall (1981, p. 330), we estimate the range of the jackrabbit in 
the United States to be less than one percent of the entire range of 
the species.
    The white-sided jackrabbit has not been confirmed as extant in 
Arizona (Cahalane 1939, p. 436), although in 1954, Hoffmeister and 
Goodpaster reportedly observed what they believed to be white-sided 
jackrabbits along the west base of the Huachuca Mountains, Cochise 
County, Arizona (Hoffmeister 1986, p. 562). There have been other, more 
recent reported sightings of the white-sided jackrabbit in Arizona; 
however, these have been refuted by experts on the species (Traphagen 
2009). Therefore, New Mexico is the only confirmed state in the United 
States where the species has been documented to occur.

Habitat

    This species is highly elusive. It inhabits predominately mature 
open grasslands that have low shrub density and level terrain, avoiding 
hills or mountains (Bednarz and Cook 1984, p. 359; Cook 1986, p. 15; 
Desmond 2004, p. 416). In the United States portion of its range, the 
white-sided jackrabbit appears to be found only in association with 
grasslands (Bednarz 1977, p. 6). More than 97 percent of all 
observations of this species have been in pure grasslands and less than 
3 percent in grasslands with varying amounts of forbs (flowering herbs) 
and shrubs (Bednarz and Cook 1984). In New Mexico, white-sided 
jackrabbits feed primarily on Bouteloua gracilis (blue grama), Buchloe 
dactyloides (buffalograss), Bouteloua eripoda (black grama), and 
Lycurus phleoides (wolftail) (Bednarz 1977, pp. 14, 16). In New Mexico, 
the white-sided jackrabbit was historically limited to two valleys, the 
Animas Valley and the Playas Valley, that differ in their vegetative 
composition. A detailed description of each follows.
    The Animas Valley is a confined basin that lies 10 km (6 mi) west 
of the continental divide. The elevation is approximately 1,550 meters 
(m) (5,085 feet (ft)). It is bounded on the east by the Animas 
Mountains, on the west by the Peloncillo Mountains, and on the south by 
the Sierra San Luis Mountains. The International Boundary between the 
United States and Sonora, Mexico, lies near the southern terminus of 
the valley. Precipitation averages about 381 millimeters (mm) (15 
inches (in)) annually, 60 percent of it falling between July and 
October. A large portion of the lower Animas Valley lies in a dry 
Pleistocene (the epoch that spanned from 2.6 million to 12,000 years 
ago) lakebed, parts of which fill seasonally to shallow depths of a few 
centimeters. Soil moisture is therefore sufficient to support a 
moderate amount of wetland vegetation, namely nutgrass (Cyperus 
rotundus), a plant that is thought to be a seasonally important food 
source for the jackrabbit (Bednarz 1977, p. 14).
    The lower Animas Valley supports a variety of grass and forb 
species, such as blue grama; Bouteloua curtipendula (sideoats grama); 
Sporobolus airoides (alkali sacaton); Muhlenbergia torreyii (ring 
muhly); Pleuraphis mutica, also known as Hilaria mutica (tobosa); 
buffalograss; black grama; wolftail; Muhlenbergia repens (creeping 
muhly); Panicum obtusum (vine mesquite); Aristida spp. (three-awn), 
Sphaeralcea spp. (globemallow); Gutierrezia sarothrae (broom 
snakeweed); Viguera annuum (goldeneye); Eriogonum wrightii (Wright 
buckwheat); and Aster spp. The occurrence of this specific grassland 
association, known as plains grassland, is uncommon and fairly unique 
in the southwestern United States, although it becomes more common 
south into Chihuahua and northern Durango, Mexico (Traphagen 2009, p. 
2). The southern Animas Valley is largely free of shrubs, probably as a 
function of soil structure, water drainage in soils, frequent fires, 
and cold air drainage. The Animas Valley is surrounded by several large 
mountain ranges that create winter microclimates too cold to support 
the establishment of shrubs such as mesquite (Prosopis spp.), cholla 
(Cylindroopuntia spp.), and creosote (Larrea spp.), which are not able 
to tolerate the cold winter nights (Traphagen 2009, p. 2).
    McKinney Flats lies 10 km (6 mi) east of the Continental Divide in 
the western fork of the southern Playas Valley just west of the 
Whitewater Mountains. This 4,266-ha (10,240-ac) site is about 1,525

[[Page 53619]]

m (5,000 ft) above sea level. Bednarz (1977) estimated the area of 
suitable habitat for Lepus callotis on McKinney Flat to be 1,425 ha 
(3,520 ac). Conditions on McKinney Flat are drier than in the Animas 
Valley, averaging about 228 mm (9 in) annual precipitation. McKinney 
Flat is characterized as Chihuahuan desert grassland (Traphagen 2009, 
p. 2). Shrub invasion in this grassland association has occurred on a 
much larger scale than in the plains grassland association that exists 
in the Animas Valley (Traphagen 2009, pp. 2-3).
    Graminoid species in the Playas Valley include blue grama, sideoats 
grama, Eragrostis intermedia (plains lovegrass), tobosa, Bouteloua 
hirsuta (hairy grama), Scleropogon brevifolia (burrograss), Setaria 
machrostachya (Plains bristlegrass), black grama, wolftail, creeping 
muhly, vine mesquite, Bothrichloa barbinodis (cane beardgrass), and 
three-awn; commonly found forbs are Solanum eliaginifolium (horse 
nettle), Wright buckwheat, various Croton spp., and Aster spp. are 
commonly found forbs. Shrubs and trees such as honey mesquite (Prosopis 
glandulosa), soaptree yucca (Yucca elata), catclaw mimosa (Mimosa 
biuncifera), and various prickly pear (Opuntia spp.) and cholla 
(Cylindroopuntia spp.) are also present.
    We have little information pertaining to the habitat of the white-
sided jackrabbit in Mexico. The primary biotic province in which the 
jackrabbit occurs is termed the Chihuahua-Zacatecas biotic province. 
This province covers the northern interior plains in Chihuahua, western 
Coahuila, Durango, Zacatecas, San Luis Potosi, and Aguascalientes 
(Goldman and Moore 1945, p. 354). It is an arid interior desert region 
consisting mainly of grassland plains interrupted by areas overgrown by 
various shrub species (Goldman and Moore 1945, p. 354). The range of 
the jackrabbit also falls within the biotic provinces termed the 
Transverse Volcanic biotic province and the Sierra Madre del Sur biotic 
province. The Transverse Volcanic biotic province spans parts of 11 
States and its diverse environmental and geographic features cannot be 
generalized; however, it includes areas of grasslands interspersed with 
shrubland (Goldman and Moore 1945, pp. 356-357). The Sierra Madre del 
Sur biotic province includes high mountain areas ranging from west to 
east through central Guerrero and the interior valleys of central and 
western Oaxaca. The climate is similar to that of the plateau of the 
northern portion of the country (Goldman and Moore 1945, p. 358). 
Although Goldman and Moore describe the major habitat types within 
Mexico, we have no information regarding the specific habitats occupied 
by the jackrabbit within these broad habitat types.

Population Abundance

    The white-sided jackrabbit has never been known to be abundant in 
the United States. The species was first discovered in New Mexico by 
Mearns in 1892 during surveys of the International Border between the 
United States and Mexico (Mearns 1895, p. 552). Specimens were not 
collected again in New Mexico until 1931 (Anderson and Gaunt 1962), and 
then again in 1975 (Bogan and Jones 1975, p. 47; Bednarz 1977, p. 1). 
The literature between the time of the initial collections and the 
subsequent collections in 1975 show argument amongst researchers as to 
whether the white-sided jackrabbit did indeed occur in the United 
States in the early 1900s. Multiple survey efforts have occurred since 
the 1975 surveys in attempts to document the extent of the range of the 
species in the United States and the size and density of the 
populations.
    As discussed above, white-sided jackrabbits are elusive and largely 
nocturnal. As such, the most effective surveys are completed in the 
dark by driving a vehicle through an area of potential habitat with a 
bright spotlight. Bednarz (1977) completed a series of such surveys and 
found a mean of 15 jackrabbits per survey in the Animas Valley. Later, 
Cook (1981) resurveyed a similar area and found a mean of 7.5 
jackrabbits per survey. Mehlhop (1995) reported on surveys in the 
Animas and Playas Valleys conducted in 1990, 1994, and 1995. The mean 
number of jackrabbits observed during the 1990 surveys was 3.2, while 
the mean for the 1994 and 1995 surveys was 1.1 (Mehlhop 1995). 
Traphagen (2010) has completed the most recent surveys for white-sided 
jackrabbits, and while the author does not report the mean number of 
jackrabbits sighted per survey effort, he notes 28 were sighted over 
the course of 9 surveys. Traphagen (2010) also notes that surveys were 
conducted by another party between 1997 and 2002, but that the results 
of those studies have not been analyzed. On its face, the survey 
information for the white-sided jackrabbit would seem to suggest a 
decline in species density in the United States over the last 35 years. 
However, each of the surveyors utilized somewhat different survey 
methods and different survey routes, thus precluding a statistical 
comparison of their results. Based on the historical and current survey 
records, this species was likely always rare and appears to continue to 
be rare in the United States.
    Some survey work has been completed in Mexico in modern times 
(Desmond 2004; Reynolds 1988); however, these surveys have tended to be 
one- or two-summer efforts, and without historical information to 
compare their numbers to, it is difficult to assess population trends. 
Reynolds (1988) interviewed ``campesinos, ranchers, and whenever 
possible, members of a local hunting club'' about their experiences 
with white-sided jackrabbits in the Mexican States of Guanajuato, 
Guerrero, Hidalgo, Jalisco, Mochoacan, Morelos, Oaxaca, Puebla, 
Queratoro, San Luis Potosi, Tlaxcala, and Zacatecas. The reliability of 
anecdotal reports can also be difficult to assess; however, Reynolds 
(1988) reported that the persons interviewed in Guanajuato, Guerrero, 
Hidalgo, and Morelos indicated that the white-sided jackrabbit may be 
reduced in numbers compared to the previous 20 to 25 years. Desmond 
(2004) reported on surveys of white-sided jackrabbits conducted in 1998 
and 1999 in central and northwestern Chihuahua, Mexico. He reported 
0.03 jackrabbits per acre surveyed in 1998, and 0.04 jackrabbits per 
acre surveyed in 1999 (Desmond 2004). When the numbers were adjusted to 
reflect just the area of plains grasslands, the preferred habitat of 
the white-sided jackrabbit in this part of its range, he reported 0.06 
jackrabbits per acre in 1998 and 0.08 jackrabbits per acre in 1999 
(Desmond 2004). Again, the importance of these numbers is difficult to 
assess because there is no prior or subsequent survey information to 
which to compare them; however, Desmond (2004, p. 417) notes, ``It is 
not clear if white-sided jackrabbits have always occupied semidesert 
grasslands at low densities or if reduced densities in this grassland 
type are related to habitat degradation.''

Summary of Information Pertaining to the Five Factors for Lepus 
callotis

    Section 4 of the Act and implementing regulations (50 CFR part 424) 
set forth procedures for adding species to, removing species from, or 
reclassifying species on the Federal Lists of Endangered and Threatened 
Wildlife and Plants. Under section 4(a)(1) of the Act, a species may be 
determined to be endangered or threatened based on any of the following 
five factors:
    (A) The present or threatened destruction, modification, or 
curtailment of its habitat or range;

[[Page 53620]]

    (B) Overutilization for commercial, recreational, scientific, or 
educational purposes;
    (C) Disease or predation;
    (D) The inadequacy of existing regulatory mechanisms; or
    (E) other natural or manmade factors affecting its continued 
existence.
    In making this finding, information pertaining to the full species 
of the white-sided jackrabbit, Lepus callotis, in relation to the five 
factors provided in section 4(a)(1) of the Act is discussed below. In 
making our 12-month finding on a petition to list the full species of 
the white-sided jackrabbit, Lepus callotis, we considered and evaluated 
the best available scientific and commercial information.
    In considering what factors might constitute threats to a species, 
we must look beyond the exposure of the species to a factor to evaluate 
whether the species may respond to the factor in a way that causes 
actual impacts to the species. If there is exposure to a factor and the 
species responds negatively, the factor may be a threat and we attempt 
to determine how significant a threat it is. The threat is significant 
if it drives, or contributes to, the risk of extinction of the species 
such that the species warrants listing as endangered or threatened as 
those terms are defined in the Act.

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

    Livestock grazing and suppression of wildfire have been shown to 
lead to shrub encroachment and degradation of grasslands, separately 
and in combination (Bureau of Land Management (BLM) 2009, p. 2; Malpai 
Borderlands Habitat Conservation Plan Technical Working Group 2008, p. 
18; Traphagen 2002, p. 12). In New Mexico, the white-sided jackrabbit 
is found only in association with mature, high-elevation (greater than 
1,460-m (4,800-ft)) plains or Chihuahuan desert grasslands, 
characterized by flat topography and few shrubs and forbs (Bednarz 
1977, p. 6). The bootheel region of southwestern New Mexico, which 
contains the range of the white-sided jackrabbit in the United States, 
was dominated by grassland until the late 19th century. Historically, 
the presence of shrubs and low growing trees was limited to drainages 
or to rocky shallow soil areas; however, changes in land use to 
accommodate agricultural practices, including livestock grazing and 
fire suppression, have led to the invasion of woody shrubs and their 
establishment into sites where they did not previously occur (BLM 2009, 
p. 10). Once invasive shrubs become established, they tend to increase 
in density and outcompete other native vegetation for soil moisture, 
nutrients, and sunlight and are less susceptible to drought than 
herbaceous species, which are green and fleshy as opposed to the 
generally more woody shrubs.
    Numerous sources substantiate that past range-management practices 
have contributed to the degradation of desert grasslands or their 
conversion to shrublands (National Museum of Natural History 2008, p. 
1; Bednarz and Cook 1984, p. 360; Desmond 2004, p. 417; Forest Service 
2007, p. 15; Service 2008, p. 53). The BLM reports in its 2009 
Environmental Assessment for the Bootheel Restoration Initiative that 
the vegetative community in the areas affected by shrub encroachment in 
southern New Mexico is far removed from the historical climax community 
and no longer supports the historical abundance and diversity of flora 
and fauna (BLM 2009, p. 13). Bednarz and Cook (1984, p. 360) postulated 
that numbers of white-sided jackrabbit had decreased in New Mexico as 
the density and vigor of grasses declined, while black-tailed 
jackrabbits and desert cottontail (Sylvilagus audubonii) numbers 
increased in response to an increase in woody shrubs. Desmond (2004, p. 
417) reported a similar pattern from Chihuahua, Mexico, where she found 
that increased shrub encroachment into grasslands likely has negatively 
affected populations of white-sided jackrabbits (Desmond 2004, p. 417).
    Traphagen (2009, pp. 1- 4) reports that the impacts of livestock 
grazing and fire suppression may differently affect the two valleys 
that compose the species' portion of the range in the United States. 
Traphagen (2009, p. 2) reports that the Animas Valley is largely free 
of shrubs, likely due to the soil structure, water drainage, frequent 
fires, and cold air drainage. Cold air drainage is a process that 
occurs in valleys as the ground cools at night, cooling the air and 
causing denser cold air from higher elevations to move down into the 
valley. The Animas Valley is surrounded by several large mountain 
ranges that create winter microclimates too cold to support the 
establishment of shrubs on the valley floor such as mesquite, cholla, 
and creosote (Traphagen 2009, p. 2). In contrast, the Playas Valley 
receives less precipitation annually and is generally drier than the 
Animas Valley (Traphagen 2009, p. 2). Shrub invasion in this grassland 
association has occurred on a much larger scale than in the grassland 
association found in the Animas Valley (Traphagen 2009, p. 2).
Livestock Grazing
    Areas where white-sided jackrabbits historically or currently occur 
in the United States were continuously grazed for over a century 
(Traphagen 2002, p. 3). Overgrazed grassland is susceptible to invasion 
by shrubs and forbs, a cover type which greatly favors the black-tailed 
jackrabbit (Baker 1977, pp. 222-223; Bednarz and Cook 1984, pp. 359-
360; Desmond 2004, p. 417; Moore-Craig 1992, p. 13; NMDGF 2006a, p. 
115).
    The Diamond A Ranch in New Mexico, which includes the historic 
range of the jackrabbit in both the Animas and Playas Valleys, has been 
very lightly grazed since 1994, and there have been several periods 
where grazing was deferred on the ranch for 4 years or more (Traphagen 
2009, p. 3). Prior to ownership by the Animas Foundation, the ranch was 
owned by The Nature Conservancy, and stocking rates were very low 
(Traphagen 2009, p. 5). During the period from 2003 to 2006 there was 
no cattle grazing in the Animas Valley where the white-sided jackrabbit 
occurs (Traphagen 2009, p. 5). We have no information about current 
grazing practices in historical habitat in the Playas Valley beyond the 
general statement that the Diamond A Ranch has been lightly grazed 
since 1994. This species appears to be extirpated from that portion of 
its range. The extent to which past grazing practices may have 
contributed to that extirpation is unknown; however, the Playas Valley 
may have been more susceptible to shrub encroachment resulting from 
past overgrazing than the Animas Valley as a result of the differences 
in grassland type and cold air drainage patterns discussed above.
    Finally, while we know that grazing of livestock occurs in Mexico 
(see, for example, Buller et al. 1960), we do not have information on 
the extent or intensity of historical or current livestock grazing 
practices throughout the range of the species in Mexico. Brown (1994) 
reported that a primary cause of loss and degradation of grasslands in 
the Chihuahuan Desert is overgrazing by cattle; however, the extent of 
those grassland losses throughout the historical range of the 
jackrabbit and the impacts of those losses on the jackrabbit are not 
known.
    Previous research had indicated that the jackrabbit required 65 
percent grass cover of species that included blue and black grama, ring 
muhly, buffalograss, wolftail, and bottlebrush squirreltail (Elymus 
elymoides) (Bednarz and Cook 1984, pp. 359-360). However, in a

[[Page 53621]]

research project commissioned by the NMDGF it was found that presence 
of the white-sided jackrabbit was highly correlated with the presence 
of buffalograss (Traphagen 2002, p. 6). No other grasses analyzed in 
the study, including blue and black grama, ring muhly, wolftail, and 
bottlebrush squirreltail, showed any correlation with white-sided 
jackrabbit habitat. The Animas Valley is dominated in many areas by 
buffalograss, but buffalograss is no longer present in the Playas 
Valley (Traphagen 2009, p. 3).
    One study found a relationship between grazing and the presence of 
buffalograss in two plots in the Animas Valley (Traphagen 2009, pp. 3-
4). The Sacahuiste Grazing Exclosure has been ungrazed since 1996. This 
plot is paired with a grazed plot located 50 m (160 ft) outside the 
exclosure. The ungrazed exclosure experienced a decline of 300 percent 
in cover of buffalograss during the 12-year period of no grazing, while 
the grazed plot declined by only 30 percent (Traphagen 2009, p. 4). If 
grazing does not occur, buffalograss is outcompeted because of its lack 
of shade tolerance (Traphagen 2009, p. 5). These results indicate that 
light grazing may be an important part of maintaining the health of the 
ecosystem.
    The best available information indicates that grazing is not 
currently occurring at a level which may constitute a threat to extant 
populations of the species in New Mexico, although grazing may have 
played a role in the presumed extirpation of white sided-jackrabbits in 
the Playas Valley. Information about the species' status in Mexico is 
very limited. As discussed above, overgrazing may have caused some loss 
or degradation of grasslands in the Chihuahuan Desert, and the 
encroachment of shrubs into grasslands may have negatively affected 
populations of white-sided jackrabbits there. However, the information 
available concerning grazing practices in Mexico does not allow us to 
assess the magnitude or immediacy of these impacts on the species, nor 
the extent of the occupied range of the jackrabbit that may be subject 
to overgrazing impacts. In the absence of information that allows us to 
make a reasonable connection between the impacts of livestock grazing 
and current or future declines of white-sided jackrabbits, we are 
unable to conclude that this species is threatened by grazing 
practices.
Wildfire Suppression
    Wildfire suppression is often a cause of grassland degradation. 
Fire exclusion has likely led to encroachment of shrubs into the 
grassland habitat of the white-sided jackrabbit. Humphrey (1958, p. 
245) believed fires were the controlling factor that kept shrubs from 
invading the desert grasslands in southeastern Arizona and southwestern 
New Mexico. The BLM came to a similar conclusion for the region of 
southwestern New Mexico where the white-sided jackrabbit historically 
occurred (BLM 2009, pp. 1-3). Alternatively, Valone et al. (2002, p. 
563) reported that two fires in 5 years did not result in high levels 
of mortality to woody shrubs such as mesquite on the Diamond A Ranch.
    Traphagen (2009, p. 4) reports that fire has occurred on a frequent 
and widespread basis across the Diamond A Ranch in recent decades, and 
that fire suppression has not occurred on the ranch in recent years. He 
states that there have been several major fires in the Animas Valley 
that have burned nearly 100 percent of the habitat of the jackrabbit 
(Traphagen 2009, p. 4). He provides a partial list of fires and area 
burned on the ranch: in June of 2009 the ``Pascoe fire'' burned 23,635 
ha (58,404 ac) in the southern Animas Valley and 12,304 ha (30,405 ac) 
in the west fork of the Playas Valley. In 1998 the ``Flat fire'' burned 
over 12,867 ha (31,796 ac) of the Animas and Playas Valleys. In 1999 
the ``Garcia fire'' burned 8,660 ha (21,400 ac) in habitat. In 2000 the 
``Fitz fire'' burned 2,007 ha (4,961 ac) in the heart of white-sided 
jackrabbit habitat. The ``Lang fire'' burned another 404 ha (1,000 ac) 
adjacent to the Fitz fire.
    From these data, we can conclude that fire suppression does not 
currently constitute a threat to the species in New Mexico because 
there is information on the dates of fires from the last several years 
as well as the approximate area burned. The best available information 
does not indicate that fire suppression occurs in New Mexico at a level 
which may impact the status of the species, by allowing for the 
conversion of its preferred habitat. We have no information about the 
frequency or distribution of wildfires throughout the species' range in 
Mexico. We have no information about the existence of wildfire 
suppression or prescribed burn programs throughout the species' range 
in Mexico.
    It is known that both shrub encroachment into grassland fostered by 
current and historical grazing practices, as well as fire exclusion, 
have degraded habitat occupied by the species in the United States 
portion of the range. However, as stated above, we do not find this to 
be at a level that would constitute a threat to extant populations of 
this species in New Mexico. Again, there is very little information 
available about the species' status and its habitat in the large 
portion of its range in Mexico. The best available information does not 
describe the historical or current trends in grassland health in the 
Mexican portion of the species' range in a way that allows us to assess 
the magnitude or immediacy of the impacts on the species. Thus, we 
cannot conclude that habitat degradation due to livestock grazing and 
fire suppression leading to shrub encroachment is a threat to the 
species as a whole, either now or in the foreseeable future.

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

    The white-sided jackrabbit is not believed to be overutilized in 
the U.S. portion of its range, and current information on its 
utilization in Mexico is limited (Traphagen 2009, p. 4). Hunting of the 
species is prohibited in New Mexico as it is currently protected under 
the New Mexico Wildlife Conservation Act (NMDGF 2008, p. 10). Further, 
in New Mexico, the white-sided jackrabbit only occurs on private land, 
thereby limiting hunting opportunities (Traphagen 2009, p. 4). 
Literature indicates that the species has been commonly hunted in 
Mexico for commercial markets (Leopold 1959, p. 349; Reynolds 1988). 
While hunting for commercial markets is no longer allowed, Reynolds 
(1988) reports that hunting for personal use continues. Matson and 
Baker (1986, p. 41) indicated that the species was heavily hunted and 
considered highly edible. While there is information that hunting of 
white-sided jackrabbits occurs in Mexico, we are unable to assess the 
level of hunting that occurs and whether it is having an impact on the 
population levels and overall status of the species.
    The vast majority of the species' range lies in Mexico and the best 
available information does not allow us to assess the magnitude and 
immediacy of this impact on the species in that country. Additionally, 
the species does not appear to be impacted by such practices in the New 
Mexico portion of its range. Therefore, we conclude that hunting is not 
currently a known a threat to the species as a whole throughout its 
range.
    There is some information which indicates that the white-sided 
jackrabbit is occasionally subject to impacts from animal damage 
control programs. Various rabbit species occasionally feed on crop 
plants and are seen as pests; however, the white-sided jackrabbit has 
not been documented as a heavy consumer of crop plants. The U.S. 
Department of Agriculture (USDA) reported that jackrabbits (Lepus spp.) 
have been taken in New Mexico as part

[[Page 53622]]

of their animal damage control program (USDA Animal and Plant Health 
Inspection Service 1994, Appendix H, pp. 18-19). More recent data from 
2007 and 2008 on the numbers and kinds of animals killed or euthanized 
by wildlife services in New Mexico report only cottontail rabbits as 
having been lost. There is no description of current or future plans 
for lethal control of any white-sided jackrabbits, nor is there a 
quantification of the amount that may have occurred historically by 
either the USDA or the general public. We have no information on the 
activities of this type throughout the species' range in Mexico. 
Therefore, we find that the best available information does not 
indicate that the white-sided jackrabbit is currently subject to animal 
damage control programs by methods such as trapping or shooting, or is 
likely to be in the future in New Mexico.
    While individual white-sided jackrabbits may be subject to 
overutilization or animal damage control programs, the available 
information on this impact does not allow us to assess whether or not 
these impacts are occurring at a level which may affect the status of 
the species as a whole. Therefore, we find that the white-sided 
jackrabbit is not threatened due to overutilization for commercial, 
recreational, scientific, or educational purposes, either now or in the 
foreseeable future.

Factor C. Disease or Predation

    We are not aware of any research that has been conducted to 
specifically examine the role of disease in the white-sided jackrabbit. 
Bednarz (1977, p. 19) indicated that a lung infection has been observed 
in white-sided jackrabbits in New Mexico; however, Moore-Craig (1992, 
p. 11) noted that the infections found by Bednarz were all of a minor 
nature, and the overall health of the jackrabbit population appeared to 
be fair to good. Tularemia, a common disease among black-tailed 
jackrabbits, has not been found in the white-sided jackrabbit in New 
Mexico (Moore-Craig 1992, p. 11). We do not have any reports of disease 
in the white-sided jackrabbit in Mexico.
    A variety of potential predators exists throughout the species' 
range, including coyote (Canus latrans), kit fox (Vulpes macrotis), 
gray fox (Urocyon cinereoargenteus), badger (Taxidea taxus), spotted 
skunk (Mephitis mephitis), and a number of predatory bird species. Of 
these carnivores, probably only the coyote is able to successfully prey 
on adult jackrabbits with much frequency, as the jackrabbit is 
nocturnal and generally avoids predation by bird species active during 
the day (Bednarz 1977, p. 18). Although the jackrabbit is subject to 
predation, there is no data from either country which indicates that 
predation is occurring at a level which may constitute a threat to the 
species throughout its range.
    Although white-sided jackrabbit individuals may be subject to 
occasional infections or predation, there is no evidence that either of 
these is occurring at a level which may affect the status of the 
species as a whole. Therefore, we find that the white-sided jackrabbit 
is not threatened due to disease or predation, either now or in the 
foreseeable future.

Factor D. The Inadequacy of Existing Regulatory Mechanisms

    To determine if existing regulatory mechanisms are adequate to 
protect the white-sided jackrabbit, we evaluated agreements and laws in 
effect within the range of the species. The white-sided jackrabbit was 
listed as threatened by the State of New Mexico on January 24, 1975. 
This designation provides the protection of the New Mexico Wildlife 
Conservation Act, which prohibits direct take of the species except 
under issuance of a scientific collecting permit. However, this only 
conveys protection from collection or intentional harm. Although the 
State of New Mexico statutes require the NMDGF to develop a recovery 
plan that will restore and maintain habitat for threatened species, the 
jackrabbit does not have a finalized recovery plan, conservation plan, 
or conservation agreement (NMDGF 2006b, p. 430).
    There is some dispute concerning the effectiveness of the 
conservation efforts of the Malpai Borderlands Group in Hidalgo County, 
New Mexico. The petitioners state that the Malpai Borderlands Group 
does not afford protection to the white-sided jackrabbit or to its 
habitat as intended (WildEarth Guardians (2008)). The apparent basis of 
this position is that the Service issued an incidental take permit 
under section 10(a)(1)(B) of the Act on private lands to the Malpai 
Borderlands Group for the Malpai Borderlands Habitat Conservation Plan 
(MBHCP). WildEarth Gardians (2008) also contends, based upon observed 
degradation of grassland habitat and declines in the jackrabbit 
population, that the Malpai Borderlands Group is not fulfilling its 
stated mission to restore and maintain natural processes that support 
diverse and flourishing animal life in the borderlands region, which 
includes the Diamond A Ranch in southern Hidalgo County, and 
constitutes the range of the white-sided jackrabbit in the United 
States. However, they provide no information that documents the extent, 
magnitude, or immediacy of the perceived inadequacies of the MBHCP or 
how they threaten the white-sided jackrabbit in New Mexico. Traphagen 
(2009, pp. 4-5) provides information indicating that the Animas 
Foundation and the Malpai Borderlands Group have supported numerous 
research, monitoring, and restoration projects, with nearly all of the 
projects focusing on aspects of rangeland health, shrub invasion, and 
endangered species conservation. Traphagen (2009, p. 5) states that 
several major prescribed burns have been conducted in the Malpai 
Borderlands Region in the last 20 years in addition to allowing natural 
fires to run free. Traphagen (2009, p. 5) also describes the 
cooperation of private ranchers in deferring grazing in order to reduce 
woody shrub cover and to allow pastures with insufficient biomass to 
recover.
    The Mexican Federal agency known as the Instituto Nacional de 
Ecologi[aacute] is responsible for the analysis of the status and 
threats that pertain to species that are proposed for listing in the 
Norma Oficial Mexicana NOM-059 (the Mexican equivalent to a threatened 
and endangered species list), and if appropriate, the nomination of 
species to the list. The Instituto Nacional de Ecologi[aacute] is 
generally considered the Mexican counterpart to the United States' Fish 
and Wildlife Service. The white-sided jackrabbit is not included in the 
NOM-059 (SEDESOL 2008) and is therefore not protected by Federal 
regulation in Mexico.
    In NatureServe, the white-sided jackrabbit's global ranking is G3 
(vulnerable) and its National and State Status rankings are N1S1 
(critically imperiled). The species' status under the International 
Union for Conservation of Nature and Natural Resources is ``near 
threatened.'' However, these lists are not regulatory mechanisms; they 
serve only to notify the public of the species' status; no conservation 
or management actions are required and no regulatory authority for 
species conservation is established through these listings. 
Additionally, the white-sided jackrabbit is on the Regional Forester's 
Sensitive Species List for the Coronado National Forest (Forest Service 
2007, p. 15); however, we found no information to that indicates the 
jackrabbit is present on any Forest Service lands in New Mexico.
    There is information that indicates that the white-sided 
jackrabbit's status as a State-listed threatened species in

[[Page 53623]]

New Mexico confers little regulatory protection (except against direct 
take). Further, the white-sided jackrabbit is not covered by any known 
regulations in Mexico. However, as discussed in the other Factors of 
this section, we have not identified any threats to this species that 
are likely to negatively affect the status of the species as a whole, 
such that the limited regulatory protection is not likely to represent 
a threat to the species. Therefore, we find that the white-sided 
jackrabbit is not threatened by inadequacy of regulatory mechanisms, 
either now or in the foreseeable future.

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

    The following natural or manmade factors may affect the white-sided 
jackrabbit or its habitat, or both, and are discussed below: climate 
change, consumption of poisonous plants, impacts by vehicles on roads, 
and fire.
Climate Change
    The Intergovernmental Panel on Climate Change (IPCC) is a 
scientific body set up by the World Meteorological Organization and the 
United Nations Environment Program in 1988. It was established because 
policy makers needed an objective source of information about the 
causes of climate change, its potential environmental and socio-
economic consequences, and the adaptation and mitigation options to 
respond to it. The Service considers the IPCC an impartial and 
legitimate source of information on climate change. In 2007, the IPCC 
published its Fourth Assessment Report, which is considered the most 
comprehensive compendium of information on actual and projected global 
climate change currently available.
    Although the extent of warming likely to occur is not known with 
certainty at this time, the IPCC (2007, p. 5) has concluded that 
warming of the climate is unequivocal and continued greenhouse gas 
emissions at or above current rates would cause further warming (IPCC 
2007, p. 13). The IPCC also projects that there will very likely be an 
increase in the frequency of hot extremes, heat waves, and heavy 
precipitation (IPCC 2007, p. 15). Warming in the southwestern United 
States is expected to be greatest in the summer (IPCC 2007, p. 887). 
Annual mean precipitation is likely to decrease in the southwestern 
United States and the length of snow season and snow depth are very 
likely to decrease (IPCC 2007, p. 887). Further, the IPCC (2007, p. 
888) concluded that grasslands and shrublands appear to be more 
sensitive than previously thought to variability of, and changes in, 
major climate change drivers, such as the increase in atmospheric 
carbon dioxide. Several climate change models project that the 
southwestern United States will become hotter and drier, and indicate 
that the portion of southwestern New Mexico currently occupied by the 
white-sided jackrabbit will be characterized by shrubland or woodland 
as a result of climate change (The Wildlife Society 2004, p. 6; 
Izaurralde et al. 2005, pp. 110-111). In their Vulnerability Assessment 
for Biodiversity in New Mexico, Enquist and Gori (2008, p. 14) consider 
the white-sided jackrabbit to be a drought-sensitive conservation 
target based upon the predicted conversion of its grassland habitat to 
shrubland. Further, information indicates that climate change might 
contribute to more frequent and intense drought within the United 
States and northern Mexico portion of the range of the jackrabbit 
(Seager et al. 2007, pp. 1181-1182).
    In consultation with leading scientists from the southwestern 
United States, the New Mexico Office of the State Engineer prepared a 
report for the Governor (D'Antonio 2006) which made the following 
observations about the impact of climate change in New Mexico:
    (1) Warming trends in the American Southwest exceed global averages 
by about 50 percent (p. 5);
    (2) Models suggest that even moderate increases in precipitation 
would not offset the negative impacts to the water supply caused by 
increased temperature (p. 5);
    (3) Temperature increases in the Southwest are predicted to 
continue to be greater than the global average (p. 5); and
    (4) The intensity, frequency, and duration of drought may increase 
(p. 7).
    The best available information indicates that the white-sided 
jackrabbit may be vulnerable to climatic changes that would decrease 
suitable habitat in New Mexico; however, while it appears reasonable to 
assume that the white-sided jackrabbit may be affected, we lack 
sufficient certainty to know specifically how climate change will 
affect the species. Despite large-scale conclusions that climate change 
is occurring in New Mexico, we have not identified, nor are we aware 
of, any data on an appropriate scale to evaluate habitat or population 
trends for the white-sided jackrabbit within its range in New Mexico or 
in Mexico at this time, or to make predictions on future trends and 
whether the species will be impacted. There are multiple hypothetical 
outcomes associated with climate change that could potentially affect 
the white-sided jackrabbit habitat. However, we lack predictive local 
or regional models on how climate change will specifically affect the 
habitat in either country. Given that reliable, predictive models have 
not been developed for use at the local scale in New Mexico's bootheel 
region or for the sites in the many States in Mexico within the 
jackrabbit's range, currently there is little certainty regarding the 
timing, magnitude, and net effect of impact. Therefore, we find it is 
not possible at this time to make reliable predictions of climate 
change effects on the status of the white-sided jackrabbit, due to the 
current limitations in available data and climate models. Based on the 
best available information and our current knowledge and understanding, 
we conclude that climate change is not a known threat to the white-
sided jackrabbit or its habitat, now or in the foreseeable future.
Food Poisoning
    A single suspected case of food poisoning of white-sided 
jackrabbits is known. Bednarz (1977, p. 18) detailed a case in which a 
New Mexico rancher found several dead white-sided jackrabbits while 
eradicating mustard plants. Bednarz (1977, p. 18) suggests that this 
mortality may have been caused by the jackrabbits' consumption of 
mustard plants and ensuing nitrate poisoning. Consumption of mustard 
plants is known to cause nitrate poisoning in cattle, and Bednarz 
(1977, p. 18) states that it likely has the same effect on jackrabbits. 
We are not aware of any other similar reports or information that 
indicates that food poisoning threatens the jackrabbit. There is no 
evidence that food poisoning is occurring at a level which may affect 
the status of the species as a whole, now or in the foreseeable future.
Impacts by Vehicles
    There is information that indicates that the white-sided jackrabbit 
is subject to fatal impacts from vehicles on roads within the species' 
range in New Mexico. Moore-Craig (1992, p. 16) and Bednarz (1977, p. 
18) reported that that white-sided jackrabbits were occasionally killed 
by vehicles. Rangewide, jackrabbits are likely somewhat protected from 
significant impacts due to vehicle collisions because they are largely 
nocturnal animals and not active in the day when most people are 
active. However, the recent increase in U.S. Border Patrol activity may 
have increased the magnitude of this impact on white-sided

[[Page 53624]]

jackrabbit populations near the international border. Due to the nature 
of the U.S. Border Patrol activities, these vehicles would be present 
on roads at night more often than vehicles were present on roads at 
night historically. Traphagan (2010) notes that U.S. Border Patrol 
agents have reported roadkills at night. However, there is no reason to 
extrapoloate these U.S. Border Patrol activities and vehicle collision 
rates to other portions of the range of the species because U.S. Border 
Patrol impacts are unique to the area near the international border. 
Based on this review of the best available information, we find that, 
although individual jackrabbits may be subject to impacts as a result 
of vehicle collisions, there is no evidence that this is occurring at a 
level that may affect the status of the species as a whole, now or in 
the foreseeable future.
Fire Management
    The active fire management program in the Malpai Borderlands area 
may affect the white-sided jackrabbit. Effects to jackrabbits during 
fire management may include mortality or injury of individuals as a 
result of direct exposure to fire, smoke inhalation, and crushing by 
the tires or tracks of vehicles used in fire management activities 
(Service 2008, pp. 64-65). We believe that the jackrabbit is capable of 
surviving such fire effects by running away (Service 2008, p. 64). We 
find prescribed burns may also expose white-sided jackrabbits to higher 
rates of predation, but may also allow the jackrabbits to more easily 
detect terrestrial predators (Service 2008, p. 65). The effects of a 
prescribed burn to habitats would likely be short term, because the 
fire-adapted grassland community usually responds quickly, with plant 
species showing regrowth within several days post-fire. Nevertheless, a 
reduction of shrubs would benefit the white-sided jackrabbit by 
improving grassland habitat. Although the management measures employed 
under the MBHCP will likely result in short-term adverse effects to the 
jackrabbit, the long-term effects will improve the grassland community 
used by white-sided jackrabbits by reducing the shrub component, 
providing additional suitable habitat, and improving the area around 
occupied habitat for potential expansion; thus, implementation of the 
MBHCP, including the fire management program, should promote the 
conservation of the white-sided jackrabbit. Based on this review of the 
best available information, we find that although individual 
jackrabbits may be subject to impacts of fire management, there is no 
evidence that the short-term impacts of fire management are occurring 
at a level that may affect the status of the species as a whole now or 
in the foreseeable future. Further, the long-term impacts of fire 
management may serve to improve white-sided jackrabbit habitat and thus 
provide a benefit to the species.

Finding for Lepus callotis

    As required by the Act, we considered the five factors in assessing 
whether the full species of the white-sided jackrabbit, Lepus callotis, 
is threatened or endangered throughout its range. We have carefully 
examined the best scientific and commercial information available 
regarding the past, present, and future threats faced by the species. 
We reviewed the petition, information available in our files, and other 
available published and unpublished information.
    Our review of the best available scientific and commercial 
information pertaining to the five factors does not indicate that the 
white-sided jackrabbit is in danger of extinction (endangered), or 
likely to become endangered within the foreseeable future (threatened), 
throughout its range. This is based on our finding in the five-factor 
analysis that stressors in New Mexico do not constitute threats to the 
jackrabbit in its current range in New Mexico, and the fact that the 
best available information concerning the jackrabbit's status and its 
habitat in Mexico, limited as it is, does not allow us to assess the 
magnitude or immediacy of those potential impacts on the species, nor 
the extent of the occupied range of the jackrabbit that may be subject 
to impacts. While we have evidence that some impacts may be occurring 
within the range of the species (e.g., shrub encroachment, grazing, 
hunting, vehicle collisions, changing climate conditions), we do not 
have any specific information that allows us to make a reasonable 
connection between these potential impacts and current or future 
declines of white-sided jackrabbits. Therefore, we find that listing 
the full species of the white-sided jackrabbit as a threatened or an 
endangered species throughout its range is not warranted at this time.

Species Information: Lepus callotis callotis

    The distribution of the subspecies of the white-sided jackrabbit, 
Lepus callotis callotis, is limited to Mexico. The northern limit of 
the subspecies' range is established by the Rio Nazas (Peterson 1976, 
p. 497). The range of the subspecies L. c. callotis spans several 
States in the Mexican interior, from Durango in the north to Oaxaca in 
the south (Hall 1981, p. 330). The range of the subspecies L. c. 
callotis is fully encompassed by the range of the species L. callotis. 
Please see the ``Species Information: Lepus callotis'' section above 
for a full discussion of white-sided jackrabbit taxonomy, species 
description, biology, distribution, habitat, and population abundance.

Summary of Information Pertaining to the Five Factors for Lepus 
callotis callotis

    In making this finding, information pertaining to the subspecies of 
the white-sided jackrabbit, Lepus callotis callotis, in relation to the 
five factors provided in section 4(a)(1) of the Act is discussed below. 
In making our 12-month finding on a petition to list the subspecies of 
the white-sided jackrabbit, Lepus callotis callotis, we considered and 
evaluated the best available scientific and commercial information.

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

    Based on extensive literature searches, we find there is no 
information available to us which describe threats to the subspecies' 
habitat or range in a way that allows us to assess the magnitude or 
immediacy of these impacts on the subspecies. It is likely that many of 
the same or similar anthropogenic activities that occur in the United 
States portion of the full species' range, discussed above, occur 
within the subspecies' range in Mexico. However, there is no 
information available to evaluate whether these factors or potential 
threats have a negative effect on the subspecies. We are not aware of 
additional or specific activities which may be contributing to the 
present or threatened destruction, modification, or curtailment of the 
subspecies' habitat or range in Mexico. Therefore, we find that the 
best available information regarding threats to the subspecies' habitat 
or range does not indicate that listing the subspecies throughout all 
or a portion of its range is warranted due to the present or threatened 
destruction, modification, or curtailment of its habitat or range, 
either now or in the foreseeable future.

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

    There are reports of the historical utilization of white-sided 
jackrabbits in Mexico. As discussed above, we are unable to assess the 
level of utilization that occurs and whether it is having an impact on 
the population levels and

[[Page 53625]]

overall status of the species or either subspecies. The best available 
information does not indicate that the subspecies is overutilized for 
commercial, recreational, scientific, or educational purposes. We have 
not encountered any information that indicates the contrary. In the 
absence of evidence that this may constitute a threat to the subspecies 
throughout all or a portion of its range, we find that listing the 
subspecies Lepus callotis callotis due to overutilization is not 
warranted, now or in the foreseeable future.

Factor C. Disease or Predation

    The full extent of information available on the subject of disease 
and predation as threats to the species, and therefore this subspecies, 
is discussed above. We have no information available to us that 
indicates that the subspecies is subject to disease or predation at a 
level that is affecting the status of the subspecies. Since we do not 
have information that this may constitute a threat to the subspecies 
throughout all or a portion of its range, we find that listing the 
subspecies Lepus callotis callotis due to disease or predation is not 
warranted, either now or in the foreseeable future.

Factor D. The Inadequacy of Existing Regulatory Mechanisms

    As discussed above, white-sided jackrabbits (including the 
subspecies Lepus callotis callotis) are not covered under any known 
regulations in Mexico. We have encountered no information that 
indicates that the status of the subspecies is declining due to the 
inadequacy of existing regulatory mechanisms. Since we have no 
information that this may constitute a threat to the subspecies 
throughout all or a portion of its range, we find that listing the 
subspecies Lepus callotis callotis due to the inadequacy of existing 
regulatory mechanisms is not warranted, either now or in the 
foreseeable future.

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

    We have no detailed information concerning additional natural or 
manmade factors affecting the subspecies' continued existence. Global 
climate change will likely affect the subspecies or its habitat; 
however, the effects of climate change on the region and their 
magnitude and imminence are unknown. We lack predictive models on how 
climate change will specifically affect the subspecies' habitat in 
Mexico. Given that reliable, predictive models have not been developed 
for use at the local scale for the sites in the many States in Mexico 
within the subspecies' range, currently there is little certainty 
regarding the timing, magnitude, and net effect of impact of climate 
change. Therefore, we find it is not possible to make reliable 
predictions of climate change effects on the status of the white-sided 
jackrabbit, due to the current limitations in available data and 
climate models. Based on the best available information and our current 
knowledge and understanding, we conclude that climate change is not 
currently a known threat to the subspecies Lepus callotis callotis, 
either now or in the foreseeable future.

Finding for Lepus callotis callotis

    As required by the Act, we considered the five factors in assessing 
whether the subspecies of the white-sided jackrabbit, Lepus callotis 
callotis, is threatened or endangered throughout all or a significant 
portion of its range. We have carefully examined the best scientific 
and commercial information available regarding the past, present, and 
future threats faced by the species. We reviewed the petition, 
information available in our files, and other available published and 
unpublished information. We know very little about the status and 
threats to the subspecies. The best available information does not 
indicate that these populations are going to experience impacts at a 
level at that would affect the status of the subspecies.
    Our review of the best available scientific and commercial 
information pertaining to the five factors does not indicate that the 
subspecies of white-sided jackrabbit, Lepus callotis callotis, is in 
danger of extinction (endangered), or likely to become endangered 
within the foreseeable future (threatened), throughout its range. This 
is based on our finding in the five-factor analysis that the best 
available information concerning the jackrabbit's status and its 
habitat in Mexico, limited as it is, does not allow us to assess the 
magnitude or immediacy of those potential impacts on the species, nor 
the extent of the occupied range of the jackrabbit that may be subject 
to impacts. While we have evidence that some impacts may be occurring 
within the range of the species (e.g., shrub encroachment, grazing, 
hunting, changing climate conditions), we do not have any specific 
information that allows us to make a reasonable connection between 
these potential impacts and current or future declines of the 
subspecies. Therefore, we find that listing the subspecies of the 
white-sided jackrabbit, Lepus callotis callotis, as a threatened or an 
endangered subspecies throughout its range is not warranted at this 
time.

Species Information: Lepus callotis gaillardi

    The subspecies of the white-sided jackrabbit, Lepus callotis 
gaillardi, occurs in both the United States and in Mexico. As discussed 
above, the historical range of the subspecies Lepus callotis gaillardia 
includes the southern Animas and Playas valleys of Hidalgo County, New 
Mexico, south into west-central Chihuahua and north-central Durango, 
Mexico (Bednarz and Cook 1984, p. 358; Reynolds 1988, p. 1), although 
it is now likely extirpated from the Playas Valley as no observations 
of the species have been made in this area during more recent surveys 
(Traphagen 2002, p. 5; Frey 2004, p. 22; NMDGF 2006a, p. 115; Traphagen 
2010, p. 1). The range of the subspecies L. c. gaillardi is fully 
encompassed by the range of the species L. callotis. Please see the 
``Species Information: Lepus callotis''section above for a full 
discussion of white-sided jackrabbit taxonomy, species description, 
biology, distribution, habitat, and population abundance.

Summary of Information Pertaining to the Five Factors for Lepus 
callotis gaillardi

    In making this finding, information pertaining to the subspecies of 
the white-sided jackrabbit, Lepus callotis gaillardi, in relation to 
the five factors provided in section 4(a)(1) of the Act is discussed 
below. In making our 12-month finding on a petition to list the 
subspecies of the white-sided jackrabbit, Lepus callotis gaillardi, we 
considered and evaluated the best available scientific and commercial 
information.

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

    The habitat of the subspecies Lepus callotis gaillardi within the 
United States may be threatened by shrub encroachment as a result of 
livestock grazing and wildfires. This threat is discussed in detail in 
the threat assessment for the full species Lepus callotis. There is 
information that this perceived threat may differentially affect the 
subspecies' separate habitats in New Mexico in the Animas and Playas 
Valleys.
    Traphagen (2009, pp. 1-2) indicates that the assertion that the 
current and historical grazing practices and suppression of wildfire, 
and the subsequent encroachment of shrubs threaten the subspecies is 
not entirely

[[Page 53626]]

accurate in regard to the habitat of the subspecies in the Animas 
Valley; however, it may have been a factor in the Playas Valley, where 
the subspecies is presumed to be extirpated.
    As discussed above, Traphagen (2009, p. 2) reports that the Animas 
Valley is largely free of shrubs, likely due to the soil structure, 
water drainage, frequent fires, and cold air drainage. Cold air 
drainage is a process that occurs in valleys as the ground cools at 
night, cooling the air and causing denser cold air from higher 
elevations to move down into the valley. The Animas Valley is 
surrounded by several large mountain ranges that create winter 
microclimates too cold to support the establishment of shrubs on the 
valley floor such as mesquite, cholla, and creosote (Traphagen 2009, p. 
2). In contrast, the Playas Valley receives less precipitation annually 
and is generally drier than the Animas Valley (Traphagen 2009, p. 2). 
Shrub invasion in this grassland association has occurred on a much 
larger scale than in the grassland association found in the Animas 
Valley (Traphagen 2009, p. 2).
    The Diamond A Ranch, which incorporates the two valleys, has 
practiced a very light grazing regime under ownership by The Nature 
Conservancy, and subsequently, by the Animas Foundation (Traphagen 
2009, p. 3). Traphagen (2009, p. 3) reports that since 1994, there have 
been several periods during which grazing was deferred on the ranch for 
4 years or more, and from 2003 to 2006, there was no cattle grazing in 
the Animas Valley.
    Traphagen (2009, p. 4) reports that fire suppression has not 
occurred in recent years on the Diamond A Ranch, and states that there 
have been several major fires in the Animas Valley that have nearly 
burned all of the white-sided jackrabbits' habitat in that valley. 
These fires are described in further detail above.
    We have no information about current grazing or fire suppression 
practices in historical habitat in the Playas Valley beyond the general 
statement that the Diamond A Ranch has been lightly grazed since 1994. 
This jackrabbit appears to be extirpated from that portion of its 
range. The extent to which past grazing or fire suppression practices 
may have contributed to that extirpation is unknown; however, the 
Playas Valley may have been more susceptible to shrub encroachment 
resulting from past overgrazing than the Animas Valley as a result of 
the differences in grassland type and cold air drainage patterns 
discussed above.
    Finally, while we know that grazing of livestock occurs in Mexico 
(see, for example, Buller et al. 1960), we do not have information on 
the extent or intensity of historical or current livestock grazing 
practices throughout the range of the species in Mexico. Brown (1994) 
reported that a primary cause of loss and degradation of grasslands in 
the Chihuahuan Desert is overgrazing by cattle; however, the extent of 
those grassland losses throughout the historical range of the 
jackrabbit and the impacts of those losses on the jackrabbit are not 
known.
    The best available information indicates that grazing and fire 
suppression are not currently occurring at a level which may constitute 
a threat to extant populations of the subspecies in New Mexico, 
although these impacts may have played a role in the presumed 
extirpation of white sided-jackrabbits in the Playas Valley. 
Information about the subspecies' status in Mexico is very limited. As 
discussed above, overgrazing may have caused some loss or degradation 
of grasslands in the Chihuahuan Desert, and the encroachment of shrubs 
into grasslands may have negatively affected populations of white-sided 
jackrabbits there. However, the information available concerning 
grazing practices in Mexico does not allow us to assess the magnitude 
or immediacy of these impacts on the subspecies, nor the extent of the 
occupied range of the subspecies that may be subject to overgrazing 
impacts. In the absence of information that allows us to make a 
reasonable connection between the impacts of livestock grazing and fire 
suppression, and current or future declines of white-sided jackrabbits, 
we are unable to conclude that this subspecies is threatened by grazing 
practices or fire suppression.

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

    In New Mexico, the subspecies is currently protected under the New 
Mexico Wildlife Conservation Act (NMDGF 2008, p. 10). Further, in New 
Mexico, the subspecies only occurs on private land, thereby limiting 
hunting opportunities (Traphagen 2009, p. 4). Literature indicates that 
the species was commonly hunted in Mexico for commercial markets 
(Leopold 1959, p. 349; Reynolds 1988). Matson and Baker (1986, p. 41) 
indicated that the species was heavily hunted and considered highly 
edible. Thus, it is possible that hunting may have played a role in the 
presumed decline of the white-sided jackrabbit in Mexico (Moore-Craig, 
1992, p. 13); however, as discussed above, we are unable to assess the 
level of hunting that occurs and whether it is having an impact on the 
population levels and overall status of the species. As the subspecies 
is legally protected from overutilization in New Mexico and the best 
available information does not indicate that overutilization 
constitutes a threat to the subspecies in Mexico, we find that 
overutilization does not constitute a significant threat to the 
subspecies. We find that listing the subspecies Lepus callotis 
gaillardi due to overutilization is not warranted, now or in the 
foreseeable future.

Factor C. Disease or Predation

    The full extent of information available on the subject of disease 
and predation as potential threats to the species, and therefore this 
subspecies, is discussed above. We have encountered no information 
which indicates that the subspecies is subject to excessive disease or 
predation. We have not encountered any information which indicates the 
contrary; however, in the absence of evidence that this may constitute 
a threat to the subspecies throughout all or a portion of its range, we 
find that listing the subspecies Lepus callotis gaillardi due to 
disease or predation is not warranted, now or in the foreseeable 
future.

Factor D. The Inadequacy of Existing Regulatory Mechanisms

    The full extent of information available on the subject of existing 
regulatory mechanisms as a threat to the species, and therefore this 
subspecies, is discussed above. There is information that indicates 
that the white-sided jackrabbit's status as a State-listed threatened 
species in New Mexico confers little regulatory protection (except 
against direct take). Further, the white-sided jackrabbit is not 
covered by any known regulations in Mexico. However, as discussed in 
the other Factors of this section, we have not identified any threats 
to this species that are likely to negatively affect the status of the 
subspecies as a whole, such that the limited regulatory protection is 
not likely to represent a threat to the subspecies. In the absence of 
evidence that the inadequacy of existing regulatory mechanisms may 
constitute a threat to the subspecies throughout all or a portion of 
its range, we find that listing the subspecies Lepus callotis gaillardi 
due to the inadequacy of existing regulatory mechanisms is not 
warranted, now or in the foreseeable future.

[[Page 53627]]

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

    The possible impacts to the subspecies Lepus callotis gaillardi due 
to other natural or manmade factors affecting its continued existence 
do not differ from those for the full species, discussed above. It is 
possible that the effects of climate change will impact the subspecies 
and its habitat; however, we don't know if the potential habitat 
changes will result in a decline in the status of the species. 
Additionally, there has been no research investigating the ways in 
which the effects will impact its specific environment. Rather, the 
models of projected change indicate a conversion to shrubland over much 
of the region of the southwestern United States and northern Mexico and 
do not account for the specific habitat types currently occupied by the 
subspecies. Due to the lack of information specific to the subspecies' 
relatively unique grassland association, detailed above in the Factor A 
discussion for this subspecies, we find that the best available 
information does not indicate that climate change may constitute a 
threat to the subspecies throughout all or a portion of its range, now 
or in the foreseeable future.
    The effects of the reported fatal impacts of the subspecies by 
vehicles on roads within the subspecies' range in New Mexico are 
discussed above. Although there is potential for this factor to affect 
individuals in the future, depending on the activity of the U.S. Border 
Patrol, impacts are currently not known to be occurring at a level that 
will affect the status of the subspecies throughout all or a 
significant portion of its range.

Finding for Lepus callotis gaillardi

    As required by the Act, we considered the five factors in assessing 
whether the subspecies of the white-sided jackrabbit, Lepus callotis 
gaillardi, is threatened or endangered throughout all or a significant 
portion of its range. We have carefully examined the best scientific 
and commercial information available regarding the past, present, and 
future threats faced by the species. We reviewed the petition, 
information available in our files, and other available published and 
unpublished information.
    Our review of the best available scientific and commercial 
information pertaining to the five factors does not indicate that the 
subspecies of the white-sided jackrabbit, Lepus callotis gaillardia, is 
in danger of extinction (endangered), or likely to become endangered 
within the foreseeable future (threatened), throughout its range. This 
is based on our finding in the five-factor analysis that stressors in 
New Mexico do not constitute threats to the jackrabbit in its current 
range in New Mexico, and the fact that the best available information 
concerning the jackrabbit's status and its habitat in Mexico, limited 
as it is, does not allow us to assess the magnitude or immediacy of 
those potential impacts on the subspecies, nor the extent of the 
occupied range of the jackrabbit that may be subject to impacts. While 
we have evidence that some impacts may be occurring within the range of 
the subspecies (e.g., shrub encroachment, grazing, hunting, vehicle 
collisions, changing climate conditions), we do not have any specific 
information that allows us to make a reasonable connection between 
these potential impacts and current or future declines of white-sided 
jackrabbits. Therefore, we find that listing the subspecies of the 
white-sided jackrabbit, Lepus callotis gaillardia, as a threatened or 
an endangered species throughout its range is not warranted at this 
time.

Distinct Vertebrate Population Segments

    After assessing whether the species and the two subspecies are 
threatened or endangered throughout their range, we next consider 
whether any Distinct Vertebrate Population Segment (DPS) of the white-
sided jackrabbit's range meets the definition of endangered or is 
likely to become endangered in the foreseeable future.

Distinct Vertebrate Population Segment

    Under the Service's Policy Regarding the Recognition of Distinct 
Vertebrate Population Segments Under the Endangered Species Act (61 FR 
4722, February 7, 1996), three elements are considered in the decision 
concerning the establishment and classification of a possible DPS. 
These are applied similarly for additions to or removal from the 
Federal List of Endangered and Threatened Wildlife. These elements 
include:
    (1) The discreteness of a population in relation to the remainder 
of the species to which it belongs;
    (2) The significance of the population segment to the species to 
which it belongs; and
    (3) The population segment's conservation status in relation to the 
Act's standards for listing, delisting, or reclassification (i.e., is 
the population segment endangered or threatened).

Discreteness

    Under the DPS policy, a population segment of a vertebrate taxon 
may be considered discrete if it satisfies either one of the following 
conditions:
    (1) It is markedly separated from other populations of the same 
taxon as a consequence of physical, physiological, ecological, or 
behavioral factors. Quantitative measures of genetic or morphological 
discontinuity may provide evidence of this separation.
    (2) It is delimited by international governmental boundaries within 
which differences in control of exploitation, management of habitat, 
conservation status, or regulatory mechanisms exist that are 
significant in light of section 4(a)(1)(D) of the Act.
    We were asked to list the northern populations of the Lepus 
callotis gaillardi subspecies, which includes two valleys in Hidalgo 
County, New Mexico, as a DPS. First, we evaluated whether the potential 
DPS met the condition of discreteness. Because we have so little 
information about the species in Mexico, we are unable to thoroughly 
assess the potential separation of the United States populations from 
the Mexico populations as a consequence of physical, physiological, 
ecological, or behavioral factors. However, as discussed in Factor D 
above, the white-sided jackrabbit is not addressed by the regulatory 
mechanisms available in Mexico. Because the white-sided jackrabbit is 
covered by regulatory mechanisms in the State of New Mexico, there is a 
difference in regulatory mechanisms, and we find that the United States 
populations of the white-sided jackrabbit are discrete under the DPS 
Policy.

Significance

    If we determine that a population segment is discrete under one or 
more of the discreteness conditions described in the DPS Policy, we 
then evaluate its biological and ecological significance based on ``the 
available scientific evidence of the discrete population segment's 
importance to the taxon to which it belongs'' (61 FR 4725). We make 
this evaluation in light of congressional guidance that the Service's 
authority to list DPSs be used ``sparingly'' while encouraging the 
conservation of genetic diversity (61 FR 4722; February 7, 1996). Since 
precise circumstances are likely to vary considerably from case to 
case, the DPS Policy does not describe all the classes of information 
that might be used in determining the biological and ecological 
importance of a discrete

[[Page 53628]]

population. However, the DPS Policy describes four possible classes of 
information that provide evidence of a population segment's biological 
and ecological importance to the taxon to which it belongs. As 
specified in the DPS Policy (61 FR 4722), consideration of the 
population segment's significance may include, but is not limited to 
the following:
    (1) Persistence of the population segment in an ecological setting 
that is unusual or unique for the taxon;
    (2) evidence that loss of the population segment would result in a 
significant gap in the range of the taxon;
    (3) evidence that the population segment represents the only 
surviving natural occurrence of a taxon that may be more abundant 
elsewhere as an introduced population outside of its historical range; 
and
    (4) evidence that the discrete population segment differs markedly 
from other populations of the species in its genetic characteristics.
    The following discussion considers the significance of the United 
States population of the white-sided jackrabbit in light of the above 
criteria. The populations of white-sided jackrabbit that occur in the 
United States occupy the plains grassland and Chihuahuan Desert 
grassland vegetation types. These vegetation types, especially the 
plains grassland, are somewhat rare in the United States, but are more 
common in Mexico, thus the United States populations do not occur in a 
unique ecological setting. The populations of white-sided jackrabbit 
that occur in the United States represent less than one percent of the 
range of the species. While populations which are on the edge or 
periphery of a species' range sometimes have unique characteristics 
which may benefit the survival of a species as a whole, or while such 
areas may play an important life-history role for a species (such as 
outlying populations composed of juvenile, non-breeding animals), there 
is no information that indicates this is the case with the jackrabbit. 
Instead, these are peripheral populations occurring in an area where 
the species was never known to be abundant. The loss of these 
populations is not likely to result in a significant gap in the range 
of the taxon. While very little is known about the species in Mexico, 
there is no information which suggests that these populations are the 
only surviving natural occurances of the taxon. Additionally, there is 
no information that indicates that there are any introduced populations 
outside of their historical range anywhere. Finally, to our knowledge, 
no genetic studies of any kind have been conducted which looked at the 
genetic differences of the United States jackrabbits as compared to the 
jackrabbits in Mexico; thus we are not able to assess whether the 
United States populations differ markedly from populations in Mexico. 
In summary, there is no information that indicates the United States 
population of the white-sided jackrabbit can be considered significant 
under our DPS Policy.

DPS Conclusion

    On the basis of the best available information, we conclude that 
the United States population of white-sided jackrabbits is discrete, 
but it is not significant under the DPS Policy. Since we found that the 
population segment did not meet the significance element and, 
therefore, does not qualify as a DPS under the Service's DPS Policy, we 
will not proceed with an evaluation of the status of the population 
segment under the Act.

Significant Portion of the Range

    Having determined that the species Lepus callotis does not meet the 
definition of a threatened or endangered species, we must next consider 
whether there are any significant portions of the range where this 
species is in danger of extinction or is likely to become endangered in 
the foreseeable future.
    On March 16, 2007, a formal opinion was issued by the Solicitor of 
the Department of the Interior, ``The Meaning of `In Danger of 
Extinction Throughout All or a Significant Portion of Its Range''' 
(United States Department of Interior 2007). We have summarized our 
interpretation of that opinion and the underlying statutory language 
below. A portion of a species' range is significant if it is part of 
the current range of the species and it contributes substantially to 
the representation, resiliency, or redundancy of the species. The 
contribution must be at a level such that its loss would result in a 
decrease in the ability to conserve the species.
    In determining whether a species is threatened or endangered in a 
significant portion of its range, we first identify any portions of the 
range of the species that warrant further consideration. The range of a 
species can theoretically be divided into portions an infinite number 
of ways. However, there is no purpose to analyzing portions of the 
range that are not reasonably likely to be significant and threatened 
or endangered. To identify only those portions that warrant further 
consideration, we determine whether there is substantial information 
indicating that: (1) The portions may be significant, and (2) the 
species may be in danger of extinction there or likely to become so 
within the foreseeable future. In practice, a key part of this analysis 
is whether the threats are geographically concentrated in some way. If 
the threats to the species are essentially uniform throughout its 
range, no portion is likely to warrant further consideration. Moreover, 
if any concentration of threats applies only to portions of the 
species' range that are not significant, such portions will not warrant 
further consideration.
    If we identify portions that warrant further consideration, we then 
determine whether the species is threatened or endangered in these 
portions of its range. Depending on the biology of the species, its 
range, and the threats it faces, the Service may address either the 
significance question or the status question first. Thus, if the 
Service considers significance first and determines that a portion of 
the range is not significant, the Service need not determine whether 
the species is threatened or endangered there. Likewise, if the Service 
considers status first and determines that the species is not 
threatened or endangered in a portion of its range, the Service need 
not determine if that portion is significant. However, if the Service 
determines that both a portion of the range of a species is significant 
and the species is threatened or endangered there, the Service will 
specify that portion of the range as threatened or endangered under 
section 4(c)(1) of the Act.
    Applying the process described above for determining whether a 
species is threatened in a significant portion of its range, we next 
addressed whether any portions of the range of the white-sided 
jackrabbit warranted further consideration. On the basis of our review 
of the five listing factors above, we found no evidence of geographic 
concentration of threats either in New Mexico or Mexico such that the 
full species or either of the subspecies may be in danger of extinction 
in that portion. The information that is known about impacts to the 
white-sided jackrabbit is generally specific to those populations in 
the United States; however, a lack of information about threats in 
other portions of the range of the species one way or another does not 
mean that threats are concentrated in the United States.
    There is no information to suggest that any portion of the range of 
the species or either subspecies contributes more significantly to the 
resiliency, redundancy, and representation of the species or either 
subspecies than any other portion of the range. There is no

[[Page 53629]]

information to suggest that any portion of the range is particularly of 
better quality than any other portion, or than any portion includes an 
important concentration of certain types of habitat that are necessary 
for the species to carry out its life-history functions, such as 
breeding, feeding, migration, dispersal, or wintering. Further, there 
is no information to suggest than any portion of the range provides a 
greater increment of redundancy than any other area. Finally, very 
little genetic information is known about white-sided jackrabbits. 
There have been some studies that used a variety to taxonomy, 
morphology, and chromosome information to differentiate white-sided 
jackrabbits from other species of jackrabbits, but no genetic studies 
have been conducted to compare various populations of white-sided 
jackrabbits, thus representation cannot be assessed. As a result of the 
above analysis, we conclude that there is no indication that a 
particular portion of the white-sided jackrabbit's range warrants 
further consideration as threatened or endangered.
    We do not find that the species is in danger of extinction now, nor 
is it likely to become endangered within the foreseeable future 
throughout all or a significant portion of its range. Therefore, 
listing the full species or either subspecies as threatened or 
endangered under the Act is not warranted at this time.
    We request that you submit any new information concerning the 
status of, or threats to, this subspecies to our Southwest Regional 
Ecological Services Fish and Wildlife Office (see ADDRESSES section) 
whenever it becomes available. New information will help us monitor 
this subspecies and encourage its conservation. If an emergency 
situation develops for this subspecies or any other species, we will 
act to provide immediate protection.

References Cited

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

Author(s)

    The primary authors of this notice are the staff members of the 
Southwest Regional Ecological Services Office (see ADDRESSES section)

Authority

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

    Dated: August 19, 2010.
Wendi Weber,
Acting Deputy Director, Fish and Wildlife Service.
[FR Doc. 2010-21774 Filed 8-31-10; 8:45 am]
BILLING CODE 4310-55-S