[Federal Register Volume 80, Number 11 (Friday, January 16, 2015)]
[Rules and Regulations]
[Pages 2487-2512]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 2015-00441]
[[Page 2487]]
Vol. 80
Friday,
No. 11
January 16, 2015
Part II
Department of the Interior
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Fish and Wildlife Service
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50 CFR Part 17
Endangered and Threatened Wildlife and Plants; Endangered Status for
the Mexican Wolf and Regulations for the Nonessential Experimental
Population of the Mexican Wolf; Final Rules
Federal Register / Vol. 80 , No. 11 / Friday, January 16, 2015 /
Rules and Regulations
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DEPARTMENT OF THE INTERIOR
Fish and Wildlife Service
50 CFR Part 17
[Docket No. FWS-HQ-ES-2013-0073; FXES11130900000-156-FF09E42000]
RIN 1018-AY00
Endangered and Threatened Wildlife and Plants; Endangered Status
for the Mexican Wolf
AGENCY: Fish and Wildlife Service, Interior.
ACTION: Final rule.
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SUMMARY: We, the U.S. Fish and Wildlife Service (Service), determine
endangered status under the Endangered Species Act of 1973, as amended,
for the Mexican wolf (Canis lupus baileyi). The effect of this
regulation will be to revise the List of Endangered and Threatened
Wildlife by making a separate entry for the Mexican wolf. We are
separating our determination on the listing of the Mexican wolf as
endangered from the determination on our proposal regarding the
delisting of the gray wolf in the United States and Mexico. This rule
finalizes our determination for the Mexican wolf.
DATES: This rule becomes effective February 17, 2015.
ADDRESSES: This final rule is available on the internet at http://www.regulations.gov and http://www.fws.gov/southwest/es/mexicanwolf/.
Comments and materials we received, as well as some of the supporting
documentation we used in preparing this rule, are available for public
inspection at http://www.regulations.gov. All of the comments,
materials, and documentation that we considered in this rulemaking are
available by appointment, during normal business hours at: Mexican Wolf
Recovery Program, U.S. Fish and Wildlife Service, New Mexico Ecological
Services Field Office, 2105 Osuna Road NE., Albuquerque, NM 87113; by
telephone 505-761-4704; or by facsimile 505-346-2542.
FOR FURTHER INFORMATION CONTACT: Sherry Barrett, Mexican Wolf Recovery
Coordinator, U.S. Fish and Wildlife Service, New Mexico Ecological
Services Field Office, 2105 Osuna Road, NE., Albuquerque, NM 87113; by
telephone 505-761-4704; or by facsimile 505-346-2542. If you use a
telecommunications device for the deaf (TDD), call the Federal
Information Relay Service (FIRS) at 800-877-8339. Further contact
information can be found on the Mexican Wolf Recovery Program's Web
site at http://www.fws.gov/southwest/es/mexicanwolf/.
SUPPLEMENTARY INFORMATION:
Executive Summary
Why we need to publish a rule. Under the Endangered Species Act
(Act), a subspecies warrants protection if it is endangered or
threatened throughout all or a significant portion of its range.
Listing a subspecies as endangered or threatened can only be completed
by issuing a rule. We proposed to delist the gray wolf and maintain
protections for the Mexican wolf by listing it as an endangered
subspecies on June 13, 2013 (78 FR 35664). At this time, we are
finalizing the proposal to list the Mexican wolf as an endangered
subspecies. Elsewhere in this Federal Register, we are finalizing
revisions to the regulations for the nonessential experimental
population of the Mexican wolf.
We note that the United States District Court for the District of
Columbia recently vacated the final rule at 76 FR 81666 (December 28,
2011) that removed protections of the Act from the gray wolf in the
western Great Lakes. Humane Society v. Jewell, 2014 U.S. Dist. Lexis
175846 (D.D.C. December 19, 2014). The court's action was based, in
part, on its conclusion that the Act does not allow the Service to use
its authority to identify distinct population segments (DPSs) as
``species'' to remove the protections for part of a listed species. We
have determined that the decision in Humane Society does not change our
conclusions in this final rule. First, the district court's
interpretation of the Act is in error, and is in any case not binding
on particular matters not at issue in that case. Second, the action
here is distinguishable from that in Humane Society. Here, the Service
is not designating a DPS, but is taking an action with respect to a
subspecies of a listed entity. In addition, the Service is not reducing
protections for the Mexican wolf or delisting it, but instead is
confirming that it is an endangered species.
This rule will finalize the listing of the Mexican wolf as an
endangered subspecies.
The basis for our action. Under the Act, a subspecies is determined
to be endangered or threatened because of any of the following factors:
(A) The present or threatened destruction, modification, or curtailment
of its habitat or range; (B) overutilization for commercial,
recreational, scientific, or educational purposes; (C) disease or
predation; (D) the inadequacy of existing regulatory mechanisms; and
(E) other natural or manmade factors affecting its continued existence.
We have determined the Mexican wolf meets the definition of an
endangered subspecies primarily because of illegal killing, inbreeding,
loss of heterozygosity, loss of adaptive potential, small population
size, and the cumulative effects of the aforementioned threats. Absent
protection by the Act, regulatory protection would not be adequate to
ensure the survival of the Mexican wolf.
Peer review and public comment. Through the National Center for
Ecological Analysis and Synthesis we sought comments from independent
specialists to ensure that our designation is based on scientifically
sound data, assumptions, and analyses. These peer reviewers were
invited to comment on our listing proposal. We also considered all
comments and information received during the public comment period.
Background
Previous Federal Actions for Mexican Wolves
Gray wolves were originally listed as subspecies or as regional
populations of subspecies in the contiguous United States and Mexico.
We listed the Mexican gray wolf subspecies, Canus lupus baileyi, as
endangered on April 28, 1976 (41 FR 17736), in the southwestern United
States and Mexico.
In 1978, we published a rule (43 FR 9607, March 9, 1978)
classifying the gray wolf as an endangered population at the species
level (Canis lupus) throughout the contiguous United States and Mexico,
except for the Minnesota gray wolf population, which was classified as
threatened. At that time, we considered the gray wolves in Minnesota to
be a listable entity under the Act, and we considered the gray wolves
in Mexico and the 48 contiguous United States other than Minnesota to
be another listable entity (43 FR 9607 and 9610, respectively, March 9,
1978). The separate subspecies listings thus were subsumed into the
listings for the gray wolf in Minnesota and the gray wolf in the rest
of the contiguous United States and Mexico.
The 1978 listing of the gray wolf was undertaken to address changes
in our understanding of gray wolf taxonomy, and recognize the fact that
individual wolves sometimes disperse across subspecific boundaries,
resulting in intergradation of neighboring populations. The 1978 rule
also stipulated that ``biological subspecies
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would continue to be maintained and dealt with as separate entities''
(43 FR 9609), and offered ``the firmest assurance that [the Service]
will continue to recognize valid biological subspecies for purposes of
its research and conservation programs'' (43 FR 9610, March 9, 1978).
Accordingly, we implemented three gray wolf recovery programs in
the following regions of the country: the Western Great Lakes
(Minnesota, Michigan, and Wisconsin, administered by the Service's
Great Lakes, Big Rivers Region), the Northern Rocky Mountains (Idaho,
Montana, and Wyoming, administered by the Service's Mountain-Prairie
Region and Pacific Region), and the Southwest (Arizona, New Mexico,
Texas, Oklahoma, Mexico, administered by the Service's Southwest
Region). Recovery plans were developed in each of these areas (the
northern Rocky Mountains in 1980, revised in 1987; the Great Lakes in
1978, revised in 1992; and the Southwest in 1982) to establish and
prioritize recovery criteria and actions appropriate to the unique
local circumstances of the gray wolf. A separate recovery effort for
gray wolves formerly listed as Canis lupus monstrabilis was not
undertaken because this subspecies was subsumed with the Mexican wolf,
C. l. baileyi, and thus addressed as part of the recovery plan for the
Southwest.
In the Southwest, on August 11, 2009, we received a petition dated
the same day from the Center for Biological Diversity requesting that
we list the Mexican wolf as an endangered subspecies or distinct
population segment (DPS) and designate critical habitat under the Act.
On August 12, 2009, we received a petition dated August 10, 2009, from
WildEarth Guardians and The Rewilding Institute requesting that we list
the Mexican wolf as an endangered subspecies and designate critical
habitat under the Act. On October 9, 2012, we published a 12-month
finding in the Federal Register stating that, because all individuals
that constitute the petitioned entity already receive the protections
of the Act, the petitioned action was not warranted at that time (77 FR
61375).
On February 29, 2012, we concluded a 5-year review of the Canis
lupus listed entity, recommending that the entity currently described
on the List of Endangered and Threatened Wildlife should be revised to
reflect the distribution and status of C. lupus populations in the
contiguous United States and Mexico by removing all areas currently
included in the Code of Federal Regulations (CFR) range except where
there is a valid species, subspecies, or DPS that is threatened or
endangered.
On June 13, 2013 (78 FR 35664), we published a proposed rule to
delist the gray wolf and maintain protections for the Mexican wolf by
listing it as an endangered subspecies. Upon publication of the
proposed rule, we opened the public comment period on the proposal. On
September 5 and October 2, 2013, we announced public hearings on the
proposed rule (78 FR 54614 and 78 FR 60813). The September 5 document
also extended the public comment period for the proposed rule to
October 28, 2013. Following delays caused by the Federal Government
lapse in appropriations, the Service announced rescheduled dates for
three of the public hearings, scheduled a fifth public hearing, and
extended the public comment period for the proposed rule to December
17, 2013 (78 FR 64192, October 28, 2013). On February 10, 2014 (79 FR
7627), we reopened the public comment period on the proposal in
conjunction with the submission of the peer review report. The comment
period closed on March 27, 2014.
Subspecies Information
Taxonomy
The Mexican wolf subspecies, Canis lupus baileyi, was originally
described by Nelson and Goldman in 1929 as Canis nubilus baileyi, with
a distribution of ``Southern and western Arizona, southern New Mexico,
and the Sierra Madre and adjoining tableland of Mexico as far south, at
least, as southern Durango (Nelson and Goldman 1929, pp. 165-166).''
Goldman (1944, pp. 389-636) provided the first comprehensive treatment
of North American wolves, in which he renamed C. n. baileyi as a
subspecies of lupus (i.e., C. l. baileyi) and shifted the subspecies'
range farther south in Arizona. His gray wolf classification scheme was
subsequently followed by Hall and Kelson (1959, pp. 847-851; Hall 1981,
p. 932). Since that time, gray wolf taxonomy has undergone substantial
revision, including a major taxonomic revision in which the number of
recognized gray wolf subspecies in North America was reduced from 24 to
5, with the Mexican wolf, C. l. baileyi, being recognized as a
subspecies ranging throughout most of Mexico to just north of the Gila
River in southern Arizona and New Mexico (Nowak 1995, pp. 375-397).
Three published studies of morphometric variation conclude that the
Mexican wolf is a morphologically distinct and valid subspecies. Bogan
and Mehlhop (1983) analyzed 253 gray wolf skulls from southwestern
North America using principal component analysis and discriminant
function analysis. They found that the Mexican wolf was one of the most
distinct subspecies of southwestern gray wolf (Bogan and Mehlhop 1983,
p. 17). Hoffmeister (1986) conducted principal component analysis of 28
skulls, also recognizing the Mexican wolf as a distinct southwestern
subspecies (pp. 466-468). Nowak (1995) analyzed 580 skulls using
discriminant function analysis. He concluded that the Mexican wolf was
one of only five distinct North American gray wolf subspecies that
should continue to be recognized (Nowak 1995, pp. 395-396).
Genetic research provides additional validation of the recognition
of the Mexican wolf as a subspecies. Studies have demonstrated that the
Mexican wolf has unique genetic markers that distinguish the subspecies
from other North American gray wolves. Garcia-Moreno et al. (1996, p.
384) utilized microsatellite analysis to determine whether two captive
populations of Mexican wolves were pure C. l. baileyi and should be
interbred with the captive certified lineage population that founded
the captive breeding program. They confirmed that the two captive
populations were pure Mexican wolves and that they and the certified
lineage were closely related. Further, they found that, as a group, the
three populations were the most distinct grouping of North American
wolves, substantiating the distinction of the Mexican wolf as a
subspecies.
Hedrick et al. (1997, pp. 64-65) examined data for 20
microsatellite loci from samples of Mexican wolves, northern gray
wolves, coyotes, and dogs. They concluded that the Mexican wolf was
divergent and distinct from other sampled northern gray wolves,
coyotes, and dogs. Leonard et al. (2005, p. 10) examined mitochondrial
DNA sequence data from 34 wolves collected from 1856 to 1916 from the
historical ranges of Canis lupus baileyi and Canis lupus nubilus. They
compared these data with sequence data collected from 96 wolves in
North America and 303 wolves from Eurasia. They found that the
historical wolves had twice the diversity of modern wolves, and that
two-thirds of the haplotypes were unique. They also found that
haplotypes associated with the Mexican wolf formed a unique southern
clade distinct from that of other North American wolves. A clade is a
taxonomic group that includes all individuals that have descended from
a common ancestor.
In another study, von Holdt et al. (2011, p. 7) analyzed single
nucleotide
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polymorphisms genotyping arrays and found Canis lupus baileyi to be the
most genetically distinct group of New World gray wolves. Chambers et
al. (2012, pp. 34-37) reviewed the scientific literature related to
classification of the Mexican wolf as a subspecies and concluded that
this subspecies' recognition remains well-supported. Most recently,
Cronin et al. (2014, p. 9) analyzed single nucleotide polymorphism
genotyping arrays and found single nucleotide polymorphisms
differentiation of Mexican wolves from other North American wolves.
However, Cronin et al. (2014, p. 9) challenge the subspecies concept
for North American wolves, including the Mexican wolf, based on their
interpretation of other authors work (most notably Leonard et al. 2005
relative to mtDNA monophyly (see southern clade discussion above)).
Maps of the Mexican wolf's historical range are available in the
scientific literature (Young and Goldman 1944, p. 414; Hall and Kelson,
1959, p. 849; Hall 1981, p. 932; Bogan and Mehlhop 1983, p. 17; Nowak
1995, p. 395; Parsons 1996, p. 106). The southernmost extent of Mexican
wolf's range in Mexico is consistently portrayed as ending near Oaxaca
(Hall 1981, p. 932; Nowak 1995, p. 395). Depiction of the northern
extent of the Mexican wolf's pre-settlement range among the available
descriptions varies depending on the authors' taxonomic treatment of
several subspecies that occurred in the Southwest and their related
treatment of intergradation zones. Recent research based on historical
specimens suggests the Mexican wolf ranged into southern Utah and
southern Colorado across zones of intergradation where interbreeding
with northern gray wolf subspecies may have occurred (Leonard et al.
2005, p. 11 and p. 15, insomuch as haplotype lu47 only had been
documented to occur in Mexican wolves and was documented in a specimen
in southern Colorado).
Hall's (1981, p. 932, based on Hall and Kelson 1959) map depicted a
range for the Mexican wolf that included extreme southern Arizona and
New Mexico, with Canis lupus mogollonensis occurring throughout most of
Arizona, and C. l. monstrabilis, Canis l. youngi, C. l. nubilus, and C.
l. mogollonensis interspersed in New Mexico. Bogan and Mehlhop (1983,
p. 17) synonymized two previously recognized subspecies of gray wolf,
C. l. mogollonensis and C. l. monstrabilis, with the Mexican wolf,
concluding that the Mexican wolf's range included the Mogollon Plateau,
southern New Mexico, Arizona, Texas, and Mexico. This extended the
Mexican wolf's range northward to central Arizona and central New
Mexico through the area that Goldman (1944) had identified as an
intergrade zone with an abrupt transition from the Mexican wolf to C.
l. mogollensis. Bogan and Mehlop's analysis did not indicate a sharp
transition zone between the Mexican wolf and C. l. mogollensis, rather
the wide overlap between the two subspecies led them to synonymize the
Mexican wolf and C. l. mogollensis.
Hoffmeister (1986, p. 466) suggested that Canis lupus mogollonensis
should be referred to as C. l. youngi, but maintained the Mexican wolf,
C. l. baileyi, as a subspecies, stating that wolves north of the
Mogollon Rim should be considered C. l. youngi. Nowak (1995, pp. 384-
385) agreed with Hoffmeister's synonymizing of C. l. mogollonensis with
C. l. youngi, and further lumped these into C. l. nubilus, resulting in
a purported northern historical range for Mexican wolf as just to the
north of the Gila River in southern Arizona and New Mexico. Nowak
(1995) and Bogan and Mehlhop (1983) differed in their interpretation of
which subspecies to assign individuals that were intermediate between
recognized taxa, thus leading to different depictions of historical
range for the Mexican wolf.
Subsequently, Parsons (1996, p. 104) included consideration of
dispersal distance when developing a probable historical range for the
purpose of reintroducing Mexican wolves in the wild pursuant to the
Act, by adding a 200-mi (322-km) northward extension to the most
conservative depiction of the Mexican wolf historical range (i.e., Hall
and Kelson 1959). This description of historical range was carried
forward in the Final Environmental Impact Statement ``Reintroduction of
the Mexican Wolf within its Historic Range in the Southwestern United
States'' in the selection of the Blue Range Wolf Recovery Area as a
reintroduction location for Mexican wolves (Service 1996).
Recent molecular genetic evidence from limited historical specimens
supports morphometric evidence of an intergradation zone between
Mexican wolf and northern gray wolves (Leonard et al. 2005, pp. 15-16).
This research shows that, within the time period that the historical
specimens were collected (1856-1916), a northern clade (i.e., group
that originated from and includes all descendants from a common
ancestor) haplotype was found as far south as Arizona, and individuals
with southern clade haplotypes (associated with Mexican wolves)
occurred as far north as Utah and Nebraska. Leonard et al. (2005, p.
10) interpret this geographic distribution of haplotypes as indicating
gene flow was extensive across the subspecies' limits during this
historical period, and Chambers et al. (2012, p. 37) agree this may be
a valid interpretation.
Subspecies Description
The Mexican wolf is the smallest extant gray wolf in North America.
Adults weigh 23 to 41 kg (50 to 90 lb) with a length of 1.5 to 1.8 m (5
to 6 ft) and height at shoulder of 63 to 81 cm (25 to 32 in) (Brown
1988, p. 119). Mexican wolves are typically a patchy black, brown to
cinnamon, and cream color, with primarily light underparts (Brown 1988,
p. 118). Solid black or white coloration, as seen in other North
American gray wolves, does not exist in Mexican wolves. Basic life
history for Mexican wolves is similar to that of other gray wolves
(Mech 1970, entire; Service 1982, p. 11; Service 2010, pp. 32-41).
Historical Distribution and Causes of Decline
Prior to the late 1800s, the Mexican wolf inhabited the
southwestern United States and Mexico. In Mexico, Mexican wolves ranged
from the northern border of the country southward through the Sierra
Madre Oriental and Occidental and the altiplano (high plains) to the
Neovolcanic Axis (a volcanic belt that runs east-west across central-
southern Mexico) (SEMARNAP 2000, p. 8), although wolf distribution may
not have been continuous through this entire region (McBride 1980, pp.
2-7). The Mexican wolf is the only subspecies known to have inhabited
Mexico. In the United States, Mexican wolves (and, in some areas, Canis
lupus nubilus and the previously recognized subspecies C. l.
monstrabilis, C. l. mogollonensis, and C. l. youngi) inhabited montane
forests and woodlands in portions of New Mexico, Arizona, and Texas
(Young and Goldman 1944, p. 471; Brown 1988, pp. 22-23) (see Taxonomy).
In southern Arizona, Mexican wolves inhabited the Santa Rita,
Tumacacori, Atascosa-Pajarito, Patagonia, Chiricahua, Huachuca,
Pinaleno, and Catalina Mountains, west to the Baboquivaris and east
into New Mexico (Brown 1983, pp. 22-23). In central and northern
Arizona, the Mexican wolf and other subspecies of gray wolf were
interspersed (Brown 1983, pp. 23-24). The Mexican wolf and other
subspecies were present throughout New Mexico, with the exception of
low desert areas, documented as numerous or persisting in areas
including the Mogollon, Elk, Tularosa, Diablo and Pinos Altos
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Mountains, the Black Range, Datil, Gallinas, San Mateo, Mount Taylor,
Animas, and Sacramento Mountains (Brown 1983, pp. 24-25). Gray wolf
distribution (of other subspecies) continued eastward into the Trans-
Pecos region of Texas and northward up the Rocky Mountains and to the
Grand Canyon (Young and Goldman 1944, pp. 23, 50, 404-405), where
intergradation between northern and southern wolf clades occurred
(Leonard et al. 2005, pp. 11-15).
Population estimates of gray wolves, and specifically Mexican
wolves, prior to the late 1800s are not available for the southwestern
United States or Mexico. Some trapping records and rough population
estimates are available from the early 1900s, but do not provide a
rigorous estimate of population size of Mexican wolves in the United
States or Mexico. For New Mexico, a statewide carrying capacity
(potential habitat) of about 1,500 gray wolves was hypothesized by
Bednarz, with an estimate of 480 to 1,030 wolves present in 1915 (ibid,
pp. 6, 12). Brown summarized historical distribution records for the
wolf from McBride (1980, p. 2) and other sources, showing most records
in the southwestern United States as being from the Blue Range and the
Animas region of New Mexico (Brown 1983, p. 10). In Mexico, Young and
Goldman (1944, p. 28) stated that from 1916 to 1918 the Mexican wolf
was fairly numerous in Sonora, Chihuahua, and Coahuila, although
McBride comments that Mexican wolves apparently did not inhabit the
eastern and northern portions of Coahuila, even in areas with seemingly
good habitat (1980, p. 2).
The 1982 Mexican Wolf Recovery Plan cautioned: ``It is important .
. . not to accept unquestioningly the accounts of the 1800s and early
1900s that speak of huge numbers of wolves ravaging herds of livestock
and game . . . . The total recorded take indicates a much sparser
number of wolves in the treated areas than the complaints of damage
state or signify, even when one remembers that these figures do not
reflect the additional numbers of wolves taken by ranchers, bounty-
seekers and other private individuals (Service 1982, p. 4).''
Mexican wolf populations declined rapidly in the early and mid-
1900s, due to government and private efforts across the United States
to kill wolves and other predators. By 1925, poisoning, hunting, and
trapping efforts drastically reduced Mexican wolf populations in all
but a few remote areas of the southwestern United States, and control
efforts shifted to wolves in the borderlands between the United States
and Mexico (Brown 1983, p. 71). Bednarz (1988, p. 12) estimated that
breeding populations of Mexican wolves were extirpated from the United
States by 1942. The use of increasingly effective poisons and trapping
techniques during the 1950s and 1960s eliminated remaining Mexican
wolves north of the United States-Mexico border, although occasional
reports of wolves crossing into the United States from Mexico persisted
into the 1960s. Wolf distribution in northern Mexico contracted to
encompass the Sierra Madre Occidental in Chihuahua, Sonora, and
Durango, as well as a disjunct population in western Coahuila (from the
Sierra del Carmen westward). Leopold (1959, p. 402) found conflicting
reports on the status of the Coahuila population and stated that wolves
were likely less abundant there than in the Sierra Madre Occidental.
When the Mexican wolf was listed as endangered under the Act in
1976, no wild populations were known to remain in the United States or
Mexico. McBride (1980, pp. 2-8) conducted a survey to determine the
status and distribution of wolves in Mexico in 1977. He mapped 3
general areas where wolves were recorded as still present in the Sierra
Madre Occidental: (1) Northern Chihuahua and Sonora border (at least 8
wolves); (2) western Durango (at least 20 wolves in 2 areas); and (3) a
small area in southern Zacatecas. Although occasional anecdotal reports
have been made during the last three decades that a few wild wolves
still inhabit forested areas in Mexico, no publicly available
documented verification exists. Several Mexican wolf individuals
captured in the wild in Mexico became the basis for the captive-
breeding program that has enabled the reintroduction to the wild (see
below, Current Distribution--In Captivity).
Current Distribution in the United States
On January 12, 1998, we published a final rule in the Federal
Register to establish the Mexican Wolf Experimental Population Area
(MWEPA) in central Arizona, New Mexico, and a small portion of
northwestern Texas (63 FR 1752). In March of 1998 we released 11
Mexican wolves from the captive-breeding program to the wild. We have
conducted additional initial releases or translocations of individuals
and family groups into the Blue Range Wolf Recovery Area (BRWRA) within
the MWEPA through 2014. At the end of 2013, a single wild population of
a minimum of 83 Mexican wolves (December 31, 2013, population count)
inhabited the United States in central Arizona and New Mexico. Mexican
wolves do not occupy the small portion of northwestern Texas included
in the MWEPA. For more information regarding the MWEPA, please see
Revision to the Regulations for the Nonessential Experimental
Population of the Mexican Wolf, which published elsewhere in this
Federal Register.
Mexican wolves associated with the MWEPA also currently occupy the
Fort Apache Indian Reservation of the White Mountain Apache Tribe,
adjacent to the western boundary of the BRWRA. Since 2000, an agreement
between the Service and the White Mountain Apache Tribe permits the
release, dispersal, and establishment of Mexican wolves onto the
reservation, providing an additional 2,500 mi\2\ (6,475 km\2\) of high-
quality forested wolf habitat for the reintroduction (Service 2001, p.
4). The White Mountain Apache Tribe does not make information about the
number and location of Mexican wolves on the reservation publicly
available.
Detailed information on the status of the experimental population
and the reintroduction project can be found in the 2001 to 2013 annual
reports, the 2010 Mexican Wolf Conservation Assessment (Service 2010),
and our online population statistics, available at http://www.fws.gov/southwest/es/mexicanwolf/.
Current Distribution in Mexico
In October 2011, Mexico initiated the reestablishment of Mexican
wolves to the wild (see Historical Distribution) with the release of
five captive-bred Mexican wolves into the San Luis Mountains just south
of the U.S.-Mexico border. Mexico has continued to release animals into
the wild during the past few years. Through August 2014, Mexico
released a total of 14 adult Mexican wolves, of which 11 died or are
believed dead, and 1 was removed for veterinary care. Of the 11 Mexican
wolves that died or are believed dead, 6 were due to illegal killings
(4 from poisoning and 2 were shot), 1 wolf was presumably killed by a
mountain lion, 3 causes of mortality are unknown (presumed illegal
killings because collars were found, but not the carcasses), and 1
disappeared (neither collar nor carcass has been found). The remaining
two adult Mexican wolves were documented with five pups in 2014,
marking the first successful reproductive event in Mexico. We expect
the number of Mexican wolves in Mexico to fluctuate from zero to
several packs in or around Sonora, Durango, and Chihuahua in the near
future.
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In Captivity
Due to the extirpation of Mexican wolves in the United States and
Mexico, the first step in the recovery of the subspecies was the
development of a captive-breeding population to ensure the Mexican wolf
did not go extinct. Between 1977 and 1980, a binational captive-
breeding program between the United States and Mexico, referred to as
the Mexican Wolf Species Survival Plan (SSP), was initiated with the
capture of the last known Mexican wolves in the wild in Mexico and
subsequent addition of wolves from captivity in Mexico and the United
States. The individual unrelated seven wolves used to establish the
captive-breeding program are considered the ``founders'' of the
breeding population. These pure Mexican wolves represent three distinct
lineages (family groups): McBride (also known as the Certified lineage;
three individuals), Ghost Ranch (two individuals), and Aragon (two
individuals). From the breeding of these 7 Mexican wolves and
generations of their offspring, the captive population has expanded to
its current size of 248 Mexican wolves in 55 facilities in the United
States and Mexico (Siminski and Spevak 2014).
The purpose of the SSP is to reestablish Mexican wolves in the wild
through captive breeding, public education, and research. This captive
population is the sole source of Mexican wolves available to
reestablish the subspecies in the wild and is imperative to the success
of the Mexican wolf reintroduction project and any additional efforts
to reestablish the subspecies that may be pursued in the future in
Mexico by the General del Vida Silvestre or by the Service in the
United States.
Captive Mexican wolves are routinely transferred among the zoos and
other SSP holding facilities to facilitate genetic exchange (through
breeding) and maintain the health and genetic diversity of the captive
population. The SSP strives to house a minimum of 240 wolves in
captivity at all times to ensure the security of the subspecies in
captivity, while still being able to produce surplus animals for
reintroduction.
In the United States, Mexican wolves from captive SSP facilities
that are identified for potential release are first evaluated for
release suitability and undergo an acclimation process. All Mexican
wolves selected for release in the United States and Mexico are
genetically redundant to the captive population, meaning their genes
are already well represented in captivity. This minimizes any adverse
effects on the genetic integrity of the remaining captive population in
the event that Mexican wolves released to the wild do not survive.
Habitat Description
Historically, Mexican wolves were associated with montane woodlands
characterized by sparsely to densely forested mountainous terrain
consisting of evergreen oaks (Quercus spp.) or pinyon (Pinus edulus)
and juniper (Juniperus spp.) to higher elevation pine (Pinus spp.),
mixed-conifer forests, and adjacent grasslands at elevations of 4,000
to 5,000 ft (1,219 to 1,524 m) where ungulate prey were numerous.
Factors making these vegetation communities attractive to Mexican
wolves likely included the abundance of ungulate prey, availability of
water, and the presence of hiding cover and suitable den sites. Early
investigators reported that Mexican wolves probably avoided desert
scrub and semidesert grasslands that provided little cover, food, or
water (Brown 1988, pp. 19-22).
Prior to their extirpation in the wild, Mexican wolves were
believed to have preyed upon white-tailed deer (Odocoileus
virginianus), mule deer (O. hemionus), elk (Cervus elaphus), collared
peccaries (javelina) (Tayassu tajacu), pronghorn (Antilocapra
americana), bighorn sheep (Ovis canadensis), jackrabbits (Lepus spp.),
cottontails (Sylvilagus spp.), and small rodents (Parsons and
Nicholopoulos 1995, pp. 141-142); white-tailed deer and mule deer were
believed to be the primary sources of prey (Brown 1988, p. 132; Bednarz
1988, p. 29).
Today, Mexican wolves in Arizona and New Mexico inhabit evergreen
pine-oak woodlands (i.e., Madrean woodlands), pinyon-juniper woodlands
(i.e., Great Basin conifer forests), and mixed-conifer montane forests
(i.e., Rocky Mountain, or petran, forests) that are inhabited by elk,
mule deer, and white-tailed deer (Service 1996, pp. 3-5; AMOC and IFT
2005, p. TC-3). Mexican wolves in Arizona and New Mexico show a strong
preference for elk compared to other ungulates (AMOC and IFT 2005, p.
TC-14, Reed et al. 2006, pp. 56, 61; Merkle et al. 2009, p. 482). Other
documented sources of prey include deer (O. virginianus and O.
hemionus) and occasionally small mammals and birds (Reed et al. 2006,
p. 55). Mexican wolves are also known to prey and scavenge on livestock
(Reed et al. 2006, p. 1129).
Summary of Comments and Recommendations
We requested written comments from the public on the proposed rule
to remove the gray wolf from the List of Endangered and Threatened
Wildlife and maintaining protections for the Mexican wolf by listing it
as endangered during a 6-month comment period from June 13, 2013, to
December 17, 2013. Between September 30, 2013, and December 3, 2013,
the Service held a series of public hearings on the proposed rule:
September 30, 2013, in Washington, District of Columbia; November 19,
2013, in Denver, Colorado; November 20, 2013, in Albuquerque, New
Mexico; November 22, 2013, in Sacramento, California; and December 3,
2013, in Pinetop, Arizona. We reopened the public comment period on
February 10, 2014, in conjunction with announcing the availability of
the independent scientific peer review report on the proposal. This
comment period closed on March 27, 2014. We also contacted appropriate
Federal, Tribal, State, county, and local agencies, scientific
organizations, and other interested parties and invited them to comment
on the proposed rule during these comment periods.
All substantive information specifically related to our proposal to
list the Mexican wolf as an endangered subspecies provided during the
comment periods, including the public hearings, has either been
incorporated directly into this final determination or addressed below.
Comments from peer reviewers and State agencies are grouped separately.
In addition to the comments, some commenters submitted additional
reports and references for our consideration, which were reviewed and
incorporated into this final rule as appropriate.
Peer Reviewer Comments
The National Center for Ecological Analysis and Synthesis (NCEAS)
was asked to perform an independent scientific review of the proposed
rule to remove the gray wolf from the List of Endangered and Threatened
Wildlife and maintain protections for the Mexican wolf by listing it as
endangered (78 FR 35664, June 13, 2013). In accordance with our peer
review policy published on July 1, 1994 (59 FR 34270), NCEAS solicited
expert opinions from seven knowledgeable individuals with scientific
expertise that included familiarity with the species, the geographic
region in which the species occurs, and conservation biology
principles. NCEAS received responses from five of the seven peer
[[Page 2493]]
reviewers they contacted during the public comment period.
Based on their panel discussion in January 2014, peer reviewers
came to general consensus that the Mexican wolf is the most
differentiated gray wolf in North America. Also, peer reviewers
discussed and seemed to reach general concurrence that the historical
range of the Mexican wolf was likely larger than described by the
Service in the proposed rule based on the presence of genetic markers
found in historical wolf specimens described by Leonard et al. 2005,
and they questioned how this information should be incorporated into
decisions about its status. They expressed concern over the Service's
reliance on the Chambers et al. 2012, manuscript within the Service's
proposal to delist the gray wolf in the United States, which included
the identification of, and discussion of the validity of, other gray
wolf subspecies, but their concerns did not lead them to conclude that
the Mexican wolf was not a valid entity to list under the Act. Rather,
they focused on how the Service should ``draw a line on a map'' to
indicate the historical range of the Mexican wolf and the appropriate
geographic extent of the listed entity.
We reviewed all comments received from the peer reviewers regarding
the proposed listing of the Mexican wolf as an endangered subspecies.
As previously noted, the peer reviewers generally concurred with our
methods and conclusions that the Mexican wolf is ecologically and
morphologically distinct. They also provided additional information,
clarifications, and suggestions to improve this final rule. Peer
reviewer comments are addressed in the following summary and
incorporated into the final rule, as appropriate.
(1) Comment: Peer reviewers stated that the Service did not use the
best available information related to the exclusive reliance on the
concordance method of identifying species/subspecies utilized by
Chambers et al. 2012. The justification for the exclusive use of this
approach is not well defended by the Service.
Our response: As required by section 4(b) of the Act, we used the
best scientific and commercial data available in making this final
determination for the Mexican wolf. We solicited peer review from
knowledgeable individuals with scientific expertise that included
familiarity with the species, the geographic region in which the
species occurs, and conservation biology principles to ensure that our
listing is based on scientifically sound data, assumptions, and
analysis. Additionally, we requested comments or information from other
concerned governmental agencies, Native American Tribes, the scientific
community, industry, and any other interested parties concerning the
proposed rule. The commenters' concerns with the Service's reliance on
the Chambers et al. 2012, manuscript primarily focused on taxonomic
issues associated with gray wolf populations other than the Mexican
wolf. Taxonomic issues related to other gray wolf populations are not
germane to this final rule to list the Mexican wolf as an endangered
subspecies. Specific to the Mexican wolf, the peer reviewers concurred
that the Mexican wolf is differentiated from other gray wolves by
multiple morphological and genetic markers documented in the scientific
literature. The Act is explicit that threatened or endangered
subspecies are to be protected.
(2) Comment: Peer reviewers noted that genetic markers indicate a
larger historical range for Mexican wolf than described by the Service
and should be taken into consideration when determining its status and
the range within which recovery could occur.
Our response: We have not attempted to define historical range for
the Mexican wolf, but rather to describe available historical range
information contained in the scientific literature, including the
research by Leonard et al. 2005 referenced by the peer reviewers.
Listing the entire Mexican wolf subspecies means that all members of
the taxon are afforded the protections of the Act regardless of where
they are found; therefore, we do not demarcate a specific geographic
area in which conservation and recovery efforts may take place. Rather,
guidance about the abundance and distribution of the Mexican wolf
necessary for delisting will be provided in a revised recovery plan
containing recovery (delisting) criteria. Therefore, we recognize that
current research such as Leonard et al. 2005 suggests a larger
historical geographic range for the Mexican wolf than described by
prior accounts (Hall 1981, p. 932; Bogan and Mehlhop 1983, p. 17; Nowak
1995, pp. 384-385). However, this information does not lead us to a
different conclusion about the endangered status of the Mexican wolf,
nor are any recovery options precluded by our discussion of historical
range.
Comments From States
(3) Comment: One State agency expressed concern that the Service
did not articulate reasons for choosing to list the Mexican wolf as a
subspecies rather than a DPS, claiming that the Mexican wolf is legally
eligible for a DPS listing under the Service's policy, and, therefore,
the choice to list it as a subspecies as opposed to a DPS is a
discretionary act subject to review under the Administrative Procedure
Act.
Our response: Under section 3(16) of the Act, we may consider for
listing any species, including subspecies, of fish, wildlife, or
plants, or any DPS of vertebrate fish or wildlife that interbreeds when
mature. As noted in our Policy Regarding the Recognition of Distinct
Vertebrate Population Segments Under the Act (61 FR 4722, February 7,
1996), Congress has instructed the Secretary to exercise authority to
list DPS's sparingly. Because a DPS is typically a subset of a species
or subspecies, we first determine whether any negative impacts appear
to be affecting the species or subspecies anywhere in its range, and
whether any of these impacts rise to the level of threats such that the
species or subspecies is endangered or threatened throughout its range.
If we determine that a species or subspecies is endangered or
threatened throughout its range, then we are not required to conduct a
DPS analysis. In other words, we typically first assess whether or not
an entity qualifies for listing as a species or subspecies before
assessing whether it qualifies as a DPS. Because the Mexican wolf
qualifies for listing as a subspecies throughout its range, we are not
analyzing whether or not it warrants listing as a DPS.
(4) Comment: Among other alternatives, the Service should also be
considering listing two DPS's of gray wolf or Mexican wolf (i.e., one
in Arizona and New Mexico and the other in Mexico), the range of which
is bisected by the International Border between the United States and
Mexico.
Our response: See response immediately above regarding listing a
DPS of the Mexican wolf.
(5) Comment: One State agency expressed concern that, if listed as
a subspecies, the Mexican wolf will never be delisted in the United
States. The commenter stated that a species or subspecies may be
delisted only when it is no longer in danger of extinction throughout
all or a significant portion of its range and that approximately 10
percent of the Mexican wolf's historical range occurs in the United
States with the remainder in Mexico. Because the Mexican wolf in the
United States will never constitute a significant portion of the
subspecies' range, delisting would require substantial wolf recovery in
Mexico.
[[Page 2494]]
Our response: ``Range'' as referred to in the phrase ``significant
portion of its range'' refers to the general geographical area within
which the species can be found at the time the Service makes a status
determination (79 FR 37578, July 1, 2014). Prior to its extirpation in
the 1900's, the Mexican wolf inhabited large portions of Mexico. Our
colleagues in Mexico are continuing to investigate whether areas that
functioned as wolf habitat historically are suitable for wolf
reintroduction and recovery efforts today (Araiza et al. 2012, entire).
Regardless, the Act does not stipulate that a species must inhabit all
of its historical range in order to be recovered. Rather, threats to
the species must be alleviated such that it is secure in its range at
the time of status determination, such as delisting, listing, or
reclassification. Therefore, listing the Mexican wolf as a subspecies
does not preclude the ability to achieve recovery and delist the
subspecies. A recovery strategy, including delisting criteria, will be
developed in a revised recovery plan for the Mexican wolf.
(6) Comment: One commenter expressed concern that if we have to
wait for recovery to occur in Mexico before we can delist the Mexican
wolf, States will be faced with unchecked population growth of Mexican
wolves with no effective mechanism for controlling population growth,
which will lead to the detriment of livestock and big game wildlife in
the United States.
Our response: See response above. The purpose of the Act is to
recover species such that they are no longer in danger of extinction
now or within the foreseeable future throughout all or a significant
portion of their range, at which time they are delisted and management
of the species is typically turned over to the State and tribal
wildlife agencies. Further, in a separate rule in this Federal
Register, we have published the Revision to the Nonessential
Experimental Population of the Mexican Wolf, which contains take
provisions for Mexican wolves by designated agencies and the public,
demonstrating that the Service is cognizant of the need to include such
(control) measures as a component of wolf reintroduction and recovery
efforts.
(7) Comment: One State agency noted that the Service's proposed
rule to list the Mexican wolf as an endangered subspecies referenced
several important documents to which the public has not had access.
Our response: All of the comments, materials, and documentation
that we considered in this rulemaking were available by appointment,
during normal business hours at: Mexican Wolf Recovery Program, U.S.
Fish and Wildlife Service, New Mexico Ecological Services Field Office,
2105 Osuna Road NE., Albuquerque, NM 87113; by telephone 505-761-4704;
or by facsimile 505-346-2542.
(8) Comment: One State agency suggested that the Service should
recognize Mexican wolf historical range as extending from central
Mexico into Arizona and New Mexico south of Interstate Highway 40.
Our response: We have utilized the best available science to
describe historical range for the Mexican wolf in the Background
section of this final rule. Maps of the Mexican wolf's historical range
are available in the scientific literature (Young and Goldman 1944, p.
414; Hall and Kelson, 1959, p. 849; Hall 1981, p. 932; Bogan and
Mehlhop 1983, p. 17; Nowak 1995, p. 395; Parsons 1996, p. 106).
Depiction of the northern extent of the Mexican wolf's historical range
among the available descriptions varies depending on the authors'
taxonomic treatment of several subspecies that occurred in the
Southwest and their related treatment of intergradation zones. In any
case, there is evidence indicating that the Mexican wolf may have
ranged north into southern Utah and southern Colorado within zones of
intergradation where interbreeding with other gray wolf subspecies may
have occurred (Leonard et al. 2005, p. 11 and p. 15).
(9) Comment: The Service does not provide cooperators and
stakeholders with sufficient time to comprehensively analyze the
Service's varied proposals on Mexican wolf listing. The Service expects
stakeholders and cooperators, in a matter of months, to review and
digest hundreds of pages of material, sort out the interconnected
points concerning all the facets of the entirety, review the
alternatives, formulate comments, and otherwise meaningfully
participate in the review process.
Our response: The Service recognizes that public involvement is an
essential part of the rulemaking process, helping to inform both the
agency and the affected public. That is why we requested written
comments from the public on the proposed rule and contacted appropriate
Federal, Tribal, State, county, and local agencies, scientific
organizations, and other interested parties and invited them to comment
on the proposed rule during the open comment period from June 13, 2013,
to December 17, 2013, and the reopened comment period from February 10,
2014, to March 27, 2014. We believe that the nearly 8-month open
comment period was sufficient time for cooperators and stakeholders to
comprehensively analyze the Service's proposed rule and provide
comment.
Comments From Tribes
(10) Comment: Any listing or delisting of the gray wolf or the
Mexican wolf must recognize the Tribe's rights and sovereignty in
managing wildlife on Tribal lands. The proposed rule fails in this
respect.
Our response: The Service recognizes the Tribe's rights and
sovereignty in managing wildlife on Tribal lands (see Government to
Government Relationships with Tribes section below). Under their
sovereign authority Tribes have the option of allowing Mexican wolves
to occupy Tribal trust land or to request their removal. Also,
elsewhere in this Federal Register, we are finalizing revisions to the
nonessential experimental population of the Mexican wolf, which will
give Tribes the option to enter into voluntary agreements with the
Service for the management of Mexican wolves on Tribal trust land.
Public Comments
(11) Comment: We received numerous requests from diverse interest
groups and individuals asking that we subdivide our final determination
on listing the Mexican wolf as endangered from the final determination
on our proposal regarding the current listing for gray wolf in all or
portions of 42 States and Mexico.
Our response: We are separating our determination on the listing of
the Mexican wolf as endangered from the determination on our proposal
regarding removing the current listing for gray wolf from the List of
Endangered and Threatened Wildlife. This rule finalizes our
determination for the Mexican wolf. A subsequent decision will be made
for the rest of the United States.
(12) Comment: A problematic aspect of the rule is the fact that the
Service does not designate the species as endangered over a specific
geographic area, but instead designates the subspecies as endangered
where found. Genetic analysis of historic Mexican wolves showed that
the range of the Mexican wolf likely extended beyond the historic range
initially inferred from limited record data.
Our response: Unless we designate a Distinct Population Segment,
which has a geographic component to the designation, a species or
subspecies listing means that all members of the taxon are afforded the
protections of the Act regardless of where they are found. We have
described the historical range
[[Page 2495]]
of the Mexican wolf in the Background section of this rule.
(13) Comment: Listing the Mexican wolf as endangered would
negatively impact the private landowners and ranchers in the State of
Arizona by imposing additional restrictions on those private lands,
which is an economic and operational burden on the public.
Our response: This final rule to list the Mexican wolf as an
endangered subspecies will not change the protected status of the
Mexican wolf as, to date, it has been listed as endangered within the
broader gray wolf listing; rather, this final rule creates an
independent listed entity for the Mexican wolf on the List of
Endangered and Threatened Wildlife, separate from the gray wolf entity.
As previously noted, we are finalizing revisions to the nonessential
experimental population of the Mexican wolf elsewhere in this Federal
Register, which relaxes some of the Act's prohibitions for take of
Mexican wolves in certain circumstances. With this final rule to list
the Mexican wolf as an endangered subspecies, there are no additional
restrictions to private landowners.
(14) Comment: Has the Service examined the biological ramifications
of the illegal killings? What analyses were used to estimate the level
of impact of a 0 to 15 percent annual mortality attributed to illegal
killing of wolves? The proposed listing stated 3 Mexican wolves died
from disease, 3 from predation, 14 from vehicular collisions, 4 from
other reason, 9 for unknown reasons, and 46 from illegal killing. What
was the fate of the 13 wolves unaccounted for in this document that
died from 1998 to 2012? The Service should show mortality graphically;
what is the ratio of illegal kills to population size?
Our response: We recognize that illegal killing is the number one
source of mortality to Mexican wolves in the wild; see Factor C.
Disease and Predation, for our discussion and assessment of this
mortality factor. Known wolf mortality is documented annually and is
available on our Web site at http://www.fws.gov/southwest/es/mexicanwolf/MWPS.cfm.
(15) Comment: The Mexican wolf experimental population has been
unsuccessful due to weak genetics that caused malformed jaws and other
deformities, hybridization with dogs after releases into the wild,
habituation to humans, dependence on human food including livestock
regardless of abundant wild ungulate prey availability, and a variety
of other fatal flaws.
Our response: We describe known instances of hybridization in
Factor E of this final rule. Based on the low number of occurrences of
Mexican wolf-dog hybrids, we do not consider hybridization to be a
threat to the Mexican wolf. We also discuss genetic concerns in Factor
E, which, although not specific to physical deformities, we do
determine inbreeding and loss of heterozygosity to be threats to the
Mexican wolf. We have not documented Mexican wolf dependence on human
food, including livestock; while Mexican wolves do occasionally prey on
livestock, their primary prey in the Mexican Wolf Experimental
Population Area is elk (see Background section).
(16) Comment: The Service fails to present the expected outcomes of
genetic depression (decreased fitness, negatively biased population
growth rate, loss of adaptive potential) on the Mexican wolf. How does
the Service quantify loss of adaptive potential? What does the Service
propose to do to address their concerns over inbreeding? If the
nonessential population is genetically depressed, why does the Service
continue to release Mexican wolves that are inbred? Over what timeframe
does the Service expect to be able to effect a change in the genetic
depression of the Mexican gray population?
Our response: Tracking of the genetic status of the captive and
wild Mexican wolf populations is conducted by the Species Survival
Plan, which tracks the mean kinship of wolves and other relevant
metrics of the captive and wild population. We describe our concerns
related to the genetic composition of the Mexican wolf population under
Factor E. In a separate rule published in this Federal Register,
Revision to the Nonessential Experimental Population of the Mexican
Wolf, and our associated Environmental Impact Statement, we address our
need to increase the number of initial releases we conduct in order to
improve the genetic composition of the nonessential population. We
expect to substantially improve the genetic status of the nonessential
population within several Mexican wolf generations, or about 12 to 16
years.
(17) Comment: Except in cases of absolute isolation, what we call
subspecies are populations with variable rates of gene flow over time
and space. It is time for the Service to abandon typological thinking,
stop using subspecies for listings, and use the biologically robust
concepts of populations with quantifiable rates of gene flow and
phylogenetic independence.
Our response: The Act is explicit that threatened or endangered
subspecies are to be protected. Our Service regulations require us to
rely on standard taxonomic distinctions and the biological expertise of
the Department of the Interior and the scientific community concerning
the relevant taxonomic group (50 CFR 424.11).
(18) Comment: According to the Service, the ``nature of the
available data does not permit the application of many traditional
subspecies criteria'', and many experts actually reject the notion of
wolf subspecies due to the ease with which wolves move and interbreed.
The Service further admits that the taxonomy for wolves is complicated
and continuously evolving. These statements clearly show the lack of
definitive information supporting the identification of gray wolf
subspecies.
Our response: We recognize that wolf taxonomy is complicated and
continuously evolving. However, the controversy in the scientific
community has focused on wolf populations other than the Mexican wolf
(but see Cronin et al. 2014, p. 9), which are outside the purview of
this final rule. The best available scientific literature, and our
Service regulations that require us to rely on standard taxonomic
distinctions, support the recognition of the Mexican wolf as a
subspecies of gray wolf.
(19) Comment: Review of the literature shows that the Mexican wolf
does not warrant subspecies status. Data for 170,000 single nucleotide
polymorphisms (Cronin et al. in preparation) and 48,000 single
nucleotide polymorphisms (vonHoldt et al. 2011) shows that single
nucleotide polymorphisms allele frequency differentiation of Mexican
wolves and other North American wolves is relatively high. However,
Mexican wolves lack mtDNA monophyly and share haplotypes with wolves in
other areas (Leonard et al. 2005), and mtDNA haplotypes in Mexican
wolves have low sequence divergence from other wolf haplotypes. This
sequence divergence is particularly low because it is for the
hypervariable control region.
Our response: As required by section 4(b) of the Act, we used the
best scientific and commercial data available and continue to recognize
the Mexican wolf (Canis lupus baileyi) as a distinct gray wolf
subspecies. Taxonomic issues related to other gray wolf populations are
not germane to this final rule to list the Mexican wolf as an
endangered subspecies. Specific to the Mexican wolf, the peer reviewers
concurred that the Mexican wolf is differentiated from other gray
wolves by multiple morphological and genetic markers
[[Page 2496]]
documented in the scientific literature. Further, Leonard et al. (2005,
p. 10) found that haplotypes associated with the Mexican wolf formed a
unique southern clade distinct from that of other North American
wolves. A clade is a taxonomic group that includes all individuals that
have descended from a common ancestor.
(20) Comment: A science-based recovery plan has the potential to
reduce conflict over the long term by minimizing litigation, minimizing
resources needed by the Service for defending its actions, and speeding
the eventual delisting of the Mexican wolf. Because lack of an updated
recovery plan seriously hampers efforts to recover the subspecies, we
encourage the Service to resume the recovery planning process
immediately.
Our response: We intend to resume the recovery planning process to
develop a revised recovery plan for the Mexican wolf after completion
of this final rule.
(21) Comment: Several commenters recommended management of the
Mexican wolf be returned to the States. Delisting of the wolf would
automatically trigger this return of State control.
Our response: In our final rule, published elsewhere in this
Federal Register, Revision to the Nonessential Experimental Population
of the Mexican Wolf, we allow for States (or other agencies) to
cooperate in the management of Mexican wolves as designated agencies.
Due to our determination of endangered status for the Mexican wolf, we
are not delisting the Mexican wolf at this time. When the Mexican wolf
has been recovered and delisted, management control will be turned over
to State and tribal agencies.
(22) Comment: The States of Arizona and New Mexico have sufficient
regulations and trained personnel and programs in place to protect
Mexican wolves so that a Federal listing is unwarranted under the Act.
Our response: We have no information to suggest that, absent the
Act's protections, illegal killing of Mexican wolves in the United
States would cease. Rather, illegal killing of Mexican wolves could
increase, as State penalties (assuming wolves were granted protected
status by the States) would be less severe than current Federal
penalties under the Act. Thus, existing State penalties in Arizona and
New Mexico would not serve as an adequate deterrent to illegal take.
Also, in 2011, the New Mexico Department of Game and Fish withdrew from
the Mexican Wolf Recovery Program and has shown no intention of
rejoining or further cooperating with the program. We address this
issue under Factor D. Adequate Regulatory Mechanisms.
(23) Comment: Several commenters stated that local citizens are
fearful of Mexican wolves and noted the need to protect themselves when
in areas occupied by wolves, psychological impacts on children, pet
safety, and related topics. One commenter stated that he would face
criminal charges if he defended himself against a wolf. These
commenters stated that the Service has not adequately recognized or
addressed these issues.
Our response: There are no historical or recent cases of Mexican
wolves attacking humans. If a Mexican wolf were to attack someone, the
Act allows a person to take (including kill) a Mexican wolf in self-
defense or in defense of another person. Elsewhere in this Federal
Register, we have published a final Revision to the Nonessential
Experimental Population of the Mexican Wolf, which provides conditional
take provisions (in addition to take for self-defense) of Mexican
wolves by the Service, designated agencies, and individuals under
certain circumstances.
(24) Comment: The Service states that the status of Mexican wolves
in Mexico is unknown. Mexican wolves should be managed through a
coordinated effort internationally according to sound biological
principles and with consideration to all other State, national, and
international laws that protect the health, safety, and welfare of
humans.
Our response: We are fully aware of the status of Mexican wolves in
Mexico, as we are in continual communication with the Federal agencies
in Mexico that are responsible for the reintroduction of the Mexican
wolf. We have clarified language in this final rule regarding the
status of wolves in Mexico; see Current Distribution in Mexico. While
we may at times coordinate various Mexican wolf management activities
with Federal agencies in Mexico (such as sharing equipment or
transferring captive wolves between captive facilities), the
reintroduction of Mexican wolves in the United States and Mexico are
independent efforts.
(25) Comment: The Service should consider the negative impacts to
our elk, deer, bighorn sheep, and javelina populations from predation
by possible reintroduced Mexican wolves. A decrease in these game
animals will create a significant economic and recreational loss to our
State.
Our response: While the Act is explicit that our listing
determinations must be made solely on the basis of the best scientific
and commercial data available, in a separate action published elsewhere
in this Federal Register we have considered the impacts to ungulate
populations from the experimental population of Mexican wolves in our
Environmental Impact Statement, Revision to the Nonessential
Experimental Population of the Mexican Wolf, available on our Web site
at http://www.fws.gov/southwest/es/mexicanwolf/NEPA_713.cfm.
Summary of Changes From the Proposed Rule
In this final rule, we make one substantive change from the
proposal. We are separating our determination on the listing of the
Mexican wolf as endangered from the determination on our proposal
regarding the delisting of the gray wolf in the United States and
Mexico. This rule finalizes our determination for the Mexican wolf. A
subsequent decision will be made for the gray wolf.
Summary of Factors Affecting the Mexican Wolf
Several threats analyses have been conducted for the Mexican wolf.
In the initial proposal to list the Mexican wolf as endangered in 1975
and in the subsequent listing of the entire gray wolf species in the
contiguous United States and Mexico in 1978, the Service found that
threats from habitat loss (factor A), sport hunting (factor B), and
inadequate regulatory protection from human targeted elimination
(factor D) were responsible for the Mexican wolf's decline and near
extinction (40 FR 17590, April 21, 1975; 43 FR 9607, March 9, 1978). In
the 2003 reclassification of the gray wolf into three distinct
population segments, threats identified for the gray wolf in the
Southwestern Distinct Population Segment (which included Mexico,
Arizona, New Mexico, and portions of Utah, Colorado, Oklahoma, and
Texas) included illegal killing and (negative) public attitudes (68 FR
15804, April 1, 2003). The 2010 Mexican Wolf Conservation Assessment
(Conservation Assessment) contains the most recent five-factor analysis
for the Mexican wolf (Service 2010, p. 60). The purpose of the
Conservation Assessment, which was a non-regulatory document, was to
evaluate the status of the Mexican wolf reintroduction project within
the broader context of the subspecies' recovery. The Conservation
Assessment found that the combined threats of illegal shooting, small
population size, inbreeding, and inadequate regulatory protection were
hindering the ability of the current population to reach the
[[Page 2497]]
population objective of at least 100 wolves in the BRWRA (Service 2010,
p. 60).
The threats we address in this five-factor analysis and our
conclusions about a given factor may differ from previous listing
actions due to new information, or, in the case of the Conservation
Assessment, the difference in perspective necessitated by the listing
process compared to that of the Conservation Assessment, which was
focused on recovery. For example, in this five-factor analysis we
analyze currently occupied habitat, whereas the Conservation Assessment
included discussion of unoccupied habitat that may be important in the
future for recovery. In this five-factor analysis, we are assessing
which factors pose a threat to the existing population of wolves in the
BRWRA or would pose a threat to these wolves if the protections of the
Act were not in place.
Factor A. The Present or Threatened Destruction, Modification, or
Curtailment of Its Habitat or Range
As previously discussed, wolves are considered habitat generalists
with fairly broad ecological capabilities and flexibility in using
different prey and vegetation communities (Peterson and Ciucci 2003,
pp. 104-111). Gray wolves hunt in packs, primarily pursuing medium to
large hooved mammals. Wolf density is positively correlated to the
amount of ungulate biomass available and the vulnerability of ungulates
to predation (Fuller et al. 2003, pp. 170-175). These characterizations
apply to the Mexican wolf and form our basis for defining suitable
habitat.
We consider suitable habitat for the Mexican wolf as forested,
montane terrain containing adequate wild ungulate populations (elk,
white-tailed deer, and mule deer) to support a wolf population.
Suitable habitat has minimal roads and human development, as human
access to areas inhabited by wolves can result in wolf mortality.
Specifically, roads can serve as a potential source of wolf mortality
due to vehicular collision and because they provide humans with access
to areas inhabited by wolves, which can facilitate illegal killing of
wolves. Although the road itself could be considered a form of habitat
modification, the primary threat to wolves related to roads stems from
the activities enabled by the presence of roads (i.e., vehicular
collision and illegal killing) rather than a direct effect of the road
on the wolf such as a boundary to dispersal. We address illegal killing
under factor C. Disease or Predation, and vehicular collision under
factor E. Other.
For the Mexican wolf, we define habitat destruction, modification,
or curtailment as a decrease or modification in the extent or quality
of forested, montane terrain in currently occupied habitat, or a
decrease in ungulate populations in currently occupied habitat, such
that wolves would not persist in that area. In order to assess whether
habitat destruction, modification, or curtailment is a threat to
Mexican wolves, we consider information related to land status (as a
characteristic of quality related to minimal human development) and the
effects of catastrophic wildfire on Mexican wolves and ungulates. Our
definitions of suitable habitat and of habitat destruction,
modification, and curtailment are the same for the United States and
Mexico. Implications of climate change are addressed under factor E.
Other.
United States--Mexican wolves currently inhabit only the BRWRA as
identified in the January 12, 1998, final rule to designate an
experimental population (63 FR 1752), as well as the adjacent Fort
Apache Indian Reservation as allowed by an agreement between the White
Mountain Apache Tribe and the Service. As noted above, we finalize
revisions to our regulations for the experimental population of the
Mexican wolf, which published elsewhere in this Federal Register. With
this MWEPA revision, Mexican wolves will be allowed to inhabit the
entire MWEPA, with the exception of any tribal areas where their
removal is requested. In the revised MWEPA, there are 32,244 mi\2\
(83,512 km\2\) of suitable Mexican wolf habitat (Service 2014, p. 25).
Of this suitable habitat, 63 percent occurs on federally owned land; of
that, the U.S. Forest Service accounts for 91 percent, the Bureau of
Land Management, 7 percent, and other Federal land ownership comprises
the final 2 percent.
We consider Federal land in the revised MWEPA to be an important
characteristic of the quality of the reintroduction area. Federal lands
such as National Forests are considered to have the most appropriate
conditions for Mexican wolf reintroduction and recovery efforts because
they typically have significantly lesser degrees of human development
and habitat degradation than other land-ownership types (Fritts and
Carbyn 1995, p. 26). We do not have any information or foresee any
change in the size, status, ownership, or management of the National
Forests in the revised MWEPA in the future. If Mexican wolves were not
protected by the Act, we cannot foresee any changes to the status of
these National Forests such that suitability for Mexican wolves would
significantly diminish.
Current and reasonably foreseeable management practices in all of
the Apache, Gila, and Sitgreaves National Forests; the Payson, Pleasant
Valley, and Tonto Basin Ranger Districts of the Tonto National Forest;
and the Magdalena Ranger District of the Cibola National Forest are
expected to support ungulate populations at levels that will sustain a
growing Mexican wolf population in the revised MWEPA. Prey populations
throughout all of Arizona and New Mexico continue to be monitored by
the State wildlife agencies within Game Management Units, the
boundaries of which are defined in each State's hunting regulations. We
do not predict any significant change to ungulate populations that
inhabit the National Forests such that habitat suitability for Mexican
wolves would diminish.
On the other hand, wildfire is a type of habitat modification that
could affect the Mexican wolf population in two primary ways--by
killing of wolves directly or by causing changes in the abundance and
distribution of ungulates. Two recent large wildfires, the Wallow Fire
and the Whitewater-Baldy Complex Fire, have burned within close
proximity to denning wolf packs. Due to their very large size and rapid
spread, both of these fires are considered catastrophic wildfires.
On May 29, 2011, the Wallow Fire began in Arizona and spread to
over 538,000 ac (217,721 ha) in Arizona (Apache, Navajo, Graham, and
Greenlee Counties; San Carlos Apache Indian Reservation, Fort Apache
Indian Reservation) and New Mexico (Catron County) by the end of June.
The Wallow Fire was human-caused and is the largest fire in Arizona's
recorded history to date. The Wallow Fire burned through approximately
11 percent of the BRWRA. Three known or presumed wolf pack denning
locations (Rim pack, Bluestem pack, Hawks Nest pack) were within the
fire's boundaries (Service 2011). Although we had initial concern that
denning pups (which are not as mobile as adults or may depend on adults
to move them from the den) may not survive the fire due to their
proximity to the rapidly spreading fire, we did not document any wolf
mortalities as a result of the fire.
Telemetry information indicated all radio-collared animals
survived, and pups from two of the packs whose den areas burned
survived through the year's end to be included in the end-of-
[[Page 2498]]
year population survey. While denning behavior was observed in the
third pack, the presence of pups had not been confirmed prior to the
fire, and no pups were documented with this pack at the year's end
(Service 2011).
In addition to possible direct negative effects of the Wallow Fire
(i.e., mortality of wolves, which we did not document), we also
considered whether the fire was likely to result in negative short- or
long-term effects to ungulate populations. The Wallow Fire Rapid
Assessment Team's postfire assessment hypothesized that elk and deer
abundance will respond favorably as vegetation recovers, with ungulate
abundance exceeding prefire conditions within 5 years due to decreased
competition of forage and browse with fire-killed conifers (Dorum 2011,
p. 3). Based on this information, we recognize and will continue to
monitor the potential for this fire to result in beneficial (increased
prey) effects for Mexican wolves over the next few years.
On May 16, 2012, the Whitewater-Baldy Complex Fire was ignited by
lightning strikes in New Mexico. It burned at least 297,845 ac (120,534
ha), including an additional (to the Wallow Fire) 7 percent of the
BRWRA. The Whitewater-Baldy Complex Fire was contained 2 mi (3 km) from
a denning wolf pack to the north (Dark Canyon pack) and 5 mi (8 km)
from a denning wolf pack to the east (Middle Fork pack). We have not
documented any adverse effects, including mortality, from the fire to
these packs. We similarly hypothesize, as with the Wallow Fire, that
elk and deer abundance will respond favorably as vegetation recovers in
the burned area, with ungulate abundance exceeding pre-fire conditions
within several years.
Given that we have not observed any wolf mortality associated with
the Wallow and Whitewater-Baldy Complex fires, these specific fires
have not significantly affected the Mexican wolf population. Moreover,
although these fires demonstrate the possibility that a catastrophic
wildfire within the reintroduction area could result in mortality of
less mobile, denning pups, we recognize that adult wolves are highly
mobile animals and can move out of even a catastrophic fire's path.
While mortality of pups would slow the growth of the population over a
year or two, the adult, breeding animals drive the ability of the
population to persist. We do not consider even these catastrophic fires
to be a significant mortality risk to adult wolves given their mobility
and, therefore, do not consider wildfire to be a significant threat to
the Mexican wolf. Further, we predict that these fires will result in
changes in vegetation communities and prey densities that will be
favorable to wolves within a few years. We have no information to
indicate there would be changes to the effects of fire on Mexican
wolves if they were not protected by the Act.
Mexico--The Mexican wolf appears to have been extirpated from the
wild in Mexico for more than 30 years. Recently, researchers and
officials in Mexico identified priority sites for reintroduction of
Mexican wolves in the States of Sonora, Durango, Zacatecas, Chihuahua,
Coahuila, Nuevo Leon, and Tamaulipas based on vegetation type, records
of historical wolf occurrence, and risk factors affecting wolf
mortality associated with proximity to human development and roads
(Araiza et al. 2012, pp. 630-637). In October 2011, Mexico initiated a
reintroduction program with the release of five captive-bred Mexican
wolves into the San Luis Mountains just south of the United States-
Mexico border. Through August 2014, Mexico released a total of 14 adult
Mexican wolves, of which 11 died or are believed dead, and 1 was
removed for veterinary care. The remaining two adult Mexican wolves
were documented with five pups in 2014, marking the first successful
reproductive event in Mexico. We expect the number of Mexican wolves in
Mexico to fluctuate from zero to several wolves or packs of wolves
during 2015 and into the future in or around Sonora and Chihuahua or
other Mexican States as wolves are released to the wild from captivity
by Mexico and subsequently may survive, breed, die of natural causes,
or be illegally killed.
We recognize that Mexican wolves are being reintroduced in Mexico
to areas identified as priority sites based on recent research (Araiza
et al. 2012). However, we also note that Araiza et al.'s habitat
assessment does not include assessment of prey availability within the
six identified areas, which is a critical indicator of habitat
suitability. Some information on prey availability is currently being
collected and synthesized by Mexico for specific locations, but is not
publicly available at this time. We also note that, due to the majority
of land in Mexico being held in private ownership, large patches of
secure public land are unavailable in Mexico to support reintroduction,
which has been an important characteristic of reintroduction sites in
the United States. We will continue to observe the status of the wolf
reintroduction effort in Mexico. At this time, because our focus in
this analysis is on currently occupied range, the absence of a Mexican
wolf population in Mexico precludes analysis of habitat threats there.
Summary of Factor A
We have no information indicating that present or threatened
habitat destruction, modification, or curtailment is significantly
affecting the Mexican wolf or is likely to do so in the future. Zones 1
and 2 of the revised MWEPA provide an adequately sized area containing
high-quality forested montane terrain with adequate ungulate
populations (deer and elk) to support Mexican wolves in the
experimental population. We do not foresee any changes in the status of
the area (primarily U.S. Forest Service land). Further, we do not
consider wildfire to be resulting in habitat destruction, modification,
or curtailment that is threatening the Mexican wolf, although we
recognize that future catastrophic wildfires have the potential to slow
the growth of the population if pup mortality occurs in several packs.
We have not conducted an analysis of threats under factor A in
Mexico due to the lack of a Mexican wolf population there for more than
30 years. Based on the mortality of reintroduced Mexican wolves in
Mexico from 2011 to 2013, we do not expect a population to be
established there for at least several years.
Factor B. Overutilization for Commercial, Recreational, Scientific, or
Educational Purposes
Since the inception of the Mexican wolf reintroduction project in
1998, we have not authorized legal killing or removal of wolves from
the wild for commercial, recreational (i.e., hunting), scientific, or
educational purposes. We are not aware of any instances of illegal
killing of Mexican wolves for their pelts in the Southwest, or of
illegal trafficking in Mexican wolf pelts or parts. Mexican wolf pelts
and parts from wolves that die in captivity or in the wild may be used
for educational or scientific purposes, such as taxidermy mounts for
display, when permission is granted from the Service; most wolf parts
are sent to a curatorial facility at the University of New Mexico to be
preserved, catalogued, and stored. A recreational season for wolf
hunting is not currently authorized in the Southwest.
We have authorized, through a section 10(a)(1)(A) research-and-
recovery permit under 50 CFR 17.32, as well as in accordance with the
Mexican wolf experimental population rule and section 10(j) management
rule under 50 CFR 17.84(k), agency personnel to take
[[Page 2499]]
any Mexican wolf in the experimental population, as well as to conduct
activities related directly to the recovery of reintroduced
experimental populations of Mexican wolf within Arizona and New Mexico.
While removal of individual Mexican wolves (including lethal take) has
occurred by the Service as a result of these measures, these actions
are conducted within the purpose of our recovery program to contribute
to the conservation of the Mexican gray wolf.
Several Mexican wolf research projects occur in the BRWRA or
adjacent tribal lands by independent researchers or project personnel,
but these studies have utilized radio-telemetry, scat analysis, and
other noninvasive methods that do not entail direct handling of, or
impact to, wolves (e.g., Cariappa et al. 2008, Breck et al. 2011,
Rinkevich 2012). Nonlethal research for the purpose of conservation is
also conducted on Mexican wolves in the SSP captive-breeding program;
projects include research on reproduction, artificial insemination, and
gamete collection and preservation (see Service Mexican Wolf Recovery
Program annual reports online at www.fws.gov/southwest/es/mexicanwolf/
for descriptions of past and current research projects). Research on
disease and conditioned taste aversion is also being conducted in the
SSP captive-breeding program. In all cases, any take authorized by the
Service for scientific, educational, and conservation purposes must
benefit the Mexican wolf and promote its recovery.
Since reintroductions began in 1998 and have continued through
December 31, 2013, we are aware of 25 incidents in which Mexican wolves
were captured in nongovernmental (private) traps, at least 7 have been
severely injured, and at least 3 have died as a result of injuries or
activities associated with being captured in a leg-hold trap. While
these seven injuries may have a significant effect on the individual
Mexican wolf and may affect that particular animal's pack, they are
relatively rare occurrences. We conclude that the 3 mortalities through
2013 have not affected the Mexican wolf's population growth because
this accounts for only 3 mortalities in 15 years, and at the end of
2013, the minimum population size was 83 Mexican wolves.
Absent the protection of the Act, Mexican wolves could be protected
from overutilization in the United States by State regulations and
programs in Arizona and New Mexico and Federal law in Mexico. The
Arizona Revised Statutes Title 17 gives the Arizona Game and Fish
Commission (Commission) the authority to regulate take of wildlife in
the State of Arizona. ``Take'' (to pursue, shoot, hunt, trap, kill,
capture, snare, or net) of wildlife in Arizona on lands under the
authority of the Arizona Game and Fish Commission is prohibited, unless
a provision (e.g., Commission Order, special rule, permit) is made to
allow take. Arizona Game and Fish Commission Rules, Article 4, outlines
additional restrictions that would provide further protections from
overutilization including regulating and outlining prohibitions on
possession and transport of illegally taken wildlife, and regulating
and placing restrictions on scientific collection/handling of wildlife.
Because Commission Order 14 (Other Birds and Mammals) does not open a
hunting season on wolves, all take of Mexican wolf in Arizona is
prohibited (except via special permit, as for science and management
purposes; permits that in-turn require the permittee to secure all
required Federal permits). A hunting season could be opened if the
agency documented a harvestable surplus or identified a need for
population reduction in a specific area. The Arizona Game and Fish
Department, the administrative, management, and enforcement arm of the
Commission, is charged with carrying out the Commission's programs and
enforcing its regulations.
Pursuant to the Wildlife Conservation Act of New Mexico, it is
unlawful to take, possess, transport, export, process, sell, or offer
for sale or ship any State or Federal endangered species or subspecies
(17-2-41 New Mexico Statutes Annotated [NMSA]), thus, as a State-listed
endangered subspecies, the Mexican wolf would be protected from take
related to overutilization.
Similarly, in Mexico, the General Wildlife Law (``Ley General de
Vida Silvestre'', 2000, as amended) provides regulation against take of
species or subspecies identified by the Norma Oficial Mexicana NOM-059-
SEMARNAT-2010, ``Protecci[oacute]n ambiental-Especies nativas de
M[eacute]xico de flora y fauna silvestres.'' These regulatory
provisions are further discussed under factor D. The Inadequacy of
Existing Regulatory Mechanisms.
Summary of Factor B
Based on available information, overutilization for commercial,
recreational, scientific, or educational purposes does not occur or is
exceedingly rare in the United States. In addition, we have no examples
of these forms of take occurring in Mexico since the Mexican
reintroduction program began in 2011. Arizona, New Mexico, and Mexico
have regulatory provisions under which Mexican wolves could be
protected against overutilization if the subspecies were not protected
by the Act. Due to the nonexistent or very low level of overutilization
occurring, and the ability of the States and Mexico to regulate
overutilization, we do not consider overutilization to be affecting the
Mexican wolf now or in the future.
Factor C. Disease or Predation
A number of viral, fungal, and bacterial diseases and endo- and
ectoparasites have been documented in gray wolf populations (Kreeger
2003, pp. 202-214). However, little research has been done specific to
disease in Mexican wolves, and little documentation exists of disease
prevalence in wild wolves in the BRWRA population. We obtain the
majority of our information on documented mortalities (from all
sources, including disease) in the BRWRA from animals wearing radio
collars. We may, therefore, underestimate the number of mortalities
resulting from disease (e.g., due to the number of uncollared wolves).
Typically, infectious diseases (such as viruses and bacteria) are
transmitted through direct contact (e.g., feces, urine, or saliva) with
an infected animal, by aerosol routes, or by physical contact with
inanimate objects (fomites). Parasites are infective through water,
food sources, or direct contact. Wolves are able to tolerate a number
of parasites, such as tapeworms or ticks, although occasionally such
organisms can cause significant disease, or even be lethal (Kreeger
2003, p. 202).
Mexican wolves are routinely vaccinated for rabies virus, distemper
virus, parvovirus, parainfluenza virus, and adenovirus before release
to the wild from captive facilities. In addition, common dewormers and
external parasite treatments are administered. Wolves captured in the
wild are vaccinated for the same diseases and administered dewormers
and external parasite treatments. Kreeger (2003, pp. 208-211) describes
the transmission route and effect of these diseases on gray wolves and
can be referenced for general information. Recent rules for the Western
Great Lakes and Northern Rocky Mountain gray wolf populations contain
information from studies of disease occurrences in those geographic
regions, and can also serve as a reference for a more comprehensive
discussion of these (and other) diseases than that provided below (72
FR 6051, February 8, 2007; 73 FR 10513, February 27, 2008).
[[Page 2500]]
Rabies, caused by a rhabdovirus, is an infectious disease of the
central nervous system typically transmitted by the bite of an infected
animal. Rabies can spread between infected wolves in a population
(e.g., among and between packs), or between populations, resulting in
severe population declines. Rabies is untreatable and leads to death. A
rabies outbreak in and near the BRWRA began in 2006 in eastern Arizona
and continued through 2009, with positive rabies diagnoses (fox
variant) in both foxes and bobcats. No Mexican wolves in the BRWRA were
diagnosed with rabies during this outbreak (Arizona Department of
Health Services 2012; New Mexico Department of Health 2011) or
throughout the history of the reintroduction.
Canine distemper, caused by a paramyxovirus, is an infectious
disease typically transmitted by aerosol routes or direct contact with
urine, feces, and nasal exudates. Death from distemper is usually
caused by neurological complications (e.g., paralysis, seizures), or
pneumonia. Distemper can cause high fatality rates, though survivors
are occasionally documented in canine populations. Distemper virus may
have been a contributing factor to high levels of pup mortality in
Yellowstone National Park during several summers (Smith and Almberg
2007, p. 18). Although wolf populations are known to be exposed to the
virus in the wild, mortality from distemper in wild Mexican wolves is
uncommon. However, we expect Mexican wolf pups, in general, would be
most susceptible to death from distemper virus at a time period prior
to when they are captured, collared, and vaccinated. Therefore, our
collared sample of pups may not be accurately documenting this source
of mortality.
Distemper has been documented in one wild litter of Mexican wolves
in the BRWRA. Two sibling Mexican wolf pups brought to a captive-wolf-
management facility in 2000 from the wild were diagnosed with distemper
(indicating they were exposed to the disease in the wild) and died in
captivity (AMOC and IFT 2005, p. TC-12). (Note: these captive deaths
are not included in the BRWRA mortality statistics.) These are the only
known mortalities due to distemper documented in relation to the
current experimental population (AMOC and IFT 2005, p. TC-12).
Canine parvovirus is an infectious disease caused by a parvoviridae
virus that results in severe gastrointestinal and myocardial (heart
disease) symptoms. Parvovirus is persistent in the environment and can
be spread by direct contact or viral particles in the environment.
Symptoms of an infected adult animal may include severe vomiting and
diarrhea, resulting in death due to dehydration or electrolyte
imbalance. Pups may die from myocardial (heart) disease if infected
with canine parvovirus while in utero or soon after birth from cardiac
arrhythmias. Although canine parvovirus has been documented in wild
wolf populations, documented mortalities due to parvovirus are few;
researchers hypothesize that parvovirus is a survivable disease,
although less so in pups. Parvovirus is thought to have slowed various
stages of colonization and dispersal of wolves in the greater Minnesota
population (Mech et al. 2008, pp. 832-834).
Parvovirus has been documented in one wild litter of wolves in the
BRWRA. Three sibling Mexican wolf pups were documented having, and then
dying from, parvovirus in 1999: One pup died in an acclimation release
pen in the BRWRA, indicating it had been exposed to the disease in the
wild (AMOC and IFT 2005, p. TC-12). The other two pups, which also may
have been exposed to the disease in the wild, were transferred to, and
died at, a prerelease captive facility and are considered captive
mortalities. Mortality from canine parvovirus has otherwise not been
documented in the BRWRA population. However, we expect pups, in
general, to be most susceptible to death from parvovirus prior to when
they are captured, collared, and vaccinated. Therefore, our collared
sample of pups may not be accurately documenting this source of
mortality.
Three of 100 total documented Mexican wolf deaths in the BRWRA
population between 1998 and 2013 have been attributed to disease: 1 to
canine parvovirus, 1 to chronic bacterial pleuritis (bacterial
infection around the lungs), and 1 to bacterial pneumonia. The
pleuritis and pneumonia cases, though bacterial diseases, are likely
both secondary to other unknown natural factors, rather than
contagious, infectious diseases. Potential pup mortality caused by
infectious disease may be poorly documented in the free-ranging
population because these pups are too young to radio collar and thus
difficult to detect or monitor. In addition, collared animals are
vaccinated, which reduces the potential for mortality to occur among
collared wolves.
We do not have evidence that disease was a significant factor in
the decline of Mexican wolves prior to its protection by the Act in the
1970's. However, we recognize that, in a general sense, disease has the
potential to affect the size and growth rate of a wolf population and
could have a negative impact on the experimental population if the
active vaccination program were not in place. We also recognize that
some diseases are more likely to spread as wolf-to-wolf contact
increases (Kreeger 2003, pp. 202-214), thus the potential for disease
outbreaks to occur may increase as the current population expands in
numbers or density, although the effect on the population may be lower
because a larger wolf population would be more likely to sustain the
epidemic. Absent the protection of the Act, the potential for disease
to affect the Mexican wolf population would primarily depend on whether
State wildlife agencies or other parties provided a similar level of
vaccination to the population as that which we currently provide.
In addition to disease, we must also assess whether predation is
affecting the Mexican wolf now or in the future under factor C. In our
assessment of predation, we focus on wild predators as well as illegal
killing of Mexican wolves.
Wild predators do not regularly prey on wolves (Ballard et al.
2003, pp. 259-271). Although large prey may occasionally kill wolves
during self-defense (Mech and Peterson 2003, p. 134), this occurrence
is rare and not considered predation on the wolf. Between 1998 and
December 31, 2013, three documented Mexican wolf mortalities are
attributed to predators (wolf, mountain lion, and unknown) (Service
2013, Mexican Wolf Blue Range Reintroduction Population Statistics).
This may be an underestimate (e.g., due to the number of uncollared
wolves), but we still consider the overall incidence to be low based on
the occurrences we have documented. Monitoring of Northern Rocky
Mountain wolf populations demonstrates that wolf-to-wolf conflicts may
be the biggest source of predation among gray wolves, but this
typically occurs from territorial conflicts and has not occurred at a
level sufficient to affect the viability of these populations (73 FR
10513; February 27, 2008). As the Mexican wolf population begins to
saturate available habitat, wolf mortalities resulting from territorial
conflicts may become more prevalent but this type of mortality is not
currently a concern. We do not foresee any change in the occurrence of
wild predation on Mexican wolves if the subspecies was not protected by
the Act and, therefore, do not consider predation from wild predators
to be affecting the Mexican wolf.
[[Page 2501]]
Illegal mortalities have been the biggest source of Mexican wolf
mortalities since the reintroduction began in 1998 (Service 2013:
Mexican Wolf Blue Range Reintroduction Project Statistics). Out of 100
wild wolf mortalities documented between 1998 and 2013, 55 deaths are
attributed to illegal killing (55 percent of total mortalities).
Documented illegal shootings have ranged from zero to seven per year
between 1998 and December 2013, with one or more occurring every year
with the exception of 1999. Illegal shooting has varied from no impact
to the population (e.g., in 1999 when no illegal shootings were
documented) to resulting in the known mortality of about 15 percent of
the population in a given year (e.g., in 2001). Documented causes of
illegal shooting in other gray wolf populations have included
intentional killing and mistaken identity as a coyote or dog (Fuller et
al. 2003, p. 181). We do not know the reason for each instance of
illegal shooting of a Mexican wolf.
We recognize that some wolf populations can maintain themselves
despite sustained human-caused mortality rates of 17 to 48 percent
(Fuller et al. 2003 [+/- 8 percent], pp. 184-185; Adams et al. 2008 [29
percent], p. 22; Creel and Rotella 2010 [22 percent], p. 5; Sparkman et
al. 2011 [25 percent], p. 5; Gude et al. 2011 [48 percent], pp. 113-
116; Vucetich and Carroll In Review [17 percent]) and that human-caused
mortality sometimes replaces much of the wolf mortality in a population
that would have occurred naturally (e.g., due to intraspecific strife
from territorial conflicts occurring in populations that have saturated
available habitat) (Fuller et al. 2003, p. 186). Regardless, for the
Mexican wolf experimental population, we think it is likely that the
majority of illegal shootings function as additive mortality (that is,
these mortalities are in addition to other mortalities that occur,
rather than compensatory mortality where the deaths from illegal
shooting would substitute for deaths that would occur naturally)
(Murray et al. 2010, pp. 2515, 2522). Illegal mortalities have a
negative effect on the size and growth rate of the experimental
population at its current small size, but the effect of these
mortalities on the population has likely been masked to some degree by
the number of captive Mexican wolves released into the wild over the
course of the reintroduction effort. Additionally, we are unable to
document all Mexican wolf mortalities (i.e., uncollared wolves) and,
therefore, may be underestimating the number of mortalities caused by
illegal shooting.
We expect that, absent the protection of the Act, killing of
Mexican wolves would continue at current levels or, more likely,
increase significantly because Federal penalties would not be in place
to serve as a deterrent. Mexican wolves could be protected from take by
State regulations in Arizona and New Mexico and Federal regulations in
Mexico, but State penalties are less severe than Federal penalties (see
a description and discussion of this under factor D), and Federal
protection in Mexico does not infer protection for Mexican wolves in
the United States. Based on the continuous occurrence of illegal
shooting taking place while the Mexican wolf is protected by the Act
and the likelihood of increased occurrences of wolf shooting absent the
protection of the Act, we consider illegal killing of Mexican wolves to
be significant to the population. We further consider the threat of
illegal shooting to Mexican wolves in ``Combination of Factors/Focus on
Cumulative Effects,'' which discusses this and other threats within the
context of the small, geographically restricted and isolated
experimental population.
In Mexico, illegal killing of Mexican wolves released to the wild
in between 2011 and 2013 has already been documented. Through August
2014, Mexico released a total of 14 adult Mexican wolves, of which 11
died or are believed dead, and 1 was removed for veterinary care. Of
the 11 Mexican wolves that died or are believed dead, 6 were due to
illegal killings (4 from poisoning and 2 were shot), 1 wolf was
presumably killed by a mountain lion, 3 causes of mortality are unknown
(presumed illegal killings because collars were found, but not the
carcasses), and 1 disappeared (neither collar nor carcass has been
found). The illegal killing of at least six Mexican wolves has
significantly hindered Mexico's initial efforts to establish a
population; continued monitoring of the wolves Mexico releases in the
future will be necessary to document whether these initial events were
by chance or are indicative of a significant, ongoing threat to Mexican
wolves in Mexico.
Summary of Factor C
Based on the low incidence of disease and mortality from wild
predators, we do not consider these factors to be significantly
affecting the Mexican wolf nor do we expect them to in the future.
Illegal shooting has been a continuous source of mortality to the
experimental population in the United States since its inception, and
we expect that if Mexican wolves were not protected by the Act the
number of shootings would increase substantially in the United States.
Therefore, we consider illegal shooting to be significantly affecting
Mexican wolves in the United States. In Mexico, four wolves released in
2011 were illegally poisoned within months of their release to the
wild, significantly hindering their reintroduction efforts. Illegal
poisoning may affect the future Mexican wolf population in Mexico
significantly if such events continue.
Factor D. The Inadequacy of Existing Regulatory Mechanisms
The Act requires us to examine the adequacy of existing regulatory
mechanisms with respect to those existing and foreseeable threats,
discussed under the other factors that may affect the Mexican wolf. In
this five-factor analysis, we consider illegal shooting (factor C),
inbreeding (factor E), and small population size (factor E) to be
significantly affecting Mexican wolves. We address regulatory
mechanisms related to illegal shooting, as no regulatory mechanisms are
available to address inbreeding or small population size beyond the
overarching protection of the Act.
As discussed in factor C, illegal killing (or ``take,'' as it is
referred to in the Act) of Mexican wolves currently occurs at
significant levels in both the United States and Mexico. In the United
States, illegal shooting of Mexican wolves has been a continuous source
of mortality over the course of the reintroduction project. In Mexico,
illegal killing has resulted in a setback to the reestablishment of a
population of Mexican wolves in the State of Sonora and the Western
Sierra Madre; we are unsure of whether this threat will continue.
The Act provides broad protection of listed subspecies to prohibit
and penalize illegal take but has not been sufficient to deter all
illegal killing of Mexican wolves in the United States. Section 9 of
the Act (Prohibited acts) prohibits the take of any federally-listed
species, subspecies, or DPS. Section 11 (Penalties and enforcement)
provides civil penalties up to $25,000, and criminal penalties up to
$50,000 and/or not more than 1 year in jail for knowing violations of
section 9. Experimental populations are treated as if they are listed
as threatened, which limits criminal penalties to up to $25,000 and
imprisonment for not more than 6 months.
All cases of suspected illegal take of Mexican wolves in the United
States are investigated by the Service's Office of Law Enforcement
Special Agents. On-
[[Page 2502]]
the-ground personnel involved in preventing illegal take of a Mexican
wolf and apprehending those who commit illegal take include Service
Special Agents, Arizona Game and Fish Department (AGFD) Game Wardens,
New Mexico Department of Fish and Game Conservation Officers, U.S.
Forest Service special agents and Law Enforcement Officers (LEOs), San
Carlos Apache Tribe LEOs, and White Mountain Apache Tribe LEOs.
Specific actions to reduce illegal take include targeted patrols during
high-traffic periods (hunting seasons and holidays); the ability to
restrict human activities within a 1-mi (1.6-km) radius of release
pens, active dens, and rendezvous sites; proactive removal of road
kills to reduce the potential of wolves scavenging, which may result in
vehicular collision or illegal take of a Mexican wolf; and monetary
rewards for information that leads to a conviction for unlawful take of
the subspecies. Of the 55 wolf mortalities classified as illegal
mortalities between 1998 and 2013, only 4 individuals have been
convicted and 1 individual has paid a civil penalty.
If Mexican wolves were not protected by the Act, they would be
protected by State regulations in Arizona and New Mexico, and by
Federal law in Mexico. In Arizona, the Mexican wolf is managed as
Wildlife of Special Concern (Arizona Game and Fish Commission Rules,
Article 4, R12-4-401) and is identified as a Species of Greatest
Conservation Need (Tier 1a, endangered) (Species of Greatest
Conservation Need 2006, pending). Species with these designations are
managed under the AGFD's Nongame and Endangered Wildlife Management
program, which seeks to protect, restore, preserve, and maintain such
species. These provisions, i.e., the Species of Greatest Conservation
Need list and the Wildlife of Special Concern list, are nonregulatory.
However, Arizona Revised Statute Title 17 establishes AGFD with
authority to regulate take of wildlife in the State of Arizona.
``Take'' (to pursue, shoot, hunt, trap, kill, capture, snare, or net)
of wildlife in Arizona on lands under the authority of the Arizona Game
and Fish Commission is prohibited, unless a provision (e.g., Commission
Order, special rule, permit) is made to allow take. Penalties for
illegal take or possession of wildlife can include revocation of
hunting license or civil penalties up to $8,000 depending on its
classification as established through annual regulations.
In New Mexico, the Mexican wolf is listed as endangered (Wildlife
Conservation Act, pp. 17-2-37 through 17-2-46 NMSA 1978). Pursuant to
the Wildlife Conservation Act, it is unlawful to take, possess,
transport, export, process, sell or offer for sale, or ship any State
or Federal endangered species or subspecies (17-2-41 NMSA). Penalties
for violating the provisions of 17-2-41 may include fines of up to
$1,000 or imprisonment.
In Mexico, several legal provisions provide regulatory protection
for the Mexican wolf. The Mexican wolf is classified as ``E''
(``probably extinct in the wild'') by the Norma Oficial Mexicana NOM-
059-SEMARNAT-2010, ``Protecci[oacute]n ambiental-Especies nativas de
M[eacute]xico de flora y fauna silvestres-Categor[iacute]as de riesgo y
especificaciones para su inclusi[oacute]n, exclusi[oacute]n o cambio-
Lista de especies en riesgo'' (NOM-059-SEMARNAT-2010), which is a list
of species and subspecies at risk. This regulation does not directly
provide protection of the listed species or subspecies; rather it
includes the criteria for downlisting, delisting, or including a
species, subspecies, or population on the list. The General Wildlife
Law (``Ley General de Vida Silvestre,'' 2000, as amended), however, has
varying restrictions depending on risk status that apply only to
species or subspecies that are listed in the NOM-059-SEMARNAT-2010.
Mexico's Federal Penal Law (``C[oacute]digo Penal Federal''
published originally in 1931) Article 420 assigns a fine of 300 to
3,000 days of current wage and up to 9 years prison to those who
threaten the viability of a species, subspecies, or population,
transport a species at risk, or damage a specimen of a species at risk.
Administrative fines are imposed by an administrative authority
(PROFEPA, ``Procuraduria Federal de Proteccion al Ambiente,'' or the
Attorney General for Environmental Protection) and are calculated on
the basis of minimum wage in Mexico City ($62.33 daily Mexican pesos).
The fines established in the General Wildlife Law range from 1,246.60
to 311,650 Mexican pesos (approximately U.S. $98 to U.S. $24,400) for
the four minor infractions, to a range of 3,116 to 3,116,500 Mexican
pesos (approximately U.S. $244 to U.S. $244,400) for the other
offenses, including the killing of a wolf. Penal fines are imposed by a
judge and are calculated on the basis of the current daily wage of the
offender including all their income.
We have no information to suggest that, absent the Act's
protections, shooting of Mexican wolves in the United States would
cease. Rather, we believe that shooting of Mexican wolves could
increase, as State penalties (assuming wolves were granted protected
status by the States) would be less severe than current Federal
penalties under the Act. Thus, existing State penalties in Arizona and
New Mexico would not serve as an adequate deterrent to illegal take.
The illegal killing of at least four wolves in Mexico (see factor C)
between 2011 and 2014 suggests that Federal penalties in Mexico may not
be an adequate deterrent to illegal take there, although Federal fines
in Mexico are potentially higher than those available under the Act in
the United States. The adequacy of these penalties to address
overutilization (factor B) is not an issue, as instances of
overutilization do not occur or are exceedingly rare and, therefore, do
not significantly affect the Mexican wolf.
Summary of Factor D
Regulatory mechanisms to prohibit and penalize illegal killing
exist under the Act, but illegal shooting of wild Mexican wolves in the
United States persists. We conclude that, absent the protection of the
Act, killing of wolves in the United States would increase, potentially
drastically, because State penalties are less severe than current
Federal penalties. In regards to regulatory protection for the Mexican
wolf in Mexico, the recent poisoning of several reintroduced wolves
suggests that illegal killing may be a challenge for that country's
reintroduction efforts as well. Thus, in the absence of the Act,
existing regulatory mechanisms will not act as an effective deterrent
to the illegal killing of Mexican wolves in the United States, and this
inadequacy will significantly affect the Mexican wolf.
Factor E. Other Natural or Manmade Factors Affecting Its Continued
Existence
We document sources of mortality in six categories as part of our
ongoing monitoring of Mexican wolves in the experimental population:
Illegal Killing, Vehicle Collision, Natural, Other, Unknown, and
Awaiting Necropsy. In factor C, we assessed illegal shooting in the
United States, disease, and predation (our mortality category
``Natural'' includes disease and predation). In factor E, we assess the
impacts to the Mexican wolf from the remaining sources of mortality--
Vehicle Collision, Natural, Other, and Unknown. As stated in our
discussions of disease, predation, and illegal shooting, we may not be
documenting all mortalities to the population because mortality of
uncollared wolves is not typically detected; similarly, we may
underestimate the number of mortalities attributed to any one cause
discussed below. We also assess intolerance of
[[Page 2503]]
wolves by humans, land-use conflicts, hybridization, inbreeding,
climate change, and small population size.
Our category of ``Natural'' causes of mortality includes a number
of mortality sources, such as predation, starvation, interspecific
strife, lightning strikes, and disease. Because we have documented
three or fewer natural mortalities per year since 1998, we do not
consider natural mortalities to be occurring at a level, individually
or collectively, that significantly affects the Mexican wolf (and see
factor C for additional discussion of disease and predation) (Service
2013: Mexican Wolf Blue Range Reintroduction Project Statistics).
Therefore, we do not further discuss these ``Natural'' causes of
mortality. Similarly, mortalities caused by ``Other'' sources of
mortality, which also includes several sources of mortality (capture-
related mortalities, public-trap mortality, legal public shooting,
etc.) and ``Unknown'' causes are occurring at very low levels (5 of 100
mortalities, and 8 of 100 mortalities, respectively) and are not
occurring at a level that significantly affects the Mexican wolf.
Vehicular collision has accounted for 14 percent of Mexican wolf
mortalities from 1998 to December 31, 2013 (14 out of 100 total
documented Mexican wolf deaths) (Service 2013: Mexican Wolf Blue Range
Reintroduction Project Statistics). Thirteen out of 14 Mexican wolf
mortalities attributed to vehicular collision throughout the course of
the reintroduction (through December 31, 2013) occurred along paved
U.S. or State highways; one wolf died on a Forest Service dirt road as
a result of vehicle collision. The number of vehicular-related
mortalities, which has ranged from zero to two per year, with the
exception of a high of four vehicular-related wolf deaths in 2003, has
not shown a trend (increasing or decreasing) over time. Given the
occurrence of these mortalities on highways, it is likely that these
collisions were accidental events that occurred from vehicles traveling
at relatively high speeds. We are cognizant that different types of
roads present different levels of threats to Mexican wolves--paved
roads with higher speed limits present more risk of wolf mortality due
to vehicular collision than unpaved roads with lower speed limit.
Roads, both paved and unpaved, in currently occupied Mexican wolf
range in the Gila and Apache National Forests primarily exist to
support forest management, livestock grazing, recreational access,
resource protection, and transport of forest products on the National
Forests (Service 1996, pp. 3-13). National Forests contain various road
types (paved, unpaved, opened, closed, etc.) and trails (motorized,
nonmotorized), but are generally considered to be driven at relatively
low speeds and have relatively low traffic volume. Non-Forest Service
roads (e.g., highways and other paved roads) are limited in currently
occupied range, and include portions of U.S Highways 191 and 180, and
State Highways 260, 152, 90, 78, 32, and 12. U.S. highway 60 runs
immediately to the north of this area.
It has been recommended that areas targeted for wolf recovery have
low road density of not more than 1 linear mile of road per square mile
of area (1.6 linear km of road per 2.56 square kilometers; Thiel 1985,
pp. 406-407), particularly during colonization of an area (Fritts et
al. 2003, p. 301). Road density in the BRWRA was estimated at 0.8 mi
road per mi\2\ (1.28 km road per km\2\) prior to the reintroduction
(Johnson et al. 1992, p. 48). The U.S. Forest Service Southwest Region
recently calculated road densities for the Gila and Apache-Sitgreaves
National Forests during analysis of alternatives to designate a system
of roads, trails, and areas designated for motor vehicle use in
compliance with the Travel Management Rule. They did not assess road
use in terms of a baseline of traffic volume or projections of traffic
volume for the future. Both the Gila and Apache-Sitgreaves National
Forests continue to have an appropriately low density of roads for the
Mexican wolf reintroduction effort, with no plans to increase road
density in either Forest--road density in the Apache portion of the
Apache-Sitgreaves National Forest is estimated at 0.94 mi road per
mi\2\ for all roads (1.5 km road per km\2\) (open, closed,
decommissioned) and motorized trails, or 0.43 mi road per mi\2\ (0.69
km road per km\2\) for open roads and motorized trails (USDA 2010a, p.
102); road density in the Gila National Forest is estimated at 1.02 mi
per mi\2\ (1.64 km per km\2\) for open and closed (but not
decommissioned) roads and motorized trails (an overall average of 0.99
mi per mi\2\ (1.59 km per km\2\) (USDA 2010b, p. 149). Therefore, these
Forests provided Mexican wolf habitat with appropriately low road
density for establishment (colonization) of the experimental
population.
The revised MWEPA includes the addition of the Sitgreaves National
Forest, Magdalena Ranger District of the Cibola National Forest, and
Tonto, Payson, and Pleasant Valley Ranger Districts of the Tonto
National Forest to the Gila and Apache National Forests as Zone 1, the
area in which we will primarily conduct initial releases; these Forests
have appropriately low road densities compared with non-Forest Service
land to support these management activities (Service 2014, Ch 3, p. 2).
In Zone 2, which comprises a wider matrix of habitat quality than Zone
1, including areas of substantially higher road density of paved, high-
speed roads, we recognize that wolf morality due to vehicular collision
may increase. However, we do not have any data to determine the degree
to which this may occur or whether it will significantly affect the
Mexican wolf.
In summary, Mexican wolf mortalities from vehicular collision show
a strong pattern of occurrence on high-speed paved State or U.S.
Highways rather than on Forest Service roads, and are currently
occurring at relatively low levels (two or fewer mortalities per year,
with the exception of 1 year in which four mortalities were attributed
to vehicular collision). We consider it possible that wolf mortalities
due to vehicular collision may increase in the future as Mexican wolves
will be allowed to disperse beyond the Gila and Apache National Forests
into areas with higher road density within the MWEPA. We will continue
to document wolf mortality due to vehicular collision to determine
whether this becomes significant. In absence of Federal protection, we
would not expect that incidence rate of wolf-vehicular collision to
change, due to the accidental nature of these incidents. Therefore,
with or without the protections of the Act, we conclude that vehicular
collisions, considered in isolation of other sources of mortality, are
not significantly affecting the Mexican wolf. We further consider the
significance of these mortalities in Combination of Factors/Focus on
Cumulative Effects.
Intolerance by Humans--Human attitudes have long been recognized as
a significant factor in the success of gray wolf recovery efforts to
the degree that it has been suggested that recovery may depend more on
human tolerance than habitat restoration (see Boitani 2003, p. 339,
Fritts et al. 2003; Mech 1995). In the Southwest, extremes of public
opinion vary between those who strongly support or oppose the recovery
effort. Support may stem from such feelings as an appreciation of the
Mexican wolf as an important part of nature and an interest in
endangered species restoration, while opposition may stem from negative
social or economic consequences of wolf reintroduction, general fear
and dislike of wolves, or Federal land-use conflicts.
Public polling data in Arizona and New Mexico shows that most
[[Page 2504]]
respondents have positive feelings about wolves and support the
reintroduction of the Mexican wolf to public land (Research and Polling
2008a, p. 6, Research and Polling 2008b, p. 6). These polls targeted
people statewide in locations outside of the reintroduction area, and
thus provide an indication of regional support.
In any case, there is no direct evidence to indicate that
intolerance by humans of Mexican wolves will result in increased
illegal killings. Without additional information, we are unable to
confirm whether, or the degree to which, disregard for or opposition to
the reintroduction project is a causative factor in illegal killings.
Similarly, in Mexico, we do not know whether the illegal poisoning of
four reintroduced Mexican wolves was purposeful and stemmed from
opposition to the reintroduction or rather was targeted more generally
at (other) predators. We recognize that humans can be very effective at
extirpating wolf populations if human-caused mortality rates continue
at high levels over time, as demonstrated by the complete elimination
of Mexican wolves across the Southwest and Mexico prior to the
protection of the Act. At this time, however, we do not have enough
information to determine whether, or the degree to which, intolerance
by humans may pose a threat to the Mexican wolf.
Land-Use Conflicts--Historically, land-use conflict between Mexican
wolves and livestock producers was a primary cause of the wolf's
endangerment due to human killing of wolves that depredated livestock.
At the outset of the reintroduction effort, the amount of permitted
grazing in the recovery area was identified as a possible source of
public conflict for the project due to the potential for wolves to
depredate on livestock (Service 1996, p. 4-4). Since the reintroduction
project began in 1998, 73 Mexican wolves have been removed from the
wild due to livestock depredation, reaching a high of 16 and 19
removals in 2006 and 2007, respectively (Service 2013 Mexican Wolf Blue
Range Project Statistics).
Since 2007, the Service, other State, Federal, and tribal agencies,
private parties, and livestock producers have increased proactive
efforts (e.g., hazing, fencing, range riders) to minimize depredations,
resulting in fewer removals from 2008 to 2013 than in the first 10
years of the program. Since 2007, we removed one Mexican wolf in 2012
and two Mexican wolves in 2013 from the experimental population due to
confirmed livestock depredation (Service 2013 Mexican Wolf Blue Range
Project Statistics). While recognizing that management removals must be
part of an overall management scheme that promotes the growth of the
experimental population, the Service is committed to actively managing
depredating Mexican wolves to improve human tolerance.
Furthermore, the Service, in cooperation with the National Fish and
Wildlife Foundation, established the Mexican Wolf/Livestock
Interdiction Trust Fund (Trust Fund), which was founded on September
23, 2009. The objective of the Trust Fund is to generate long-term
funding for prolonged financial support to livestock operators with the
framework of cooperative conservation and recovery of Mexican wolf
populations in the Southwest. Funding is provided for initiatives that
address management, monitoring, and proactive conservation needs for
Mexican wolves related to livestock protection, measures to avoid and
minimize depredation, habitat protection, species protection,
scientific research, conflict resolution, compensation for damage,
education, and outreach activities. The Trust Fund is overseen by the
Mexican Wolf/Livestock Coexistence Council, an 11-member group of
ranchers, Tribes, county coalitions, and environmental groups that may
identify, recommend, and approve conservation activities, identify
recipients, and approve the amount of the direct disbursement of Trust
Funds to qualified recipients. It is the current policy of the
Coexistence Council to pay 100 percent of the market value of confirmed
depredated livestock and 50 percent market value for probable kills.
Based on these efforts, we conclude that land-use conflicts are not
significantly affecting the Mexican wolf. As noted above, since 2007 we
removed three Mexican wolves from the experimental population due to
confirmed livestock depredation (Service 2013 Mexican Wolf Blue Range
Project Statistics). Also, when we remove Mexican wolves due to
confirmed livestock depredation, many of the wolves are released back
into a different part of the experimental population area where they
are less likely to cause livestock depredations. We are able to manage
problem Mexican wolves in a manner that does not significantly affect
the experimental population. In the absence of protection by the Act,
land-use conflicts would still occur in areas where Mexican wolves and
livestock coexist. However, because the Mexican wolf is protected by
State law in Arizona and New Mexico, we expect that livestock producers
and State agencies would continue to employ effective practices of
hazing or other active management measures to reduce the likelihood of
occurrence of depredation incidents. Therefore, we conclude that land-
use conflicts are unlikely to significantly affect the Mexican wolf if
it was not protected by the Act.
Hybridization--Hybridization between wolves and other canids can
pose a significant challenge to recovery programs (e.g., the red wolf
recovery program) (Service 2007, pp. 10-11) because species in the
Canis genus can interbreed and produce viable offspring. In the Mexican
wolf experimental population, hybridization is a rare event. Three
confirmed hybridization events between Mexican wolves and dogs have
been documented since the reintroduction project began in 1998. In the
first two cases, hybrid litters were humanely euthanized (Service 2002,
p. 17, Service 2005:16.). In the third case, four of five pups were
humanely euthanized; the fifth pup, previously observed by project
personnel but not captured, has not been located and its status is
unknown (BRWRA Monthly Project Updates, June 24, 2011, http://www.fws.gov/southwest/es/mexicanwolf/CEBRWRA.cfm). No hybridization
between Mexican wolves and coyotes has been confirmed through our
genetic monitoring of coyotes, wolves, and dogs that are captured in
the wild as part of regular management activities of canids in the
wild.
Our response to hybridization events has negated potential impacts
to the BRWRA population from these events (e.g., effects to the genetic
integrity of the population). Moreover, the likelihood of hybrid
animals surviving, or having detectable impacts on wolf population
genetics or viability, is low due to aspects of wolf sociality and
fertility cycles (Mengel 1971, p. 334; Vila and Wayne 1999, pp. 195-
199).
We do not foresee any change in the likelihood of hybridization
events occurring, or the potential effect of hybridization events, if
the Mexican wolf was not protected by the Act; that is, hybridization
events and effects would continue to be rare. Therefore, we conclude
that hybridization is not significantly affecting the Mexican wolf
population now nor is it likely to do so in the future.
Inbreeding, Loss of Heterozygosity, and Loss of Adaptive
Potential--Mexican wolves have pronounced genetic challenges resulting
from an ongoing and severe genetic bottleneck (that is, a reduction in
a population's size to a small number for at least one generation)
caused by its near
[[Page 2505]]
extirpation in the wild and the small number of founders upon which the
captive population was established. These challenges include inbreeding
(mating of close relatives), loss of heterozygosity (a decrease in the
proportion of individuals in a population that have two different
alleles for a specific gene), and loss of adaptive potential, three
distinct but interrelated phenomena.
When a population enters a genetic bottleneck, the strength of
genetic drift (random changes in gene frequencies in a population) is
increased and the effectiveness of natural selection is decreased. As a
result, formerly uncommon alleles may drift to higher frequencies and
become fixed (the only variant that exists), even if they have
deleterious (negative) effects on the individuals that carry them.
Conversely, beneficial alleles may become less common and even be lost
entirely from the population. In general, rare alleles are lost quickly
from populations experiencing bottlenecks. Heterozygosity is lost much
more slowly, but the losses may continue until long after the
population has grown to large size (Nei et al. 1975, entire). The
extent of allele and heterozygosity loss is determined by the depth
(the degree of population contraction) and duration of a bottleneck.
Heterozygosity is important because it provides adaptive potential and
can mask (prevent the negative effects of) deleterious alleles.
Inbreeding can occur in any population, but is most likely to occur
in small populations due to limited choice of mates. The potential for
inbreeding to negatively affect the captive and reintroduced Mexican
wolf populations has been a topic of concern for over a decade (Parsons
1996, pp. 113-114; Hedrick et al. 1997, pp. 65-68). Inbreeding affects
traits that reduce population viability, such as reproduction
(Kalinowski et al. 1999, pp. 1371-1377; Asa et al. 2007, pp. 326-333;
Fredrickson et al. 2007, pp. 2365-2371), survival (Allendorf and Ryman
2002, pp. 50-85), and disease resistance (Hedrick et al. 2003, pp. 909-
913). Inbreeding is significant because it reduces heterozygosity and
increases homozygosity (having two of the same alleles) throughout the
genome.
Inbreeding depression is thought to be primarily a result of the
full expression of deleterious alleles that have become homozygous as a
result of inbreeding (Charlesworth and Willis 2009, entire). In other
words, rare deleterious alleles, or gene variants that have deleterious
effects such as deformities, are more likely to be inherited and
expressed in an offspring of two related individuals than of unrelated
individuals (that is, the offspring may be homozygous). Theory suggests
that, although lethal alleles (those that result in the death of
individuals with two copies) may be purged or reduced in frequency in
small populations (Hedrick 1994, pp. 363-372), many other mildly and
moderately deleterious alleles are likely to become fixed in the
population (homozygous in all individuals) with little or no reduction
in the overall genetic load (amount of lethal alleles) (Whitlock et al.
2000, pp. 452-457). In addition, there is little empirical evidence in
the scientific literature that purging reduces the genetic load in
small populations.
As previously described, Mexican wolves experienced a rapid
population decline during the 1900s, as predator eradication programs
sought to eliminate wolves from the landscape. Subsequently, a captive-
breeding program was initiated. The McBride lineage was founded with
three wolves in 1980. The Ghost Ranch and Aragon lineages were each
founded by single pairs in 1961 and around 1976, respectively. These
lineages were managed separately until the mid-1990s, by which time all
three lineages had become strongly inbred. Inbreeding coefficients (f)
(a measure of how closely related two individuals are) for McBride pups
born in the mid-1990s averaged about 0.23--similar to inbreeding levels
for offspring from outbred full sibling or parent-offspring pairs (f =
0.25). Inbreeding coefficients for Aragon and Ghost Ranch lineage pups
born in the mid-1990s were higher, averaging 0.33 for Aragon pups and
0.64 for Ghost Ranch pups (Hedrick et al. 1997, pp. 47-69).
Of the three lineages, only the McBride lineage was originally
managed as a captive-breeding program to aid in the conservation of
Mexican wolves. However, out of concern for the low number of founders
and rapid inbreeding accumulation in the McBride lineage, the decision
was made to merge the Aragon and Ghost Ranch lineages into the McBride
lineage after genetic testing confirmed that this approach could
improve the gene diversity of the captive population (Garcia-Moreno et
al. 1996, pp. 376-389). Consequently, pairings (for mating) between
McBride wolves and Aragon wolves and between McBride and Ghost Ranch
wolves began in 1995 with the first generation (F1) of these pups born
in 1997. Although the parents of these first generation wolves were
strongly inbred, the offspring were expected to be free of inbreeding
and free of the inbreeding depression. Forty-seven F1 wolves were
produced from 1997 to 2002. Upon reaching maturity, the F1 wolves were
paired among themselves, backcrossed with pure McBride wolves, and
paired with the descendants of F1 wolves called ``cross-lineage''
wolves to maintain gene diversity and reduce inbreeding in the captive
population.
Although there was slight statistical evidence of inbreeding
depression among captive wolves of the McBride and Ghost Ranch
lineages, the outbred F1 wolves proved to have far greater reproductive
fitness than contemporary McBride and Ghost Ranch wolves (which were
strongly inbred) as well as minimally inbred wolves from early in the
McBride and Ghost Ranch pedigrees. Pairings between F1 wolves were 89
percent more likely to produce at least one live pup, and mean litter
sizes for F1 x F1 pairs were more than twice as large as contemporary
McBride pairings (7.5 vs 3.6 pups per litter; Fredrickson et al. 2007,
pp. 2365-2371). The large increases in reproductive fitness among F1
wolves suggested that the McBride and Ghost Ranch lineages were
suffering from a large fixed genetic load of deleterious alleles. In
other words, McBride and Ghost Ranch wolves had accumulated identical
copies of gene variants that had negative effects on their health or
reproductive success at many locations (loci) throughout their genome.
In addition, pups born to cross-lineage dams (mother wolves) had up to
21 percent higher survival rates to 180 days than contemporary McBride
lineage pups (Fredrickson et al. 2007, pp. 2365-2371).
Although the F1 wolves had high reproductive fitness, strong
inbreeding depression among cross-lineage wolves in captivity has been
documented. Inbreeding levels of both dams and sires (mother and father
wolves, respectively) were found to negatively affect the probability
that a pair would produce at least one live pup. For example, the
estimated probabilities of a pair producing at least one live pup
dropped from 0.96 for F1 x F1 pairs (with no inbreeding in the dam and
sire) to 0.40 for pairs with a mean inbreeding coefficient of 0.15
(Fredrickson et al. 2007, pp. 2365-2371). Consistent with the finding
that inbreeding levels of sires affected the probability of producing
at least one live pup, Asa et al. (2007, pp. 326-333) found that two
measures of semen quality, sperm cell morphology and motility of sperm
cells, declined significantly as inbreeding levels increased. Among
pairs that produced at least one live pup, increases of 0.1 in the
inbreeding coefficients of both the dam and pups
[[Page 2506]]
was estimated to reduce litter size by 2.8 pups. Inbreeding levels of
the pups were found to have about twice the detrimental effect as
inbreeding in the dam, suggesting that inbreeding accumulation in pups
was causing pups to die prior to being born (Fredrickson et al. 2007,
pp. 2365-2371).
As of July 2014, the captive population of Mexican wolves consisted
of 258 wolves, of which 33 are reproductively compromised or have very
high inbreeding coefficients, leaving 225 wolves as the managed
population (Siminski and Spevak 2014). The age structure of the
population, however, is heavily skewed, with wolves 7 years old and
older comprising about 62 percent of the population--meaning that most
of the population is composed of old wolves who will die within a few
years. This age structure, which has resulted from the high
reproductive output of the F1 wolves and their descendants in
captivity, the combination of few releases of captive-born wolves to
the wild in recent years, removal of wolves from the wild population to
captivity, and limited pen space for pairings, means that additional
gene diversity will be lost as the captive population continues to age
(R. Fredrickson, pers. comm., 2014).
The SSP strives to minimize and slow the loss of gene diversity of
the captive population but (due to the limited number of founders)
cannot increase it. As of 2014, the gene diversity of the captive
program was 83.36 percent of the founding population, which falls below
the average mammal SSP (93 percent) and below the recognized SSP
standard to maintain 90 percent of the founding population diversity.
Below 90 percent, the SSP states that reproduction may be compromised
by low birth weight, smaller litter sizes, and related issues.
Representation of the Aragon and Ghost Range lineages in 2014 was
17.94 percent and 20.07 percent, respectively (Siminski and Spevak
2014, p. 8). More specifically, the representation of the seven
founders is very unequal in the captive population, ranging from about
30 percent for the McBride founding female to 4 percent for the Ghost
Ranch founding male. Unequal founder contributions lead to faster
inbreeding accumulation and loss of founder alleles. The captive
population is estimated to retain only 3.00 founder genome equivalents,
suggesting that more than half of the alleles (gene variants) from the
seven founders have been lost from the population.
With the current gene diversity of 83.36 percent and current space
limitations of 300 captive Mexican wolves, retaining 75 percent gene
diversity for only 41 years from present is possible with the current
generation length of 5.8 years in the captive population, population
growth rate of [lambda] = 1.065, effective population size (Ne) of
26.96, and a ratio of effective to census size (Ne / N; that is, the
number of breeding animals as a percentage of the overall population
size) of 0.1266 (Siminski and Spevak 2014, p. 7). The genetically
effective population size is defined as the size of an ideal population
that would result in the rate of inbreeding accumulation or
heterozygosity loss as the population being considered. The effective
sizes of populations are almost always smaller than census sizes of
populations. A rule of thumb for conservation of small populations
holds Ne should be maintained above 50 to prevent substantial
inbreeding accumulation, and that small populations should be grown
quickly to much larger sizes (Ne = 500) to maintain
evolutionary potential (Franklin 1980, entire). The low ratio of
effective to census population sizes in the captive population reflects
the limitations on breeding (due to a lack of cage space) over the last
several years, while the low effective population size is another
indicator of the potential for inbreeding and loss of heterozygosity.
The gene diversity of the experimental population of Mexican wolves
can only be as good as the diversity of the captive population from
which it is established. Based on information available in July 11,
2014, the genetic diversity of the wild population was 74.52 percent of
the founding population (Siminski and Spevak 2014, pp. 9), with 5.36
percent and 14.56 percent representation of Aragon and Ghost Range
lineages, respectively. At the end of 2013, the minimum population in
the Mexican wolf experimental population was 83 Mexican wolves, but the
experimental population is a poor representative of the genetic
variation remaining in the captive population. Founder representation
in the experimental population is more strongly skewed than in the
captive population. Mean inbreeding levels are 65 percent greater, and
founder genome equivalents are 35 percent lower than in the captive
population. In addition, the estimated relatedness of the Mexican wolf
experimental population is on average 65 percent greater than that in
the captive population (population mean kinship: 0.2548 versus 0.1664;
Siminski & Spevak 2014, p. 9). Without substantial management action to
improve the genetic composition of the population, inbreeding will
accumulate and heterozygosity and alleles will be lost much faster than
in the captive population.
There is evidence of strong inbreeding depression in the Mexican
wolf experimental population. Fredrickson et al. (2007, pp. 2365-2371)
estimated that the mean observed litter size (4.8 pups for pairs
producing pups with no inbreeding) was reduced on average by 0.8 pups
for each 0.1 increase in the inbreeding coefficient of the pups. For
pairs producing pups with inbreeding coefficients of 0.20, the mean
litter size was estimated to be 3.2 pups. Computer simulations of the
experimental population incorporating the Mexican wolf pedigree suggest
that this level of inbreeding depression may substantially reduce the
viability of the experimental population (Carroll et al. 2014, p. 82).
The recent history of Mexican wolves can be characterized as a
severe genetic bottleneck that began no later than the founding of the
Ghost Ranch lineage in 1960. The founding of the three lineages along
with their initial isolation likely resulted in the loss of most rare
alleles and perhaps even some moderately common alleles. Heterozygosity
loss was accelerated as a result of rapid inbreeding accumulation. The
merging of the captive lineages likely slowed the loss of alleles and
heterozygosity, but did not end it. The consequences to Mexican wolves
of the current genetic bottleneck will be future populations that have
reduced fitness (for example, smaller litter sizes, lower pup survival)
due to inbreeding accumulation and the full expression of deleterious
alleles. The loss of alleles will limit the ability of future Mexican
wolf populations to adapt to environmental challenges.
Based on data from the SSP documenting loss of genetic variation,
research documenting viability-related inbreeding effects in Mexican
wolves, and our awareness that the wild population is at risk of
inbreeding due to its small size, we conclude that inbreeding, and loss
of heterozygosity, and loss of adaptive potential are significantly
affecting Mexican wolves and are likely to continue to do so in the
future. If the Mexican wolf was not protected by the Act, these risks
would remain, and may increase if States or other parties did not
actively promote genetic diversity in the experimental population by
releasing wolves with appropriate genetic ancestry to the population.
Small Population Size--Rarity may affect the viability (likelihood
of extinction or persistence over a given time period) of a subspecies
depending
[[Page 2507]]
on the subspecies' biological characteristics and threats acting upon
it. We consider several types of information to determine whether small
population size is affecting the Mexican wolf, including historical
conditions, consideration of stochastic (or, chance) events,
theoretical recommendations of population viability, and applied
population-viability models specific to Mexican wolves. We discuss
three types of stochastic events--demographic, environmental, and
catastrophic--as the fourth type of stochastic event--genetic--is
addressed under the subheading of Inbreeding. We further discuss the
significance of small population size in Combination of Factors/Focus
on Cumulative Effects, below.
Historical abundance and distribution serve as a qualitative
reference point against which to assess the size of the current
population. Prior to European colonization of North America, Mexican
wolves were geographically widespread throughout numerous populations
across the southwestern United States and Mexico. Although we do not
have definitive estimates of historical abundance, we can deduce from
gray wolf population estimates (Leonard et al. 2005, p. 15), trapping
records, and anecdotal information that Mexican wolves numbered in the
thousands across its range in the United States and Mexico. We,
therefore, recognize that the current size and geographic distribution
of the Mexican wolf represents a substantial contraction from its
historical (pre-1900s) abundance and distribution.
Scientific theory and practice generally agree that a subspecies
represented by a small population faces a higher risk of extinction (or
a lower probability of population persistence) than a subspecies that
is widely and abundantly distributed (Goodman 1987, pp. 11-31; Pimm et
al. 1988, p. 757). One of the primary causes of this susceptibility to
extinction is the sensitivity of small populations to random
demographic events (Shaffer 1987, pp. 69-86, Caughley 1994, p. 217). In
small populations, even those that are growing, random changes in
average birth or survival rates could cause a population decline that
would result in extinction. This phenomenon is referred to as
demographic stochasticity. As a population grows larger and individual
events tend to average out, the population becomes less susceptible to
extinction from demographic stochasticity and is more likely to
persist.
Two Mexican wolf population-viability analyses were initiated
subsequent to the development of the 1982 Mexican Wolf Recovery Plan
but prior to the reintroduction of Mexican wolves into the experimental
population in 1998 (Seal 1990 entire, IUCN 1996 entire, Service 2010,
p. 66), although neither was completed. Population-viability modeling
will be conducted as part of the development of draft recovery
criteria; these results will be available to the public when the draft
recovery plan is published. In the meantime, Carroll et al. (2014, p.
81) conducted a population viability model for Mexican wolves and found
that the risk of extinction varied by both population size and the
number of effective migrants per generation. The risk of extinction for
population sizes below 200 was affected by the number of migrants, such
that populations of 100 had a greater than 5 percent extinction risk,
even with 3 effective migrants per generation, while populations of 125
were more secure with 2.5 to 3.0 effective migrants per generation, and
populations of 150 were secure with greater than 0.5 effective migrants
per generation (Carroll et al. 2014, p. 81). Given our understanding of
the high extinction risk of the current size of the experimental
population and our awareness that this rarity is not the typical
abundance and distribution pattern for Mexican wolves, we consider the
small population size of the Mexican wolf.
At the end of 2013, the minimum population size was 83 Mexican
wolves, meaning the experimental population is, by demographic
measures, considered small and has a low probability of persistence
(Shaffer 1987, p. 73; Boyce 1992, p. 487; Mills 2007, p. 101; Service
2010, pp. 63-68). Absent the protection of the Act, the extinction
risks associated with small population size would remain, and may
increase if Arizona or New Mexico does not actively support the
experimental population through appropriate management measures. The
vulnerability of a small population to extinction can also be driven by
the population's vulnerability to decline or extinction due to
stochastic environmental or catastrophic events (Goodman 1987, pp. 11-
31; Pimm et al. 1988, p. 757). While we consider these types of events
to be critically important considerations in our recovery efforts for
the subspecies, we have not identified any single environmental event
(i.e., disease, climate change (below)) or catastrophic event
(wildfire) to be significantly affecting Mexican wolf based on our
current information and management practices (e.g., vaccinations,
monitoring). However, we reconsider the concept of vulnerability to
these events below, in Combination of Factors/Focus on Cumulative
Effects.
Climate Change--Our analyses under the Act include consideration of
ongoing and projected changes in climate. The terms ``climate'' and
``climate change'' are defined by the Intergovernmental Panel on
Climate Change (IPCC). ``Climate'' refers to the mean and variability
of different types of weather conditions over time, with 30 years being
a typical period for such measurements, although shorter or longer
periods also may be used (IPCC 2013, p. 1450). The term ``climate
change'' thus refers to a change in the mean or variability of one or
more measures of climate (e.g., temperature or precipitation) that
persists for an extended period, typically decades or longer, whether
the change is due to natural variability, human activity, or both (IPCC
2013, p. 1450). Various types of changes in climate can have direct or
indirect effects on the Mexican wolf. These effects may be positive,
neutral, or negative, and they may change over time, such as the
effects of interactions of climate with other variables (e.g., habitat
fragmentation). In our analysis, we use our expert judgment to weigh
relevant information, including uncertainty, in our consideration of
various aspects of climate change. Research to investigate the possible
impacts of climate change specifically on the Mexican wolf has not been
conducted. Therefore, we base our analysis on pertinent information
from the scientific literature related to Mexican wolf habitat and
prey.
Throughout their circumpolar distribution, gray wolves persist in a
variety of ecosystems with temperatures ranging from -70 to 120 degrees
Fahrenheit (-56 to 48 degrees Celsius) with wide-ranging prey type and
availability (Mech and Boitani 2003, p. xv). Mexican wolves
historically inhabited, and still inhabit, a range of southwestern
ecotypes subsisting on large ungulate prey as well as small mammals
Mexican wolves did not historically, (nor currently), inhabit extreme
desert areas or semi-desert grasslands except potentially during
dispersal movements (Service 2010, p. 39). Due to their plasticity and
lack of reliance on microhabitat, we generally do not consider Mexican
wolves to be highly vulnerable or sensitive to climate change (Dawson
et al. 2011, p. 53). However, we recognize that climate change is
already having detectable impacts on the ecosystems of the Southwest,
and future changes could affect Mexican wolves or their prey. For
[[Page 2508]]
example, warmer temperatures, more frequent and severe drought, and
reductions in snowpack, streamflows and water availability are
projected across the southwestern US (Garfin et al. 2014, pp. 464-466).
To the degree that warmer temperatures and increased aridity or
decreased water availability (Dai 2011, p. 58) or any of these other
conditions, limit prey abundance, we would also expect decreased
Mexican wolf densities. Information suggests that ungulate prey
populations in more xeric ecoregions in the Southwest may be impacted
more negatively than those in wetter areas due to decreased forage
quality and availability (deVoss and McKinney 2012, p. 19). However,
Mexican wolves are associated with mid-to high-elevation montane
forests and adjacent grasslands rather than areas with more xeric
conditions. Reduced water in the system, due to reduced summer base
flow in streams, and the earlier onset of summer low-flow conditions,
may reduce or localize big game populations in the summer months; such
changes have the potential to adversely affect the wolf within the next
50 to 100 years through reductions or distributional shifts in wild
ungulate populations. Information also suggests that mule deer may be
more susceptible to climate change impacts that alter vegetation
patterns than elk (deVoss and McKinney 2012, pp. 16-19), but elk are
currently a much more important source of prey for Mexican wolves than
mule deer.
Both Mexican wolves and their primary prey (elk) may exhibit
reasonable adaptive capacity (Dawson et al. 2011, p. 53), such that
they could shift habitats in response to changing climatic conditions
or potentially persist in place. Elk, which make up approximately 77 to
80 percent of the Mexican wolf's diet in the experimental population,
are known to be habitat generalists due to their association with wide
variation in environmental conditions (Kuck 1999, p. 1). Both positive
and negative impacts to elk from climate change have been hypothesized
in the literature, although no specific regional research has been
conducted (deVoss and McKinney 2012, p. 18). For example, if climate
change results in decreased winter snow pack in the Colorado Plateau
Region (which includes central Arizona and New Mexico), elk populations
could expand in number due to milder winters and increased forage
availability (National Wildlife Federation 2013, p. 14). Conversely, if
migratory elk herds stop migrating in response to milder winters,
increased elk densities in some areas could lead to higher levels of
disease transmission between elk, which may increase mortality (ibid).
With these types of positive and negative considerations in mind,
several sources tentatively suggest that overall elk may respond
favorably in range and population size to climate change (National
Wildlife Federation 2013, p. 14, deVoss and McKinney 2012, p. 19).
In Mexico, elk are not present as a source of prey for Mexican
wolves. Therefore, the effects of climate change on deer populations
could be important for the establishment and maintenance of a wolf
population there. Seasonal decreases in precipitation and resulting
changes in vegetation quality and availability could lead to the same
type of impacts to ungulates as hypothesized in the United States, such
as range contraction or decreasing populations. However, as with
Factors A-D and because our focus in this analysis is on currently
occupied range, the absence of a Mexican wolf population in Mexico
precludes analysis of climate change there.
Therefore, based on the relatively low vulnerability and
sensitivity of the Mexican wolf to changes in climate, and the
potential for elk to respond favorably to climate change in this
region, we conclude that climate change is not substantially affecting
the Mexican wolf at the current time nor do we expect it to do so in
the future.
Summary of Factor E
Inbreeding, loss of adaptive potential, loss of heterozygosity, and
small population size are significantly affecting the Mexican wolf.
Inbreeding and loss of heterozygosity have the potential to affect
viability-related fitness traits in Mexican wolves and, therefore, to
affect the persistence of the subspecies in the wild in the near term;
loss of genetic variation (adaptive potential) significantly affects
the likelihood of persistence of the Mexican wolf over longer
timeframes. Absent the protection of the Act, inbreeding, loss of
heterozygosity, and loss of adaptive potential would persist and
possibly increase depending on whether the States or other parties
undertook active promotion of the maintenance of gene diversity.
The small size of the Mexican wolf experimental population results
in a high risk of extinction due to the susceptibility of the
population to stochastic demographic events. The minimum estimated
population of 83 Mexican wolves at the end of 2013 is not a sufficient
size to ensure persistence into the future. Absent the protection of
the Act, small population size would continue to significantly affect
the Mexican wolf, or may increase if States or other parties did not
actively support the experimental population through appropriate
management measures. Intolerance by humans, land-use conflicts,
hybridization, and climate change are not significantly affecting the
Mexican wolf, nor are they expected to do so in the future. Vehicular
collision is not significantly affecting the Mexican wolf; however, we
expect that this source of mortality may increase in the future due to
wolf dispersal and occupancy in areas of higher road density than
currently occupied habitat. We do not have data to estimate how
significant this may become.
Combination of Factors/Focus on Cumulative Effects
In the preceding review of the five factors, we found that the
Mexican wolf is most significantly affected by illegal killing,
inbreeding, loss of heterozygosity, loss of adaptive potential, and
small population size. In absence of the Act's protections, these
issues would continue to affect the Mexican wolf, and would likely
increase in frequency or severity. We also identify several potential
sources of mortality or risk (disease, vehicular collision, wildfire,
hybridization, etc.) that we do not currently consider to be
significantly affecting the Mexican wolf due to their low occurrence,
minimal impact on the population, or lack of information. However, we
recognize that multiple sources of mortality or risk acting in
combination have greater potential to affect the Mexican wolf than each
factor alone. Thus, we consider how factors that, by themselves may not
have a significant effect on the Mexican wolf, may affect the
subspecies when considered in combination.
The small population size of the Mexican wolf exacerbates the
potential for all other factors to disproportionately affect the
Mexican wolf. The combined effects of demographic, genetic,
environmental, and catastrophic events to a small population can create
an extinction vortex--an unrecoverable population decline--that results
in extinction. Small population size directly and significantly
increases the likelihood of inbreeding depression, which has been
documented to decrease individual fitness, hinder population growth,
and decrease the population's probability of persistence. Small
population size also increases the likelihood that concurrent
mortalities from multiple causes that individually may not be resulting
in a population decline (e.g., vehicular collisions, natural sources of
mortality)
[[Page 2509]]
could collectively do so, depending on the population's productivity,
especially when additive to an already significant source of mortality,
such as illegal shooting. Effects from disease, catastrophe,
environmental conditions, or loss of heterozygosity that normally could
be sustained by a larger, more resilient population have the potential
to rapidly affect the size, growth rate, and genetic integrity of the
small experimental population when they act in combination. Therefore
we consider the combination of factors C, D, and E to be significantly
affecting the Mexican wolf.
Summary of Five-Factor Analysis
We do not find habitat destruction, curtailment, or modification to
be significantly affecting the Mexican wolf now, nor do we find that
these factors are likely to do so in the future regardless of whether
the subspecies is protected by the Act. The size and federally
protected status of the National Forests in Arizona and New Mexico are
adequate and appropriate for the reintroduction project. These National
Forests provide secure habitat with an adequate prey base and habitat
characteristics to support the current wolf population. The Wallow Fire
and the Whitewater-Baldy Complex Fire, while catastrophic, were not
sources of habitat modification, destruction, or curtailment that
affected the Mexican wolf because there were no documented wolf
mortalities during the fires, and prey populations are expected to
increase in response to post-fire positive effects on vegetation.
We do not find overutilization for commercial, recreational,
scientific, or educational purposes to be significantly affecting the
Mexican wolf because we have no evidence to indicate that legal killing
or removal of wolves from the wild for commercial, recreational (i.e.,
hunting), scientific, or educational purposes is occurring. The killing
of wolves for their pelts is not known to occur, and Mexican wolf
research-related mortalities are minimal or nonexistent. Incidents of
injuries and mortalities from trapping (for other animals) have been
low. In absence of Federal protection, State regulations in Arizona and
New Mexico, and Federal regulations in Mexico, could provide
regulations to protect Mexican wolves from overutilization.
Overutilization of Mexican wolves would not likely increase if they
were not listed under the Act due to the protected status they would be
afforded by the States and Mexico.
Based on known disease occurrences in the current population and
the active vaccination program, we do not consider disease to be
significantly affecting the Mexican wolf. Absent the protection of the
Act, a similar vaccination program would need to be implemented by the
States or other parties, or the potential for disease to significantly
affect the Mexican wolf could increase.
Predation (by nonhuman predators) is not significantly affecting
the Mexican wolf. No wild predator regularly preys on wolves, and only
a small number of predator-related wolf mortalities have been
documented in the current Mexican wolf experimental population. We do
not consider predation likely to significantly affect the Mexican wolf
in the future or if the subspecies was not protected by the Act.
Illegal shooting is identified as significantly affecting the
Mexican wolf and is a significant threat. Adequate regulatory
protections are not available to protect Mexican wolves from illegal
shooting without the protection of the Act. We would expect shooting of
Mexican wolves to increase if they were not federally protected, as
State penalties (assuming Mexican wolves were maintained as State-
protected) are less than Federal penalties.
Inbreeding, loss of heterozygosity, loss of adaptive potential, and
small population size are significantly affecting the Mexican wolf. We
recognize the importance of the captive management program and the
active reintroduction project and recovery program in addressing these
issues. Absent the protection of the Act, their effects on Mexican wolf
would continue, or possibly increase depending on the degree of active
management provided by the States or other parties.
Vehicular collisions, intolerance by humans, land-use conflicts,
hybridization, and climate change are not significantly affecting the
Mexican wolf, nor are they expected to do so in the near future or if
the Mexican wolf was not protected by the Act.
Climate change is not significantly affecting the Mexican wolf nor
would it do so in the absence of the Act's protections. The effects of
climate change may become more pronounced in the future, but as is the
case with all stressors that we assess, even if we conclude that a
species or subspecies is currently affected or is likely to be affected
in a negative way by one or more climate-related impacts, it does not
necessarily follow that these effects are significant to the species or
subspecies. The habitat generalist characteristics of the wolf and
their primary prey, elk, lead us to conclude that climate change will
not significantly affect the Mexican wolf in the future.
The cumulative effects of factors that increase mortality and
decrease genetic diversity are significantly affecting the Mexican
wolf, particularly within the context of its small population size (a
characteristic that significantly decreases the probability of a
population's persistence). The cumulative effects of these threats are
significantly affecting the Mexican wolf at the current time and likely
will continue to do so in the future. Absent the protection of the Act,
the cumulative effects of these threats may increase due to the
potential for more killing of Mexican wolves, increased risk of
inbreeding, and other sources of mortality, all exacerbated by the
Mexican wolf's small population size.
Determination
Section 4 of the Act (16 U.S.C. 1533), and its implementing
regulations at 50 CFR part 424, set forth the procedures for adding
species to the Federal Lists of Endangered and Threatened Wildlife and
Plants. Under section 4(a)(1) of the Act, we may list a species,
subspecies, or DPS based on (A) The present or threatened destruction,
modification, or curtailment of its habitat or range; (B)
Overutilization for commercial, recreational, scientific, or
educational purposes; (C) Disease or predation; (D) The inadequacy of
existing regulatory mechanisms; or (E) Other natural or manmade factors
affecting its continued existence. Listing actions may be warranted
based on any of the above threat factors, singly or in combination.
We have carefully assessed the best scientific and commercial data
available regarding the past, present, and future threats to the
Mexican wolf and have determined that the subspecies warrants listing
as endangered throughout its range. As required by the Act, we
considered the five potential threat factors to assess whether the
Mexican wolf is endangered or threatened throughout its range. Based on
our analysis, we find that the Mexican wolf is in danger of extinction
throughout all of its range due to small population size, illegal
killing, inbreeding, loss of heterozygosity and adaptive potential, and
the cumulative effect of all threats. Also, existing regulatory
mechanisms are not adequate to ensure the survival of the Mexican wolf.
Our finding that the Mexican wolf is in danger of extinction
throughout all of its range is consistent with our administrative
approach to determining which subspecies are on the brink of extinction
and, therefore, warrant listing
[[Page 2510]]
as endangered. Prior to the early 1900s, the Mexican wolf was
distributed over a large geographic area that included portions of the
Southwest and much of Mexico. The Mexican wolf was nearly eliminated in
the wild by the mid-1900's due to predator eradication efforts, which
led to its listing as an endangered subspecies in 1976 and again as
part of the species-level gray wolf listing in 1978. Therefore, the
Mexican wolf is a subspecies that was formerly widespread but was
reduced to such critically low numbers and restricted range (i.e.,
eliminated in the wild) that it is at high risk of extinction due to
threats that would not otherwise imperil it.
At the time of its initial listing, no robust populations of
Mexican wolves remained in the wild. The establishment and success of
the captive-breeding program temporarily prevented immediate absolute
extinction of the Mexican wolf and, by producing surplus animals, has
enabled us to undertake the reestablishment of Mexican wolves in the
wild by releasing captive animals into the experimental population. In
the context of our current proposal to list the Mexican wolf as an
endangered subspecies, we recognize that, even with these significant
improvements in the Mexican wolf's status, its current geographic
distribution is a very small portion of its former range. Moreover,
within this reduced and restricted range, the Mexican wolf faces
significant threats that are intensified by its small population size.
The Mexican wolf is highly susceptible to inbreeding, loss of
heterozygosity, and loss of adaptive potential due to the bottleneck
created during its extreme population decline prior to protection by
the Act, the limited number of and relatedness of the founders of the
captive population, and the loss of some genetic material from the
founders. The effects of inbreeding have been documented in Mexican
wolves and require active, ongoing management to minimize.
Mexican wolf mortality from illegal killing, as well as all other
sources of mortality or removal from the wild experimental population,
is occurring within the context of a small population. Smaller
populations have low probabilities of persistence compared to larger,
more geographically widespread populations. Absent the protection of
the Act, illegal killing would likely increase dramatically, further
reducing the population's size and increasing its vulnerability to
genetic and demographic factors, putting the Mexican wolf at imminent
risk of extinction. These factors are occurring throughout the Mexican
wolf's range in the wild, resulting in our determination that the
subspecies warrants listing as endangered throughout its range.
After a thorough review of all available information and an
evaluation of the five factors specified in section 4(a)(1) of the Act,
as well as consideration of the definitions of ``threatened species''
and ``endangered species'' contained in the Act and the reasons for
delisting as specified in 50 CFR 424.11(d), we revise the List of
Endangered and Threatened Wildlife (50 CFR 17.11) by listing the
Mexican wolf subspecies (Canis lupus baileyi) as endangered. The
Mexican wolf is in danger of extinction throughout all of its range and
thus warrants the protections of the Act. Listing the entire Mexican
wolf subspecies means that all members of the taxon are afforded the
protections of the Act regardless of where they are found.
The Act defines an endangered species as any species that is ``in
danger of extinction throughout all or a significant portion of its
range'' and a threatened species as any species ``that is likely to
become endangered throughout all or a significant portion of its range
within the foreseeable future.'' We find that the Mexican wolf is in
danger of extinction throughout all of its range due to illegal
killing, inbreeding, loss of heterozygosity, loss of adaptive
potential, small population size, and the cumulative effects of factors
C, D, and E. Historically, the Mexican wolf was distributed across
portions of the southwestern United States and northern and central
Mexico. The subspecies may have also ranged north into southern Utah
and southern Colorado within zones of intergradation where
interbreeding with other gray wolf subspecies may have occurred
(Leonard et al. 2005, pp. 15-16). The Mexican wolf was near extinction
prior to protection by the Act in the 1970's, such that the captive-
breeding program was founded with only seven wolves. Although our
recovery efforts for the Mexican wolf, which are still under way, have
led to the reestablishment of a wild population in the United States,
the single, small population of Mexican wolves would face an imminent
risk of extinction from the cumulative effects of small population
size, inbreeding, and illegal shooting, without the protection of the
Act. Absent protection by the Act, regulatory protection, especially
against illegal killing, would not be adequate to ensure the survival
of the Mexican wolf. Therefore, on the basis of the best available
scientific and commercial information, we list the Mexican wolf as
endangered in accordance with sections 3(6) and 4(a)(1) of the Act. We
find that a threatened subspecies status is not appropriate for the
Mexican wolf because of the contracted range, because the threats are
occurring rangewide and are not localized, and because the threats are
ongoing and expected to continue into the future.
Under the Act and our implementing regulations, a subspecies may
warrant listing if it is endangered or threatened throughout all or a
significant portion of its range. The threats to the survival of the
Mexican wolf occur throughout its range and are not restricted to any
particular significant portion of that range. Accordingly, our
assessment and proposed determination applies to the Mexican wolf
throughout its entire range.
Effects of the Rule
This final rule lists the Mexican wolf as an endangered subspecies.
As a matter of procedure, in a separate but concurrent rulemaking
published in this Federal Register, we also finalize the revision to
the regulations for the nonessential experimental population of the
Mexican wolf to ensure appropriate association of the experimental
population with this Mexican wolf subspecies listing.
Required Determinations
National Environmental Policy Act
We determined that an environmental assessment or an environmental
impact statement, as defined under the authority of the National
Environmental Policy Act of 1969, need not be prepared in connection
with regulations adopted pursuant to section 4(a) of the Act. We
published a notice outlining our reasons for this determination in the
Federal Register on October 25, 1983 (48 FR 49244).
Paperwork Reduction Act of 1995
Office of Management and Budget (OMB) regulations at 5 CFR part
1320, which implement provisions of the Paperwork Reduction Act (44
U.S.C. 3501 et seq.), require that Federal agencies obtain approval
from OMB before collecting information from the public. This rule does
not contain any new collections of information that require approval by
OMB under the Paperwork Reduction Act. This rule will not impose
recordkeeping or reporting requirements on state or local governments,
individuals, businesses, or organizations. An agency may not conduct or
sponsor, and a person is not required to respond to, a collection of
information unless it displays a currently valid OMB control number.
[[Page 2511]]
Government-to-Government Relationship With Tribes
In accordance with the President's memorandum of April 29, 1994,
Government-to-Government Relations with Native American Tribal
Governments (59 FR 22951), E.O. 13175, and the Department of the
Interior's manual at 512 DM 2, we readily acknowledge our
responsibility to communicate meaningfully with recognized Federal
Tribes on a government-to-government basis. In accordance with
Secretarial Order 3206 of June 5, 1997 (American Indian Tribal Rights,
Federal-Tribal Trust Responsibilities, and the Endangered Species Act),
we readily acknowledge our responsibilities to work directly with
Tribes in developing programs for healthy ecosystems, to acknowledge
that tribal lands are not subject to the same controls as Federal
public lands, to remain sensitive to Indian culture, and to make
information available to Tribes. We have coordinated with affected
Tribes through correspondence and meetings in order to both (1) provide
them with an understanding of the changes, and (2) to understand their
concerns with those changes. We fully considered all of the comments on
the proposed rule that were submitted by Tribes and Tribal members
during the public comment period, and we addressed those concerns, new
data, and new information where appropriate.
References Cited
A complete list of all references cited in this document is posted
on http://www.regulations.gov at Docket No. FWS-HQ-ES-2013-0073 and
available upon request from the New Mexico Ecological Services Field
Office, Albuquerque, NM (see FOR FURTHER INFORMATION CONTACT).
Data Quality Act
In developing this rule we did not conduct or use a study,
experiment, or survey requiring peer review under the Data Quality Act
(Pub. L. 106-554).
Authors
The primary authors of this rule are the staff members of the
Mexican Wolf Recovery Program (see FOR FURTHER INFORMATION CONTACT).
List of Subjects in 50 CFR Part 17
Endangered and threatened species, Exports, Imports, Reporting and
recordkeeping requirements, Transportation.
Regulation Promulgation
For the reasons set forth in the preamble, the Service amends 50
CFR part 17 as follows:
PART 17--[AMENDED]
0
1. The authority citation for part 17 continues to read as follows:
Authority: 16 U.S.C. 1361-1407; 1531-1544; and 4201-4245, unless
otherwise noted.
0
2. Amend Sec. 17.11(h) in the List of Endangered and Threatened
Wildlife under Mammals by:
0
a. Revising the entry for ``Wolf, gray (Canis lupus)''; and
0
b. Adding two entries for ``Wolf, Mexican (Canis lupus baileyi)'' in
alphabetic order.
The revision and additions read as follows:
Sec. 17.11 Endangered and threatened wildlife.
* * * * *
(h) * * *
--------------------------------------------------------------------------------------------------------------------------------------------------------
Species Vertebrate population
------------------------------------------------------ Historic range where endangered or Status When listed Critical Special
Common name Scientific name threatened habitat rules
--------------------------------------------------------------------------------------------------------------------------------------------------------
Mammals
* * * * * * *
Wolf, gray...................... Canis lupus........ Holartic........... U.S.A.: All of AL, AR, E 1, 6, 13, 15, NA NA
CA, CO, CT, DE, FL, 35
GA, KS, KY, LA, MA,
MD, ME, MO, MS, NC,
NE, NH, NJ, NV, NY,
OK, PA, RI, SC, TN,
TX, VA, VT and WV; and
portions of AZ, IA,
IN, IL, ND, NM, OH,
OR, SD, UT, and WA as
follows: (1) Northern
AZ (that portion north
of the centerline of
Interstate Highway
40); (2) Southern IA,
(that portion south of
the centerline of
Highway 80); (3) Most
of IN (that portion
south of the
centerline of Highway
80); (4) Most of IL
(that portion south of
the centerline of
Highway 80); (5)
Western ND (that
portion south and west
of the Missouri River
upstream to Lake
Sakakawea and west of
the centerline of
Highway 83 from Lake
Sakakawea to the
Canadian border); (6)
Northern NM (that
portion north of the
centerline of
Interstate Highway
40); (7) Most of OH
(that portion south of
the centerline of
Highway 80 and east of
the Maumee River at
Toledo); (8) Western
OR (that portion of OR
west of the centerline
of Highway 395 and
Highway 78 north of
Burns Junction and
that portion of OR
west of the centerline
of Highway 95 south of
Burns Junction); (9)
Western SD (that
portion south and west
of the Missouri
River); (10) Most of
Utah (that portion of
UT south and west of
the centerline of
[[Page 2512]]
Highway 84 and that
portion of UT south of
Highway 80 from Echo
to the UT/WY
Stateline); and (11)
Western WA (that
portion of WA west of
the centerline of
Highway 97 and Highway
17 north of Mesa and
that portion of WA
west of the centerline
of Highway 395 south
of Mesa). Mexico
* * * * * * *
Wolf, Mexican................... Canis lupus baileyi Southwestern United Entire, except where E ............... NA NA
States and Mexico. included in an
experimental
population as set
forth in 17.84(k).
Wolf, Mexican................... Canis lupus baileyi Southwestern United U.S.A. (portions of AZ XN ............... NA 17.84(k)
States and Mexico. and NM)--see 17.84(k).
* * * * * * *
--------------------------------------------------------------------------------------------------------------------------------------------------------
* * * * *
Dated: January 7, 2015.
Stephen Guertin,
Director, U.S. Fish and Wildlife Service.
[FR Doc. 2015-00441 Filed 1-15-15; 8:45 am]
BILLING CODE 4310-55-P