Daily Rules, Proposed Rules, and Notices of the Federal Government
Section 4(b)(3)(B) of the Act (16 U.S.C. 1531
The Mexican wolf was listed as an endangered subspecies on April 28, 1976 (41 FR 17736). In 1978, we published a rule (43 FR 9607, March 9, 1978) reclassifying the gray wolf as an endangered population at the species level (
In 1996, we published a Final Environmental Impact Statement, “Reintroduction of the Mexican Wolf within its Historic Range in the Southwestern United States,” after assessing potential locations for the reintroduction of the Mexican wolf (61 FR 67573; December 23, 1996). On April 3, 1997, the Department of the Interior issued its Record of Decision on the Final Environmental Impact Statement (62 FR 15915). We published a final rule, “Establishment of a Nonessential Experimental Population of the Mexican Gray Wolf in Arizona and New Mexico,” on January 12, 1998 (63 FR 1752), which established the Mexican Wolf Experimental Population Area in central Arizona and New Mexico and designated the reintroduced population as a nonessential experimental population under section 10(j) of the Act. In March of that year, 11 Mexican wolves from the captive breeding program were released to the wild.
On April 1, 2003, we published a final rule revising the listing status of the gray wolf across most of the conterminous United States (68 FR 15804). Within that rule, we established three DPS designations for the gray wolf. Gray wolves in the Western DPS and the Eastern DPS were reclassified from endangered to threatened, except where already classified as threatened or as an experimental population. Mexican wolves in the Southwestern DPS retained their previous endangered or experimental population status. On January 31, 2005, and August 19, 2005, U.S. District Courts in Oregon and Vermont, respectively, ruled that the April 1, 2003, final rule violated the Act (
The status of the Mexican wolf as endangered was not changed by the listing rule or the Courts' invalidation of the rule. Invalidation of the rule establishing the three DPSs did cause the suspension of formal separate recovery planning for the Southwestern DPS, as that entity no longer existed as such, but recovery efforts for the Mexican wolf continued as part of the reinstated 1978 lower-48-State-and-Mexico gray wolf listing. On May 5, 2010, we announced the availability of the Mexican Wolf Conservation Assessment (75 FR 24741), a nonregulatory document intended to provide scientific information relevant to the conservation of the Mexican wolf in Arizona and New Mexico as a component of the Service's gray wolf recovery efforts (Service 2010). In December 2010, we convened a new Mexican Wolf Recovery Team, which is tasked with revising and updating the 1982 recovery plan. The new recovery plan will provide objective recovery criteria for the delisting of the Mexican wolf. A draft revised recovery plan is anticipated in 2013, and the final plan in late 2014.
On August 11, 2009, we received a petition from the Center for Biological Diversity requesting that the Mexican wolf be listed as an endangered subspecies or DPS and critical habitat be designated under the Act. On August 12, 2009, we received a petition dated August 10, 2009, from WildEarth Guardians and The Rewilding Institute requesting that the Mexican wolf be listed as an endangered subspecies and critical habitat be designated under the Act. The petitions clearly identified themselves as such and included the requisite identification information for the petitioner(s), as required by 50 CFR 424.14(a). On October 22, 2009, we responded with letters to the petitioner(s) indicating that the petitions were under review and that we would make a finding as to whether or not the petitions present substantial information indicating that the requested action may be warranted. In response to complaints from the petitioners, we agreed, pursuant to a stipulated settlement agreement, to complete the 90-day finding in response to these petitions by July 31, 2010.
On August 4, 2010, we published in the
The Mexican wolf is a genetically distinct subspecies of the North American gray wolf; adults weigh 23-41 kilograms (kg) (50-90 pounds (lbs)) with a length of 1.5-1.8 meters (m) (5-6 feet (ft)) and height at shoulder of 63-81 centimeters (cm) (25-32 inches (in)) (Young and Goldman 1944; Brown 1983, p. 119). Mexican wolves are typically a patchy black, brown to cinnamon, and cream color, with primarily light underparts (Brown 1983, p. 118); solid black or white Mexican wolves do not exist as seen in other North American gray wolves.
Integration of ecological, morphological, and genetic evidence supports several conclusions relevant to the southwestern United States regarding gray wolf taxonomy and range. First, there is agreement that the Mexican wolf is distinguishable from other gray wolves based on morphological and genetic evidence. Second, recent genetic evidence continues to support the observation that historic gray wolf populations existed in intergradations across the landscape as a result of their dispersal ability (Leonard
Historically, Mexican wolves were associated with montane woodlands and adjacent grasslands (Brown 1983, p. 19) in areas where ungulate prey were numerous. Wolf packs establish territories, or home ranges, in which they hunt for prey. Recent studies have shown the preferred prey of Mexican wolves to be elk (Reed
Gray wolves die from a variety of causes including disease, malnutrition, debilitating injuries, interpack strife, and human exploitation and control (Service 1996, p. A-2). In the reintroduced Mexican wolf population, causes of mortality have been largely human-related (vehicular collision and illegal shooting). Additionally, reintroduced Mexican wolves have been removed from the wild for management purposes. To date, the Mexican wolf population has had a failure (mortality plus removal) rate too high for natural or unassisted population growth, and, as stated above, the population has oscillated between 40 and 60 wolves since 2003. The most recent end-of-year population survey in 2011 documented a minimum of 58 Mexican wolves in the wild.
The Mexican wolf has been listed as endangered as part of the broader lower-48-State-and-Mexico gray wolf listing, as revised, since 1978 (43 FR 9607, March 9, 1978). Thus, although not currently listed separately as a subspecies or DPS, Mexican wolves have been protected by the Act for the last 36 years. As a result of this protection, and the actions described below, the minimum number of Mexican wolves in the wild in the United States has risen from none in the late 1990's to 58 in 2011. It is important to note that the 1978 reclassification rule stipulated that “biological subspecies 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).
In accordance with these assurances, the Service has actively focused on Mexican wolf conservation and recovery beginning with our involvement in the establishment of the captive breeding program in the late 1970s (Parsons 1996, Lindsey and Siminski 2007), the completion of the Mexican wolf recovery plan in 1982 (Service, 1982), the establishment of the Mexican Wolf Experimental Population Area in central Arizona and New Mexico in 1998 (63 FR 1752), and the reintroduction of Mexican wolves into the wild later that same year. Further, we are currently in the process of revising and updating the 1982 recovery plan, which we anticipate releasing for public and peer review in 2013. These actions demonstrate the Service's long-standing commitment to Mexican wolf recovery.
The current listing of all gray wolves in the lower 48 states and Mexico (save for those in the western Great Lakes, and the northern Rocky Mountains) encompasses any gray wolf subspecies or DPS that may occur in those same states or Mexico. More generally, the listing of any species as endangered or threatened encompasses within it all subspecies or potential DPSs comprising that species. Were the Service to separately list each constituent subspecies or potential DPS comprising an already listed entity, the endangered and threatened list would almost certainly be expanded several fold, and the limited resources of the Service would be consumed for years by the task, only to give again the protection of the Act to individual plants and animals that already had it. There is no indication in the Endangered Species Act that Congress intended the Service to list separately each of the constituent subspecies or DPSs encompassed within a broader listed entity, and it has been the consistent practice of the Service not to do so.
Therefore, because all individuals that comprise the petitioned entity already receive the protections of the Act, and in fact are collectively the focus of a significant Service-led recovery effort consistent with the 1978 revised listing, we find the petitioned action is not warranted at this time. However, we continue to review the appropriate conservation status of all gray wolves that comprise the 1978 lower-48-State-and-Mexico gray wolf listing, as revised, and we may revise the current listing based on the outcome of that review. In particular, we note that we could not, consistent with the requirements of the Act, take any action that would remove the protections accruing to Mexican wolves under the 1978 lower-48-State-and-Mexico listing, as revised, without first determining whether the Mexican wolf warranted listing separately as a subspecies or a DPS, and, if so, putting a separate listing in place.
A complete list of references cited is available on the Internet at
The primary authors of this notice are the staff members of the U.S. Fish and Wildlife Service, Headquarters Office, Endangered Species Program.
The authority for this action is section 4 of the Endangered Species Act of 1973, as amended (16 U.S.C. 1531