The annual Mexican gray wolf population count revealed a steady increase in numbers, but what does it mean for the long-term survival and genetic health of these endangered Southwestern native wolves?
The United States Fish & Wildlife Service (USFWS) released the results of its annual wild Mexican gray wolf population count today, revealing that the number of wolves has increased to a minimum of 186 wolves. This increase of 14% from last year comes despite the critical decline in genetic health of the wild population. Each year, young wolves disperse in search of mates to form new packs, but the next generation is less likely to be more genetically diverse without the release of more wolves from captive breeding facilities participating in the Mexican Wolf Species Survival Plan (SSP).
Wolf advocates continue to celebrate the efforts of SSP facilities in both the United States and Mexico. Some of these facilities have worked with the USFWS to introduce young pups into active, wild dens in Arizona and New Mexico, a difficult process called cross-fostering. Cross-fostering efforts in 2020 were more successful than in the past, with USFWS placing a record 20 pups into dens.
“The Mexican Wolf Species Survival Plan is an integral partner in Mexican gray wolf conservation. In 2020, institutions in the SSP worked with USFWS under the extremely challenging conditions of the pandemic to achieve incredible success in the field, giving 20 pups an opportunity to grow up in the wild. The dedication demonstrated by the SSP and the field team are inspiring, as is the resilience of these native Southwestern wolves,” said Erin Hunt, Coordinator for Lobos of the Southwest.
Nevertheless, many experts fear that cross-fostering alone may not be sufficient to prevent a rapid decline in gene diversity that could be catastrophic for these rare Southwestern wolves. Cross-fostering depends on “stars aligning,” with a match in age between captive litter and wild litter, wild dens being located, and a variety of other factors. If one or more factor is not aligned, a cross-fostering operation may not take place at all. Cross-fostered pups also have to grow up and raise families of their own in order to contribute their valuable genes to the population, making this a longer-term technique to support recovery in the wild. To date, of the 50 pups introduced into wild packs from the SSP, only 12 cross-fostered wolves have been documented as surviving and only three have established packs of their own.
USFWS and other partner agencies continue to make the deliberate choice to avoid releasing well-bonded family groups of wolves with their pups, putting the long-term health of the wild population at risk. The Mexican Wolf SSP houses suitable family groups that could be released, providing an immediate boost to the number of breeding pairs and improving the wild gene pool.
“The Mexican wolves in human care are more genetically diverse than the wild population. This means that adult releases and continued fostering of Mexican wolf pups from these zoological institutions into the wild population are vital to the conservation work to help this critically endangered population survive and grow,” stated Regina Mossotti, biologist at the Endangered Wolf Center and Pup Foster Advisor to the Mexican Wolf SSP.
For years, scientists have recommended to the USFWS that there be three subpopulations of at least 200 wolves each (and 750 total), spread throughout the Southwest United States. Scientists warn that this metapopulation structure and geographic distribution is imperative to the success of Mexican wolves. We are still far short of this scientific recommendation.
Emily Renn with the Grand Canyon Wolf Recovery Project said “With the population of Mexican gray wolves in the wild continuing to grow, wolves need access to additional suitable habitat where packs can spread out and provide ecological benefits as a keystone species. As USFWS enters the next phase of court-ordered revisions for the wolves’ management plan, now is the perfect opportunity to increase the area where wolves can be released and establish territories north of Interstate 40 and in the Grand Canyon region.”
Wolf advocates have requested that the USFWS include reporting on the genetic health of the Mexican gray wolf as they release information about the population. The genetic value of each individual wolf to the whole population is never reported to the public, leaving some questioning how mortalities and removals from the wild might be impacting the population.
In 2020, USFWS removed 10 endangered Mexican gray wolves from the wild and lethally controlled an additional 5 wolves. Additionally, at least 29 Mexican gray wolves died in the wild in 2020, with some of those deaths still under investigation. A year with such high mortality and the largest number of lethal removals since 2006 is no cause for celebration.
Logan Glasenapp, an attorney with New Mexico Wilderness Alliance, said, “We’re happy to see a steady increase in the overall population but are still disappointed to also recognize such a deadly year for the Lobo. As we continue to encourage the Fish and Wildlife Service to designate the Lobo as an essential species with full protection under the Endangered Species Act, we look forward to renewed opportunities under the Biden administration. Four years of anti-wildlife policies have not kept the Lobo down, and forward-thinking management of the Lobo requires the utmost protections from the increasingly severe impacts of climate change, habitat encroachment, and the continuous problems that arise from being a woefully misunderstood species.”
These rare wolves are more than just numbers. They are essential to Southwestern ecosystems and deserve safety and freedom, not continued persecution.
Background on Mexican Gray Wolves
The lobo, or Mexican gray wolf, is the smallest, most genetically distinct, and one of the rarest subspecies of gray wolf. The subspecies was listed under the Endangered Species Act in 1976, but conservation efforts have suffered without implementation of recommended recovery actions.
Although lobos once widely roamed across the southwestern United States and Mexico, the Mexican gray wolf was purposefully eradicated from the U.S. on behalf of American livestock, hunting, and trapping interests. In 1998, after the few remaining wolves were put into captivity to save the species, the Service released 11 Mexican wolves to a small area on the border of Arizona and New Mexico now known as the Blue Range Wolf Recovery Area.
Mexican wolves are still at tremendous risk due to their small population size, limited gene pool, threats from trapping, and illegal killings. Wolves breed only once a year, most often in monogamous pairs. The count occurs in January and February to capture the population at its most stable point. More at www.mexicanwolves.org.