05-03-2025
Mexican gray wolf numbers rise for 9th year, but advocates question foster pup strategy
The number of endangered Mexican gray wolves living in the United States has grown for the ninth consecutive year, according to a new report issued this week by state wildlife agencies in Arizona and New Mexico.
At least 286 individual wolves have been counted in the two states as a part of the 2024 annual census, an 11% increase from last year's count of 257. A minimum of 124 wolves have been recorded in Arizona and 162 individuals in New Mexico. This year's count also marks the longest continuous population growth streak in the recovery program's history.
The wolf subspecies neared extinction in the 1970s, but has been recovering in the wild since reintroduction began in 1998. The goal of the program is to establish two resilient and genetically distinct populations of Mexican wolves in the United States and Mexico.
'As we evaluate Mexican wolf recovery efforts, examining the last decade of data certainly provides confidence that recovery will be achieved,' Stewart Liley, the chief of wildlife for the New Mexico Department of Game and Fish said in a news release.
Population data is collected by an interagency field team consisting of state, federal and tribal government partners. The team compiles the census using a variety of methods including remote cameras, scat collection and visual observation.
Among the 2024 findings in the report:
A minimum of 60 packs were documented at the end of 2024: There were 37 in New Mexico and 23 in Arizona. A wolf pack is defined as two or more wolves that maintain an established home range.
A minimum of 164 pups were born in 2024, with 79 surviving until the end of the year (a 48% survival rate).
At least 26 breeding pairs (16 in New Mexico, 10 in Arizona) were recorded in 2024.
There were 112 collared wolves in the wild at the end of the year, which is 39% of the counted wolves.
'The results of this year's count reflect the hard work of many people and agencies that lead recovery. It also supports the recovery strategies in the 2022 Mexican Wolf Recovery Plan as we see both demographic and genetic objectives being exceeded this year," said Clay Crowder, assistant director at Arizona Game and Fish Department.
Despite the gains in the Mexican wolf population over the past decade, wildlife advocacy groups have criticized the recovery efforts for limiting population growth and genetic diversity.
Imperiled species: Fate of Mexican gray wolves is caught in a battle over their place in the landscape
The Mexican wolf, or lobo, is the smallest subspecies of gray wolf in North America, weighing between 50-80 pounds with a characteristic buff, gray, rust and black fur coat. The wolves are also the rarest and most genetically distinct subspecies, according to the U.S. Fish and Wildlife Service.
Historically, the species roamed throughout much of the Southwest through central Mexico before being nearly eradicated from the wild by the 1970s, largely due to conflicts with the livestock industry.
The current population of Mexican gray wolves are all descended from the seven surviving wolves that originated a binational captive breeding program in the 1980s and 1990s. By 1998, the wolves were reintroduced into the wild.
State and federal agencies manage the species inside of a designated area known as the Mexican Wolf Experimental Population Area, which includes all of Arizona and New Mexico south of Interstate 40. The agencies consider this area to be the species' historic range, but conservation groups have argued that the boundary is hindering recovery efforts by preventing wolves from establishing in quality habitat.
In recent years, Mexican wolves that have wandered north of the I-40 boundary have been relocated or killed, including a female wolf that died near Flagstaff in late 2024.
'We really want them to start letting wolves live north of I-40, where they're showing us that the habitat is really great for them. That's happened in both Arizona and New Mexico,' Cyndi Tuell, a director for Western Watersheds Project told told The Republic last year. 'The wolves are showing us where to go, we just need to listen.'
In a recent news release, Arizona Game and Fish wolf experts said that Interstate 40 "is not an arbitrary boundary for Mexican wolf recovery, it is a generous extension northward and based on the best historical, ecological, and genetic scientific information available. The best available science on Mexican wolf recovery shows that habitat north of I-40 is not needed for successful recovery."
Recovery efforts: Wildlife agencies place a record 27 Mexican gray wolf pups in wild dens this year
The major threat facing the Mexican gray wolf is genetic diversity, according to Michael Robinson, a senior conservation advocate for the Center for Biological Diversity.
Due to its limited gene pool, the species is vulnerable to the problems caused by inbreeding. The release of captive wolves into the wild population can help in strengthening the species' genetics, and since 2016, wildlife agencies have been placing fostered pups born in captivity into wild dens.
Conservation groups have urged the U.S. Fish and Wildlife Service to release well-bonded breeding pairs with pups into the wild from captivity instead of the current strategy of fostering pups.
According to a 2024 letter to the federal agency signed by 18 conservation groups, between 2016 and 2023 only about 25% of foster pups were documented a year after reintroduction compared to an approximate 50% survival rate of a wild pup kept with its mother. The letter also argues that pups born in captivity are less inbred than those born in the wild.
In 2022, conservation advocacy groups sued U.S. Fish and Wildlife for approving a management rule they say harms the species by confining their range to south of Interstate 10 and limits their genetic diversity. The groups brought a similar lawsuit in 2015 and won in federal court, forcing the agency to revise the rule.
Oral arguments for the lawsuit will be heard this week in a federal court in Tucson.
John Leos covers environmental issues for The Arizona Republic and azcentral. Send tips or questions to
Environmental coverage on and in The Arizona Republic is supported by a grant from the Nina Mason Pulliam Charitable Trust.
Sign up for AZ Climate, our weekly environment newsletter, and follow The Republic environmental reporting team at and @azcenvironment on Facebook and Instagram.
This article originally appeared on Arizona Republic: Mexican gray wolf numbers rise to 286, 9th year of population growth
