At least one more endangered Mexican gray wolf is roaming the American Southwest compared with a year earlier, and U.S. wildlife officials said Wednesday that lower survival rates among pups are primarily to blame for the lack of strong growth in the population.
The annual survey documented 114 wolves in the wild in Arizona and New Mexico. The number reflects on-the-ground data collected over the winter along with aerial surveys done in January and February.
The latest figure includes 26 pups that survived through 2017. In 2016, the number of surviving pups was nearly double that.
Officials lamented that the numbers were not what they had hoped for and said they were focused on improving the genetics of the wild population as a way to build more robust numbers.
"We all understand the challenges involved in protecting and restoring wild populations of this endangered species," Amy Lueders, Southwest regional director for the U.S. Fish and Wildlife Service, said in a statement.
Environmentalists pointed to stagnation in the population, saying managers need to rethink their approach to helping the species recover.
"It is essential that science, not politics, guides recovery efforts for these rarest of wolves," said Bryan Bird with the group Defenders of Wildlife.
The Fish and Wildlife Service has been criticized for its management of the predators by both ranchers, who say the animals are a threat to their livelihoods, and environmentalists who want more captive-bred wolves to be released.
Mexican wolves, a subspecies of the gray wolf, nearly disappeared in the 1970s before the federal government added them to the endangered species list in 1976.
The Fish and Wildlife Service began reintroducing the wolves in New Mexico and Arizona in 1998, but the effort has been hampered by everything from politics to illegal killings and inbreeding concerns.
According to the survey, there are 22 packs, with at least 51 wolves in New Mexico and 63 wolves in Arizona.
Two dozen wolves were captured and radio-collared during the annual count, including 10 that had not been captured previously.
Officials also said one of four captive-bred pups that had been placed with foster wolf packs in the wild was confirmed to be alive.
In 2017, there were 12 documented wolf deaths.
Michael Robinson with the Center for Biological Diversity said the survey results should serve as a warning for the Fish and Wildlife Service. He said the low numbers mean each wolf in the wild counts.
Mexican wildlife managers also are working to restore the species south of the U.S.-Mexico border. Officials say there are about 30 Mexican gray wolves in the wild there.
Under a recently adopted recovery plan for the species, management of the wolves in the U.S. would eventually revert to state wildlife agencies in New Mexico and Arizona but not until the population averages 320 wolves over an eight-year period. In each of the last three years, the population would have to exceed the average to ensure the species doesn't backslide.
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