Thirty conservation organizations are calling on wildlife agencies to take immediate action to protect Mexican gray wolves after new data showed the endangered species’ genetic diversity has declined for the fourth straight year.
The groups sent a letter Thursday to the U.S. Fish and Wildlife Service, Arizona Game and Fish Department and New Mexico Department of Game and Fish, requesting the release of wolf families from captivity, citing that the captive population contains 37% more genetic diversity than wild wolves.
“Mexican wolves won’t recover unless agencies restore as much genetic diversity as can be salvaged from what’s already been squandered,” said Michael Robinson, a senior conservation advocate at the Center for Biological Diversity.
The organizations also asked officials to stop removing genetically valuable wolves from the wild and allow Mexican gray wolves to mate with northern gray wolves, as occurred naturally for millennia before human intervention.
The last release of a captive-born wolf family occurred in 2006, and those packs showed high success rates, according to the conservation groups. Genetic diversity peaked in 2008 after offspring from those releases matured and bred.
Since 2016, agencies have relied on cross-fostering, taking captive-born pups from their mothers and placing them in wild dens shortly after birth. However, only 24 of 99 pups released through 2023 are known to have survived through their first year.
The genetic decline of Mexican gray wolves directly affects New Mexico, where the endangered species roams across public and private lands in the southwestern part of the state as part of their designated recovery area south of Interstate 40.
“Cross-fostering pups makes for heart-warming stories and cute photos, but it is an inadequate strategy to recover Mexican wolves,” said Chris Smith, wildlife program director for WildEarth Guardians.
Since April, agencies have removed seven genetically rare wolves through lethal control and captures, including shooting a pregnant female in Arizona and capturing four wolves from an Arizona pack while killing one of their pups, according to the letter.
The conservation groups also urged agencies to stop relocating wolves that cross Interstate 40, arguing that natural dispersal between Mexican wolves and northern gray wolves is essential for genetic health.
Mexican gray wolves are among North America’s most genetically limited wolf populations. The entire population descends from just seven animals captured decades ago — six in Mexico and one in Arizona — after a government eradication campaign eliminated the rest of the subspecies.
The wolves currently suffer from lower reproductive rates, nasal carcinomas and congenitally fused toes, which scientists consider indicators of inbreeding, according to David Parsons, former Mexican gray wolf recovery coordinator for the U.S. Fish and Wildlife Service.
“Natural selection in response to changing environmental conditions, also known as evolution, can only work if there are multiple gene forms to select from,” Parsons said in the letter.
As long as these animals are allowed to be killed by residents or on demand (for just being wolves) by USDA/Fish & Wildlife Services, how can they recover?
Thanks for highlighting this important analysis by non-governmental