A new count of wild Mexican gray wolves released Wednesday by the U.S. Fish and Wildlife Service has heightened wolf advocates’ concerns that inbreeding among the species’ population in Arizona and New Mexico has led to a decline in growth.
The federal agency reported 114 wild Mexican wolves in 2017, just one more than in 2016.
“Our goal is to have at least a 10 percent growth in the population each year,” said John Bradley, a spokesman for the Fish and Wildlife Service. The agency is tasked with managing a 20-year-old reintroduction program for the endangered subspecies — an effort that pits conservationists against ranchers.
In the last three years combined, however, the agency has seen an increase of less than 5 percent, following at least two years of strong growth. In its report on the new wolf count, the agency cited a steep decline in pup survival numbers.
While 50 wolf pups born in 2016 survived the year, just 26 survived last year, the agency said.
It cited 12 documented wolf deaths in 2017 and 10 wolves that were removed from the wild packs.
Asked if the mild, dry winter had an affect on the number of wild wolves, Bradley said the agency didn’t have data on the impact of climate factors, “but it’s something we’ll take a look at over time.”
Michael Robinson of the nonprofit Center for Biological Diversity and members of other advocacy groups blamed the stagnating population on poor management of the packs, lax oversight of wolf poaching and inbreeding — a problem they say could be solved by releasing breeding-age adult wolves that are now in captivity.
Robinson described the Mexican wolves’ situation as a “genetic crisis,” saying nearly every Mexican wolf in the wild is so genetically similar to every other Mexican wolf that they are related “as if they were full siblings.”
Bradley agreed that inbreeding is a concern.
In one of the 22 Mexican wolf packs roaming in the southern reaches of the two states, he said, is a young wolf that was cross-fostered in 2017 — which means it was born in captivity and released as a newborn into a wild wolf den. The radio-collared pup is one four the federal agency attempted to cross-foster last year, Bradley said.
The process, which involves swapping pups from a wild den with captive-born pups, is intended to help diversify the wolves’ gene pool. The Fish and Wildlife Service has proposed releasing 12 newborn pups this year through the cross-fostering program.
But Robinson said it is an imperfect and experimental solution “that is not fitting the genetic emergency.”
The process is labor-intensive, he said, requiring staff to find a wolf den in which the timing of a litter’s birth closely matches that of a captive-born litter, and coordinating a quick swap of pups in the wilderness shortly after the births occur.
A wild wolf mother could reject pups that aren’t her own.
And even if all goes as smoothly as possible, Robinson said, it takes at least two years for a pup released into the wild to begin breeding. “These newborn pups should be released with their parents,” he argued. “… The Mexican wolf really can’t afford too much tinkering.”
But the state of New Mexico has rejected Fish and Wildlife’s requests for a permit to release Mexican wolves here since 2015. The federal agency’s first attempt to cross-foster captive pups into a wild den, without a permit, sparked a legal battle between the state and the federal government.
The state now allows the agency to cross-foster as long as it removes one wild pup for each captive-born pup it releases. Still, the state hasn’t approved releases of adult wolves.
One of the state’s complaints in recent years was that Fish and Wildlife hadn’t updated its management plan for the species.
That process was completed in November. The new Mexican wolf management plan calls for up to 320 wolves in New Mexico and Arizona — a number that advocates say is far too low. They also complain that the plan is too restrictive about where the wolves may roam — limiting the species’ range to south of Interstate 40.
“Population growth is being undermined by state agencies in New Mexico and Arizona and a ‘recovery plan’ driven by politics and special interests rather than science,” said Christopher Smith, with Santa Fe-based WildEarth Guardians, in a statement Wednesday.
Several groups filed lawsuits last month over the management plan.
Meanwhile, Bradley said the breeding season for Mexican wolves is underway.
“We’re hopeful that this spring will be a successful season,” he said.