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NM: With mother’s death, the endangered Prieto wolf pack is gone

By Kendra Chamberlain

Peering at a map of red dots, Michael Robinson became worried when he couldn’t locate AF1251, the last adult Mexican gray wolf of the Prieto pack, who was also a mother with a yearling. 

Robinson, senior conservation advocate at the Center for Biological Diversity, was keeping an eye on the remaining two members of the Prieto pack after the alpha male of the pack and a pup had been killed by the federal Wildlife Services agents earlier this year. Wildlife Services is a secretive federal agency that offers predator removal services for ranchers. 

The two wolf killings followed the removal of a total of seven pack members over the last two years.

“I’d been very interested in what would happen to the Prieto pack after [that],” Robinson said. 

The mapping tool, provided by the U.S. Fish and Wildlife Service, tracks endangered Mexican gray wolves using radio collar data. The map is usually updated every two weeks, but amid the pandemic, the map hadn’t been updated in over a month. When it was finally updated this week, Robinson said he checked the numbers of each red dot on the map, hoping to locate the female. But she wasn’t there. After a series of unanswered phone calls to the Fish and Wildlife Service, he received the news. The nine-year-old female was dead, and the yearling had fled. 

That was the end of the Prieto pack. 

The endangered Mexican gray wolf once roamed across much of northern Mexico and the southwestern United States, before the animals were brought to the brink of extinction by a federal program designed to exterminate the species. In 1976, the Fish and Wildlife Service officially added the Mexican gray wolf to the Endangered Species List and began recovery efforts for the apex predator, in collaboration with the government of Mexico. 

The recovery has been a slow, uphill battle for the species. Today, just two populations of Mexican gray wolves exist in the world. The U.S. population, which was re-introduced to portions of western New Mexico and eastern Arizona in 1998, now contains 36 packs, totalling 163 individuals. There are an estimated 18 packs in New Mexico, and another 18 located in Arizona. The Mexico population is much smaller, made up of just 30 individuals at last count. 

The wolf AF1251’s grandmother was one of the first 11 wolves introduced to the wild back in 1998. She was captured by the federal government in 2005 near the Rainy Mesa area of the Gila National Forest, and later died of capture myopathy, a term that refers to an exertion-induced or stress-induced muscle degenerative condition that occurs in animals held in captivity that is often fatal. Fifteen years later, AF1251 would suffer the same fate: she was caught in a trap near Rainy Mesa, and died a day later of stress. 

A Fish and Wildlife spokesperson told NM Political Report AF1251’s trapping incident is being investigated by the Fish and Wildlife Service’s Office of Law Enforcement. 

“The good news is the yearling is still alive, and there are other animals, from previous generations of the Prieto pack, that I believe are alive as well,” Robinson said. “The bad news is, quite a few wolves were taken out of the population, and most significantly, the alpha male who was shot by Wildlife Services had inordinate genetic importance. Fish and Wildlife Service knew that and shot him anyway.”

Genetic diversity has become a central obstacle to the Mexican gray wolf’s recovery. Inbreeding, which occurs when there are too few mating individuals within a population, can increase the likelihood of genetic disorders or susceptibility to disease that can threaten the survival of the species. Each loss of a “genetically valuable” individual sets back recovery. 

Conservationists describe the federal government’s Mexican gray wolf recovery program as one step forward, two steps back. On the one hand, strides have been made in boosting populations. In March, the Fish and Wildlife Service announced 20 new wolves in New Mexico, the second year in a row of population growth for the species. 

But on the other hand, the Fish and Wildlife Service also maintains a program to remove wolves, either by capture or lethal force, that threaten livestock. Wolves are also frequently caught in private traps on public lands in New Mexico, sustaining injuries that often require them to be removed from the wild and treated. Some are released later, while others remain in captivity.

Those removals further contribute to a loss of genetic diversity among the population. 

“Over and over again, [Fish and Wildlife Service] end up taking out genetically valuable animals because of pressure from the livestock industry,” Robinson said. “We’ve got severe genetic problems afflicting the population today, as a result. And it’s getting worse year after year, as the remaining genetic diversity is lost from this population.”

The removals can also seriously disrupt the dynamics of a pack, Robinson said, which can lead to more livestock predation, further straining the relationships between wolves and ranchers. 

“A pack is essentially a multi-generational family. These are, by nature, social and cooperative animals. They’re much more effective at everything from bringing down prey to pup rearing to hold their territory, if the integrated of the pack is maintained,” Robinson said. “What I wouldn’t want to see, and what we do see, is the current situation where wolf families are disrupted. They’re losing one, two, three, five members.”

The Prieto pack, which was established in 2013 and was considered one of the longer-tenured packs in the state, was known to stick to a five-mile radius near Rainy Mesa in the Gila National Forest, Robinson said. 

That points to another challenge in the wolf’s recovery, Robinson said: grazing allotments. 

“Problem grazing allotments on National Forests end up being these terrible mortality pits for wolves,” he said. “They’ve got good habitat, and yet, the husbandry and the stocking levels are such that wolves keep getting attracted to them, keep getting into trouble.” 

“The wolves become scapegoats and end up dead or in captivity,” he said.