ALBUQUERQUE, N.M. -- Conservation groups asked the federal government Thursday to investigate the deaths of three endangered Mexican gray wolves found dead in southwestern New Mexico.
The deaths were a significant blow to the decade-long effort to reintroduce the species in the Southwest. The most recent survey showed there were just 52 wolves scattered between New Mexico and Arizona at the end of 2008.
"Because Mexican gray wolves are so rare, every wolf out there is important to the population," said Michael Robinson of the Center for Biological Diversity.
The center was among the 16 groups that made a formal request for the inquiry in a letter sent to Interior Secretary Ken Salazar. The groups listed more than a dozen questions they want answered, including who was allowed near the wolves' den prior to their deaths.
In the letter, conservation groups said the agency has a "troubling record of disregard for science in managing Mexican wolves," and that the Interior Department needs to conduct an investigation that will result in policy changes that could help prevent such losses in the future.
Christine Tincher, a spokeswoman with the Fish and Wildlife Service, said agency personnel were in the area monitoring the wolves before the deaths but reiterated that they do their best to keep from interfering with the dynamics of the wolves.
She said the agency is looking into the deaths of the first two pups in June but declined to speculate on their cause of death or why they might have been left in the den.
Officials had been monitoring the pack's alpha male because it was linked to four livestock killings within the past year.
Officials have also said it does not appear the pups' deaths were suspicious.
Wildlife agents rescued two pups last week but found three others dead. The pups - all from the San Mateo Pack - were born in April.
The Mexican wolf, a subspecies of the gray wolf, was exterminated in the wild in the Southwest by the 1930s. In 1998, the government began reintroducing wolves along the Arizona-New Mexico line in a 4 million acre-plus territory interspersed with forests, private land and towns.
Biologists had hoped to have at least 100 wolves in the wild by now and 18 breeding pairs.
The reintroduction team has documented three packs with litters in the two states, and there's a possibility there are at least five more reproducing packs, according to the U.S. Fish and Wildlife Service.
The conservationists questioned in the letter whether human activity around the pack's den could have prompted the parents to leave the area and abandon some of their pups.
They want to know, among other things, who was in the area at the time, how close they got to the den and why officials did not close the area to limit disturbance of the wolves.
If it's determined that human presence led to the incident, "we hope that would lead to greater protection around den sites in the future," Robinson said.
Two of the pups were found dead in June. The mother, the pack's alpha female, then moved one pup to a new den, and the remaining three were left behind because they couldn't be coaxed out of the den.
The agency said the mother left scratch marks from her efforts to get the pups out of a deep crevice in the den.
Officials with the wolf program tried to reunite one of the abandoned pups with the mother and father, but it was later found dead. The other two pups were rescued and taken to the Sevilleta National Wildlife Refuge.