The Mexican wolf population in Arizona and New Mexico plunged to its lowest level in seven years in 2009, with eight wolves including four pups found dead last year, officials said Friday.

Last year's total of 42 wolves found in the wild was down nearly 20 percent from 52 wolves in 2008. Since the wolf recovery plan began back in 1998, the U.S. government has spent about $20 million trying to restore wolves in Eastern Arizona and southwest New Mexico, federal records show. Ninety-two total wolves have been released into the wild.

The decline is "tremendously disconcerting and very disturbing," said Benjamin Tuggle, the U.S. Fish and Wildlife Service's regional director for the Southwest.

Officials thought this would be a good year for wolf pups. Also, the service didn't permanently remove any wolves from the wild last year, as it usually does after ranchers complain the wolves are eating cattle, he said.

"I am determined to identify the reasons for this decline and turn the situation around so we can see more Mexican wolves in the wild during 2010," Tuggle said in a news conference by telephone Friday.

Two wolves were confirmed to have been shot to death last year. Tuggle said he is not ruling out the possibility that the other six dead wolves were shot. Those deaths are under law enforcement investigation.

"I don't think we can make any assumptions," Tuggle said. "It has a lot to do with the condition of carcasses. I think the two that we can clearly say were shot were fresh enough" carcasses to make such a determination, he said.

An unusually poor survival rate among wolf pups appeared to play a key role in last year's population decline, officials indicated. Thirty-one pups were born last year in seven wolf packs. Seven survived, the wildlife service said.

Normally, the wild wolf pup mortality rate is about 50 percent, Tuggle said. Only four of the non-surviving pups were found dead, meaning that the rest either "slipped under the census or they are no longer on the landscape," he said, meaning they are dead.

Typically, the service relies on pup survival and reintroductions of wolves who come from breeding facilities to add wolf populations. Since there were no reintroductions last year, "we were relying primarily on pup counts," he said.

Craig Miller, who works with Defenders of Wildlife, a national conservation organization, blamed poaching as the likely culprit.

"Mexican wolves are in big trouble. With numbers so perilously low, every single wolf in the wild counts toward the animal's survival. Turning this dire situation around will require every effort by the U.S. Fish and Wildlife Service to craft a science-based recovery plan that pays careful attention to genetic issues. The service must also make a renewed commitment to keep wolves on the ground," said Miller, Defenders' Southwest representative.

Tom Buckley, a service spokesman, said he expects the service will prepare a wolf recovery plan but he doesn't know when. Recovery plans are usually required for endangered species such as Mexican wolves but are often delayed due to budget issues and other reasons.

BY THE NUMBERS

Last year's federal wolf census found 27 wolves in Arizona and 15 in New Mexico, compared with 23 in Arizona and 29 in New Mexico in 2008.

COMING SUNDAY

Will Sonoran wolves make it to Arizona? In Sunday's Arizona Daily Star.

Contact Tony Davis at tdavis@azstarnet.com or 806-7746 and Tim Steller at tsteller@azstarnet.com or 807-8427.