April 16, 2008

Army's transfer of Mojave Desert tortoises tripped up by coyotes

The Press-Enterprise

Coyotes have killed at least 11 desert tortoises recently moved to make way for Army tank training exercises north of Barstow.

The problem coyotes, thought to be attacking tortoises because the drought has left fewer rabbits in its wake, will be tracked and possibly killed by a federal agency to help protect the tortoises -- a species threatened with extinction

All together, 23 tortoises have been killed since the large-scale relocation of more than 700 reptiles began in March south of the National Training Center at Fort Irwin, said John Wagstaffe, an Army spokesman.

Some of the tortoises were already living in the relocation area.

Roy Averill-Murray, who is the desert tortoises recovery coordinator for the U.S. Fish and Wildlife Service, said three tortoises survived attacks. Two tortoises had one of their legs chewed off, and one of the reptiles required treatment after being found flipped over on its shell for three days in a row, Averill-Murray said.

Dr. Leonard Sigdestad at Loma Linda Animal Hospital in San Bernardino operated on two of the tortoises last week and amputated one maggot-infested leg from each of them. He released them back to the federal biologists who are monitoring the tortoises in the wild.

Kristin Berry, a research wildlife biologist with the U.S Geological Survey, took one of the tortoises to her Riverside home to care for it. She said it can barely walk but she hopes it can one day be returned to the wild.

Out by Fort Irwin, biologists have been tracking the relocated tortoises with transmitters glued to their shells on a daily basis and found the ones that died, Wagstaffe said.

The Army started moving the tortoises in late March from the southern boundary of the National Training Center at Fort Irwin as part of an $8.5 million effort to deal with the threatened species while expanding its training grounds into the land considered critical for the tortoises.

The move capped a 20-year battle between the military and environmentalists.

The U.S. Bureau of Land Management oversees much of the land selected for relocating the displaces tortoises. BLM officials a few days ago discussed strategies with other federal and state agencies on how to solve the coyote problem, said Doran Sanchez, acting associate manager of the agency's California desert district.

Attacks by coyotes on tortoises are rare, said Averill-Murray. He said that with the drought in the Mojave Desert over the past few years, coyotes outnumber rabbits, their typical food source,
"The coyotes are just desperate and the tortoises are a tough food item to eat with that big shell," he said. "Rabbits would be easier, but when there aren't many rabbits, then tortoises seem to be their next choice."

Berry, with the USGS, said short-lived animals like rabbits don't bounce back quickly from drought.

She said coyotes recently have killed tortoises in other study plots in California and Nevada but it is infrequent. This spring, she said, presented a good time to relocate the reptiles from Fort Irwin because of the abundance of wildflowers, their main food source.

"We hoped with the flush of wildflowers we might be seeing some ground squirrels and other rodents the coyotes could eat," she said. "You can take it into account but we can't control every aspect of nature, if any."

The wildlife service division of the U.S. Department of Agriculture, the same agency that plans to shoot ravens found preying on young tortoises in other parts of the Mojave Desert, will help the Army remove the coyotes in three, one-square-mile plots where many of the dead reptiles were found. The U.S. Fish and Wildlife Service concurred with the Army's plans to shoot or use traps and decoy dogs to capture the coyotes.

The job of decoy dogs "is to respond to coyotes calls and lure the coyote within shooting range," according to an April 15 letter to the Army by the U.S. Fish and Wildlife Service.

Averill-Murray said it will be up to the crews in the field to determine whether to shoot the coyotes. He said he was unsure if they could be relocated.

"The plan is just to keep this as targeted and as limited as possible to alleviate the pressure. It's not widespread," he said. He added that there's no evidence of major preying throughout the habitat where the tortoises were moved.

Two environmental groups have threatened to sue the Army over the large-scale relocation of the tortoises, and they plan to go ahead with the lawsuit to ensure the new habitat is managed actively, said Ileene Anderson, a biologist with the Center for Biological Diversity.

Anderson agreed with Averill-Murray that the drought has caused an imbalance in the ecosystem. But she said that's no excuse for putting the tortoises in harm's way.

"While we're devastated, we're not shocked this is happening," she said. "You're putting these animals out there and if they're the only thing moving, they're going to be a target for predators."

Wagstaffe said the move was done to the best of the Army's ability with the help of federal and state biologists, and the tortoises will continue to be closely monitored.

"Part of the beauty of doing a detailed study is we're going to learn a lot of stuff," he said. "And we'll find some things that we did very well and some that didn't go well."