Marines move imperiled desert tortoises out of harm’s way
By David Danelski
The Press-Enterprise
Wildlife biologist Scott Welch looked out over the Mojave Desert and readied for action when he heard a distant helicopter flying in.
Just seconds after the aircraft landed, he and two others began loading it with plastic storage bins containing desert tortoises captured at an expansion area of the U.S. Marines Corps training base at Twentynine Palms.
They carefully packed 26 of the imperiled reptiles — one or two per bin — onto cargo carriers on the helicopter that looked like oversized saddlebags.
And within minutes, the tortoises were flying toward a safer haven of the recently created Mojave Trails National Monument — about 25 miles away from the crushing treads of tanks, the boots of soldiers and the blasts of bombs.
Operation Desert Tortoise was in its fifth day. As of Wednesday morning, 266 of the animals had been moved out of the Johnson Valley, about 30 miles northwest of Yucca Valley.
Before the end of the month, the Marines, working with about 125 wildlife biologists expect to have moved 1,156 tortoises, with a focus on clearing transportation corridors and other areas expected to be most disturbed by live-ammunition training missions.
It’s part of a multi-year, $50 million-plus tortoise relocation and study program at the base that was OK’d by the U.S. Fish and Wildlife Service following a 2013 vote by Congress to add about 88,000 acres in Johnson Valley to the combat center.
For the Marines, the expansion will allow them to hold longer and more-involved live-ammunition desert training missions to prepare Marines to intervene in global hot spots, such as the Middle East, should it be necessary. Such training is expected to start this summer.
For the tortoise, a species listed as threatened with extinction, it means the loss of more than a hundred square miles of quality habitat, as evidenced this year by robust blooms of yellow desert dandelions and other annual plants that are their primary food source.
The resources of the U.S. Defense Department were put to work to minimize harm to the tortoises, said Brian Henen, an ecologist for the Marine Corps Air Ground Combat Center at Twentynine Palms.
Analysis and field work for the move began more than two years ago. Scores of specially trained biologists have methodically walked the valley and fitted each tortoise they found with radio transmitters, so the animals could be gathered for this month’s move. It’s the largest tortoise move yet in the Mojave Desert.
The five areas of public land around the base that are receiving the animals were carefully chosen for their quality habitat and their distances from human habitation, Henen said.
Tortoises that lived near each other are being released in similar proximity in the recipient areas to preserve their social structure.
“We are moving them in groups. We are trying to sustain the similarity and the structure of their origin,” said Henen, standing by a makeshift medical checkup station for the tortoises.
There, Peter Praschag, a world-renowned tortoise and turtle expert from Austria, was working with veterinarian Shannon DiRuzzo to screen tortoises for signs of disease and other health issues.
A large male dubbed MC-2013 appeared frightened by the checkup and voided the water stored in his bladder, called a coelomic cavity. This was a serious matter, because a tortoise may get only one or two chances a year to get a good drink of water.
So Praschag used a syringe to carefully refill the animal’s coelomic cavity with a saline solution of water.
The work of the biologists won’t be finished until long after the last load of tortoises are flown out this month. Henen explained that the biologists will return frequently during the next four years to search for any reptiles that may have been left behind. They expect to move another 300 tortoises during that time.
The plans also include tracking and studying the relocated tortoises, as well as those already in the recipient area, for as long as 30 years. For this research, three groups of 225 tortoises — relocated ones, those already there and an unaffected control group — will be fitted with transmitters to track their movements and survival rates.
Biologists hope that the knowledge gained from this research will help the species recover.
But the loss of more than 100 square miles of prime habitat is still harmful to the tortoises, which has faced declines since the 1970s, prompting its 1990 listing under the Endangered Species Act, said Ileene Anderson, a biologist with the Tucson-based Center for Biological Diversity.
“It is going to be a big hit on the species,” she said.
She said it is not known if the public property outside the base will have enough food and other resources for both residents and newcomers to survive, and that wildlife biologists don’t know for sure why tortoises numbers have dropped in those areas.
She’s also worried that the tortoises may try to find their way back to their birthplaces in the base expansion areas.
But the U.S. Fish and Wildlife Service (FWS) determined in January that moving the tortoises from the Johnson Valley won’t jeopardize the survival of the species.
Scott Hoffman, who was observing the relocation effort for the FWS, said the species may benefit in the long run.
“Yes, we are losing habitat. But are we are using the relocated tortoises to supplement the populations in the critical habitat areas,” said Hoffman, referring to some of the recipient areas.
