Roughly 1,185 desert tortoises will be airlifted from prospective combat training grounds in California's Mojave Desert by the U.S. Marine Corps. Relocating the tiny tortoises to safer, nearby terrain ensures they will not be crushed by military equipment during the 165-square-mile expansion of the Marine Corps' Air Ground Combat Center.
Wildlife officials report that breeding populations of desert tortoises in California's drought-stricken Mojave Desert have declined by 50 percent over the last decade. Therefore, conservationists have raised concerns that the $50 million relocation effort will accelerate the animals' decline.
Populations of adult desert tortoises in California plummeted from the 1970s to the 1990s. Studies of dead tortoise carcasses at the time revealed many had been trampled by livestock, crushed by vehicles, succumbed to diseases or were shot. The proposed relocation of 1,185 desert tortoises represents one of the largest translocations of tortoises ever to be undertaken.
"I wish the U.S. Fish and Wildlife Service would get some backbone and say it can't permit another tortoise translocation by the military," said Glenn Stewart, a biologist and member of the board of directors of the Desert Tortoise Council conservation group. "The situation makes us feel like we'll have to write off California's Mojave population."
William Boarman, a wildlife scientist and expert on the desert tortoise, adds the relocation "is not a conservation strategy or a means of helping tortoise populations grow. It is simply a way of moving them out of harm's way."
What's worse is tortoise translocation initiatives have a poor track record, as the animals experience great stress from being handled by humans, adapting to unfamiliar terrain and new threats. Moving the tortoises will also disrupt the animals' complex social networks and family lines.
For instance, when the Army moved 670 tortoises from its National Training Center near Barstow in March 2008 to new homes in the western Mojave, as many as 90 tortoises died, most from being eaten by unfamiliar predators such as coyotes.
However, Walter Christensen, head of environmental planning at the Marine Corps base, is optimistic.
"We've learned a lot from past mistakes of others," he said. "We wouldn't be doing this if we felt the desert tortoise wasn't viable in the Mojave."
Compared to the $8.6 million translocation project of 2008, the forthcoming initiative has a much more significant budget. Brian Henen, a biologist and head of the Marine Corps' translocation effort, noted this ensures researchers will be able to monitor the health of the tortoises for the next 30 years and "demonstrates how much we [the Marine Corps] care about this species."
The relocation, approved by the U.S. Fish and Wildlife Service, requires the help of 100 contract biologists to capture 900 adult tortoises from the expansion area. The animals will then be released across three sites on military property and nearby public lands.
An additional 235 juveniles will be raised in pens at the military base and released when they have grown strong enough to defend themselves against birds that prey on thin-shelled babies. Officials estimate the project will take between two and four weeks.
