Edwards Air Force Base in Rosamond may have lots of planes flying overhead, but down on the ground are some small critters getting ready for release into the wild — desert tortoise hatchlings.
Back around 2002, EAFB constructed pens to begin a head-starting program. This keeps desert tortoise hatchlings in a safe enclosure within their natural habitat until they reach a size that gives them a better chance of survival, said Wes King, a biological scientist for the base, in an email. After the U.S. Geological Survey began working with San Diego Zoo Global on head-starting research, they asked to utilize the base's pens, conveniently located in the Mojave Desert.
The question for the scientists is, "What are the critical factors that would increase survivorship?" said Lisa Nordstrom, associate director of the San Diego Zoo Institute for Conservation Research.
By comparing Agassiz's desert tortoises that will grow up to different age groups before release at both EAFB and Mojave Trails National Monument, Nordstrom said the scientists are observing how the factors of habitat and size can help determine the best strategies for success.
"We want to see if we can generalize the findings across the entire range," Nordstrom said.
The head-starting program is funded by a grant from the California Energy Commission. In spring, female tortoises brought and released from the wild successfully laid 73 eggs at the base, King said.
These tortoises will grow up to 18 months old and then be released into the same habitat type as that at the base, Nordstrom said. The process will repeat with a group of tortoises that will grow to 6 months prior to release.
The Agassiz's desert tortoise is listed as a threatened species under the Endangered Species Act. Nordstrom said a variety of factors have affected its decline, including habitat loss, disease and death on roads. She and King also mentioned that certain growing predators, including ravens, are a threat to young tortoises, who still have soft shells.
King said that the head-starting pens are in a carefully selected location separate from Air Force activities. He said the base is also continually committed to environmental efforts.
"Edwards Air Force Base is very proactive when it comes to environmental protection of all types: air, water, waste, historically significant sites, plants, animals and much more," King said.