September 5, 2014

New Center for Tortoises Opens In Mojave Preserve

A baby desert tortoise | Photo: National Park Service

by Chris Clarke
KCET.org


A first-of-its-kind center for studying the federally Threatened desert tortoise was formally donated to the Mojave National Preserve on Friday.

The Ivanpah Desert Tortoise Research Facility, built by Chevron on land provided by the mining firm Molycorp, will enable researchers to find out whether so-called "headstarting" programs for juvenile tortoises are really helping combat the tortoises' population decline.

The facility, which includes two acres of tortoise habitat with predator-proof fencing and a state-of-the-art laboratory, was completed in 2012, and was managed by the nonprofit National Park Trust until Friday's formal land transfer and dedication.

"This new facility provides scientists the opportunity to test methods for increasing the survival of juvenile tortoises to reproductive age," said Stephanie Dubois, Superintendent of the Mojave National Preserve. "This research could lead to the development of proven methods for recovering this species that continues to decline. We appreciate the work of our partners in making this facility a reality."

Juvenile desert tortoises have it tough. They're easy pickings for predators such as coyotes and ravens, both of which species have increased in number as a result of human development of the desert. Tortoises in their first few years of life haven't yet grown a shell tough enough to withstand a hungry raven's beak or coyote jaws. Increased predation by coyotes and ravens is considered a major factor in the federally Threatened species' decline.

In "headstarting" programs, female desert tortoises known to be carrying fertilized eggs are moved to the facility, allowed to lay their eggs, and then returned to their home territories. The hatchlings are kept in areas protected from predators, then released into new territories when their caretakers deem them tough enough to go it alone.

Headstarting is an expensive undertaking, and may not be an appropriate long-term tool for supplementing tortoise populations. While the practice has been used to boost populations of other tortoise and turtle species, it hasn't been conclusively shown helpful for desert tortoises. One 2009 study, in fact, suggests that headstarting might not be of much use for protecting desert tortoises if local breeding females aren't protected from the threats causing the decline in the first place.

Backers hope, however, that the practice might prove useful for temporarily boosting local desert tortoise populations. That's an issue the Park Service hopes to explore in the facility, built as partial mitigation of projects by Chevron and Molycorp that posed risks to desert tortoises. Researchers will try to craft "best practice" procedures for running effective headstarting programs.

The facility has already sheltered and released 46 tortoises since it started operating in 2012, out of a total of 185 hatchlings born at the facility. The released tortoises are being carefully monitored in their new homes.