SAN DIEGO — Dozens of desert tortoises are getting a second chance to thrive in the wild.

The tiny tortoises represent big hopes for the people who take care of them.

Last summer, new hatchlings and eggs of desert tortoises were evacuated when an intense heat wave in the region put them at risk. Biologists have found that young desert tortoises cannot develop normally at nest burrow temperatures above 95.5 degrees Fahrenheit.

San Diego Zoo Wildlife Alliance transferred the juvenile tortoises from their outdoor head starting habitats at Edwards Air Force Base to an indoor facility at The Living Desert Zoo and Gardens.

Melissa Merrick is the associate director of recovery ecology at San Diego Zoo Wildlife Alliance. She was part of the team who jumped into action to remove all the eggs from the threatening temperatures and brought them to The Living Desert Zoo and Gardens, where they could hatch safely and have a chance to grow before being reintroduced into native habitat.

“Some of them were eggs. We weren’t planning on bringing eggs, we were planning on bringing hatchlings,” Merrick said. “And so we also were able to bring some incubators that the Living Desert team were able to set up in this room behind me in addition to some of the home enclosures.”

Desert tortoise populations were once common throughout the Mojave and Sonoran deserts of California, Nevada and Arizona, but they have declined by an estimated 90% in the last 20 years.  

Merrick said climate change is affecting wildlife around the globe and the extreme heat is an example of the dangers of rising temperatures.

“When you’re an ectotherm, your behavior, your ability to eat, your ability to digest your food, everything comes down to temperature and how well you’re able to thermo-regulate,” she said.

San Diego Zoo Wildlife Alliance and The Living Desert Zoo and Gardens are working in partnership with Edwards Air Force Base, the U.S. Fish and Wildlife Service and the U.S. Geological Survey, using head start techniques designed to increase the survival rate for young tortoises.

Emily “Lou” Thomas helped care for more than 65 hatchlings every day and watched them grow bigger and develop thicker shells over several months.

“Pretty impressive to us. Even that many under really good care don’t always survive, so we’ve been incredibly fortunate,” she said.

Thomas said this “head start” program is critical because it gives hatchlings a higher chance of survival during their most vulnerable years. By tracking desert tortoises carrying eggs, monitoring the adult females as they lay eggs in human care, and rearing hatchlings for one to two years in sheltered facilities, to be reintroduced to native habitat when they are no longer at their most vulnerable, conservationists are giving juvenile tortoises a fighting chance at survival.

“We’re hopeful for them to learn a lot in the next six months,” Thomas said. “It will really be the next building block for them to be successful once they’re released.”

“We are very fortunate to have the skill, the resources and the space to be able to care for these juvenile desert tortoises, and help them grow at a much faster rate than they would in the wild,” said James Danoff-Burg, director of conservation at The Living Desert Zoo and Gardens. “By rearing hatchlings safely inside and in human care, we’re reducing the risk of mortality during their most vulnerable stage, and ultimately giving these young tortoises a fighting chance when they are reintroduced into the wild.”

Now, young tortoises are heading onto the next part of their journey. They were transported back to Edwards Air Force Base, where they’ll be trained on how to avoid predators and how to identify important foods in a protected outdoor enclosure.

Tom Radzio, a researcher at San Diego Zoo Wildlife Alliance, helped evacuate the eggs. On their last day at Living Desert Zoo and Gardens, he equipped them all with a temperature gage to help continue to monitor them.

The hope is with the extra help, they now have a higher chance of reaching a reproductive age and will increase the genetic diversity within local, wild and threatened populations.

“Maybe we won’t have to do this anymore. There’s a lot of challenges, it’s a dream,” Radzio said. “The idea is to one day create a situation where we have self-sustaining, viable tortoise populations and that requires a long-term commitment.”

Everyone hopes this is just the start of something that will save desert tortoises.

“It’s just been great,” Merrick said. “Everybody’s been growing and doing so well, we couldn’t be more excited with this collaboration.”