ENGLE, NM (AP) — While the average life expectancy of North America’s largest and rarest turtle species is unknown, biologists say it could be more than a century.
So saving the endangered species is a long game — one that got a further boost Friday when U.S. wildlife officials signed an agreement with Ted Turner’s Endangered Species Fund, paving the way for the release of more Bolson’s tortoises at the media mogul’s ranch in central New Mexico.
The Safe Harbor Agreement will facilitate the release of captive tortoises at the Armendaris Ranch to establish a wild population. Martha Williams, director of the U.S. Fish and Wildlife Service, said the agreement, which offers private landowners protection from regulations, could serve as a model as officials look for more innovative ways to work under the Endangered Species Act.
Dozens of people gathered Friday for the release of 20 more adult turtles on the property, which already houses 23 of them as well as dozens of hatchlings. With the sun high in the sky and temperatures reaching nearly 32 degrees Celsius, the release was delayed until the evening to ensure their well-being.
The turtles typically spend about 85% of their time in their burrows, which in some cases can be about 21 yards (20 meters) long.
Shawn Sartorius, a field supervisor with the Fish and Wildlife Service, said the results of breeding and recovery efforts for the slow-reproducing and long-lived animals would not be known in his lifetime.
“What we’re doing here is building a population here that can be passed on to the next generation,” Sartorius said.
It’s a step toward wider release of the turtle in the Southwest one day, as conservationists urge the federal government to consider developing a recovery plan for the species. The tortoise is just the latest example of growing efforts to provide new homes for endangered species as they are driven from their historic habitats by climate change and other threats.
Now found only in the grasslands of north-central Mexico, the turtle once had a much larger range that included the southwestern United States. Fossil records also show that it once occurred in the southern Great Plains, including parts of Texas and Oklahoma.
The wild population in Mexico is believed to number fewer than 2,500 turtles, and experts say the threat to the animals is increasing as they are hunted for food and collected as pets. Their habitat is also shrinking as more and more desert grassland is converted into farmland.
While it has been eons since turtles roamed freely in what is now New Mexico, Mike Phillips, director of the Turner Endangered Species Fund, said it is time for biologists to rethink which ecological benchmarks should be most important when considering recovery an endangered species.
Climate change is reshuffling the ecological deck and changing the importance of historical conditions in the recovery equation, Phillips said. He pointed to the case of the turtle, noting that suitable habitat is moving north again as conditions become drier and warmer in the southwestern United States.
Without wildlife managers’ willingness to think more broadly, species like the Bolson’s tortoise could face a bleak future, he said.
“It appears that the historical range should be taken into account in the context of the recovery. Sometimes the prehistoric range also plays a role,” he said in an interview. “But what matters most is future reach – because recovery is about righting wrongs, it’s about improving conditions. The future is of great importance for the recovery.”
Sartorius of the U.S. Fish and Wildlife Service agreed, saying managers can’t limit themselves to just the historic range and still keep animals like the turtle on the planet.
The question biologists have tried to answer is whether Armendaris Ranch is a good home.
So far, the ranch, with an area of more than 1,450 square kilometers, is proving to be an ideal location. The landscape is similar to that in which the turtles are found in Mexico, and work at the ranch and at the Living Desert Zoo and Gardens in Carlsbad has resulted in more than 400 turtles hatching since 2006.
Overall, the Turner Endangered Species Fund and its partners were able to increase the population from 30 turtles to about 800, said Chris Wiese, who leads the project at Armendaris Ranch.
“The releases are the crucial step in getting them back to the ground and making them wild turtles,” she said. “For us, this is the culmination of our work.”
The turtles released on Friday can move freely in the 1.5-acre enclosure, just like in the wild. They are equipped with transponders so they can be tracked, and wildlife managers will check on them once a year.
Depending on weather conditions and food availability, it may take a few years or longer for a young animal to reach a length of just over 110 millimeters. They can eventually reach a size of around 14.5 inches (370 millimeters).
The species was unknown to science until the late 1950s and was never extensively studied.
“Every day we learn more and more about the natural history of the Bolson’s tortoise,” Phillips said.
The goal is to build a robust captive population that can serve as a source for future releases into the wild – both in the U.S. and Mexico. This work includes obtaining state and federal permits to release turtles outside of enclosures on Turner lands.
Those released Friday ended up crawling on the ground, wandering through tussocks of grass and around desert scrub as the Fra Cristobal mountain range loomed in the distance.
It was a perfect scene as one of the turtles walked to the western edge of the enclosure, trailing its shadow behind it. It was a moment that Wiese and her team had been working toward for years.
“We are not in the business of producing pets,” she said. “We are in the business of breeding wild animals and that means they have to be released.”