Riverbanks Zoo helps establish colony for critically endangered turtle species

Beyond the Banks: Sulawesi Forest Turtle

COLUMBIA, SC (WIS) - You’ve never seen them on exhibit, but for years Riverbanks Zoo has been working to help ensure the survival of a critically endangered turtle species.

The species is called the Sulawesi Forest Turtle and is only found on the island of Sulawesi in Indonesia.

“Anytime you’re in an island situation, that species is in danger of surviving because of the demands on that habitat,” said Kathy Vause, the senior reptile keeper at Riverbanks Zoo.

Vause adds there are also many unknowns about the Sulawesi Forest Turtle. The species was discovered just 25 years ago. Not long after, the species was deemed critically endangered during the Asian Turtle Crisis.

“Turtles were being over-collected for food, pet trade, medicine…so we wanted to give this species a try and get them into a breeding program,” Vause said.

Riverbanks has housed Sulawesi Forest Turtles since 2001. Keeper Kathy Vause says they started trying to breed them in 2011, but didn’t get hatchlings until 2016. And now that they’ve had 10, they’re running out of space.

“If we grew them to adulthood we would not have room,” Vause said.

So, we followed Vause as she took four of the Sulawesi juveniles to the Turtle Survival Center in Berkeley County where they have plenty of room. The center is run by the Turtle Survival Alliance, which is also an Association of Zoos and Aquariums (AZA) accredited institution like Riverbanks, and the center is home to the largest assurance colony of Sulawesi Forest Turtles in the U.S.

“Most of these animals are wild caught and came through the pet trade 20 years ago,” said Cris Hagan, the director of animal management with the Turtle Survival Alliance. “They’re all refugees of the pet trade,” he added as he showed us around the large green-house like facility.

The center is home to nearly 50 Sulawesi Forest Turtles, and their partnership with Riverbanks Zoo is all a part of the Association of Zoos and Aquariums Species Survival Plan.

“We compare notes, the genetic bloodlines of each animal, making sure we’re keeping the pairings so we can maximize genetic diversity,” said Rick Hills, Executive Director of the Turtle Survival Alliance.

The center says they haven’t had near the success that Riverbanks Zoo has had in breeding the Sulawesi Forest Turtle, but they will continue to try. They also plan to maintain this assurance colony for years to come.

“We’re trying to be proactive and not wait until there’s only 100 species left in the wild,” Hagan said. “So, this is a priority species for captive management.”

In addition to transferring the four juveniles to the Turtle Survival Center during this trip, Riverbanks has given the center three others in the past. Riverbanks Zoo’s adult male turtle that has led much of the zoo’s breeding efforts is actually on loan from the alliance.

To put in perspective Riverbanks’ success in breeding these turtles, Hagan says only 7 institutions and 6 private individuals worldwide are known to have successfully bred Sulawesi Forest Turtles in captivity.

Riverbanks has had 10 hatchlings, and the Turtle Survival Center has had one.

Hagan says they are currently working to determine why some institutions have more success in breeding the turtles than others. He adds the animals are kept separate in captivity because they are aggressive and fight often when left together. However, they are working to determine what factors impact breeding when they are brought together.

“People hypothesize is it diet? Is it stress levels? Is it individual compatibility with mate selection?” Hagan said. “Just because you have a male and female put them together doesn’t mean they’re compatible-- even with turtles.”

When asked if it could be that the animals are attempting to breed in a captive environment, Hagan says they haven’t ruled that out but pointed to the Denver Zoo’s efforts as evidence that it appears to have more to do with compatibility.

“Denver Zoo had a male and 3 females in a very large enclosure and they hatched 22 individuals in an 18-month time period,” Hagan said. “They removed the male and brought in a new male for genetic purposes, and they haven’t hatched another egg since.”

Hagan adds as they work to continue to manage the captive population, they also have their eyes on the wild one. He says it is unclear how many Sulawesi Forest Turtles are still in the wild, but they are still listed on IUCN’s Red List as Critically Endangered. Hagan adds for the first time there are research studies underway on the turtle and they hope that will give them even more insight in the coming years.

If you’d like to learn more about the Turtle Survival Alliance visit the Turtle Survival website here.

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