• Sun. Oct 25th, 2020

A Turtle With a Permanent Smile Was Brought Back From Extinction

Conservationists are not known for delivering a lot of good news. But in the Burmese roofed turtle — a giant Asian river turtle whose bug-eyed face is naturally set in a goofy grin — they have cause for celebration. Just 20 years ago, the species was presumed extinct. But after rediscovering a handful of surviving animals, scientists have grown the population to nearly 1,000 animals in captivity, some of which have been successfully released into the wild in Myanmar over the past five years.

“We came so close to losing them,” said Steven G. Platt, a herpetologist at the Wildlife Conservation Society. “If we didn’t intervene when we did, this turtle would have just been gone.”

Turtles and tortoises face one of the highest extinction risks of any animal group, with more than half the planet’s 360 species listed as threatened. The crisis is most acute for Asian species, which are pummeled by both habitat loss and high levels of hunting for food, medicine and the pet trade.

The Burmese roofed turtle is among the species that has faced this toll. The turtles once basked in the hundreds at the mouth of the Irrawaddy river south of Yangon, Myanmar’s largest city, with a range stretching all the way to Bhamo in the country’s north. Females — which grow significantly larger than males — can exceed the size of a steering wheel, while males undergo a dramatic breeding-season color transformation that causes their usually green heads to turn a bright chartreuse-yellow with bold black markings.

By the mid-20th century, intensified fishing pressure and indiscriminate trapping techniques were killing many adult turtles, while overharvesting of eggs prevented the population from replenishing itself.

For decades, though, Western scientists had no idea how the species was faring, because the country’s borders were closed to foreigners. When Myanmar began to reopen in the 1990s, researchers could find no trace of the Burmese roofed turtle. Many presumed it to be extinct.

Credit…Myo Min Win/WCS Myanmar
Credit…Rick Hudson
ImageEmploying radio telemetry on a bluff overlooking the Chindwin River in Myanmar to monitor the movements of turtles released a few weeks earlier.
Credit…Steven Platt/WCS

In 2001, however, a villager in a former war zone handed Dr. Platt a shell from a Burmese roofed turtle. The bad news was that the turtle had recently been eaten. The good news was that the species wasn’t extinct, reigniting hope for it.

Around the same time, a live specimen turned up in a market in Hong Kong and subsequently found its way to an American collector, who still has it in his possession.

“When the species showed up in a pet shop in Hong Kong, it raised a lot of eyebrows,” said Rick Hudson, president of the Turtle Survival Alliance. “There were a number of local dealers smuggling star tortoises out of Burma at that time, so we just assumed it had been smuggled out by the same traders.”

Encouraged by these developments, Gerald Kuchling, a biologist now at the University of Western Australia, secured permission to initiate a joint expedition with the Myanmar Forest Department to survey the upper Chindwin River, where an American expedition in the 1930s had collected Burmese roofed turtles.

When the summer monsoon grounded the team in Mandalay, Dr. Kuchling killed time by visiting the turtle pond at a Buddhist temple. Gazing out at the murky water, he suddenly saw three smiley heads pop up. They bore an uncanny resemblance to photos of Burmese roofed turtles he had seen in old natural history catalogs.

Dr. Kuchling returned the following day and lured the three turtles to the edge of the pond with a bit of grass. In the seconds before the guards began shouting for him to back away from the animals, he was able to confirm that they were indeed the long-lost species.

“I was very excited, and definitely flabbergasted,” he said.

Dr. Kuchling and his Burmese colleagues worked with the temple’s board to transfer the rare reptiles, a male and two females, to the Mandalay Zoo.

The species’ luck was just beginning. Dr. Kuchling found several additional surviving individuals in the Dokhtawady River, a tributary of the Irrawaddy, and arranged for their transfer to the Mandalay Zoo. The timing was fortunate: a major damming project soon after destroyed all suitable nesting habitat for the turtles in the area.

When Dr. Kuchling finally made it to the upper Chindwin River, fishermen from the Shan ethnic group also confirmed that a handful of females still nested there each dry season.

Credit…Steven Platt/WCS
Credit…Myo Min Win/WCS Myanmar
Credit…Steven Platt/WCS

Rather than capture the turtles in the upper Chindwin River, Dr. Kuchling worked with the Forest Department and the Wildlife Conservation Society to set up a conservation stewardship program to annually hire nearby villagers to fence off the beach, watch for nesting females and carefully excavate the eggs. Later, the Turtle Survival Alliance also joined the village partnership.

Around 1,000 Burmese roofed turtles — some hatched from eggs laid in the wild and others bred in captivity — now live at three facilities in Myanmar. Five wild females also continue to go back to the Chindwin beach to lay eggs.

No one knows how many wild males remain, but in 2015, all the females stopped producing fertile eggs, suggesting that the few or only remaining male had died. After the researchers released 50 turtles from captivity, all five wild females began producing viable young, including one that had never laid fertile eggs before.

While the species is no longer in danger of complete extinction, Dr. Platt cautioned that unsustainable fishing practices remain a problem for the turtles’ recovery in nature. “I don’t expect we can raise the flag of success during my career,” he said.

Scientists also still do not fully understand the turtle’s biology and ecology. Barely a month ago, Dr. Platt and his colleagues published the first description of baby Burmese roofed turtles. The lack of basic knowledge makes it difficult to determine which aspects of the environment need to be protected to enable the species to survive in the wild.

All that said, Mr. Hudson added, “this is one of the best global-level turtle conservation successes we have.”