Back from the brink, baby Burmese roofed turtles make their debut

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  • Once considered extinct, the Burmese roofed turtle was brought back from the brink by an ambitious conservation program.
  • The captive population is now approaching 1,000 turtles, and the species appears to be in little danger of biological extinction.
  • Scientists have now published descriptions and photos of the hatchlings of this little-known river turtle.

Once considered extinct, the Burmese roofed turtle (Batagur trivittata) was brought back from the brink by an ambitious conservation program. Now, almost 30 years after its rediscovery in the wild, scientists have finally gotten around to describing the hatchlings of this little-known river turtle.

Photos and descriptions of hatchlings and eggs, as well as some background information about the conservation of the species were recently published in the journal Zootaxa by scientists from Wildlife Conservation Society (WCS) Myanmar, Turtle Survival Alliance (TSA), Global Wildlife Conservation, and Georgetown University.

A newly hatched Burmese roofed turtle. Note the egg-tooth (caruncle), which is lost during the two months after hatching. Photo by Myo Min Win/WCS Myanmar (Platt et al 2020).
A newly hatched Burmese roofed turtle. Note the egg-tooth (caruncle), which is used to cut through the egg when the turtle hatches.  It is then lost during the two months after hatching. Photo by Myo Min Win/WCS Myanmar (Platt et al 2020).

The newly hatched turtle shows its umbilical scar, where it was attached to a nutrient giving yolk sack. This scar will disappear in a few weeks. Photo by Myo Min Win (Platt et al 2020).
The newly hatched turtle shows its umbilical scar, where it was attached to a nutrient-giving yolk sack. This scar will disappear in a few weeks. Photo by Myo Min Win (Platt et al 2020).

The Burmese roofed turtle is the second-most critically endangered turtle in the world. Once abundant, hunting and overexploitation of eggs has driven the population to near-extinction, with only five or six adult females and two adult males known to exist in the wild today.

The species was presumed extinct until 2001, when researchers found the shell of a recently killed turtle in a village along the Dokhtawady River in Myanmar. Shortly after, a U.S. turtle collector found a living turtle at a wildlife market in China.

Encouraged by these findings, researchers conducted field surveys to find the wild populations. After following locals’ descriptions of “duck-sized eggs,” the researchers found living turtles in two separate rivers in Myanmar. However, the population had collapsed to a whisper, with fewer than 10 adult females surviving in the wild at that time.

“The biggest threat is that there are so few left in the wild and so if there’s an accident we’ve lost a big chunk of the population,” Steven Platt, first author of the study and WCS associate conservation herpetologist for Southeast Asia, told Mongabay. “Otherwise its mostly fishing. I worry about them getting entangled in fishing gear and drowning. And if we didn’t monitor, the eggs would be collected.”

More than half of the world’s turtle and tortoise species are now threatened with extinction. Loss of habitat is their biggest threat globally, but turtles also face dangers from the pet trade, overconsumption for food and medicine, fishing, pollution, invasive species, and climate change.

The sharp rearward pointing spines on the bony ridge of the Burmese roofed turtle’s shell become blunt by age three and disappear by age four. Photo by Myo Min Win (Platt et al 2020).
A hatchling photographed for science. The sharp rearward pointing spines on the bony ridge of the Burmese roofed turtle’s shell become blunt by age three and disappear by age four. Photo by Myo Min Win (Platt et al 2020).

In an effort to bring the Burmese roofed turtle back from the brink of extinction, WCS and the Turtle Survival Alliance (TSA) in collaboration with the Myanmar Ministry of Environmental Conservation and Forestry began a program to “headstart” the species in 2007. Researchers and technicians collected eggs from wild turtles for a captive-breeding program.

Now, turtles are bred, hatched and reared in conditions safe from predation by large fish, birds, and lizards, poaching and egg collection. Complementary conservation efforts are also focused on the remaining known wild turtles: five to six adult females and as few as two males living on a remote stretch of the upper Chindwin River. Their nests are monitored and eggs are collected and incubated in a secure facility in Limpha village in the Sagaing region of Myanmar.

The captive population is now approaching 1,000 turtles, and the species appears to be in little danger of biological extinction. The goal is to eventually release them back into their wild habitat in the Chindwin River.

Burmese roofed turtle moments after emerging from an egg collected from a sandbank along the Chindwin River and incubated at a head-starting facility in Limpha village, Sagaing region, Myanmar. Photo by Myo Min Win/WCS Myanmar (Platt et al 2020).
Burmese roofed turtle moments after emerging from an egg collected from a sandbank along the Chindwin River and incubated at a head-starting facility in Limpha village, Sagaing region, Myanmar. Photo by Myo Min Win/WCS Myanmar (Platt et al 2020).

In 2015, WCS and TSA reintroduced some male turtles back to the wild, but reintroduced turtles can be hard to follow and locate in the river when the wet season rolls in, Platt says. For now, the team is trying a different strategy, keeping some of the turtles in floating cages in the river as a “soft release” of sorts. The hope is that once the turtles become acclimated to the area they can be released and won’t stray too far.

“River turtle conservation is really difficult,” Platt said. “Tortoises can move about a kilometer, or, normally just stay within a few hectares of where we release them, but these turtles, once they’re in the river, they can go up or down for several hundred miles if they just keep swimming. So, you know, river turtle conservation is a tough nut to crack.”

“But the captive breeding program has produced about 170 turtles a year for the past two years,” Platt said. “So the turtles are biologically secure. They’re not going to go extinct.”

Citation:

Platt, S. G., Lwin, T., Win, M. M., Platt, K., Haislip, N. A., Van Dijk, P. P., & Rainwater, T. R. (2020). First description of neonate Batagur trivittata (Testudines: Geoemydidae). Zootaxa4821 (2), 394-400. doi:10.11646/zootaxa.4821.2.10

Liz Kimbrough is a staff writer for Mongabay. Find her on Twitter @lizkimbrough_

Article Source: Mongabay