With the demise of Lonesome George (Chelonoidis nigra), the Burmese Roofed Turtle (Batagur trivittata) now has the dubious honor of being among the most endangered turtles in the world – first place on “extinction row” belongs to the Giant Chinese Softshell Turtle – Rafetus swinhoei; only three are known to survive.
Officially, “less than 10” Burmese Roofed Turtles are said to survive in the wild, although the actual number is probably about half that. This small, critically endangered population occurs along a 50 km stretch of the upper Chindwin River in west-central Myanmar, with most nesting activity centered near Limpha Village where the WCS and TSA Turtle Conservation Program maintains a permanent outpost known as Camp Batagur. A conservation program was initiated by WCS/TSA in 2006, and every year since then we have hired local villagers to serve as “Beach Wardens” and protect nesting sites along the river, collected eggs, and transported them to a sandbank near Limpha for incubation.
Given that only about 70-80 viable eggs are collected every year, population recovery has been slow, albeit steady. By 2014 the number in captivity had increased to about 700 turtles. Then disaster struck – in 2014 only a single egg from over 100 collected along the river proved viable. The following year we again collected over 100 eggs, but this time none proved viable. We feared the worst – a doomsday scenario in which the population now lacked males; a sure recipe for extinction in the wild. In March 2015, we released 60 head-started turtles in the Chindwin River near Limpha. About half of these turtles were males, although none were thought to be sexually mature.
Our annual egg collection got underway early this year with the discovery of a small clutch of six eggs in early February, only days before I arrived in Limpha in company of Myo Min Win (Project Manager) and his wife, Dr. Tint Lwin (WCS/TSA veterinarian), and Khin Myo Myo. This discovery was followed by a lull and it wasn’t until February 26 that we found our next clutch. Shortly after daybreak that morning, U Ba Shwe, the “Beach Warden” hired to monitor and protect the nesting beach arrived in our camp to let us know that he had just found fresh tracks on Pagoda Island. It appeared that a female had emerged from the river during the night, climbed high on the sandbank, and deposited her eggs. Hurriedly downing our breakfast of oily cuisine, we loaded the boat and headed the short distance downstream to Pagoda Island. Sure enough, a very fresh trackway, still damp in places, was visible leading from the river, up a very steep sandbank, and then back down to the water.
Unlike most turtles, female Roofed Turtles have the unusual habit of depositing their eggs in several holes (sometimes as many as 6 or 7). Because the eggs are spread out in multiple holes and deeply buried, finding them is difficult, and recovering all of the eggs usually requires the better part of a morning. This is where Zaw Zaw’s particular expertise comes to fore. The son of a local man who once regularly harvested turtle eggs to eat, Zaw Zaw learned early on how to find the deeply buried eggs and now uses his unique skills to help ensure the survival of the species.
Paying careful attention to confusing twists and turns of the trackway, Zaw Zaw moved slowly, probing the packed sand deeply with a blunt stick, noting subtle changes in texture that belie the presence of buried eggs. Once the eggs were located, the team began to dig until the top-most eggs are exposed. The eggs were then gently removed and placed in a sand-filled box for transport to our incubation area just across the river. This scene was played out four more times and by 7 March we had 90 eggs incubating in the sand.
Our incubation area is nothing more than a patch of beach that has been fenced to protect the eggs from humans, dogs, and free-ranging livestock. In fact, in past times Roofed Turtles no doubt nested on this very same beach. U Ba Shwe – our Beach Warden who has worked for the project since its inception 10 years ago – erects a small hut adjacent to the incubation area where, in company of a motley pack of surly canines, he resides until the eggs hatch (or as in recent years, fail to hatch) in early June. To incubate the eggs we simply recreate the natural nesting environment; a hole is excavated in the sand, ten eggs buried in each hole, and then we wait.
In late March, Kalyar Platt (TSA Myanmar Program Coordinator) arranged for some thermal data recorders to be delivered to Limpha that could be used to monitor incubation temperatures. It was with some trepidation that we gathered at the incubation area on 11 March and carefully began to excavate each clutch to insert a data recorder.
Fertile turtle (and crocodile) eggs display an obvious white spot where the embryo and eggshell membrane attach to the eggshell. Would any of the eggs we collected prove viable or was 2016 destined to be another washout? Our hearts sank as we opened each hole; clutch after clutch showed no signs of embryonic development. But then we examined the last clutch, the eggs collected from Pagoda Island. Disappointment turned to joy. There was no mistaking it – large conspicuous white bands creeping across the eggshell! Eggs with developing embryos, 30 in all. We deployed the data recorders and carefully covered the eggs with warm sand.
All we can do now is wait – and hope – that a new generation of young Roofed Turtles emerges from the sand in June. I’ll keep you posted.
Steven G. Platt, Ph.D.