Singapore, 28 December 2010 – Only a handful of these elusive and rare giant river terrapins are known to be left in their native homeland Cambodia – but the Singapore Zoo has successfully bred four of them, with more expected to join the family of eight in the months to come.
Both female terrapins at the zoo were recently found to be gravid with eggs, which are due to be laid anytime now. X-ray examinations on 13 December 2010 revealed that they were carrying over 40 eggs between them. The incubation period for these terrapins ranges from 68 to 112 days.
Giant river terrapins lay their eggs only once a year and the Singapore Zoo has successfully had four hatchlings to date in 2007 and 2009 – two of which are now on display at the Proboscis Monkey pool, while the others are behind the scenes in our turtle hatchery facility. The park is currently home to the two adult females, two adult males and the four hatchlings. Considered an extremely rare species, this breed, also known as Batagur affinis, is native to Peninsular Malaysia, Thailand, Cambodia and Sumatra.
“It is relatively easy to get the terrapins to mate but the challenge is getting them to nest on an artificial beach. In the past, the terrapins have laid their clutches of eggs in water and we were only able to rescue a few of the eggs. This is why we have had only a small number of hatchlings despite each clutch consisting over 20 eggs,” said Biswajit Guha, Director, Singapore Zoo. “Similarly in the wild, as they migrate to their nesting beach, they can be deterred from laying their eggs by disturbances on or around the beach.”
During the mating season, the males’ head, neck and legs turn black and their irises change, from yellow to pure white, with the colours reverting at the end of the mating season. Females swim far upstream from their usual estuarine habitats, as far as 80km, to nest communally on sand bars and river banks.
Due to their picky breeding requirements and obscure nature, conservationists have tried very hard to rebuild their dwindling populations. In fact, this species was thought to be extinct in Cambodia until some specimens were rediscovered in 2001. They play a key role in the overall ecosystem by aiding in seed dispersal and vegetation management, controlling insect and snail populations, and keeping freshwater systems clean by scavenging on dead animals.
The giant river terrapin is listed as critically endangered in the 2009 IUCN Red List and in CITES Appendix I. This species and other Asian turtles are in grave danger for a number of reasons including the thriving illegal wildlife trade, and their appeal as a delicacy in Asia.
Earlier this year, Wildlife Reserves Singapore (WRS), which operates the Singapore Zoo, Night Safari, Jurong Bird Park and the upcoming River Safari, signed a memorandum of understanding with the Wildlife Conservation Society (WCS) to embark on joint studies in the region, including a project to conserve giant river terrapins in Asia. WRS also works closely with local authorities and conservation groups such as Turtle Survival Alliance (TSA) to re- home confiscated wild turtles and tortoises or distribute them to partner zoos to be integrated into breeding programmes and educational animal exhibits.