An Overview of the Current Population and Conservation Status of the Critically Endangered River Terrapin, Batagur baska (Gray, 1831) in Myanmar, Thailand and Malaysia

Abstract

The river terrapin, Batagur baska (Gray, 1831) formerly occurred in large rivers from western India and Bangladesh, through much of Southeast Asia. Populations throughout much of this region have declined or been extirpated as a result of chronic over-harvesting of eggs and adults, destruction of nesting beaches due to sand mining and sedimentation, and mangrove forest clearance. Consequently, B. baska is regarded as Critically Endangered throughout its geographic distribution. Herein, we provide an overview of the conservation status of B. baska in Myanmar, Malaysia, Thailand and the results of recent surveys in these countries. Owing to the paucity of recent records, the IUCN regards B. baska as extinct in Myanmar. However, our surveys indicate that small populations persist in coastal regions of Mon and Rakhine States, and Ayeyarwady and Tanintharyi Divisions where a combination of local religious beliefs and areas of armed conflict confer some degree of protection. Peninsular Malaysia represents the last stronghold of B. baska and relatively large populations occur in several rivers on both the east and west coasts. Captive breeding programs have been conducted in Malaysia since the late 1960s. Despite the release of thousands of head-started hatchlings since the inception of these projects, populations of B. baska in the Perak River continue to decline. Recent estimates indicate that less than 50 breeding females remain in the river. There is little information on the historic occurrence and distribution of B. baska in Thailand. As late as the 1970s remnant populations were known to occur at Pak Payoon, Amphur Ranote, and some rivers of Ranong Province. A captive propagation center was established in 1983 at Satun Inland Fisheries Station. Our survey of the Langu Canal found small numbers of B. baska, and documented the occurrence of at least three nests; other potential nesting beaches are located along the river.