A critically endangered resident of the Sunderbans is set to get a new home, beginning a slow journey to recovery from a disastrous decline in the wild. It is more threatened than the Bengal tiger, but far less known.
Before winter this year, three fresh water ponds in the Sunderbans Tiger Reserve will house the rare Northern river terrapin ( Batagur baska ), whose presence in the wild in West Bengal and Odisha had declined to undetectable levels a decade ago.
Batagur baska , the 60-cm-long turtle that is presumed extinct in several Southeast Asian countries, is classified as critically endangered by the International Union for Conservation of Nature ( IUCN) in its Red List of threatened species. The tiger, by comparison, is endangered.
For the past ten years, officials of the Sunderban Tiger Reserve with support from experts at Turtle Survival Alliance (TSA), have coordinated a recovery program for what is described as the world’s second most endangered turtle, through captive conservation breeding. The Yangtze giant soft shell turtle, Rafetus swinhoei , is considered the most endangered freshwater turtle.
Needs other homes
While conservation breeding to save the Northern river terrapin is ranked among the best programmes, Ravi Kant Sinha, Chief Wildlife Warden and Principal Chief Conservator of Forests, West Bengal, said it would be bad management to put all eggs in one basket. Having more sites to breed is a natural extension of the ongoing effort, he said.
The terrapin, which has a river estuarine habitat, has had a lucky spell in recent years. Nilanjan Mallick, the field director of the Sunderban reserve said there was not much early success in the breeding programme, but things looked up after 2012.
“The number of turtles at Sajnekhali is well over 200. This year alone we got 87 hatchlings,” Mr. Mallick said.
The field director of STR said the decision to get a new enclosure for the breeding programme would protect the species against natural risks, and also facilitate genetic management. Last year, forest officials and the TSA reintroduced ten turtles into the wild, using acoustic transmitters to monitor their progress.
This year more may be released with satellite transmitters to determine survival and dispersal.
Shailendra Singh, the director at the TSA India program, pointed out that habitat loss and clandestine harvesting had decimated the population of the species.
“In 2008 we did a survey in Odisha and West Bengal and could not locate Batagur baska in the wild. Conservation started with only 13 adults turtles at Sajnekhali,” he recalled.
Of six large fresh water turtles of the genus Batagur , three are found in India. Batagur kachuga (Red-crowned roofed turtle) and Batagur dhongoka (Three-striped roofed turtle) are found in the tributaries of the Ganga, such as Chambal.
The Northern river terrapin is the most endangered of the three species, and their long-term fortunes depend on an ecologically functional colony getting re-established in the wild. “Before that, we will have to reach a figure of about 1,000 individuals in captivity,” Mr. Singh said.