Endangered Species Day fell on May 19 this year. To call attention to the wildlife we’re most in danger of losing, Nature inFocus has launched a multi-part series on endangered species across India. We’ve chosen to focus on each species individually, by asking a researcher who’s been most involved in the fight for their survival to write about them. These aren’t intended to be solely dire missives either – if there’s good news, or a small milestone that’s been achieved in the field, we want to highlight it. If their numbers are inching up with the help of conservationists, researchers, policy makers and nature itself, we want to celebrate this. Here is the fourth story of the series.

A brackish water species, the Northern River Terrapin (Batagur baska) is one of the largest turtles to be found in Southeast Asia. It is one of the world’s most endangered turtles – classified as Critically Endangered by the IUCN Red List. Up until the 1960s, they were very common – in fact, they were possibly one of the most common turtle species, according to the literature available from the British era in the Zoological Survey of India. Earlier, B baska used to be found in the river mouths of Odisha and the Sunderbans. Today, it is considered extinct in much of its former range. Fewer than 50 adults remain, in four captive locations around the world.

One of the reasons that populations crashed is unsustainable harvesting across the subcontinent and Southeast Asia. The turtles used to be exploited for their meat, and were once commonly sold in the fish markets of Kolkata. Often, their eggs would be harvested too. Habitat degradation (such as around the Swarnarekha River in Odisha) is another factor that has pushed them almost to the brink of extinction. These terrapins prefer to nest in tidal areas of estuaries and the river mouths of mangrove forests – fragile ecosystems that are especially vulnerable to anthropogenic activities and climate change.

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Artist Philbert Charles Berjeau's impression of a Northern River Terrapin, 1878. Illustration courtesy Biodiversity Heritage Library and Wikimedia Commons

NGOs and authorities started thinking about the conservation of the terrapin more seriously in 2007.  It was when Peter Prashag, the eminent turtle zoologist, discovered that the Batagur baska found in South Asia is different from the Southeast Asian one. His research revealed that the Batagur baska was in much more trouble than was previously thought, and its range was far more restricted across India and the Bangladesh Sunderbans, and possibly some part of Myanmar.

In fact, when researchers from the Turtle Survival Alliance (TSA) carried out surveys in Odisha and West Bengal between 2007-2009, they did not encounter any Batugur baska. However, by following up on some reliable leads, they did "rediscover" some captive specimens in village ponds within Indian and Bangladesh Sunderbans. 

After sustained efforts, in 2012, the Sunderbans Tiger Reserve and TSA were finally successful in breeding Batagur baska in captivity. TSA also established a successful conservation breeding program in association with the Bangladesh Forest Department and Vienna Zoo, sourcing animals from the illegal trade, and animals kept as pets in village ponds in remote areas. Two years later, in 2014, the Madras Crocodile Bank received a male from Vienna Zoo, as part of an animal exchange to initiate a conservation breeding program involving their two rescued females. Just last year, they bred successfully.  

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A male Batagur baska. Photograph: Shailendra Singh

Today, juveniles number around 450 in the four captive locations in India, Bangladesh and Vienna. There could be a few surviving individuals in the wild in Myanmar, but this would need further scientific validation. Earlier surveys have suggested that there may be a few juvenile individuals surviving deep in the Bangladesh Sunderbans.  

Last year, a pilot reintroduction program was initiated in India and Bangladesh. Scientists use monitoring equipment to determine the turtles’ dispersal and survival, and the results are currently being studied in the lead-up to a sustained release program. Conservation agencies are always on the lookout for any surviving individuals in the wild to strengthen genetic diversity, and help sustain these critical breeding programs. They also work to evaluate the remaining safe habitats, where populations can be reintroduced and re-established. 

Conservationists also spread awareness among key local fishing communities to ensure they return any tagged released animal they encounter. The possibility of starting a “community buy-back initiative” is currently being evaluated. However, release sites are being kept undisclosed to avoid unwanted attention. TSA's work with this animal wouldn't have been possible without the teams from the Sunderbans Tiger Reserve, the West Bengal Forest Department, Madras Crocodile Bank Trust, Vienna Zoo, Turtle Island, the Bangladesh Forest Department, and IUCN Bangladesh.

The public can do its bit to help protect this species too. Don’t buy turtles or turtle products for any reason, don’t litter water bodies, and do what you can to support the conservation agencies dedicated to saving these turtles and other enigmatic wetland creatures. 

To read more stories from the Endangered Species Series, click here