Survival in the Sundarbans

With each passing year’s arrival of Spring in the Sundarbans, a time of critical importance emerges for the beleaguered Batagur baska, one of the most imperiled species of chelonian on our planet. Listed as Critically Endangered by the IUCN, the Northern river terrapin has seen dramatic declines throughout its entire range and is now either extinct or functionally extinct in most of its former haunts. The decimation of this species, coupled with the continued pressures on the remaining wild specimens preserves B. baska’s standing as a top priority species for the Turtle Survival Alliance.

[caption id="attachment_278" align="alignright" width="208"] A nest-protection cage is installed at the Karamjal Forest Station[/caption]

Beginning in March, the nesting season for B. baska in the Sundarbans of India and Bangladesh - a UNESCO world heritage site - is a time of little rest for park rangers, members of the TSA, and our partner organizations. These dedicated individuals work diligently to locate new specimens, provide optimal breeding conditions, identify, excavate, and protect nests, and incubate eggs at the in-situ assurance colonies for the species. With no known active nesting beaches in the wild remaining for the species, the five well-maintained and secure assurance colony facilities in India and Bangladesh provide the only hope for B. baska

A prominent exercise in maintaining the productivity of the five assurance colonies for the species is the search for and acquisition of new parental-generation specimens for the groups. With so few animals of reproductive value held at the facilities, locating new specimens – females in particular – to populate the ponds is a monumental task in itself. Typically, these acquisitions are facilitated by informants providing the whereabouts of a specimen. In most cases, the specimens are privately owned by families as a source of egg-protein, as long-time pets, or residents of ponds under the governance of religious temples. Negotiating the transfer of these individuals to an assurance colony is often-times a very difficult task as the extremely rare turtles are prized by the families or communities and in-fighting amongst members often curtails the acquisition.

Fishermen attempt to capture two male B. baska in a community pond This February, Rupali Ghosh, representing the TSA and our partner, Vienna Zoo, traveled from her home in India to Bangladesh to negotiate the acquisition of four individual B. baska; who were long-time captives of the families and communities that held them. After several unsuccessful attempts to negotiate the sale of several of the individuals she had been informed about, Rupali received news of two male B. baska, that a community political leader in the village of Parshuram, would allow the acquisition of. Rupali was met by political leader, Mayor Nizam Uddin and numerous villagers to capture the two males by net from a private community pond. After several unsuccessful attempts, one of the male B. baska was netted and retrieved, while the second was unsuccessfully located.

[caption id="attachment_279" align="alignleft" width="300"] Fishermen attempt to capture two male B. baska in a community pond[/caption]

Two days after its capture it was transported to its permanent home at the new assurance colony at the Karamjal Forest Station in the Sundarbans, which houses 7 male and 4 female terrapins. Without this type of dedication to locate and retrieve new specimens for the assurance colonies, B. baska would be one step closer to extinction. The TSA owes a huge debt of gratitude to both Rupali and Peter Praschag for their dedication to saving this species; they work tirelessly, often under difficult and adverse conditions, and Rupali has aptly been described as a “force of nature.

Early Spring in India and Bangladesh also means a focus on the maintenance of, or creation of, new nesting beaches for female B. baska at the various assurance colonies. In the wild, female B. baska typically choose exposed sandy beaches or river bars in which to deposit their clutches of eggs. With no known active nesting beaches remaining for the species in the wild, providing optimal nesting conditions in captivity is paramount to breeding and nesting success.

[caption id="attachment_282" align="alignright" width="300"] Rupali Ghosh holds two captive-hatched terrapins at the assurance colony[/caption]

This February, with the nesting season looming, workers at the Karamjal Forest Station assurance colony in the Sundarbans of Bangladesh, a cooperative between the Turtle Survival Alliance, Vienna Zoo, the Forest Department, and the Prokriti O Jibon Foundation, worked diligently to create a new nesting beach for the four adult females. Within weeks of creating this nesting beach, park staff noticed track marks left overnight by the adult females inspecting the new beach.

Shortly thereafter, on March 02, 2017, the first-ever nest at the Karamjal Forest Stationwas deposited! This nest contained an astounding 31 eggs, near the top of the range of clutch-size for the species. This clutch size of a first-ever nest at the Karamjal Forest Station is a testament to the importance and efficacy of the high-quality husbandry practices the turtles receive at the assurance colony. With this species teetering on the brink of extinction in the wild, all 31 eggs were collected for incubation with high hopes of rearing the hatchlings in the protected environment of Karamjal.

For any species clinging to survival in the wild, with trials come success stories, but also tribulations. To better understand their migratory patterns and habitat utilization, TSA’s Rupali Ghosh and Turtle Island’s Peter Praschag, in coordination with the Vienna Zoo and the Prokriti O Jibon Foundation (POJF), affixed two adult male B. baska with satellite transmitters this past December. To test the durability and reliability of the transmitters, both males were kept in the breeding ponds of the Karamjal Forest Station assurance colony for two months prior to release. The quarantine period proved successful for the efficacy of the transmitters and both animals were deemed suitable for release.

[caption id="attachment_283" align="alignleft" width="300"] Male B. baska in breeding coloration fitted with satellite transmitter[/caption]

This February, with the assistance of the POJF and the Forest Department, Rupali and Peter traveled back to the Sundarbans of Bangladesh to release the two individuals into a remote and undisclosed location within the immense riverine matrix of the mangrove forest. The release of two beautiful specimens of a critically endangered species was met with much fanfare and media attention. As such, photo opportunities, television, and printed news coverage, and attendance by community leaders was held at a location in the Sundarbans far from the actual site of release. This was done for the purpose of protecting the actual whereabouts of the animals from anyone with nefarious intent on recapturing the specimens.

For nearly two weeks, the satellite transmitters provided valuable data on the activities of the turtles. Then, the tribulations of such a trial release were felt. The transmitter of one male suddenly failed to register a “ping” and to date the whereabouts of this turtle is unknown. Additionally, news quickly returned that the second male was found for sale in a market, having been captured by fishermen only two-weeks post-release. Luckily for this male B. baska, no one had purchased this animal and it was confiscated from the market by local police officers. With the quick aid of rangers from the Forest Department, the individual male was retrieved from the authorities and returned to the assurance colony at Karamjal. While the tribulations of this release are distressing for those who work tirelessly to protect the species, a silver lining of these events can be seen in that local authorities were quick to identify and confiscate this animal before it could be purchased from market and that the male will continue to lend its genetic footprint in the safe confines of the breeding colony at Karamjal.

[caption id="attachment_284" align="alignright" width="300"] TSA – India coordinator Shailendra Singh and company release turtles into the assurance colony at Sajnekhali[/caption]

As of this writing, good news continues to come in weekly from India and Bangladesh regarding this enigmatic species. At the first assurance colony for the species in Bhawal National Park, Bangladesh, which also houses 7 male and 4 female terrapins, two nests have been laid on the beach bordering the stock pond. Both nests contained large numbers of eggs for the species. Similar to those at Karamjal, all eggs have been relocated to both protected cages for natural incubation and indoors for artificial incubation.

Elsewhere, TSA-India coordinator Shailendra Singh reported that 20 individuals from the assurance colony at the Sundarbans Tiger Reserve at Sajnekhali were translocated to establish a second assurance colony at Chamut Forest Preserve.  This second population is to avoid the “all eggs in one basket” scenario and to avoid a catastrophic loss of a single population due to disease or disaster. We have high hopes of reproductive activity from two additional captive groups of the species. Comprised of one male and two females, a trio held at the Madras Croc Bank Trust in Chennai, India, successfully reproduced in 2016.  The other, a captive group managed by Peter Praschag in Vienna also produced offspring last year.

With nesting season underway, the coming months should continue to provide numerous stories of success from our assurance colonies in India and Bangladesh regarding captive breeding and the potential of new individual acquisitions of specimens from private owners. For up-to-date news on this busy time for Batagur baska please follow us on our Turtle Survival Alliance Facebook page.