For the 5th year the critically endangered red-crowned roof turtle (Batagur kachuga) has reproduced in captivity at the Madras Crocodile Bank Trust (MCBT). The 2009 season saw a maximum production of hatchlings – 29 in all – and these are all doing well, with one month old animals having increased in weight by 50% compared to recently hatched ones.
The first clutch of eggs was discovered at MCBT in 2003, but these were infertile. Between 2004 and 2009, there were from one to five clutches every year, save for 2006 when no nesting occurred. Eggs were collected in February – March of every year, except in 2004, 2008, and 2009 when nests were missed and hatching occurred naturally in the enclosure. The number of nests rose to six in 2009 indicating multiple clutching by females, almost certainly due to improved husbandry conditions. Possible contributing factors include increased height of the communal nesting mound, trimming of branches that provided more access to sunlight, a mesh haul out ramp that facilitated basking by adults, and the introduction of soya pellets into the diet.
132 total eggs were laid through 2009 with an overall viability of 69%. A total of 75 hatchlings were produced from these eggs, with 24 animals going to back to Uttar Pradesh for release in 2007. Several eggs collected were found to be cracked, but as long as the shell membrane remained intact these eggs usually incubated to term.
Courtship of adults is observed in September through October, probably remaining true to the natural range of the species in Northern India. The group of breeding animals at MCBT did not experience the major fluctuations experienced in their natural habitat, but lower temperatures could have been achieved by selecting deeper areas of the breeding pond.
Expansion of the captive program for B. kachuga at MCBT began in 2004 with construction of new rearing and breeding ponds. These were funded by the TSA with support from the Turtle Conservation Fund, British Chelonia Group, and Walter Sedgwick.
Acknowledgements: Most thanks is due to the folks at Turtle Survival Alliance, for their advice on husbandry, veterinary issues, and their assistance in designing and funding grow-out ponds for hatchlings and juvenile, in addition to their on site visits and valuable discussions. . I particularly thank Rick Hudson, Brian Horne, Shannon Farrel. D. Basu, B. C. Choudhury, Lonnie McCaskill, Rom Whitaker, Gowri Mallapur, Soham Mukherjee, Gangadurai, Pindey, Seth, and our in-situ field scientist, Shailendra Singh, who assisted this project in a number of ways. Jeff Lang is acknowledged for his donation of equipment.
-Nikhil Whitaker, Curator