Bourret’s box turtles are critically endangered due to habitat loss and collection for the food, pet and medicinal trade. One specific conservation effort zoos are mastering right now is building assurance populations. If something catastrophic were to suddenly happen to the wild populations, those in zoos could provide a backup so the species does not go extinct.
There is still a lot we don’t know about the husbandry and breeding of Asian box turtles. Here at the Smithsonian’s National Zoo, we only recently made a breakthrough with breeding Bourret’s box turtles in 2017. Those hatchlings were the first of their species to hatch both at the Zoo and as a part of the North American Association of Zoos and Aquariums’ (AZA) Species Survival Plan (SSP) for Bourret’s box turtles!
These turtles are very complicated to breed. It requires mimicking a winter cooling period, known as brumation, for the adults where temperatures drop down to 40 degrees Fahrenheit. Then, we have to slowly bring it back up to spring temperatures, around 70 degrees Fahrenheit. We were not able to achieve these low temperatures inside, so we kept them in a sectioned off area in the outdoor Chinese Alligator Exhibit. The Chinese alligators need a cooling period in the winter as well, so the space was perfect! We worked as a team to keep an eye on the thermostat daily and make small adjustments whenever necessary.
Incubation also requires a lot of patience. Bourret’s box turtle eggs can take up to four months to hatch. Although the parents had produced and laid eggs in previous years, they either were not fertile or did not develop fully inside the egg. It was really exciting in 2017 when the first of our hatchlings pipped (broke through the shell for the first time)!