Smallest turtle in the land becomes more scarce

The Wildlife Conservation Society's Bronx Zoo veterinarians, U.S. Fish & Wildlife Service, New York State Department of Environmental Conservation, and the Massachusetts Natural Heritage and Endangered Species Program have joined forces to answer a perplexing wildlife question: Why are bog turtles getting sick?

The dilemma shines a light on North America's smallest turtle; an adult bog turtle reaches only 4.5 inches in length and as many ounces. Wildlife managers working in a few known bog turtle habitats in the Northeast have reported higher than average mortality rates for these threatened reptiles in the past few years.

To determine the cause of the increase in mortality at some sites and identify the baseline health condition at other sites, WCS's Global Health Program—based at the Bronx Zoo—is lending its expertise in wildlife health assessments. WCS health experts have joined federal and state wildlife managers in the field at locations in New York State and Massachusetts.

The bog turtle team is currently locating wild turtles for health assessments to determine these baseline conditions and possibly identify a common cause to explain recent turtle mortality. After conducting a physical exam of individual turtles, health experts will collect a number of samples—blood, feces, cloacal swabs, biopsies—for later analysis.

“We're conducting a broad screening in order to identify a cause or causes for the increase in bog turtle deaths,” said Dr. Bonnie Raphael, WCS's Department Head for Wildlife Medicine. “This information will be used to help determine if these recent losses are attributable to infectious disease, environmental perturbations, or other factors.”

Although there are no reliable range-wide population estimates for bog turtles, the species is currently protected on state, national, and international levels. The number of known habitats for the threatened northern population of the bog turtle—which has a patchy distribution stretching from Massachusetts to Maryland—is shrinking. The bog turtle is federally listed as “Threatened,” and is “Endangered” in New York State and Massachusetts. All international trade in the species is prohibited through CITES (Convention on International Trade in Endangered Species).

“The U.S. Fish and Wildlife Service has made bog turtle recovery a priority,” said Alison Whitlock, Northeast Region Bog Turtle Recovery Coordinator for the U.S. Fish and Wildlife Service. “We are working with many partners from state agencies, non-governmental organizations, and private landowners to address the threats to this species. Working with the Wildlife Conservation Society to conduct this health assessment addresses one of the recovery objectives, and we are looking forward to continuing this partnership in conservation.”

WCS has been involved in the study and conservation of bog turtles since 1973. A bog turtle research project conducted by Dr. Whitlock was one of the first conservation initiatives funded by WCS's North America Program in 1995. WCS Global Health Program veterinarians are recognized as experts in turtle health programs in national and international field efforts as well as zoological park based programs and thus are uniquely qualified for this investigation.