Bad news for bog turtles

The federally protected bog turtle faces a new threat in the northern portion of its contiguous range.  On Aug. 5, the U.S. Fish and Wildlife Service issued an advisory bulletin that an unusually high number of dead and apparently diseased bog turtles has been reported from four states, including New York and Massachusetts.

“The number of bog turtles found dead in their wetland habitat (two to four dead turtles in each of four wetlands in New York and Massachusetts) exceeds that which is typically reported.  In some cases, dead bog turtles have been found entirely intact, with no obvious cause of death. On several live bog turtles, a grayish or whitish substance and/or discoloration has been documented on the skin of the head, neck and limbs, as well as on the claws. In some cases, these appear as skin lesions. Acute sloughing and loss of claws and toes has also been observed.

“Based on data collected at a Massachusetts site, the symptoms appear to worsen over time.

“At this time, the causative agent(s) of the observed symptoms has not been identified.â€

This is extremely troubling news.  When I was with The Nature Conservancy, bog turtle conservation in Massachusetts, Connecticut and part of eastern New York was a major focus of my work.  The bog turtle is at the extreme northern extent of its contiguous range in nearby Massachusetts.

The Fish and Wildlife Service Recovery Plan for the bog turtle’s northern population identifies just three bog turtle sites in the commonwealth — altough two of them are considered good sites and are under conservation management. I am intimately familiar with both of these, and know that if one has lost two to four adults to a new threat, the viability of what would otherwise be considered a strong and vital population is in grave peril.   

Past research indicates that the loss of just one breeding adult a year at these sites would be enough to tip the balance toward extirpation.

Bog turtles are already under threat from many sides. Loss of habitat, as is so often the case for rare species, is for them the paramount concern.

They are also cursed with cuteness, and poachers collect them from the wild  for the illegal pet trade.

There is a bog turtle site in New York that, back in the late 1990s, showed evidence of an upper respiratory tract disease often found in captive turtles. What is most disturbing about this latest disease advisory is that it appears to be something entirely new. An unknown and highly lethal pathogen will take time to analyze, let alone to isolate causes and develop a meaningful response. Time is running out for the bog turtles.

Tim Abbott is program director of Housatonic Valley Association’s Litchfield Hills Greenprint. His blog is at greensleeves.typepad.com.