The diamondback terrapin, once hunted nearly to extinction and currently designated a threatened species in Massachusetts, is slowly making a comeback on Cape Cod—thanks in large part to the efforts of staff and volunteers at Mass Audubon Wellfleet Bay Wildlife Sanctuary.
“In the 1980s, it was rare to see a diamondback terrapin,” says sanctuary director Bob Prescott. “Most people who lived their whole lives here had never seen one.”
The WBWS Diamondback Terrapin Conservation Program began protecting terrapin nests in 2005, resulting in the successful release of more than 15,000 hatchlings into local marshes. While most of the monitored areas are located in Wellfleet, nesting activity is also monitored in Eastham and Orleans.
This species is unique, as it is the only North American turtle adapted to brackish water habitats. After mating in the water in the spring, female terrapins come out of the marshes to lay their eggs in sandy areas above the high tide lines. During the months of June and July, each mature female (age 10 to 60) lays two clutches of eggs, approximately two weeks apart. Program staff and volunteers monitor nesting areas twice a day. When a nest is located, it is surrounded by a protective enclosure to ward off predators such as foxes, raccoons and crows. The turtle eggs then incubate for 60 to 90 days. The surviving hatchlings emerge and are evaluated and released into the upper marshlands where they burrow under brush or in the mud for the winter.
Interested in learning more? Visit the Wellfleet Bay Wildlife Sanctuary, 291 State Highway (Route 6) in South Wellfleet, massaudubon.org/wellfleetbay or call 508-349-2615. Visitors may inquire about volunteer and conservation opportunities, including Field School, a unique, hands-on learning experience for adults, a wide range of summer day camps and activities for children and families, as well as an extensive array of programs for all ages.