One of the many historical Lloyd Center research endeavors has been protection and monitoring for the Northern Diamondback Terrapin, (Malaclemmys terrapin terrapin). Listed as “threatened” under the Massachusetts Endangered Species, the terrapin is our only turtle associated with estuaries, salt marshes, and sandy habitats where it nests each spring and summer. The species ranges from Cape Cod to Florida to Texas, with ours being the northernmost of the seven subspecies. Often sharing beaches with the endangered Piping Plover, terrapins suffer similar impacts as shorebirds, including habitat loss, human use, and predators. Before laws were passed, terrapins were hunted for food, especially in the Chesapeake Bay region, which contributed to declines.
Initially, local environmental organizations formed the “South Coast Terrapin Consortium” (SCUTES) due to the realization that small subpopulations existed in various areas along the western shore of Buzzards Bay, but little was known about the population. Starting in 2004, the Lloyd Center began assisting with searching habitats, focusing on the Slocum River, Westport River, and Allens Pond, to find nesting evidence and areas where turtles were active. Findings were primarily swimming turtles in estuaries and multiple predated nests, until 2005, when a nesting female was observed at Demarest Lloyd State Park by researchers doing plover work. This evolved into a more focused effort on the nesting population in the Slocum River at Demarest Lloyd, where habitat is optimal and high nest densities exist. This effort generated over a decade of nesting data and over 20 marked female turtles.
This season terrapin work resumed by accident, again incidental to plover work at Salters Pond, when a private landowner discovered a nesting female digging a nest in her driveway that is a mix of soil and gravel, obviously marginal habitat. The female was transported to the pond after nesting, and then the eggs dug up and counted. Eggs can be handled (by qualified personnel) initially, including relocation to a better area if necessary because the yolks aren’t yet “set”. Twelve eggs were laid and the owners built an extravagant nest protector to prevent predation by mammals such as fox and coyote. The choice was made to minimize tampering and experiment with this driveway nest.
Nest incubation ranges from 60 to 120 days and averages around 70, a relatively slow process. At 60 days the nest was checked to determine status of the eggs. Three to six of the original 12 were still viable, the others unfortunately not. As it turned out, both a gravel driveway that probably caused lower moisture and overheating of the clutch, and roots from weed growth (and insects attracted to them) surrounding some eggs, resulted in a suboptimal microclimate for the eggs compared to moist sand. The eggs appearing viable were brought to the Lloyd Center in a controlled environment, where we’re happy to report that on August 21st (71 days), three hatchlings emerged. Two were released to the salt marsh mud at the edge of the pond on August 24th, while one will be “head started” at the Center, to hopefully be released in the spring. Terrapin hatchlings have a very high mortality rate, so while we want to minimize intervention, head starting can increase the chances the turtle will survive a harsh winter or predation.
This finding suggests that a terrapin population exists in the pond, with both protection of nests in marginal areas, and determination of nesting habitat extent, important objectives going forward in this new Lloyd Center research venture.
by Lloyd Center Research Associate Jamie Bogart
