Late on the balmy afternoon of October 6th, and a month after the last Piping Plovers had departed south on the fall migration, I visited Demarest Lloyd State Park to retrieve the last beach fencing which was left to protect a Diamondback Terrapin (Malaclemys terrapin) nest from the summer. The other task was to remove, from their sandy confines, any lingering hatchlings and transport them to the safety of the nearby salt marsh. There the young would rebury themselves for the winter, avoiding the treacherous crawl from the beach where many hatchlings succumb to predators.
This Terrapin nest was discovered on July 2nd, with first hatchlings seen on September 29th, for an estimated incubation length of 80 to 85 days. The nest was found along Giles Creek in the picnic areas, but relocated to the safety of the sand spit which receives protection from the plover refuge.
Nests can incubate anywhere from approximately 55-120 days, making this an average incubation span. Initially 14 eggs were laid, but many dried out and some embryo didn’t develop, so unfortunately only four hatched.
Currents and sands from a recent stormy high tide had mangled the fencing and shifted the small metal exclosure, but after some digging, two of the four hatchlings were found near the sand surface, and brought to the marsh. The other two were surely nearby and will simply crawl back beneath the sand at the nest site, no more phased by my intrusive dig than they were by the storm tide.
These two turtles will either re-emerge during a fall warm spell and head for the marsh to reunite with their siblings, or remain beneath the sand for the winter before emerging in the spring. So with luck, all four will survive that critical first season, and be recruited into the robust Slocum River terrapin population.
Diamondback Terrapins are the state’s only estuarine turtle, living in the estuary itself with females coming ashore twice each summer in June and July to nest on the beach and high marsh. Nesting occurs usually when moon tides coincide with warm temperatures, the high tide decreasing travel distance, and warm temperatures increasing body temperature and activity as occurs in all the cold-blooded reptiles.
Terrapins are endangered and listed as “threatened” under the Massachusetts Endangered Species Act, with current significant threats being development of shoreline areas, associated road travel, and other human use on or near beaches and salt marshes. Although some terrapins nest along Giles Creek in the picnic areas of Demarest Lloyd State Park, as was the case with this terrapin, nesting females are increasingly congregating on the large protected spit at the mouth of the estuary. Demarest Lloyd remains one of the few pristine areas in Buzzards Bay from which terrapin knowledge is in its infancy.
Tune in next season as we strive to protect as many terrapin nests as possible, but continue to be thankful for every nest and turtle that survives.
by Lloyd Center Research Associate, Jamie Bogart