Wednesday was a graduation day of sorts for four Blanding’s turtles (Emydoidea blandingii) that arrived on Central Wharf in October as part of a headstart program to help the threatened species.

The four, which were returned to the Groton, MA, wetlands area from which they came, are part of Zoo New England’s Grassroots Wildlife Conservation Program, which aids about 100 of these turtles each year.

The quartet of turtles was featured in a First Friday Facebook Live in November, about a month after the Aquarium began taking care of them. At that time, they were weeks old, weighed about 10 grams, and were about the size of a half dollar. On Wednesday, when they were released, they weighed about 200 to 300 grams—about the size of a 3- to 4-year-old turtle in the wild.

Each year, turtle hatchlings are picked up in early autumn and distributed to several sites, including school classrooms and wildlife organizations around Massachusetts, and are raised indoors for the winter. The turtles are fed a lot during a time when they normally would be dormant. Their handlers try to get the turtles as big as possible so they are better protected from predators and more likely to survive and breed in the wild. Zoo New England estimates that the headstarted turtles have about a 30 times better chance of surviving to adulthood. Over the years, Zoo New England’s program has overseen the successful headstarting and release of hundreds of young Blanding’s turtles at five sites in eastern Massachusetts.

And if all goes right, the turtles could live to be 70 years old and grow to a length of just shy of a foot. 

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On Wednesday, the turtles were taken to the Groton area, weighed, and some were fitted with radio tags for further tracking. This allows for researchers to monitor the turtles and their nests through the late summer. As soon as the turtles’ eggs hatch, the researchers, aided by volunteers, will gather hatchlings and bring them inside and begin the process all over again!

Watch the First Friday Facebook Live episode from last November to learn more about Blanding’s turtles and the headstart program.

At the Aquarium

While the young headstart turtles remained behind the scenes during their stay at the Aquarium, there is one special Blanding’s turtle that makes appearances during our Live Animal Presentations. Learn more on our blog about Skip and other marine animals you can meet during Live Animal Presentations.

Learn More

The Aquarium has also been involved in a headstart program for northern red-bellied cooters. Read about that effort and more about Blanding’s turtles on our blog.

Conservation Context

The East Coast populations of Blanding’s turtles are endangered. A major threat is habitat fragmentation. Since this species travels long distances between wetland habitats, they are vulnerable to being killed while crossing roads. In fact, roads are the primary cause of adult mortality, according to the Mass. Division of Fisheries and Wildlife. Another challenge for this species is that they are very long-lived and don’t reach sexual maturity until later in their teenage years.  According to Zoo New England, the Great Meadows National Wildlife Refuge in Concord, MA, is home to one of New England’s largest and most genetically unique Blanding’s turtle populations. However, the number of turtles there has declined from an estimated 135 adults and older juveniles in 1971 to about 55 individuals at present. Over the same time period, many smaller New England populations of Blanding’s turtles have either disappeared entirely or dwindled to a handful of older adults with few or no young turtles in the population. The causes of the decline, in addition to car strikes, include the loss of dense but treeless wetlands through a variety of human land-use factors; the disappearance of scrubby field-edges, critically important to nesting female turtles; and an increase in the density of several mammal species that eat turtle eggs and juveniles, such as raccoons, mink, and even eastern chipmunks, which are major predators of hatchlings.