Bog Turtle (Glyptemys muhlenbergii)

Meet the Bog Turtle

The bog turtle is North America’s smallest turtle, growing only to 4.5 inches in length.

Easily recognized by the orange patch on either side of its head, the bog turtle favors open, groundwater-fed wet meadows and bogs dominated by tussock sedge and grasses.

Bog turtles thrive in mountain bogs, or isolated wetlands with acidic, wet soil, thick moss and deep layers of mud. These deep mucky soils, fed by groundwater, provide protection from predators and other elements. Short clumps of vegetation let in plenty of sunlight for incubating eggs and basking. If any of these conditions change, a bog turtle population can decline and may eventually disappear from the area.

Northern & Southern Populations

Bog turtles are native to the eastern United States.

The bog turtle occurs only in the eastern United States, with distinct northern and southern populations separated by a 250-mile gap through most of Virginia and West Virginia. The northern population is larger than the southern, with bog turtles occurring in northern Maryland, Delaware, eastern Pennsylvania, southern New York and most of New Jersey and extending as far north as Massachusetts. Although populations were once abundant in the Southern Blue Ridge of North and South Carolina and Georgia, the bog turtle is now facing unprecedented challenges to its survival.

Threats to Bog Turtles

The bog turtle is classified as federally threatened on the U.S. Fish and Wildlife Service’s Endangered Species List.

The bog turtles are classified as federally threatened and are often eaten by predators such as skunks, raccoons, and foxes, when in the egg. Once, hatched, bog turtle hatchlings are also vulnerable to birds, snakes, and small mammals

However, habitat loss, fragmentation and forest succession represent the primary reasons for the decline of this species. In the past, bog turtles could move to nearby habitats if conditions changed. However, the remaining habitats have become more isolated because of land development. 

How TNC is Protecting Bog Turtles

In Pennsylvania

In Pennsylvania, small, spring-fed streams trickle down South Mountain towards the sandstone valley below. In some areas, the water collects to form soft, muddy wet meadows, surrounded by clumps of grassy tussock sedges and other low-lying vegetation. Creating the ideal habitat for bog turtles.

In Massachusetts

Hidden away in the wetlands of Western Massachusetts, a small-but-mighty bog turtle population is stabilizing—thanks to TNC and partners’ ongoing study of the endangered species and careful management of their habitat. Every April to November, TNC staff, interns, volunteers and others, radio track and search for turtles to help fill out the existing population data.

TNC in Massachusetts has been involved with monitoring the species since the 1980s, building a record of the number of turtles of certain ages, population growth and health, and turtle locations. This data helps inform the management strategies used to ensure the habitat is supporting turtles’ needs.

“Weekly tracking guides our restoration efforts by showing us what kinds of habitat they prefer for nesting, basking, foraging and overwintering,” says Angela Sirois-Pitel, stewardship manager for TNC in Massachusetts. “If turtles show up in areas where we recently removed invasive plants or opened up the canopy, it confirms that our management actions are beneficial.”

There are estimated to be less than 40 adult turtles at each of two sites TNC owns and manages in the area. Protecting bog turtles is key to sustaining the many other species found in these wetland ecosystems.

In the summer of 2020, 53 turtles were spotted through a combination of tracking those with transmitters and searching for them in the underbrush of the wetland. The number included both old and new individuals. Eight of the turtles that turned up have been around since the studies began in the 1980s, making them over 40 years old. In addition to these long-timers, another eight of the turtles found had never been seen before. These observations indicate that older turtles are still around and that the population is reproducing and those young turtles are growing into adults.

“These promising population numbers, paired with the observation that turtles are exploring areas of the habitat that we’ve recently opened up, are a positive sign that our habitat management strategies are working,” says Sirois-Pitel.

In 2021, University of Massachusetts graduate student and former TNC AmeriCorps member Julia Vineyard will begin her first field season studying the bog turtle populations in Massachusetts, in coordination with MassWildlife, building on the past two years of rigorous monitoring at these sites. Much of TNC’s ongoing research and restoration work has been funded through a MassWildlife Habitat Management Grant and a Natural Resource Damages Fund for the Housatonic River, and Julia’s continued study is supported by a U.S. Fish and Wildlife Service State Wildlife Action Grant.