Bog Turtle (Glyptemys muhlenbergii)
Meet the Bog Turtle
- Bog turtles research has been ongoing at one of TNC's Pennsylvania nature preserves since 1969—one of the longest running studies of bog turtles in their northern range.
- Recent surveys have revealed a female bog turtle that is at least 61 years old, the oldest documented bog turtle in the wild.
- TNC also recently documented two other bog turtles that were marked in the 1970’s, and 12 bog turtles that are at least 40 years of age.
Saving a Species
The bog turtle is Pennsylvania'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, similar to what exists in parts of south-central Pennsylvania.
In these wetland habitats, 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.
A Fragile Balance
The bog turtle is classified as federally-threatened on the U.S. Fish and Wildlife Service’s Endangered Species List. It occurs in very low numbers in southeastern Pennsylvania and, as a result, is also listed as endangered in the state.
Habitat loss and fragmentation and forest succession represent the primary reasons for the decline of this species. For example, in the past, bog turtles could move to nearby habitat if conditions changed. However, remaining habitats have become more isolated because of land development throughout southeastern Pennsylvania. Bog turtles are also threatened by diminished water quality, mortality on roadways, growing populations of predators like raccoons, and by reptile collectors who consider this rare turtle a valuable prize.
Protecting Bog Turtles
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. This creates ideal habitat for bog turtles.
In 1989, The Nature Conservancy acquired land near South Mountain in order to maintain, and restore habitat required by these turtles that are no larger the palm of a human hand. Over the years, this work has included managing burns, cutting trees, and introducing cattle and goat grazing in order to foster the growth of native vegetation and maintain the soft mucky soils that the turtles prefer.
TNC also conducted a radio telemetry study that documented bog turtle locations, hibernation, travel patterns and habitat use within the preserve. Studies have revealed the existence of a 61-year-old bog turtle, the oldest documented bog turtle known in the wild.