The Bog Turtle


The Bog Turtle (Glyptemys muhlenbergii) has the distinction of being one of the smallest and most rare freshwater turtles found in North America, with Maryland containing about 1/3 of the known population. All known bog turtle colonies found in Maryland occur in Carroll, Baltimore, Harford, and Cecil Counties. Bog turtles are about four inches long and five ounces in weight at maturity.

This small turtle is easily identified by the orange patches found alongside its head.  

Image credit: Wikimedia Commons

During the winter months, bog turtles hibernate underwater in deep areas of bogs in about 6 to 18 inches of mud. Immature turtles do not hibernate in deep mud until they are 2 to 3 years old. The turtles emerge from hibernation in late March to April and may migrate short distances to feeding and breeding sites.

Bog turtles inhabit open, water-saturated wetlands that are normally spring fed.  They can be found in bogs, fens, meadows, and marshes. There are two distinct populations of this turtle found in the east: a southern population that is found in North Carolina, South Carolina, and Georgia; and a northern population that extends from Maryland, north to Vermont.  The Southern population contains about 100 known colonies, while the northern population contains twice that many colonies.  It is estimated that 80% of bog turtle numbers were lost during the last 30 years due to loss of critical habitat; invasion of invasive species like purple loosestrife, multiflora rose, and reed canary grass, species that clogs up these meadows and makes it difficult for the turtles to move around; loss of wetlands for alternate uses; encroachment by trees and other wood vegetation; predation; and illegal confiscation for the underground pet industry.


The bog turtle is active during the day, spending its time basking in the sun, searching for food or hiding in a network of underground tunnels. Bog turtles are omnivores, feeding on plants, insects, small fish, salamanders, and frogs. The small size, secretive nature, and inaccessibility of the habitat means that these turtles are rarely seen by the casual observer. Bog turtles hibernate from late September until late April in our region, emerging when the average temperature rises above 62 degrees.  The female bog turtle lays a clutch of about 3 eggs each season, and it takes about 8 - 11 years for the young turtles to become mature.  Bog turtles live 20 to 30 years in the wild.  Management efforts to help restore bog turtle habitat includes practices such as manually removing small trees and shrubs, controlled burning to maintain grassy vegetation, grazing by goats and cattle, and encouraging beaver activity to maintain swampy grasslands.  Captive breeding programs are now being carried out in various institutions and aquariums to help bolster populations.