Species Fact Profile: Bog Turtle (Glyptemys muhlenbergii)

Bog Turtle

Glyptemys muhlenbergii (Schoepff, 1801)

Range: Eastern United States, from western Massachusetts to northeastern Georgia is a highly discontinuous range, generally described as a larger northern population (Massachusetts through Maryland) and southern population (Virginia through Georgia)

Habitat: Shallow, spring-fed upland wetlands with muddy or silt-covered bottoms and lots of grasses and sedges, open and unshaded conditions

Diet: Small Invertebrates (Insects, Mollusks, Crustaceans, Worms), Seeds, Berries, Greens, Carrion

Reproduction: Breed in spring. Courtship consists of male budging and biting the female, then mounting her and thumping her shell with his plastron.  Females nest from May to July, most eggs are laid in June.  Nest on higher, dryer ground (but sometimes in elevated tussocks in the middle of the bog).  Single clutch laid per year of 1-6 elongated white eggs (up to 3 centimeters long) with pliable shells.   Multiple clutches per year have been reported in captivity.   Incubate 45-65 days.  Hatchlings are 2-3 centimeters long when they hatch, mature at 4-10 years old.   

Social Grouping: Mildly territorial, may chase other turtles out of small areas around themselves.  May share hibernation sites.

Lifespan: 40 Years

Conservation Status: IUCN Critically Endangered, CITES Appendix I, US Endangered Species Act - Threatened

 

• Smallest North American turtle and one of the smallest in the world.  Adult carapace length 7.9-11/4 centimeters.  Adult weight 110 grams
• Carapace is dark brown or black, may be marked with some light radiating lines or blotches.  Skin is typically dark brown with variable red or yellow spots or streaks.  Large reddish-orange or yellow blotch behind each tympanum, sometimes merging into a continuous band.  Plastron is brown or black with light yellow blotches.  Carapace often has rough rings and ridges on the scutes, though they may be worn smooth with age and wear
• Genus name comes from the Greek for “Carved Turtle.”  Species name honors the Reverend Gotthilf Heinrich Ernst Muhlenberg, an 18^th century botanist from Pennsylvania who found the type specimen in his mill pond.
• Male turtle has concave plastron and longer, thicker tail, vent is posterior to rear edge of carapace when tail is extended.  Female has flat plastron, thinner and shorter tail.  Males also tend to be slightly larger than females
• Primarily active by day, may do some activities such as nesting at night.  Spend cool days basking, hot days hiding in the vegetation.  In winter, hibernate in burrows in the mud or vegetation.  May use same hibernation site for several years in a row
• Very small size makes even the adults of this species vulnerable to many predators, including raccoons, skunks, foxes, snapping turtles, and wading birds, which will also prey on eggs and hatchlings.  The small shell offers relatively little protection.  Primary defense is to dive into soft mud and swim through it
• Despite highly fragmented range, no geographic subspecies have been identified.  It is believed that the northern and southern populations became isolated from one another due to habitat loss resulting from farming in Virginia’s Shenandoah Valley during the American Civil War
• In 2003, listed by the Turtle Conservation Fund as one of the 25 most endangered turtle species in the world.  Habitat loss and fragmentation is the main threat to the survival of the species, both due to draining of wetlands as well as pollution and invasive plant species.  Both fire and cattle grazing can be beneficial for these turtles as they help maintain open habitats.  Illegal collection for the pet trade is an additional threat.  May be hit by cars when crossing roads.  Increased difficulty in moving between different populations can lead to loss of genetic diversity