northern map turtle (Graptemys geographica)
This is a large freshwater turtle reaching a maximum carapace length of about 10 inches. This species has a broad jaw surface, a spot on the side of the large head of the female, and a low and flattened carapace with a central keel that may or may not be elevated to form a tubercle. The carapace is brown to olive with a pattern of fine, yellow reticulations. Juveniles are colored and patterned as adults, except that the carapace is rounded for the first 1-2 years of life. Mating occurs from May to July and sometimes again in the fall. Nesting is done in soft soil or sand always in full sunlight, with 10-16 eggs being laid. Eggs hatch in August and September. This turtle is primarily nocturnal, remaining asleep in the sunshine most of the day. It is reluctant to hibernate and has been known to be caught on the beach after the lake freezes over. It is usually active from April to September throughout its range. This turtle is extremely gregarious, sometimes piling 4 deep. Map turtles are wary baskers and will dive off basking sites at the least disturbance. Large turtles will often physically displace smaller ones at the most used basking sites and large ones will bask further away from shore than small ones. It is seldom seen on land. It hibernates under slow water, beneath rocks or ledges.
The map turtle is found in the upper Tennessee drainage system, including the Clinch, Powell, and Holston rivers and their tributaries, in southwestern Virginia. This species inhabits the pools and riffles of rivers and creeks. Areas with large sandy or grassy beaches are favored.
This turtle eats primarily freshwater mollusks. It will also consume snails, crayfish, aquatic insects, water mites, worms, some plant material, and fish carrion. It feeds by probing through aquatic vegetation or along the bottom.