False Map Turtle

Graptemys pseudogeographica

Excerpted from: Animal Diversity

  Description

The carapace is olive, brown, or black with dark blotches that have yellow lines around them. The lines sometimes form a web pattern over the entire carapace and may or may not have blotches. It gets the name False Map Turtle because the lines form a sort of map across the shell. These markings are brighter on young turtles than on adults.

The carapace has serrate margins and a vertebral keel that is more prominent in the young. The plastron is cream to yellow colored, but the young have a dark pattern there as well. False map turtles have olive to brown skin with yellow lines on their legs, tail, chin, and neck. The head is moderately broad and on some there is a backwards L behind each eye.

Males are 3-6 inches in length and females are 5-10 inches in length. Adult females, on average, are 1.50 times larger than adult males and have wider heads. Adult males have elongated second and third fore claws, a longer tail, and their anal opening is posterior to the carapacial margin. Females in captivity were found to have a mass from 2.5 to 4 pounds.

  Lifespan

A male False Map Turtle that was caught as a juvenile lived for 35 years at the Columbus Zoo. It is impossible to reliably estimate the ages of individuals over 15 years because the rings become less and less visible as they shed their epidermal scutes.

  Behavior

False Map Turtle activity varies geographically, but usually lasts from late March to mid-October. They spend most of the day basking in the sun on muskrat lodges, logs, rock piles, sand bars, or stumps that are located near the shore. False map turtles stretch their hind limbs, spread the webbing between their toes, and extend their head and forelimbs when they are basking in the sun. By stretching out in this manner it allows grackles to remove leeches from their neck and leg cavities. When the turtles are basking they are extremely wary and difficult to approach; therefore entrance into the water by one turtle is usually followed by all those basking in the general vicinity. During the winter in the northern regions, they burrow 4-12 inches into the river bottom or use the entrance of a muskrat lodge for an overwintering site. False Map Turtles emerge from overwintering sites when water temperatures are 40-45° F, usually in April.

  Communication

False Map Turtles use touch and body language (postures and movements) to communicate. Male turtles display tactile behaviors during courtship; the male uses his fore claws to drum over his potential mate’s eyes.

  Diet

False Map Turtles are generalist omnivores. The difference in size between males and females provides a partitioning of food resources. Females eat mollusks, and insects including caddisflies, mayfly larvae, and damselfly larvae. Males eat the same insects as females, along with beetles, flies, other insect larvae, mollusks, fish carrion, and small amounts of vegetation.

Further Reading:

 Beavers — Nature's Hydrologist, Part 2
 Garter Snakes — The Gardener's Friend
 Wisconsin Native Salamanders
 Goundhog or Woochuck: All The Facts
 Voles, Both The Good and The Bad