Northern Map Turtles, photo by Nick Scobel

May 23rd is World Turtle Day and Michigan is home to 10 native turtle species. I’ve now profiled 7 (most with Nick’s awesome photography), and you can get the full list at one of the most popular posts on Michigan in Pictures: Know Your Michigan Turtles.

Graptemys geographica (Common Map Turtle, Northern Map Turtle) from the University of Michigan Animal Diversity web says (in part):

Common map turtles get their name from the markings on the carapace. The light markings resemble waterways on a map or chart. The lines on the carapace are a shade of yellow or orange and are surrounded by dark borders. The rest of the carapace is olive or grayish brown. The markings on the older turtles may be barely visible because of darker pigment. The carapace is broad with moderately low keel. The hind of the carapace is slightly scalloped shaped due to the scutes. The plastron of an adult map turtle tends to be plain yellowish color. The head, neck and limbs are dark olive, brown or black with thin yellow, green or orangish stripes. There is also a oval spot located behind the eye of most specimens. There is sexual dimorphism in size and shape. The females are much larger than the males…

The common map turtle is dormant from November through early April. Most of that time is spent under the water, wedged beneath submerged logs, in the bottom mud of a lake or in a burrow. They have been known to change locations in the middle of the winter. They are avid baskers and they bask in groups. They are diurnal, active both in the day and at night. They are also a very wary animal, at the slightest hint of danger they slip into the water and hide. During courtship the male initiates by tapping his long claws on the front of the female but few details are known.

Common map turtles are omnivores. The feeding always takes place in the water. The adult females, due to their large heads and strong jaws eat larger prey than the males. The females consume snails, clams, and crayfish. The males eat aquatic insects, snails, and smaller crustaceans. Both are also known to eat dead fish and some plant material.

Read on for more and also see the Michigan DNR’s page on Common Map Turtles which includes a distribution map.

View Nick’s photo bigger, see more of his Northern Map Turtle photos or just dive into his huge collection of turtle pics! Nick also runs the Herping Michigan Blog that features all kinds of photo-rich features of Michigan frogs, snakes, salamanders and turtles. Definitely check out his Kayaking for Turtles post to see dozens of turtles from several turtle species that he photographed on one river paddle in Northern Michigan.

American Tortoise Rescue, a nonprofit organization established in 1990 for the protection of all species of tortoise and turtle, is sponsoring its 14th annual World Turtle Day™ on May 23rd. The day was created as an observance to help people celebrate and protect turtles and tortoises and their disappearing habitats around the world. Click the link to learn more about turtles and how you can protect them.