northern map turtle

There are fifteen recognized species of map turtles, three of which occur in Minnesota. Northern map turtle is the most common and widespread of the map turtles. It occurs in the United States and southern Canada west of the Appalachian Mountains and east of the Great Plains, and in eastern New York and eastern Pennsylvania. It is found in medium and large lakes and rivers with deep water and with fallen trees, snags, and other opportunities for basking. In Minnesota it occurs in the Mississippi, Minnesota, and St. Croix Rivers.

Northern map turtle is a large freshwater turtle. Size is usually given given as the length of the upper shell (carapace). Males are 4″ to 6¼″ (10 to 16 cm) long. Females are much larger, 71⁄16″ to 10⅝″ (18 to 27 cm) long. The carapace is olive green to grayish-brown. It is marked with a network of fine yellow or orange lines. The lines resemble contour lines on a map. This is the feature that gives the genus its common name. The lines become less distinct as the turtle matures. On older individuals, they may not be visible unless the carapace is wet. There is a long, dark blotch along the keel that spreads along the edges on the scutes, and often many smaller scattered dark blothces, but these also fades as the turtle matures. The rear margin is flared, sawtoothed, and slightly scalloped due to the scales (scutes). On young turtles the carapace is distinctly keeled and the scutes are bordered with dark lines. On mature adults it is only slightly keeled and the lines fade.

The lower shell (plastron) is uniformly yellow.

The head, neck, and limbs are dark olive green, brown, or black, with thin yellow, green, or orangish stripes. Most have a small yellow spot behind each eye.

Male carapace length: 4″ to 6¼″ (10 to 16 cm)

Female carapace length: 71⁄16″ to 10⅝″ (18 to 27 cm)

Medium and large lakes and rivers with deep water and with fallen trees, snags, and other opportunities for basking

5½ years (in captivity)

Mostly clams, crayfish, and snails, but also aquatic insects, fish, and plants

Sources

4, 6, 14, 24, 29, 30, 76, 78.

Northern map turtle was previously known as common map turtle.

Northern Map Turtle nesting?

I took these pictures and a video in front of our townhouse in Victoria, MN on July 3rd, 2023. This was actually my second sighting in this small area. She left shortly after I saw her one weekend morning a week or three ago. This time it was late afternoon/early evening. We believe she is a Northern Map Turtle.

She appears to be nesting in the yard of our townhouse association. We have a lawn service that mows the lawn and are wondering, should we protect the space when the hatchlings are due to emerge?

Northern Map Turtle at TNC Cox Unit near entrance

Northern Map Turtle on 598th Street by DNR Overflow Parking Lot

Northern Map Turtle nesting?
Jul 5, 2023

Northern Map Turtle (Graptemys geographica)
Wisconsin Citizen-based Monitoring Network

Map Turtle, Graptemys geographica
Todd Crail

Mike Poeppe
6/3/2024

Location: Houston County, on the Minnesota side of the river just under I-90

Location: Victoria, MN

I took these pictures and a video in front of our townhouse in Victoria, MN on July 3rd, 2023. This was actually my second sighting in this small area. She left shortly after I saw her one weekend morning a week or three ago. This time it was late afternoon/early evening. We believe she is a Northern Map Turtle.

She appears to be nesting in the yard of our townhouse association. We have a lawn service that mows the lawn and are wondering, should we protect the space when the hatchlings are due to emerge?

We are next to a pond on Madelyn Creek. We assume she is climbing a hill out of the pond to nest in the yard which is not sandy. She left within ten minutes of me taking the video. I was going to send the video as well, but it is too large for me to email.

Protecting the area might be a good idea. Of course, it would have to be done with the consent and ideally with the assistance of the property manager or caretaker.

Location: Weaver Dunes Preserve, Cox Unit

Northern Map Turtle at TNC Cox Unit near entrance

Location: Reno (MN) Dike Trail

I spotted it on a log while biking along the Reno (MN) Dike Trail.

Location: near Lock & Dam 7