Northern Map Turtle
S. Gillingwater
Graptemys geographica
The lines covering this turtle are thought to resemble rivers or contour lines on a road map. This is how the animal acquired its name.
Description
- Female turtles are medium-sized, growing up to 27 cm. in length (10 in.), while the males are smaller, only growing to 13 cm. (5 in.).
- Olive or brown coloured carapace, covered with yellow or orange squiggly lines, yellow stripes cover the head and limbs.
- Head is large in relation to its body when compared with other turtles.
- Most have a small oval or triangular light spot behind the eye.
- Carapace has a toothed appearance along the rear scales and a peak or keel running along the back.
Food
- Females will eat crayfish, clams and snails.
- Males eat smaller aquatic insects.
- Both will eat some carrion and plants.
Habits and Reproduction
- Hibernate from early November to early April.
- Highly aquatic and can swim long distances.
- A wary turtle that will dive in the water at the first sign of danger.
- Mating takes place in deeper waters, so little has been observed, however it probably occurs in spring and fall.
- In late June to early July, clutches of 10-12 oval eggs are laid in sunny, sandy areas.
- Hatching occurs late August to September. Nest temperature will determine the sex of the turtle. Temperatures of approximately 30 degrees Celsius produce females and cooler temperatures produce males.
- Males reach maturity between 3-5 years; females do not mature until 10 to 14 years.
Habitat
- Shows preference for larger lakes, bays, rivers and open marshes, with mud, sand or gravel bottom.
Threats
- Habitat loss through shoreline development and recreational use. These turtles are sometimes struck by boats and boat wakes or the rise in water levels from a dam can damage nesting areas.
- Prey species such as clams may have high levels of heavy metals and other toxins.
Conservation Actions
- Operate watercraft with care. Please slow down near shorelines. This will benefit other species as well, from the Common Loon to the threatened Least Bittern.
- Read the Ontario Turtle Conservation Centre’s guide to Turtle Nests and Nest Protection.
- Find an injured turtle? Please see the information on the Ontario Turtle Conservation Centre’s website.
Range Map
