Common Map Turtle

Map Turtle Photo Credit: Gary Allen

Graptemys geographica

Status:

  • COSEWIC – Special concern.
  • COSSARO – Special concern.

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.

Habitat:

  • Shows preference for larger lakes, bays, rivers and open marshes, with mud, sand or gravel bottom.

Food:

  • Females will eat crayfish, clams and snails.
  • Males eat smaller aquatic insects.
  • Both will eat some carrion and plants.

Habits:

  • 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.

Reproduction:

  • 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.

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.

Did you know?

  • 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.

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.

For more information www.speciesatrisk.gc.ca/search/speciesDetails_e.cfm?SpeciesID=712