About Blanding’s Turtle & Northern Map Turtle

Blanding’s Turtle – Emydoidea blandingii

Blanding’s Turtles have a high-domed shell.  Species with shells of this shape are usually not good swimmers.

Appearance: This turtle is easily recognizable by the domed shape of the shell.  In adult Blanding’s Turtles the shell is relatively longer and narrower than in most other species, although juveniles have broader, more flattened shells.  The carapace is black with numerous small yellow flecks.  The head and limbs are dark and unmarked, but the underside of the head and neck are bright yellow.  The neck is relatively long.  The plastron is yellow with black patches in adults and almost completely black in juveniles.  The Turtles is flexible, allowing the shell to partially close.  In males turtles is concave, while in females it is flat or slightly convex.

Habitat and Behavior: Blanding’s Turtles live in shallow water, usually in large marshes, shallow lakes, and similar bodies of water.  They are rather poor swimmers and often move about by walking on the bottom.  They feed on aquatic insects, mollusks, crustaceans, and vegetation.  They may wander on land, although they usually do not travel far from water except to nest.  Blanding’s Turtles overwinter at the bottom of water bodies.

Reproduction: Eggs are laid in early summer, and females may travel considerable distances to nest.  Between 6 and 11 eggs are produced.  The young turtles hatch in late summer and move to water.  Young Blanding’s Turtles are seldom seen, possibly because they spend their time among thick vegetation at the water’s edge.

 

Northern Map Turtle – Graptemys geographica

Northern Map Turtles are normally found only in larger water bodies.  The size difference between males and females can make identification confusing.

Appearance: The carapace and skin of Northern Map Turtles are dark green.  The head and limbs are covered with yellow stripes and spots.  The carapace has a serrated rear margin and numerous irregular yellow or light brown markings that suggest a contour map.  The plastron is yellow with no pattern.  In smaller individuals the scouts along the dorsal mid line are slightly pointed at the rear, giving the turtles a “saw back” appearance.

Females are larger than Males: Females are much larger than males, growing up to 11 inches in shell length, while males reach only 5 inches.  In males, the claws of the forefeet are longer than the claws of the hind feet, but in females the claws are the same length.  Because they feed on mollusks, female Northern Map Turtles have large jaws and powerful jaw muscles, giving their heads a proportionately large appearance than those of many other turtle species.

Habitat and Behavior: Northern Map Turtles prefer large bodies of water and may swim long distances over the course of a summer.  They can often be seen basking on logs or rocks near the water’s edge.  Females feed primarily on mollusks, while males and juveniles consume insects, crayfish, and carrion.  Northern Map Turtles overwinter on the bottom of a lake or river.  Adults often congregate to hibernate and may travel a considerable distance to the overwintering site.

Reproduction: Eggs are laid in June, at which time females leave the water to search for nesting sites.  They may travel some distance from water to nest, although usually not as far as Snapping Turtles.  The number of eggs is typically 10-12.  The eggs hatch in September, leaving the young turtles only a short time to feed and store reserves before winter.

 

 

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