Blanding’s Turtle

IUCN Red List

EN - Endangered

NatureServe

N4 - Apparently Secure
S2 - Imperiled

Minnesota

Threatened
Species in Greatest Conservation Need

Blanding’s Turtle is a long-lived, medium-sized turtle. Adult males are of 6¾″ to 10¾″ in length. Females are a little smaller.

The hard upper shell (carapace) is elongated, smooth, and high domed. It is black with scattered yellow flecks or dots. It does not have a longitudinal raised ridge. In some individuals the carapace appears almost entirely black. The scales (scutes) that form the carapace are flat, not sculpted.

The lower shell (plastron) is hinged between the forward (pectoral) and rear (abdominal) scutes, allowing it to completely close its shell. There is a V-shaped notch near the tail. Each scute has a large dark blotch on the outer edge, at least at the rear corner. On males the plastron is slightly concave. On females it is more flat.

The head, neck, legs, and tail are black or dark brown and are sometimes speckled with yellow. The chin, throat, and underside of the neck are bright yellow.

The head is elongated and small. The snout is short and rounded. The upper jaw is notched, giving the appearance of a permanent smile. On females the upper jaw has some yellowish, vertical striping. On males, the upper jaw is black and unmarked. The neck is short. The neck and head together are less than half as long as the plastron.

The legs are modified for swimming but are not flipper-like. The toes are webbed.

The tail is short, less than half as long as the carapace. The female has a narrower tail than the male.

Size

Carapace length: 6¾″ to 10¾″

Similar Species

Shallow wetlands near sandy uplands.

Behavior

The hinged plastron allows the turtle to close the front of its shell. The concave plastron on males facilitates mating.

It is the first turtle to submerge when disturbed and the last to emerge after being disturbed.

Lifespan

75 years or more

Life Cycle

As the temperature drops in mid-October, Blanding’s Turtles turtles burrow into the muddy bottom of the deepest parts of a marsh, pond, or stream. They enter a state of sluggishness, inactivity, and torpor (brumation). It is similar to hibernation in mammals, but they stir occasionally to drink water or to bask in warm sunshine at ice margins. They emerge the following April and bask in the sun away from the shore. Mating takes place throughout the warm season but mostly in April and May. In late May to early June, after mating, the female finds an open sandy area to nest. She digs a hole about 6¾″ deep and deposits her clutch of eggs. The clutch size about 10 eggs on average but may be from 6 to 21. The eggs are elliptical and about 1½″ long. Hatchlings emerge from early August to mid-October. In mid-October Blanding’s

Hatchling mortality is high. Adults can survive 75 or more years. Females reach sexual maturity in 12 or more years.

Food

Crayfish, insects, leeches, snails, small fish, frogs, berries, and other plant material.