Emys blandingii (Holbrook, 1838)

Size

Blanding's turtle (Emys blandingii (Holbrook, 1838)) is a medium-sized turtle, with an average straight carapace (upper shell) length of 18 to 23 cm (7.1 to 9.1 in) and a maximum length of 25.5 cm (10.0 in).

Distinguishing Feature

A key distinguishing feature of this species is its bright yellow chin and throat.

Carapace Appearance

The domed carapace is slightly flattened along its midline, oblong when viewed from above, and covered in numerous yellow or light-colored flecks or streaks over a dark background.

Plastron Appearance

The plastron (lower shell) is yellow with symmetrically arranged dark blotches.

Head and Leg Coloration

It has dark head and legs that are usually speckled or mottled with yellow.

Common Name Origin

This species is sometimes called the "semi-box" turtle: while its plastron is hinged, the plastral lobes do not close as tightly as those of true box turtles.

Range Core

The geographic range of Emys blandingii is centered around the Great Lakes.

Main Range Extent

It extends from central Nebraska and Minnesota, where it twice failed to gain designation as the state reptile, eastward through southern Ontario and the south shore of Lake Erie as far east as northern New York.

Nebraska Distribution

In Nebraska, the species is uncommon in the eastern part of the state, but common to abundant in lakes, ponds, and streams of the Sand Hills region.

Isolated Populations

Isolated populations also exist in southeastern New York's Dutchess County, New England, and Nova Scotia.

Primary Habitat

Blanding's turtle generally inhabits clean shallow-water wetlands.

Basking and Movement

It basks on logs, and will wander far from water, especially when nesting.

Nesting Site Preferences

It typically nests in sunny areas with well-drained soil.

Juvenile Basking and Travel Behavior

Younger turtles may bask on sedge and alder hummocks, and both young and older turtles will often travel long distances to find mating sites, new habitat, or new food sources.

Sexual Maturity Age

Blanding's turtle reaches sexual maturity between 14 and 20 years after hatching.

Mating and Nesting Timing

Mating begins between March and April, and females dig nests from late May into early July.

Clutch Size Variation

Clutch size varies by region: in New York, clutch size ranges from five to twelve eggs, with an average of eight.

Temperature-dependent Sex Determination

Hatchling sex is determined by egg temperature during development: colder temperatures produce males, while warmer temperatures produce females.