Blanding's turtle (Emys blandingii or Emydoidea blandingii ) is a semi-aquatic turtle of the family Emydidae. This North American turtle is considered to be an endangered species throughout much of its range.

Taxonomy
There are differences of opinion as to the genus for this species; both Emys and Emydoidea occur in published sources in 2009, 2010, and 2011.

Etymology
Both the specific name, blandingii, and the common name, Blanding's turtle, are in honor of American naturalist Dr. William Blanding (1773-1857).

Description
Blanding's turtle is a medium-sized turtle with an average shell length of approximately 18 to 23 cm (7.1 to 9.1 in) with a maximum of 25.5 cm (10.0 in). A distinguishing feature of this turtle is the bright yellow chin and throat. The carapace, or upper shell, is domed, but slightly flattened along the midline, and is oblong when viewed from above. The carapace is speckled with numerous yellow or light-colored flecks or streaks on a dark background. The plastron, or lower shell, is yellow with dark blotches symmetrically arranged. The head and legs are dark, and usually speckled or mottled with yellow. Blanding's turtle is also called the "semi-box" turtle, for although the plastron is hinged, the plastral lobes do not shut as tight as the box turtle's.

Reproduction
Blanding's turtles take 14?20 years to reach sexual maturity. Mating probably occurs in April and early May with nesting beginning in early June and lasting throughout the month. The clutch size varies from region to region. In New York, the clutch size ranges from 5?12 eggs with an average of eight.

Behavior and life span
Blanding's turtles overwinter under or near water, in mud, or under vegetation or debris. During the nesting season, a female Blanding's turtle may be found more than a kilometer from where it hibernated. It is omnivorous, eating crustaceans and other invertebrates, fish, frogs, crayfish, carrion, berries, and vegetable debris. It is capable of catching live fish. Blanding's turtle may live to be 80 years. Based on the extreme lack of aging symptoms and lack of age related decline, these turtles are considered a negligibly senescent species.

Blanding's turtle is a timid turtle and may plunge into water and remain on the bottom for hours when alarmed. If away from water, the turtle will withdraw into its shell. It is very gentle and rarely attempts to bite. It is very agile and a good swimmer.

Blanding's turtles do not appear to age once they have reached adulthood. When compared to, for example, a 20-year-old turtle, a 70-year-old exhibits negligible senescence, and may, in fact, be "better at scouting out the good nesting places and also produce more progeny".

This species' range centres on the Great Lakes, and extends from central Nebraska and Minnesota (where it twice failed to become the state reptile) eastward through southern Ontario and the south shore of Lake Erie as far east as northern New York. There are also isolated populations in southeastern New York (Dutchess County), New England and Nova Scotia. Its general habitat is wetlands with clean shallow water. It is known to bask on logs, and will wander far from water, particularly when nesting. They generally nest in sunny areas, with well drained soil. Younger turtles may bask on sedge and alder hummocks. Young will often travel far in search of mating sites, new habitat, or new food sources, as do elder turtles.

Conservation status
The primary threat to Blanding's turtle is habitat fragmentation and destruction as well as nest predation by unnaturally large populations of predators. It is listed as an endangered species on the IUCN Red List as endangered in some U.S. states, and as either threatened or endangered throughout Canada, though it has no federal status in the U.S. The Blanding's turtle is also not currently listed under CITES (the Convention on International Trade in Endangered Species of Wild Fauna and Flora) protection, but is under consideration as of 2013. The U.S. states in which it is considered endangered are Indiana, Illinois, Missouri, Maine, New Hampshire, Massachusetts, and South Dakota. It is considered threatened in New York. Blanding's turtle is also fully protected in Michigan as a special concern species, and is not to be collected or harmed. In Nebraska, this turtle is uncommon in the eastern portion of the state, but common to abundant in the Sand Hills region lakes, ponds, and streams. In Canada, the Great Lakes-St. Lawrence River population in Ontario and Quebec is federally threatened and the Nova Scotia population is endangered.