Blanding's Turtle

About the Blanding's turtle

Blanding's turtle is a semi-aquatic turtle in the family Emydidae, native to central and eastern Canada and the United States. It's named for the American naturalist Dr. William Blanding, and it carries an older name too: in Indigenous oral tradition it's known as "the turtle with the sun under its chin," from a creation story in which the turtle rescues the sun and carries it back to the sky in its mouth, leaving a permanent glow on its neck and chin ever since. Scientists still disagree on exactly which genus it belongs to, with both Emys and Emydoidea appearing in published research.

It's a medium-sized turtle, with an average straight carapace length of about 7.1 to 9.1 in (18 to 23 cm) and a maximum recorded length of 10 in (25.5 cm). Its most recognizable feature is a bright yellow chin and throat, set against dark, speckled head and legs. The domed carapace is slightly flattened along the midline and oblong when viewed from above, speckled with yellow or light flecks on a dark background. The lower shell, or plastron, is yellow with symmetrical dark blotches, and it's hinged — but unlike a true box turtle, the plastral lobes don't close tightly, which is why Blanding's turtle is sometimes called the "semi-box" turtle.

One trait that stands apart in the reptile world: Blanding's turtle is a subject of longevity research because it shows few or none of the usual signs of aging. Researchers consider it a negligibly senescent species, meaning individuals stay physically active and reproductively capable well into old age, sometimes into their eighth or ninth decade of life.

Behavior and diet

Blanding's turtle overwinters in a state called brumation, burrowing under or near water, into mud, or beneath vegetation and debris until conditions warm again. During nesting season, a female may travel more than a kilometer from the site where she spent the winter, and young turtles will also wander widely in search of new habitat, food, or mates.

It's an omnivore with a broad diet: crustaceans such as crayfish, insects including dragonfly nymphs and aquatic beetles, snails and other invertebrates, fish and fish eggs, frogs, carrion, berries, seeds, and vegetable debris. It's also a capable hunter, able to catch live fish, and it browses on aquatic plants such as coontail, duckweed, sedge, and bulrush. Despite this range of prey, the turtle behaves timidly when threatened — retreating into its shell or staying submerged for hours rather than fleeing or fighting — and it's a highly agile swimmer when it needs to move.

Blanding's turtles take a long time to mature, not reaching reproductive age until 14 to 20 years old. Mating occurs between March and April, with nesting from late May into early July. Clutch size varies by region; in New York, for example, females lay five to twelve eggs, averaging eight. As with many turtles, the temperature of the nest determines the sex of the hatchlings — colder conditions produce males, warmer ones produce females.

Range and habitat

The species' range centers on the Great Lakes, stretching from central Nebraska and Minnesota eastward through southern Ontario and along the south shore of Lake Erie as far as northern New York. In Nebraska it's uncommon in the eastern part of the state but common to abundant in the lakes, ponds, and streams of the Sand Hills region. Isolated populations also persist in southeastern New York's Dutchess County, in New England, and in Nova Scotia.

Blanding's turtles favor wetlands with clean, shallow water, and are often seen basking on logs. They'll wander well away from water, especially while nesting, generally choosing sunny spots with well-drained soil for their nests. Younger turtles may bask on sedge and alder hummocks.

Conservation status

Blanding's turtle is listed as endangered on the IUCN Red List, and its status varies by jurisdiction: it's considered endangered in Indiana, Illinois, Missouri, Maine, New Hampshire, Massachusetts, and South Dakota, and threatened in New York and Iowa, though it carries no federal protected status in the United States. In Michigan it's a protected species of special concern, making it illegal to kill, capture, or sell. In Canada, the Great Lakes–St. Lawrence River population in Ontario and Quebec is federally threatened, while the Nova Scotia population is endangered. International trade is restricted under CITES Appendix II.

The main threats are habitat fragmentation and destruction, along with nest predation by unnaturally large predator populations; prescribed burns can also harm the species if timed during the fall and late spring, when hatchlings are moving overland. Conservation programs are active in several places — Lake County, Illinois has run a long-term recovery program since 2009, and in Nova Scotia, two decades of habitat and life-history monitoring have relied on the work of conservation practitioners, researchers, and volunteers, including annual nest-protection efforts by Parks Canada staff and volunteers in Kejimkujik National Park.