Species Spotlight November 2022

Western Painted Turtles

The painted turtle is brightly marked with a smooth shell. It has a relatively flat upper shell with red and yellow markings on a black or greenish-brown background. Males mature at 3 to 5 years when their lower shell is about 2.8 to 3.7 inches long. Females take longer to mature, up to 10 years, and get larger, up to 5 inches for their lower shell. Turtles continue to grow slowly after maturity, and their upper shell can reach almost 10 inches when living for many decades.

The most widespread North American turtle, the painted turtle is the only turtle whose native range extends from the Atlantic to the Pacific. Their habitat requirements include water bodies with soft and muddy bottoms, basking sites, and aquatic vegetation. In the spring, when the water reaches 59–64° F, the turtles begin actively foraging. Being a cold-blooded reptile, the turtle starts its day at dawn, emerging from the water to bask for several hours. Warmed for activity, it returns to the water to forage. After becoming chilled, the turtle re-emerges for one to two more cycles of basking and feeding. At night, the turtle drops to the bottom of its water body or perches on an underwater object and sleeps. To be active, the turtle must maintain an internal body temperature between 63–73° F.

Most painted turtles hibernate in the colder months. While hibernating, the body temperature averages 43°F. They bury themselves on the bottom of a body of water, in a shore-bank or in woods or pastures. In this state, the turtle does not breathe, although if surroundings allow, it may get some oxygen through its skin. Adaptations of its blood chemistry, brain, heart, and particularly its shell allow the turtle to survive extreme lactic acid buildup while oxygen-deprived.

Painted turtles feed on plants, small fish, crustaceans, aquatic insects, and some carrion. Young painted turtles are mainly carnivorous, acquiring a taste for plants later in life. Because they have no teeth, the turtle jaw has tough, horny plates for gripping food. It holds large prey in its mouth and tears the prey apart with its forefeet.

Breeding occurs once yearly. Turtles are polygamous. The breeding season lasts from late spring to early summer. The female stores sperm in her oviducts to be used for up to three clutches. So, a single clutch may have multiple fathers. The females choose soft, sandy soil with good sun exposure to dig a hole and lay 4 to 15 oval, soft-shelled eggs. Once the female lays the eggs, she covers the hole and leaves. About 72 days later the young hatch and dig out of the nest on their own, they are independent immediately.

A variety of predators will capture painted turtles. Raccoons, otters, mink, foxes, and other medium-sized predators will prey on turtles and their eggs. Painted turtles are vigilant and seek refuge in the water at the slightest sign of danger. They can also retract their head and legs into the protection of their shell.

The painted turtle is common in the fossil record. The oldest, found in Nebraska, date to about 15 million years ago. Fossils from 15 million to 5 million years ago are restricted to the Nebraska-Kansas area. Fossils newer than 300,000 years old are found in almost all the United States and southern Canada.

Fun Facts:  The turtle’s ribs are fused to the shell so it cannot expand its chest to breathe but must force air in and out of the lungs by alternately contracting the flank and shoulder muscles.

Painted turtles must eat in the water, their tongue does not move freely, and they cannot manipulate food well on land.

-Susan Setterberg, Contact Station Volunteer
-image by Susan Setterberg (check out our Contact Station article this month for more turtle-y awesome turtle images)