Painted turtles are brightly marked. They have a smooth shell about 90 to 250 mm long. The upper shell is relatively flat with red and yellow markings on a black or greenish brown background. Their shell acts as protection, but since the ribs are fused to the shell, they cannot expand their chests to breathe. Instead they must force air in and out of the lungs by contracting the flank and shoulder muscles.
The growth rate, for both male and female, is rapid during the first several years of the of their lives. Female turtles become mature at 7 years old and males at 3 years old. (Harding, 1997)
Painted turtles are native to the Nearctic region. They are found from southern Canada to northern Mexico and are one of the most widespread and common turtles in North America. (Canadian Forest Service, 2005; Kawartha Turtle Watch, 2005)
Painted turtles prefer living in freshwater that is quiet, shallow, and has a thick layer of mud.
Whether a turtle embryo becomes male or female depends on the temperature at which the egg develops. Eggs that develop above 84 degrees Fahrenheit become female, those that develop at lower temperatures become male.
Mating begins after hibernation and before feeding begins when the water temperatures are still low. Fall mating may also occur. Environmental temperature determines when the sexes are ready to mate.
The breeding season lasts from late spring to early summer. Males mature at about 70-95 mm plastron (lower shell) length, usually at 3-5 years of age. Females take longer (6-10 years) and are larger at maturity (c. 100-130 mm plastron length).
In the early summer females lay 4 to 15 oval, soft-shelled eggs, in a flask-shaped hole. Females choose soft, sandy soil with good exposure to the sun in which to dig the hole. Once the eggs are laid they cover the hole and leave. The young hatch and dig out of the nest on their own, they are independent immediately.
Painted turtles may live as long as 35 to 40 years, but most will not survive for this long. (Harding, 1997)
Painted turtles bask in large groups on logs, fallen trees, and other objects. The sunning helps rid them of parasitic leeches. In many areas turtles hibernate during the winter months by burrowing into the mud and allowing their bodies to become very cold. Because of their small body size, they can move easily. Turtles dive quickly at the first hint of danger. Painted turtles are diurnal; that means they are active during the day. At night they will rest on the bottom of a pond or on a partially submerged object, such as a rock. During the day, painted turtles will bask in the sun, sometimes as many as 50 on one log, stacked on top of each other.
Sound perception is poor in turtles, but they do have a good sense of smell and color vision. They use touch to communicate with each other, particularly during mating.
Painted turtles feed mainly on plants, small animals, such as 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. Painted turtles must eat in the water, their tongue does not move freely and they cannot manipulate food well on land.
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.
Painted turtles are important predators of small fish, crustaceans, and other invertebrates in aquatic ecosystems of North America.
Caution should be taken when handling these turtles. They often carry Salmonella bacteria in their digestive tracts. These bacteria are apparently harmless to the turtle, but can make humans very sick. Salmonella was found to be especially common in turtles sold in pet stores and, because of this, pet stores are not allowed to sell baby turtles any more. As long as you wash your hands after you handle a turtle you should be fine.
Painted turtles are often used for educational purposes, they make excellent pets with proper care.
Painted turtles are relatively common and abundant throughout most of their range. However, in some areas they are threatened by the destruction of freshwater habitats, such as ponds and small lakes. In some areas many painted turtles are killed on roadways. In Canada, painted turtles have been placed on the federal blue list, which identifies animals considered vulnerable to human activities or natural events, but not immediately threatened. (Canadian Forest Service, 2005; Harding, 1997; Kawartha Turtle Watch, 2005)
Painted turtles are the most common and most widely distributed turtles in the North America. They are also frequently studied.
Katie Knipper (author), University of Michigan-Ann Arbor.
Ganzhorn, Darrie and Licht, Paul. 1983. The Regulation of seasonal gonadal cycles by temperature in the painted turtle, Chrysemys picta. Copeia 2: 347-58.
Gutzke, William and Paukstis, Gary L. 1984. A low threshold temperature for sexual differentiation in the painted turtles, Chrysemys picta. Copeia 2:546-7.
Canadian Forest Service, 2005. "Turtles of Ontario" (On-line). Natural Resources Canada. Accessed July 28, 2005 at http://www.glfc.cfs.nrcan.gc.ca/landscape/turt_e.html.
Harding, J. 1997. Amphibians and Reptiles of the Great Lakes Region. Ann Arbor, Michigan: The University of Michigan Press.
Kawartha Turtle Watch, 2005. "Midland Painted Turtle (Chrysemys picta marginata)" (On-line). Kawartha Turtle Watch. Accessed July 28, 2005 at http://www.trentu.ca/biology/turtlewatch/painted.htm.