Painted Turtle
| Scientific Name | Chelydra serpentina |
| Survival Strategy | Brumation |
| Conservation status | Least Concern |
Spring
Adult painted turtles come out of brumation and begin active foraging when the water temperature reaches about 20°C (68°F), typically in March or early April. Hatchlings that overwintered buried in their nest cavity emerge and head to the nearest water source. The breeding season runs from late spring to early summer.
Summer
In early summer, females lay 4 to 15 soft-shelled eggs in loose soil with good sun exposure. After covering the eggs, females leave the nest site and provide no parental care for their offspring. Young painted turtles hatch in late summer or early fall as tiny independent versions of adult turtles (precocial).
Fall
As colder weather sets in, painted turtles become lethargic and seek the refuge of deeper waters to get safely through the winter. In October or November, adult turtles enter a state of brumation, remaining dormant (mostly) in the muddy bottom of a pond or lake.
Winter
Painted turtles conserve their energy supply and reduce their need for oxygen by remaining in a state of brumation all winter. However, both painted turtles and snapping turtles can sometimes be seen swimming sluggishly under the ice.
Behavior
Soak Up the Sun
Painted turtles are cold-blooded (ectotherms) and need to bask in the sun to regulate their body temperature. They typically bask by crawling onto a log or rock. Turtles need UV light from the sun to produce Vitamin D, which improves calcium absorption and helps build strong bones and healthy shells. The sunlight kills fungus and creates an unwelcome environment for sun-hating leeches.
Physiology
Brumation
Like hibernation in mammals, brumation is a physiological response to cold conditions that conserves energy and allows an animal to survive until warm weather returns. Mammals are warm-blooded (endotherms) and reduce their body temperature during hibernation.
Painted turtles, like all reptiles, are cold-blooded (ectotherms), so their body temperature matches the surroundings. They can reduce their metabolism by 99% in near-freezing water and survive without food or oxygen for 100 days. One study found that painted turtles in brumation can reduce their heart rate to 8 beats per hour. Unlike in hibernation, brumating animals may become temporarily active if the weather warms.
Cold Water Protects Turtles from Even Colder Air
The water temperature under the ice stays above freezing, even as winter air temperatures drop below zero. Although cold, the water in a pond protects the turtle from the extreme cold only a few feet above its head. Some cold-blooded animals can survive ice crystals forming in their body tissue; adult turtles cannot.
Frozen Baby Turtles
Hatchling painted turtles are the exception to the “No Ice” rule. After hatching in the fall, young painted turtles remain in their underground nest all winter. These nests are well above the frost line and experience cold temperatures for months. The overwintering baby turtles have fat reserves that provide the energy needed to remain underground from late summer until spring without eating. In response to subfreezing temperatures, newly hatched turtles produce higher levels of glucose and glycerol, which may function as a form of antifreeze. One study found hatchling turtles survived with more than 50% of their body water as ice.
Gender Determined by Incubation Temperature
The temperature determines the gender of painted turtles during incubation. Warmer temperatures, between 29°C (84°F) and 32°C (90°F), tend to produce females, and cooler temperatures, between 21.5°C (70°F) and 27°C (80°F), tend to produce males
Diet
Painted turtles are omnivorous and eat aquatic invertebrates, such as insects, crustaceans, snails, leeches, and worms. They will also eat small fish, tadpoles, and carrion. While young painted turtles are mainly carnivorous, plants make up a large part of the diet of adult turtles, including algae, duckweed, and rooted plants.
Like snapping turtles, painted turtles cannot swallow food while on land, relying on the pressure of the water to help move food down their esophagus.
Lifespan and Mortality
Painted turtles live for about 5 to 10 years in the wild.
Predators
Nest predators, including raccoons, skunks, and foxes, destroy more than 90% of painted turtle nests. Newly hatched turtles are an easy meal for otters, snakes, herons, minks, and raccoons. Otters, minks, and foxes eat adult painted turtles.
Human Impact
Painted turtles often need to cross roadways to reach nesting sites or more suitable habitats, increasing the risk of accidental or deliberate mortality from vehicles.
Climate Vulnerability
Painted turtle eggs incubated at warmer temperatures produce more females, while cooler temperatures favor males. A warmer climate will possibly reduce, or eliminate, the number of male turtles in some parts of their range.
Never stop learning
First Nations: The Ojibwe word for painted turtle is “miskwaadesi.”
Paleontology: Fossil records of painted turtles date back 15.97 million years.
Anatomy: Male painted turtles have front claws 2 to 3 times longer than the front claws of female turtles.
References
| Knipper, K. 2002. “Chrysemys picta” (On-line), Animal Diversity Web. Accessed February 18, 2022 at https://animaldiversity.org/accounts/Chrysemys_picta/ |
| Is That a Turtle Under the Ice? https://blog.nature.org/science/2017/01/30/turtles-under-ice-winter-survival-hibernation-adaptation/#:~:text=Painted%20turtles%20spend%20most%20of,the%20mud%20beneath%20the%20water. |
| How do Turtles Hibernate? https://youtu.be/pcqcfFd2htg |
| Iowa State University. “Climate change could devastate painted turtles.” ScienceDaily. ScienceDaily, 13 March 2019. www.sciencedaily.com/releases/2019/03/190313114731.htm. |
| Jackson DC, Ultsch GRy. 2010. Physiology of hibernation under the ice by turtles and frogs. J. Exp. Zool. 313A:311–327. https://onlinelibrary.wiley.com/doi/pdf/10.1002/jez.603 |
| The secret to turtle hibernation: Butt-breathing https://www.pbs.org/newshour/science/the-secret-to-turtle-hibernation-butt-breathing |
| Storey KB, Storey JM, Brooks SP, Churchill TA, Brooks RJ. Hatchling turtles survive freezing during winter hibernation. Proc Natl Acad Sci U S A. 1988 Nov;85(21):8350-4. doi:10.1073/pnas.85.21.8350. PMID: 3186730; PMCID: PMC282428. http://www.ncbi.nlm.nih.gov/pmc/articles/pmc282428/ |
| The Ojibwe People’s Dictionary: Painted Turtle https://ojibwe.lib.umn.edu/main-entry/miskwaadesi-na |
| Painted Turtle: Encyclopedia of Life https://eol.org/pages/795380 |