Cold-blooded Winter: How Turtles Hibernate

Nothing says summer like seeing rows of turtles basking on a log, taking in all the warmth from the sun's rays. But summer is over & the temperatures are dropping, and our ectotherm (cold-blooded) friends will soon be heading for their winter dwellings. While the whimsical thought of a turtle sitting in front of a roaring fire, sipping hot cocoa & snacking on flies may be a plausible idea for a children's book, in reality we know that is far from the truth. So what do turtles do in the winter?

Common Snapping Turtle (Chelydra serpentina) - Species of Special Concern in Ontario
While they do hibernate, Snapping Turtles can occasionally be seen under solid ice, cruising the bottoms of shallow ponds.

Unlike humans and other endothermic (warm-blooded) animals, turtles do not rely on internally generated heat to maintain a proper body temperature. Reptiles, amphibians, fish, and invertebrates are ectothermic, meaning that they depend on external sources of heat, and that their body temperature changes with their environment. Turtles can't survive freezing, so in order to escape the bitter cold of our Canadian winter, starting in October they will sink deep in to water bodies where it does not freeze to the bottom, typically ponds or lakes. The consistent temperature of the water in these areas allow for turtles to maintain an extremely low metabolic rate, so that their bodies do not require anything to eat to survive the duration of their hibernation. During this time, their heart rate drops so low that it almost cannot be detected at all. In the summer a turtle's heart beats 40 times per minute on average, and drops to just a single beat per minute during hibernation!

The most important factor in their survival is of course, oxygen. There is more oxygen at the bottoms of ponds and lakes than in the water at the surface, but without gills, how do they take it in? Turtles are ancient creatures who have evolved many astonishing traits over millions of years, but this one ability takes the cake: butt-breathing (or cloacal respiration, technically speaking). Yes, turtles have developed the capability to take in oxygen from the water through their cloacas. While in their hibernation state, turtles require very little oxygen to stay alive, and typically the water running over them contains enough to sustain them until spring.

During hibernation, a turtle's body slows down so much that its immune system begins to shut down. This leaves them extremely vulnerable to illnesses, and because of this, turtles who are already sick or injured are likely to perish during hibernation. Fortunately for us & our turtles, we have organizations dedicated to helping our native turtles in need, such as the Ontario Turtle Conservation Centre, and START - Saving Turtles at Risk Today.

The Ontario Turtle Conservation Centre (home of the Kawartha Turtle Trauma Centre) is a registered non-profit charity organization located in Peterborough, Ontario, that provides care for over 900 sick and injured turtles annually. All turtles that are admitted to OTCC that are not properly healed in time for winter remain in the care of OTCC staff until they are ready for release in warm weather. If you find a sick or injured turtle it is important that you call the Centre immediately to get the turtle in to their care as soon as possible. Click here for OTCC contact information and information on handling an injured turtle.

Spotted Turtle (Clemmys guttata) - Endangered Species in Ontario

START - Saving Turtles at Risk Today is an conservation project organized by the Canadian Wildlife Federation, which serves to monitor Species at Risk turtle populations in Muskoka and north Simcoe. During active turtle season (April to October) research teams perform surveys along roadways and wetlands to catch and process turtles, and also count road casualties. Field technicians weigh, measure, notch, and photograph each individual turtle to aid in conservation efforts before releasing them back in to their habitat. Some turtles are also fitted with radio transmitters to track movement, habitat use, nesting sites, and overwintering sites. If you see a rare, injured or nesting turtle, you can call the START Turtle Hotline to report your finding at 705-955-4284.

All wildlife rehabilitation centres and most research projects in Ontario are publicly funded, meaning they run on donations. Without help from the public, these organizations would not exist and our native wildlife in need would be left helpless. Click here for information on how you can help our turtles survive and thrive in Ontario.

Happy Trails!

- Shayna