The difference between hibernation and overwintering

Considering that our residents at the Quebec Turtle Rehabilitation Center have already been hibernating for a few days, we'd like to take this opportunity to explain the differences between overwintering and hibernation.

First of all, it's good to know that animals have different ways of preparing for winter.

• Some change their coat or gain weight, such as the hare, which adopts a white hue, or the red fox, which develops a denser coat.
• Others choose to migrate to warmer regions to escape the rigours of the winter climate, a phenomenon observed in many birds, some bats, as well as certain insects such as the monarch butterfly and even cetaceans, which travel long distances.
• Others hibernate or overwinter!

Many people mistakenly think that hibernation and overwintering are the same thing! Do you know the difference?

Overwintering

Overwintering is when certain animal species take refuge during the winter. Although their metabolism and body temperature drop slightly, they do not fall into a deep sleep. An illustrative example would be a beaver resting in its lodge, or a black bear.

This means that if you approach a bear burrow in winter and make a noise, you could wake up its occupants! Contrary to popular belief, animals don't enter overwintering simply because temperatures drop. It's a more complex process; researchers have observed that reduced access to food, as well as the duration of sunlight (known as the photoperiod), also play an important role for some species.

An interesting fact: Although bears move very little during winter, they retain almost all their muscle mass during this period. Unlike bears, humans lose a lot of muscle mass when they're inactive.

Hibernation

In hibernation, animals enter a deep sleep that lasts several months. Their metabolism slows considerably and their body temperature drops drastically. In short, they fall into a kind of lethargy. Quebec marmots, amphibians and reptiles are examples of animals that hibernate to survive the winter.

What's more, even though turtles don't need much oxygen during hibernation, they still have to breathe, even underwater. Without gills, they breathe through the mucous membranes of their mouth and cloaca. The latter is the orifice through which reptiles (including birds) evacuate their waste and reproduce. Yes, you've got it right... turtles breathe through their posterior!

An interesting fact: The painted turtle has a natural antifreeze protein that prevents it from freezing.

Our resident turtles at the Rehabilitation Center also undergo a hibernation process similar to what would occur in nature, which is beneficial to their health. This process, developed by our experts following veterinary protocols, involves preparing the turtles to spend the winter... in a refrigerator!

P.S.: Our biologists are very clear! Do not attempt to hibernate your turtles at home, without veterinary supervision!

To find out more about how freshwater turtles adapt to winter, click here.
You can visit our laboratory and the Centre de réhabilitation pour tortues du Québec as a bonus during your visit of the museum.