As winter comes to Alberta, many of our animals are preparing for the long season ahead. Some are migrating far away, some are eating and growing thicker fur, some are changing their colour, and some are getting ready to hibernate! Hibernation is when an animal goes into a deep state of inactivity for a long period of time to conserve energy. They don’t move, drink, or eat, they just sleep! Everyone knows bears hibernate, but did you know there are many other animals around us that sleep the winter away? Not only that, but there are many different types of hibernation. In this post we will talk about four hidden hibernators that you might not know about!
Ground Squirrels, also called gophers, are a very common type of rodent in Alberta. There are 5 species of Ground Squirrels in Alberta, and each of them has unique colours and habits. Although they look different, all Ground Squirrels share one important trait in common. They all hibernate! Ground Squirrels will hibernate for 4-9 months out of the year, through most of the fall and winter. These little guys each hibernate in their own isolated burrow called a hibernaculum, and stay curled into a small ball to keep warm. During their hibernation, Ground squirrels will often go into a state called torpor, where all their bodily functions will get extremely slow to the point that they will not wake up to anything, even someone or something picking them up! To keep safe, they will close off any entrance into their burrow, and will have to dig a new tunnel out when they want to leave. Male Ground squirrels will begin to come out of their hibernaculum once the temperature is above freezing, while females will usually emerge 2 weeks after the males.
Hibernating Thirteen-Lined Ground Squirrel
Active Thirteen-Lined Ground Squirrel
What do Wood Frogs do in the winter? They hibernate! But do you know how? The answer is even more surprising. While many other frogs spend the winter at the bottom of ponds or rivers, Wood Frogs do something much more extreme. When winter comes, these frogs will burrow under the leaves, dirt, and snow, and they will freeze solid! Wood frogs will freeze for up to 8 months to survive in even the coldest conditions, but this has other advantages too. Because they stay on land, they are able to thaw out earlier in the year and lay eggs before other types of frogs emerge from hibernation. You must be wondering, how do they stay alive? When winter comes and everything starts to freeze, the frogs body freezes too. It lets its body get covered in ice, inside and out! At the same time, it begins to produce a sugary substance called glucose and pumps it through its bloodstream. The glucose in its blood stops the water and oxygen from freezing, and therefore keeps everything flowing in its body even when the heart and brain have frozen solid! At the end of the winter, the frog is able to thaw its body and begin its year as if nothing even happened.
A Frozen Wood Frog
An Active Wood Frog
Little Brown Bat
Little brown bats are very common in Alberta. These bats spend their springs and summers eating bugs and getting ready for the winter. Between August and October, bats from many different places will gather together in huge swarms at caves and abandoned mines to breed. Some of these bats will travel up to 1000 kilometers to join in these swarms, and will then stay the winter in these places. The caves or mines where these bats gather are called hibernacula, and provide the large groups of bats with a winter home that stays humid and above freezing temperatures all season. Little Brown Bats, like Ground Squirrels, will enter a state or torpor during their hibernation where they do not eat, but will sometimes wake up to drink water or go to the bathroom. Bats usually hibernate from September to May before heading back to their summer homes. A large problem facing hibernating bats is a disease called White Nose Syndrome. This disease causes the bat to wake up more often during hibernation, and as a result it spends more energy that it has saved up. Most bats with White Nose Syndrome do not survive, and it has had a very big effect on Little Brown Bat population. Although it is hard to control the spread of WNS, some Little Brown Bats have been seen to have an immunity to the disease. If these bats have offspring that are also immune, it will carry hope for the species into the future.
Little Brown Bats hibernating
Active Little Brown Bat
Garter Snakes are a very common snake to see around during the summer. You may see them basking in the sun or zooming through a field while on a hike. These snakes are not venomous, but it is still best to keep your distance if you spot one. There are 3 different species of Garter Snakes in Alberta, but they are all not too big and look and act very similar. Garter snakes usually hibernate from October until March or April, but may come out on warmer winter days to soak in the sun. Hibernation in reptiles is called brumation! Garter Snakes come together in large groups in underground hiding places to keep extra warm during the winter months, and may travel a long way to reach a good spot that they recognize. Typically, they will find spots such as old rodent burrows, in old stumps, under rocks, or other small, hard to reach spots. Although they don’t eat anything while in brumation, Garter Snakes will still stay hydrated by absorbing moisture through their skin from the environment around them.
Hibernating Garter Snakes
Active Garter Snake
Hibernation: When an animal spends a long period of time doing very little or no activity to save energy
Hibernaculum (Plural: Hibernacula): The home that an animal, or animals, use to hibernate in.
Torpor: A state where all of a hibernating animals body functions get extremely slow to conserve energy
Burrow: An underground area dug by Ground Squirrels or other animals to be used as a temporary or permanent home.
Glucose: A sugary substance produced by Wood Frogs to keep its blood flowing when its body freezes
White Nose Syndrome: A disease that affects Little Brown Bats during their hibernation period
Brumation: The hibernation of Garter Snakes and other cold-blooded animals, who get heat from the environment around them
Gail R. Michener. Hibernation Phisiology of Richardsons Ground Squirrels (also known as gophers). Retrieved from https://research.uleth.ca/rgs/hib_physiol.cfm.html
National Park Service. (2020). Biological Miracle. Retrieved from https://www.nps.gov/gaar/learn/nature/wood-frog-page-2.htm
Hinterland Who’s Who. Little Brown Bat. Retrieved from https://www.hww.ca/en/wildlife/mammals/little-brown-bat.html Dickinson County Conservation Board. (2019). How Garter Snakes spend the Winter. Retrieved from https://dickinsoncountyconservationboard.com/2019/12/09/how-garter-snakes-spend-the-winter/
Hibernating Thirteen-lined Ground Squirrel: https://www.science.org/doi/10.1126/science.359.6379.982
Active Thirteen-lined Ground Squirrel: https://www.aaalawncare.com/thirteen-lined-ground-squirrels-lawn-damage/
A Frozen Wood Frog: https://www.nps.gov/gaar/learn/nature/wood-frog-page-2.htm
Active Wood Frog: https://phys.org/news/2018-05-wood-frogs-option-pee-winter.html
Little Brown Bats Hibernating: https://guides.nynhp.org/little-brown-bat/
Active Little Brown Bat: https://www.batcon.org/bat/myotis-lucifugus/
Garter Snakes Hibernating: https://www.cbc.ca/news/canada/saskatchewan/frisky-snakes-fort-livingstone-1.5153483