Winter Survival: How Animals Beat the Cold

Hibernation is a common winter survival tactic, but let’s clarify what hibernation is. Hibernation is when animals enter a state of drastically reduced activity to conserve energy. Sounds cosy does it! But hibernation can be risky strategy if food scarcity reduces an animals ability to bulk before its sleep. Here is how some animals go about this surviving whilst hibernating:

1. Bears Don’t Sleep All Winter Long
   Bears enter a state called torpor, different from true hibernation, where their metabolism slows but they’re still semi-alert. Their body temperature drops slightly, so they can wake to eat or nurse cubs if necessary. In spring, they emerge lighter, leaner, and often with new cubs born during the denning season!
2. Hedgehogs Curl into a Ball
   Hedgehogs hibernate by curling into a tight ball, reducing heat loss and dramatically slowing their heart rate and breathing. During this time, they can survive months without food, relying on stored body fat to keep them alive!
3. Wood Frogs Freeze
   Did you know that Wood frogs in North America use a type of natural “antifreeze” to survive freezing winter temperatures. Their hearts stop, and they essentially “pause” all life processes until they thaw in spring, surviving freezing and thawing cycles for up to seven months. Walt Disney, eat your heart out!
4. Ground Squirrels Cool Extreme Lows
   Taking a leaf out of the Wood frog’s book, some ground squirrels in the Arctic cool their bodies to just above freezing, the lowest body temperature recorded in mammals. They enter a true hibernation state where they wake periodically to raise their temperature and avoid freezing entirely.
5. Fat-tailed Dwarf in Trees
   In Madagascar, fat-tailed dwarf lemurs hibernate in tree holes, relying on the fat stored in their tails to survive. Name the name makes sense! It’s one of the only primates known to hibernate, and it can survive almost half a year without food.

Animals that don’t migrate or hibernate have evolved amazing physical and behavioural adaptations to survive. Here are just a few examples:

1. Snowshoe Hares and Camouflage
   This is a pretty famous example of a winter adaptation. Snowshoe hares develop white fur that blends into the snow, making it harder for predators to spot them. Their large, wide feet also act as natural snowshoes, allowing them to move quickly when threatened.
2. Arctic Foxes and Insulation
   The ultimate fur coat. Arctic foxes have a dense coat and a layer of fat beneath their skin to insulate them against the Arctic cold. Their fur-covered paws help them walk on ice, and their coat changes from brownish-grey in summer to white in winter.
3. Ptarmigans Grow Feathered Feet
   The ptarmigan, a grouse native to the Arctic and subarctic, grows thick feathers on its feet in winter, which acts like snowshoes. This adaptation allows it to stay mobile and maintain body heat in icy conditions!
4. Muskoxen Have Thick Woolly Coats
   Muskoxen have a double coat, with long outer hair and a dense wool layer called qiviut, which is eight times warmer than sheep’s wool. This insulation keeps them warm even when temperatures drop to -40°F.