How do Animals Survive the Winter?

During the fall time people enjoy looking at the beautiful fall colors of the Rocky Mountains and spending time outside in the crisp days.  The air is finally a bit cooler after a long, hot summer and the days are getting shorter.  These are all signs that winter is coming.

rocky mountains in winterThen once winter arrives it can be extremely harsh in the Rocky Mountains, with freezing temperatures, snow, ice, and cold winds.  All animals, including people, know that winter is coming and start to get ready for it.  Preparing for winter can mean a lot of different things to different animals – such as migrating to warmer climates or eating lots of food.

How animals prepare for winter depends on their strategy to survive the winter.  Different animals choose different strategies to give them the best chance at survival.  Some animals go to a different area that is not quite as cold, and others stay in the same area, but adapt to the cold and snow.

Here are the main strategies that animals choose in order to survive winter.  I will give more information about each of these in future posts that focus on more specific topics, such as mammals in winter, and bugs in winter.

Migration

Migrating birds

Migrating birds

Many animals leave the areas that will become very cold and snowy during the winter for places that are warmer and have more food available.   Some animals migrate far distances, such as caribou that travel thousands of miles, and others like moose only move lower to the valley bottoms where the snow is not as bad.

Hibernation or Staying Hidden During Winter

Some animals truly hibernate or sleep all winter long – a chipmunk hibernates all winter long.

Hibernation – is a long period of deep sleep and inactivity.  During this time breathing slows, heart rate slows down, and body temperature gets lower.

mammals black bear eat fishSome animals, including bears, do not truly hibernate, but go into a deep sleep called torpor.  The difference between torpor and hibernation is that in torpor the animal can wake up quickly if it hears a loud noise or is moved.  In hibernation, the animal can not wake up quickly.  Also, in hibernation the animal’s body temperature drops to the same temperature as the surrounding, but in torpor the body temperature remains high.

Other animals stay in their den or a safe place all winter where they sleep a lot and eat the food they have stored for winter – a squirrel sleeps and snacks, but on warmer days will come outside to get the food it stored in the fall.

Adaptation

Change the kind of food they eat – a red fox changes it’s diet.

A mountain goat with its thick winter coat.

A mountain goat with its thick winter coat.

Grow a thicker fur coat for winter – such as a deer or mountain goat.

Change the color of their fur – a snowshoe hare changes the color of its fur from brown in the summer to white in the winter.