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What is hibernation?

The temperature is low, the trees are bare, not much is growing and there’s not much to eat. Winter is a hard time of year for many animals, and they’ve evolved different ways of dealing with it. One way to get through the cold dark months is to sleep all the way through. Sounds like a great idea!

This is called hibernation, and although it does look a little like sleep, it’s actually much more amazing than that.

What is hibernation?

Animals that hibernate actually slow down all their bodily processes, so they don’t need to wake to find food or go to the toilet, which means they need less energy to stay alive.

They drop their body temperature, and go into a kind of stasis so need less energy to stay alive and burn less body fat. So long as they’ve eaten plenty of food before hand and have a good store of energy in the form of body fat, they’ll be able to stay safe and hidden all the way through, and will emerge in spring. Sometimes animals will wake up for a short while over the course of the winter, but not for very long, and it’s really important that if you discover a hibernating animal that you don’t disturb it.

It’s not just the animals body temperature that drops. They also drop their heart rate and their breathing rate!Animals that hibernate will find a safe and hidden place to hibernate, because if they are hibernating and asleep they won’t be able to look out for predators that might want to turn them into a winter snack!

Bats hibernating in a silver mine, by ????  CC BY-SA 4.0
Bats hibernating in a silver mine, by ???? CC BY-SA 4.0

Which British animals hibernate?

There are many animals in the UK that use hibernation as a way of surviving winter.

  • Hedgehogs
  • Badgers
  • Field mice
  • Bats
  • Frogs and toads
Hedgehog  by Gaudete
Hedgehog by Gaudete

What to do if you discover a hibernating animal

Most hibernating animals have only stored enough energy to see them through to spring. If they get woken up in the middle of winter, it can use up a lot of those precious reserves, and may mean they don’t have enough to see them through. Therefore it’s very important to not disturb any hibernating animals you might find.

However, there is one possible exception, and that’s with hedgehogs. They often like to snuggle up to hibernate in piles of leaves, twigs and woods; exactly the kind of thing that people make bonfires out of. Therefore it’s really important that you check your bonfire before you light it, just in case there’s a hedgehog in it. Ideally, if you find one, leave it be, don’t wake it and of course don’t set light to the bonfire. If you do have to move it, there’s some great advice on what to do on the St Tiggywinkles website. St Tiggywinkles is a hedgehog rescue charity and wildlife hospital.

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