Hibernation

Paul often says that I am "solar powered" - and that certainly seems to be the case lately!  Now that it has become distinctly chillier and is getting dark by 4pm, the prospect of hunkering down is very attractive. So, did you know....

Hibernation is the condition or period of an animal [or plant] spending the winter in a dormant state.  Some animals enter a state of almost total inactivity during the winter months by slowing the heart rate (by 10x slower) and lowering the body temperature.  The animal sleeps deeply in protective quarters but their bodies have also adapted to wake them up from their dormant hibernating state if they are in danger of freezing due to drastic temperature drops!

The only mammals that truly hibernate in the UK are hedgehogs, dormice and bats.

Hedgehogs eat as much as possible during October and November to prepare for hibernation, as they need to weigh between 500-700 grams in order to have the best chance of survival. Once they have reached the appropriate weight, and the average temperature has dropped to around 5°C, hedgehogs will be on the hunt for the perfect hibernation spot. They may hibernate under compost heaps or under garden sheds or decking, and sometimes they will collect leaves and twigs to create the perfect hibernation spot.
 
Dormice begin to hibernate in tiny woven nests between October and November, and do not emerge until April. Nesting takes place under logs, moss or amongst dead leaves at the base of hedges; dormice will choose a moist place to hibernate so that they don’t become dehydrated (water vapor is lost as they breathe) and so their fat reserves will last longer.

During November, bats will hunt for appropriate hibernation spots, known as roosts. They will often choose underground caves, but can also roost in hollow trees, roofs and bat boxes, as long as the roosts are cool and remain at a constant temperature.  Bats are particularly well adapted to hibernation. They are able to slow their breathing to only five breaths a minute in order to reserve energy.

Other species, such as badgers, do not hibernate but enter a period of lower inactivity which is known as a state of torpor. Badgers will retreat into their setts during cycles of torpor that only last for around 29 hours and survive there without food when the weather is too harsh to venture outside. Other species that go into torpor include squirrels and amphibians.
 
And here is a term I've never come across before - Brumation:  a state of winter dormancy entered into by some cold-blooded animals as part of their normal annual rhythm.