The clocks have gone back, the nights are drawing in and the first frosts are already occurring, so it really feels like winter is on its way. What does this mean for our hedgehogs and other woodland wildlife?
Often when we think of hibernation, we imagine animals curling up in a dark, quiet, cosy spot and sleeping peacefully for a few months until spring returns. Though they seem to disappear, that’s not really the case. Hibernating animals enter a state of inactivity, slowing their heart rate and breathing and lowering their body temperature and metabolism. A hedgehog’s heart rate is usually around 190 beats per minute but drops to just 20 during hibernation.
All this means that they can survive for long periods without eating, but they do need to get up occasionally to look for food and go to the toilet. Their clever bodies can also wake them up automatically if it becomes so cold that they are in danger of freezing.
Where and when do hedgehogs hibernate?
To prepare for their hibernation, hedgehogs eat as much as they can during autumn, munching on beetles, caterpillars and earthworms to build up good fat reserves. To survive winter, they need to weigh 500-700 grams. They will then seek out a quiet spot to rest for the coming months, usually in piles of dead leaves, stacks of logs, compost heaps or under garden sheds. The exact time they retire to this spot will depend on how mild the weather is; hibernation can take place any time from October to April, but in a warmer winter you may still see hedgehogs out and about in December.
Help our hedgehogs
Hedgehogs can be found in woodland edge habitats, hedgerows, farmland, parks and gardens, but numbers have dropped dramatically in recent years. They are less common in gardens now as lots of perimeter fencing and tidier outdoor spaces mean they can’t move around so easily, but you can help them get through hibernation by putting food in an accessible place and providing a safe shelter for them, like our igloo hogitat.
What should I feed hedgehogs?
They will appreciate any special hedgehog food, meat flavoured cat biscuits or chopped unsalted nuts and a shallow dish of water. Wet food isn’t a good idea as it could freeze and bread and milk is bad for them. You can read more feeding tips here.
Icy temperatures make winter survival tough for some wildlife – maintaining body temperature and looking for food can burn energy quicker than they can consume it. As well as a lack of food and shelter, small mammals have to deal with losing heat more quickly due to their larger surface area to volume ratio and short, thin fur. Rabbits, shrews, mice and voles all seemingly disappear.
The only mammals that truly hibernate in the UK are hedgehogs, dormice and bats. Other woodland residents enter ‘torpor’, which is also a state of inactivity but doesn’t last as long as hibernation.
The hibernation period for dormice begins around now, in October to November and they will stay in their nests until April or May. These tiny creatures slow their heartbeat and breathing and lower their body temperature to just a few degrees above freezing. They can lose half their body weight over winter, so they eat so much at the end of summer that they grow to twice their normal size!
A dormouse's body weight fluctuates dramatically before and during hibernation (Photo: WTML)
Bats hunt for hollow trees, roofs, caves and bat boxes to spend their winter months, usually hibernating from November to April. Like hedgehogs, they slow their heart rate to just 20 beats per minute. They also slow their breathing to as few as five breaths a minute; some species can last almost an hour without breathing at all!
Many people think that squirrels go to sleep for winter too, but while you’re less likely to see them, they are still awake. Red squirrels prepare for winter by storing surplus food near their home so they don’t need to travel far to forage and when the weather is especially bad, they can stay in their dreys for several days at a time.
Badgers are also less active in winter and go through cycles of torpor which last for around 29 hours. Like squirrels, they will stay in their home – an underground sett - for days without food during particularly bad conditions.
Frogs, toads and newts also go into a state of torpor when it’s cold, dropping their body temperatures, breathing and heart rates. They can withstand winter better than others, but will creep under rocks or logs or lay buried at the bottom of ponds when the temperature really drops, before emerging again from January onwards.
The hum and buzz of spring and summer turns almost silent in winter, as bees and butterflies find overwinter homes to hibernate. Queen bees will gorge on pollen and nectar to store fat before burrowing deep into soil in early autumn and staying there for up to nine months.
Most butterfly species spend winter in the larval stage, but some hibernate as adults, including the brimstone, peacock, comma, small tortoiseshell and red admiral. Seeking outdoor structures like sheds and farm buildings, they settle down and enter a dormant state as the weather turns cold, waking again around April or May.
So what wildlife can I see in the woods this winter?
Winter is definitely a quieter time in the woods, but if you’re lucky you may see badgers or squirrels pop out to look for sustenance on milder days.
Foxes and deer stay active throughout winter and fungi, such as wood blewit, continue to appear and thrive.
With fewer leaves on the trees, birds are much easier to spot. There are plenty to see at this time of year, such as tits, finches and winter thrushes.
Should you accidentally disturb a hibernating or sleepy creature, please don’t move it. If you uncovered it, cover it back over and leave it alone to go back to sleep.