Most wildlife goes into hibernation in autumn. It’s the most efficient way of surviving winter. Rather than searching for food (of which there’s very little), they shut down and sit it out.
True hibernation involves slowing of the heart rate and breathing, and dropping body temperature, but most enter a state of ‘torpor’, where body temperature falls only slightly. They wake periodically and bring their body temperature back to normal, before returning to sleep. It’s not fully understood why they do this, but it may explain occasional hedgehog or bat sightings in winter.
Those hibernating in your garden in winter include hedgehogs, amphibians, reptiles and insects – particularly bumblebees, butterflies and wasps. Some insects hibernate as adults, such as peacock and small tortoiseshell butterflies. Others hibernate as larvae or pupae. Whatever the species, it has evolved its own method to survive the cold months, into spring.
You usually won’t be able to see wildlife hibernating but that’s the point – it’s safer for wildlife to stay hidden. They might have buried themselves deep in the soil or your compost bin, snuggled into ornamental grass or folded their wings beneath a piece of bark or shed roof – and we must be careful not to disturb them. However, you may spot signs of hibernating wildlife. Discover five key signs of hibernation, below.
A pile of leaves may appear in a corner of your garden, in your compost bin or behind your shed. This could mean a hedgehog is hibernating, as they often gather their own material to line their hibernacula. Be aware that hedgehogs may choose to hibernate in bonfire piles, which can cause horrific injuries, and death, when lit.
Movement in your pond
Shadows and movement at the bottom of your pond could mean frogs are hibernating here. These are usually male frogs, which seem to prefer hibernating here rather than in mud or beneath leaves, as females and other amphibians do. They can breathe through their skin and may move around the pond periodically.
Leaves on walls
Leaves attached to a wall may not actually be leaves. Peacock, small tortoiseshell, red admiral and comma butterflies hibernate as adults. They sometimes hibernate in groups, closing their wings and clinging to a dry, sheltered surface, such as a beneath a piece of wood placed at an angle against a wall, or beneath the roof of your shed.
Mounds of soil
Small mounds of soil in spring could indicate that mining bees were nesting in your lawn and/or borders. In which case, their offspring will be hibernating there until next spring, when they’ll emerge from their nests, mate and lay eggs, before dying. Daughter bumblebee queens also hibernate in the earth, digging
themselves into the soil.
Long grass isn’t strictly a sign of hibernation, but there will doubtless be hibernating critters there. Caterpillars of butterflies and moths may bury themselves into long grass, along with beetles and other grubs. Some butterflies spin chrysalises that hang from blades of grass.
How to protect hibernating wildlife
- Before lighting bonfires check for any creatures sheltering in them.
- If you accidentally dig up a bumblebee, don’t re-bury it. Pop it somewhere cool and dry, such as on a pile of leaves.
- If you disturb a slow-worm, place it on your compost heap, covering it lightly with material.
- If you wake a butterfly, catch it in a shoe box and take it to your shed. It will be fine there, but remember to release it in spring.
- If you spot a moving hedgehog, offer it water and food (chicken flavour, cat or dog food will do) and leave it. It will soon settle down somewhere.