Many different kinds of animals hibernate, from tiny insects to larger mammals, and some even go into similar deep-sleep states like torpor or aestivation.

What ā€œhibernateā€ means

Hibernation is a long, seasonal state where an animalā€™s body temperature, heart rate, and breathing drop way down so it can survive times when food and warmth are scarce, usually in winter. Some species show ā€œtrueā€ hibernation (very deep, long-lasting), while others enter lighter, bearā€‘style hibernation or torpor.

Common mammals that hibernate

Many of the animals people think of first are mammals, especially small ones.

  • Ground squirrels and other small rodents (like some marmots and dormice) are classic true hibernators and can remain in deep hibernation for many months.
  • Groundhogs (woodchucks) in North America can stay in deep rest for roughly 150 days over winter.
  • Hedgehogs hibernate in nests of leaves and grass, with their heart rate and body functions dropping dramatically.
  • Bears, including brown and grizzly bears, den for 2ā€“5 months; this is often called hibernation, though physiologically it is a slightly lighter form than in small rodents.
  • Some lemurs, like the fatā€‘tailed dwarf lemur of Madagascar, are rare primates that hibernate for up to about seven months in tree hollows.

Other surprising hibernators

Hibernation (or related states) isnā€™t just for the ā€œusualā€ furry animals.

  • The common poorwill is a small bird and is the only bird species known to truly hibernate, sometimes staying in this state for months under rocks or logs.
  • Certain salamanders, such as the Siberian salamander, can stay in a frozen, hibernationā€‘like state for up to about 10 months and survive extremely low temperatures.
  • Some snails seal themselves in their shells and can remain in a dormant state that can last years under harsh conditions.
  • Bumblebee queens hibernate alone in soil or sheltered spots through winter before starting new colonies in spring.

Torpor and aestivation (related ā€œsleepā€ states)

Not every animal that ā€œsleeps through bad timesā€ is in true winter hibernation, but the idea is similar.

  • Chipmunks often cycle in and out of torpor in underground burrows rather than staying in one continuous deep hibernation; they periodically wake to eat stored food.
  • The African lungfish shows aestivation, a summer equivalent of hibernation, hiding in a mucous cocoon underground for months or even several years when water dries up.

Quick miniā€‘story to picture it

Imagine a rocky hillside in late autumn: a bear curls up in a den, a groundhog disappears into its burrow, a hedgehog tucks into a leaf nest, and high up in a tree a tiny dwarf lemur settles into a hollow. Under a loose rock, a common poorwill slows its body almost to stillness, while deep in frozen ground a Siberian salamander waits out months of ice. Each is using some version of hibernation to ā€œpauseā€ life until conditions improve.

TL;DR: Animals that hibernate include many rodents (ground squirrels, marmots, dormice, groundhogs), hedgehogs, bears, some lemurs, a hibernating bird (common poorwill), certain amphibians and reptiles like salamanders, and even invertebrates like snails and bumblebee queens.

Information gathered from public forums or data available on the internet and portrayed here.