Hedgehogs are known for their nocturnal habits and a survival strategy: hibernation. This deep state of inactivity allows them to endure harsh environmental conditions. While wild hedgehogs naturally engage in this process, pet hedgehogs require specific care.
The Nature of Hedgehog Hibernation
Hibernation is a complex physiological process, not merely deep sleep. A hedgehog’s metabolism significantly slows, conserving energy when food is scarce and temperatures are low. Body temperature can drop dramatically from 35°C (95°F) to 7-10°C (45-50°F), sometimes even as low as 1°C.
Heart rate decreases from 190 to 14-20 beats per minute, and breathing becomes infrequent, almost ceasing at times. This profound reduction in bodily functions allows survival on fat reserves built before winter.
Hibernation is not continuous; hedgehogs periodically awaken for a day or two, burning fat to raise body temperature and engage in minimal activity. These brief arousals are energetically demanding but necessary for physiological maintenance, such as restoring brain function.
Why and When Hedgehogs Hibernate
Hedgehogs hibernate primarily as a survival mechanism against cold temperatures and the scarcity of their natural food sources. As insectivores, their diet of insects, slugs, and worms is limited during colder months. Hibernation allows them to avoid starvation and maintain energy balance.
Declining food availability, dropping temperatures, and decreasing daylight hours trigger hibernation. Wild hedgehogs in regions like the UK typically begin hibernation between October and December, emerging in March or April. Timing and duration vary with local weather, with milder winters sometimes delaying or shortening the hibernation period. They prepare by consuming large amounts of food in autumn to build fat reserves, which can constitute up to a third of their body weight.
Wild Versus Pet Hedgehogs
A key distinction exists between wild hedgehogs and their domesticated counterparts, African pygmy hedgehogs, regarding hibernation. While European wild hedgehogs are adapted to hibernate, African pygmy hedgehogs generally do not naturally hibernate. Attempts at hibernation in pet hedgehogs are dangerous and can be fatal.
Pet hedgehogs lack the metabolic adaptations and sufficient fat reserves to safely undergo true hibernation. If their environment becomes too cold, they may enter a state of torpor, a partial hibernation that can lead to severe health complications. These include dehydration, organ damage, pneumonia, and a compromised immune system.
A pet hedgehog attempting hibernation might appear lethargic, unresponsive, have a cold belly, or exhibit a wobbly gait. Maintaining a consistent ambient temperature, typically between 20°C (68°F) and 26°C (80°F), is important for pet hedgehogs to prevent accidental torpor.
Supporting Hedgehogs Through Winter
Supporting wild hedgehogs through winter involves providing resources that aid their preparation and survival. In autumn, offering supplementary food, such as meaty cat or dog food (not fish-based) or specialized hedgehog food, can help them build fat reserves. Fresh water should always be available, especially as natural sources may freeze.
Creating safe nesting sites, known as hibernacula, is also beneficial. This can involve leaving undisturbed log piles, leaf piles, or brushwood in gardens, or providing purpose-built hedgehog houses.
If a hedgehog is seen out during the daytime in winter, or appears small, injured, or wobbly, it likely needs help. Such individuals may be ill, underweight, or disturbed from hibernation.
Gently place the hedgehog in a high-sided box with a towel, provide a gentle heat source like a warm (not hot) water bottle wrapped in a towel, and offer shallow dishes of water and appropriate food. It is advisable to contact a local wildlife rescue center or hedgehog charity for further guidance, as they can provide expert care and rehabilitation.