Hedgehogs are spiny mammals from the Erinaceinae subfamily. There are a total of 16 species of hedgehogs across 5 genera that are found in Europe, Asia, Africa, and New Zealand. These nocturnal mammals feed on invertebrates, and are prominently recognized by their spines, which they use to defend themselves from their predators. When threatened, hedgehogs roll into a ball, thus exposing their predators to hundreds of sharp spines. This defensive adaptation is not the lone interesting thing about the species though; the fact that they go into hibernation equally is.
Hibernation in Hedgehogs Explained
Hedgehogs maintain a nearly constant body temperature in summer. In winter, when the temperature decreases, they increase their metabolic rate to generate heat and keep their body temperature constant. Hedgehogs undergo thermoregulation when they are hibernating or when they are about to go into hibernation. This is one of the most important activities of their life. With the arrival of winter, they tune their body in such a way that their body temperature is around +5 to +6 °C. This is a necessity for the species as food becomes scarce in this season and it is not possible for them to maintain their summer body temperature.
Hedgehogs are so amazingly in sync with nature that during hibernation they use their stored quota of fat to make it through. They use this energy minimally―just to keep their vital functions going. They create their home or habitat for hibernating, called the 'hibernacula'. They don't go into hibernation before they gain the sufficient weight. The minimum weight required for a young hedgehog to hibernate in the wild is 500 - 700 grams. In addition to that, there is a sex specification in hedgehogs, males go into hibernation first and then, are followed by females. The duration of hibernation ranges from 3 - 5 months.
The common places that hedgehogs use to hibernate are timber buildings, under piles of wood or leaves, or in compost heaps. However, if there is enough food and the climate is sufficiently warm, they may not even hibernate. Hedgehogs in captivity should not be allowed to hibernate, as it can lead to a few problems.
Low and Sudden Dip in Temperature
In most of the cases, hibernation in hedgehogs is triggered by a fall in temperature, especially if there is a sudden dip in the temperature.
Inconsistency in Day-night Cycle
Inconsistency in the amount of light and dark can prompt the species to go into hibernation. If a domesticated hedgehog is forced to wake up at erratic and different times of the day, there is a possibility that he will go into hibernation. Hedgehogs can tell it is winter when days become short and nights become long, and adjust their biological clock accordingly.
Another factor which can prompt the species to hibernate is illness. During an illness, hedgehogs, rather than wasting their energy in movement, lower their metabolism to fight infection. If your pet is ill, make sure that it is warm enough and take it to a veterinarian.
In hedgehogs, the process of hibernation varies according to species, sex, and age. Additionally, there are stages when they rise during hibernation, move around a bit to hunt for food, and reset their metabolism. These spiny animals definitely know how to conserve their energy.