What happens inside the hedgehog during hibernation?

 Hedgehogs are night active mammals feeding almost entirely on invertebrates. They use their spines to protect themselves, curling up into a ball. We know that these cute animals have a nearly constant body temperature of about 35 degrees Centigrade in the summer, but what kind of regulation do they use to keep this temperature? And what happens when the outdoor temperature falls and winter is approaching?

When environmental temperatures fall, hedgehogs keep their body temperature constant by increasing their metabolism to generate heat. They thermoregulate in this way within a wide range of low outer temperatures. But when winter comes, food becomes scarce, and the hedgehog would not survive until spring with a constant body temperature as high as 35 degrees. Therefore, hedgehogs switch to another type of temperature regulation with the arrival of winter. During their winter hibernation, hedgehogs keep a body temperature of +5 to +6 degrees Centigrade using energy only to keep their most vital body functions active. At this temperature, their energy need is so drastically reduced and they are able to survive on their fat stores, without eating, until spring.

Because their hairs have been converted to spines, hedgehogs have lost the insulating properties of the mammalian fur. When they are well fed, they are able to compensate for this by having a thick layer of fat in their skin.

When hedgehogs wake up from hibernation, they use their brown adipose tissue. This is a special kind of fat stored in certain parts of their body. The brown fat is used to generate heat which is distributed to all body parts by blood flow. This fat can also be utilized when outdoor temperature falls during summer. Hedgehogs are also able to increase their heat production by shivering.

So, next time you see a hedgehog in the late autumn, you will remember the energy saving mechanisms, which ensure the hedgehog’s survival during the winter!