My dear, why are you hibernating in the snow? Aren't you cold?

In the last ten months of winter, when the snow is falling, we all look forward to hibernating in our beds, but some animals choose to rest in the snow. For example, polar bears who are about to become mothers will dig a snow pit and hibernate in it while raising their babies.

Is there another mammal that hibernates in the snow? Yes, there is, and it is the small bat found in China, Russia, North Korea, and Japan - the Ussuri tube-nosed bat (Murina ussuriensis). Sometimes, the Ussuri tube-nosed bat population in Japan is classified as the forest tube-nosed bat (M. silvatica).

These little guys are only about 4 cm long, round and cute. When winter comes, they will dig a cylindrical or conical cave out of the snow and lie in it comfortably to spend the cold winter ZZZzzz…

The spherical Ussuri tube-nosed bat | Hirofumi Hirakawa & Yu Nagasaka / Scientific Reports (2018)

Hibernating in the snow may sound painful, but it actually has three great advantages:

1. Constant temperature. Although we feel that snow is very cold, it has a heat-insulating effect. The interior of the snow cave becomes a "constant temperature box" with a relatively stable temperature, similar to the ice brick house of the Eskimos.

Second, safety. Although hibernating in the snow carries the risk of being dug out by predators, the probability of being discovered in the snow is lower than in tree holes. After all, the entrances and exits of tree holes are too obvious, and finding them in the white snow is like finding a needle in a haystack. When weighing the two evils, the clever Ussuri tube-nosed bats will of course choose a way with a lower probability of being discovered.

Sleeping in the snow | Hirofumi Hirakawa & Yu Nagasaka / Scientific Reports (2018)

3. Water supply. Hibernating in a snow cave has another great convenience, that is, the snow cave can not only provide a certain humidity, but also can get water on the spot. It is extremely dangerous for hibernating bats to go out to drink water, but when hibernating in a snow pile, they can lick the "wall" directly when thirsty, and there will be no worries about dehydration!

Ussuri tube-nosed bats usually live alone in piles of fallen leaves, tree holes, or peeled bark. Their breeding season is concentrated in the summer from June to August. In high-latitude areas, bat mothers must seize this rare warm season to breed offspring. At this time, female bats will gather in groups, called "maternity colonies", and these "mother groups" usually consist of 2-22 individuals.

The concern of mother bats for their young has amazed humans. They will hardly let their pups out of their sight. In order to avoid being discovered by predators, mothers will also make "strategic transfers" at any time, sometimes even to the point of moving every day.

Ussuri tube-nosed bat hanging from a branch | Pxc06142 / Wikimedia Commons

The young bats grow very fast and can reach maturity in a few months, which is also the key to their survival in winter. The life span of the Ussuri tube-nosed bat is not long, with the maximum life span of males being 4 years and females being 4.5 years.

Due to the deforestation of some virgin forests and the large-scale planting of fast-growing forests, the living environment of the Ussuri tube-nosed bat is decreasing. Protecting the homes of wild animals is also protecting our homes. I hope they can always hibernate happily in the snow in winter.

Author: Luo Xiaofeng

Edit: Red Queen

This article comes from the Species Calendar, welcome to forward

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