The world's hibernation champion can sleep soundly for 9 months

Long johns, heaters, and hot packs... these magical tools for wintering are constantly in use, and humans have taken great pains to survive the winter. However, how do animals resist the cold without these external supports? Today, Pangke will show you what "tricks" animals have!

1. Is hibernation just sleeping?

When it comes to the way animals spend the winter, the most familiar thing to everyone must be "hibernation", but what exactly is hibernation? Is it really as simple as "closing your eyes and opening them again, and spring comes and flowers bloom"?

What is hibernation? What is the longest hibernation animal in the world?

Here, Pangke needs to correct a statement, that is, hibernation does not equal sleep. Compared with normal sleep, animals in the "hibernation" state will change their metabolism, reduce it to the minimum range to save energy, and change their body temperature, reduce heart rate and breathing. Such changes can allow animals to survive longer in harsh climates or food shortages.

Moreover, animals hibernating will neither freeze to death nor starve to death, because these hibernating animals have acquired special proteins in their bodies during the long process of evolution, such as ice nucleation proteins and antifreeze proteins, which can control the formation of ice crystals outside cells. Another reason is that when these animals hibernate, their body temperature drops, their metabolism slows down, their breathing slows down, their heart beats slow down, and their energy consumption is extremely small, so they can only rely on the nutrients stored in their bodies to sustain their lives.

For cold-blooded animals such as frogs and snakes, there are actually two types of "hibernation": one is the "sleeping" mentioned above, and the other is freezing tolerance. Freezing tolerance refers to the phenomenon that a few animals can tolerate a certain degree of body freezing and avoid frostbite. When the bodies of these animals freeze, ice crystals form outside the cells, thus avoiding ice crystals from damaging the cell membrane.

The hibernation of mammals is more complicated than that of cold-blooded animals. They not only have to prepare for hibernation, but also stay in a state of waking up and sleeping during the entire hibernation period. The preparations for mammals to hibernate can be roughly divided into two types: one is the storage of food in the nest, and the other is the storage of food in the body.

Chipmunks, hamsters, etc. belong to the first case. They will collect and store a lot of food in their nests before hibernation; while marmots, dormice, hedgehogs and brown bears all adopt the second method, that is, they will eat a lot of food in advance and then convert the food into fat and store it.

In addition, the requirements for animals to hibernate are also different. For example, snakes will hibernate when the ambient temperature is below about 13°C, while frogs will hibernate when the ambient temperature is below about 8°C. Moreover, different species of the same animal have very different requirements for hibernation. Therefore, when studying the hibernation conditions of animals, it is also necessary to classify them and make targeted observations and interpretations.

In addition, the hibernation duration of different animals also varies greatly. Let me ask you a question:

What animal hibernates the longest in the world?

Dormouse

Yes, it is this one. In a year, it sleeps for about 9 months, hibernating from late autumn to winter. It really deserves the title of "the animal with the longest hibernation time in the world"!

After talking about hibernation, there is another large group of people’s wintering methods that we must pay attention to, and that is “migration”.

2. Go the longest way to find the warmest winter

When it comes to the best representatives of "migration", birds are definitely one of them. Common house swallows and wild geese in our lives are all migratory birds that spend the winter. Pangke will start with bird migration and let everyone learn about this wintering method. First, let me ask you a question: What are migratory birds?

Migratory birds refer to birds that migrate periodically with the seasons. Many birds have the characteristics of seasonal migration along longitude and latitude. In late summer and early autumn, these birds will leave their breeding grounds and go to tropical areas with lower latitudes to spend the winter, and then return to their breeding grounds from the wintering grounds in the spring of the following year.

Migratory birds are divided into two types: summer migratory birds and winter migratory birds. Summer migratory birds fly to a certain area in spring and summer to build nests and breed offspring. When the young birds grow up, it is late autumn, and they fly to warmer places to hibernate. They fly back to the place to breed in the spring of the following year. For this place, these birds are summer migratory birds. For example, house martins are found in northern cities in my country in summer and spend the winter in Hainan Island and other places. For northern cities in my country, house martins are summer migratory birds.

Winter migratory birds refer to birds that spend the winter in a certain area and fly to a warmer place to breed in the next spring. When the young birds grow up, they fly back to the original area in late autumn to spend the winter. For this area, these birds are called winter migratory birds. For example, swans are winter migratory birds in the middle and lower reaches of the Yangtze River in my country.

It can be seen that whether it is a winter migratory bird or a summer migratory bird is closely related to the observation point, that is, the same migratory bird may be classified into different categories at different observation points.

3. The animals around you have tricks for wintering

After talking about hibernation and migration, let's take a look at how cats and dogs around us, who neither hibernate nor migrate, spend the winter. Their trick is to "change their fur". Changing to thicker fur is an effective way for animals to cope with the cold winter.

Of course, cats and dogs with their own owners don’t have to worry about wintering because their owners will definitely prepare wintering equipment for them in advance. However, small animals that need to fend for themselves outside need to prepare for wintering in advance, including measures from their own perspectives such as changing fur and storing fat, as well as external measures such as finding a relatively warm place to spend the winter. In the cold winter, they all work hard to stay alive.

That’s all I have to say about how animals spend the winter!

Creative team: China Science and Technology Museum

Review expert: Ran Hao, a well-known popular science writer