You may only live for 5 years in your life, and spend 3.75 years sleeping! Are you crazy envious, or are you impressed?

This article was reviewed by Lin Zhideng, PhD in Zoology, East China Normal University

We only live for 5 years in our lifetime, and spend 3.75 years sleeping!

When talking about the animals that sleep the longest, many people will immediately think of sloths that hang on trees and sleep soundly all day long.

However, sloths may not be as good at sleeping as another sleep-deprived animal: the dormouse. How sleepy is the dormouse?

Let me put it this way, they are so exaggerated that they can starve to death in their sleep. They are really sleeping with their lives.

Today, let’s get to know this little animal that spends half its life sleeping.

In the name of sleep

Dormouse is not a single animal, but a general term for a variety of animals in the order Rodentia, the suborder Sciuromorpha, and the family Gliridae. The more common species include the hazel dormouse (Muscardinus avellanarius), the forest dormouse (Dryomys nitedula), and the garden dormouse (Eliomys quercinus). Dormouse is small in size, with an adult body length of only 6-19 cm and a weight of between 15-180 grams. It looks somewhat similar to a mouse.

The most prominent feature of dormouse is that it can sleep a lot. It hibernates in spring, late autumn and most of winter. There are many animals that can hibernate (or aestivate), but it is rare to see an animal like dormouse that sleeps for half a year. Perhaps it is because they can sleep so much that they are called dormouse.

Don’t think that dormice are slow like equally sleepy sloths just because they sleep for a long time. In fact, dormice are quite agile little animals. Most of them live in trees, have strong climbing abilities and are very agile.

Dormice are mostly active and forage at dusk and dawn, when the light is dim. To adapt to this habitat, they have developed keen hearing and often make various calls to communicate information.

Dormice are omnivorous, partially carnivorous animals that can eat a wide range of foods, including plant fruits, flowers, insects, and other small invertebrates. Among them, nuts rich in protein and fat are their favorite.

Compared to other rodents, dormice lack a cecum in their digestive tract (the place where rodents digest plant cellulose), so they have poor digestion of cellulose-rich foods.

Due to the long sleep time, the dormice can only complete the tasks that need to be completed in a year, such as feeding offspring, in less than half a year.

Generally speaking, when the baby dormouse wakes up from its first hibernation, its childhood is over (that is, it reaches sexual maturity). They wake up around spring and summer when the weather is already very warm. The first thing they do when they wake up is naturally to look for food to fill their stomachs, and then they hurry to complete the task of reproducing offspring.

Generally speaking, dormice reproduce once a year (occasionally twice), giving birth to 3-4 cubs (up to 6-7) each time. Before they can live independently, the cubs need to be cared for by their mother for 6-8 weeks. When the cubs are almost able to find food to feed themselves, autumn is approaching, and the dormice have to prepare for the upcoming hibernation.

How much sleep can you get?

How much sleep do dormouse actually get?

Usually in October when the weather is not too cold, they start to prepare for a long hibernation, and will not wake up until May of the following year when the weather has become quite warm.

During hibernation, the metabolism level and heart rate of dormouse will be reduced to the lowest level - just enough to maintain basic life activities. Only in this way can they save the energy stored in the body to the maximum extent to survive the long hibernation period.

During hibernation, dormice occasionally wake up briefly and eat some food stored nearby to replenish energy, but they will not wake up until the weather warms up completely. Sometimes the temperature rises slowly, and some dormice even starve to death in their sleep because they fail to wake up in time.

It seems a little too late to end hibernation in May, but in fact, dormice can only get enough food at such temperatures. If they wake up too early, the food available to them will be relatively insufficient due to the increase in their body's metabolic level, making it difficult for them to survive.

You know, dormice (and other hibernating animals as well) that have just woken up from hibernation are often particularly vulnerable. Their previously stored energy has been basically exhausted, and their body's energy consumption has begun to return to normal levels, so they urgently need to find food to replenish their energy. Usually hibernating animals will determine the best time to wake up based on weather changes - usually the time when they can get enough food.

In recent years, increasingly unstable temperature fluctuations have had a great impact on hibernating animals around the world. Sometimes warm winters cause some hibernating animals to wake up early, but in fact there is not enough food supply at this time, which makes their survival very difficult.

For dormice, a long hibernation period is just a manifestation of their ability to sleep. Even when not hibernating, they can still sleep a lot.

In summer, dormice begin to move around at dusk, but return to their nests in the bushes to sleep during the day. Although this type of sleep does not require a reduction in metabolism like hibernation, it is also a very deep sleep, and if disturbed, it may take several minutes to wake up.

Let’s put it this way, the lifespan of a dormice is generally more than 5 years, of which about 3.75 years are spent sleeping. I wonder if those office workers who complain about lack of sleep every day are envious of this amount of sleep time.

Maybe sleeping is their way of survival.

Seeing that dormice just sleep every day, you might think that they have no competitiveness for survival, but the fact is that they have adapted to the environment quite successfully.

There are currently 28 species of dormouse in nine genera, distributed in Europe (north to southern Scandinavia), Asia (east to southern China and Japan), and Africa (south to sub-Saharan Africa), and they can adapt to temperate, subtropical and tropical climates. Most dormouse species are not in small numbers and are in little danger of extinction, but there are still four species of dormouse that are listed on the Red List of Endangered Species and need to be protected.

In general, the extra-long sleep of dormice is very energy-efficient, allowing them to use less energy to survive. During hibernation, they do not need to move around to find food, but instead look for a relatively safe place to lie down, which also reduces the competition between dormice and other animals to a certain extent.

Perhaps the "lying flat" posture of eating when awake and sleeping when full is the dormice's way of survival.

References:

[1] Learning Research Co., Ltd. Animals: [M]. Zhengzhou: Henan Science and Technology Press, 2004.

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

Source: Tadpole Musical Notation (ID:kedo2011), Author: A Bowl of Chopsticks

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