Want to know how animals sleep? What determines their restful sleep, and is it really so easy for animals to fall asleep?
Contrary to popular belief, modern domestic horses do not sleep while standing. While standing, they can only be in a state of some kind of slumber. Such a pastime cannot be called a full sleep. In order to plunge into a real, deep sleep, during which both body and brain will rest, horses, of course, lie down. Most often on the side.
However, due to the peculiarities of the structure of the body, its mass, as well as the thinness of the bones, horses can sleep in this state no more than 3-4 hours. If the horse lies on its side for more than 6 hours, it will develop pulmonary edema.
Dolphins, unlike other mammals, sleep in a very interesting way. When it's time to rest, the dolphin turns off only one hemisphere of the brain, while closing the opposite eye. The other half of the brain at this time monitors the environment, controls breathing, and other basic physiological processes.
During such sleep, dolphins can remain on the surface of the water, sometimes slowly swim with the current. In captivity, dolphins sometimes sleep at the bottom of the pool, periodically rising to the surface for air.
Perhaps one of the most interesting questions is how do giraffes sleep? Indeed, at first glance, with such a long neck, it is quite problematic to get a vacation. But nature has everything thought out. Giraffes sleep with their necks bent so that their head is on the lower part of the hind limb. The entire installation process takes 15–20 seconds. First, the giraffes descend onto the chest and then onto the belly.
Interestingly, giraffes sleep only for a few minutes at a time. The duration of deep sleep per night does not exceed 20 minutes.
For a long time, it was believed that whales sleep the same way as dolphins - turning off one hemisphere alternately. But recent research by scientists has shown that this is not the case. It turned out that the whales sleep during short periods of rapid immersion in the water. Thus, they do not have a clear distribution of the day for sleep and wakefulness. Whales “gain” 10-15 minutes of sleep for several hours.
As with horses, there is a myth that penguins sleep while standing. This, of course, is not so, at least not quite so. First: there are several species of penguins on Earth, and many of them sleep in different ways. For example, gentoo penguins and some others sleep as if they had a great party yesterday. Well, just no hind legs
And next to it are the emperor penguins, which, however, can hardly be called standing either. Rather, it is a sitting posture. Penguins stand and walk in a completely different way.
Hippos spend most of their lives in water. They usually sleep either in the shallows with the top of their heads exposed, or completely submerged in water. In the latter case, hippos reflexively float to the surface every 3-5 minutes to inhale. However, they do not even wake up.
10 surprising facts about how animals sleep
You can often hear squirrels sleeping wrapped in their tail. Not that this was not at all the case, rather, it is part of the truth. In fact, squirrels are like many other animals in this respect: they sleep as they lay down. Just like us. Sometimes they wrap themselves in a tail, and sometimes they look like penguins returning from a party.
To begin with, there are African and Indian elephants, and they sleep in different ways. African people often sleep standing, leaning sideways against the trunk of a tree or clasping it with a trunk. This is due to the fact that African elephants are afraid of overheating the body from too hot soil. If the ground is not too hot, then they can sleep alive, bending their legs under them, or on their side.
Indian elephants often sleep lying, bending their hind legs, and stretching their front legs forward and resting their heads on them. The elephants sleep lasts about 2-3 hours. The animal can wake up, listen and sniff for danger, and then fall asleep again.
Other animals that disprove the myths about their own sleep are possums. Yes, they have a very strong tail, yes, they can hang on it upside down on a tree branch, but they do not sleep in this position. In general, possums are nocturnal animals, during the day they rest, sleep, and when it gets dark, they go for prey. Possums sleep a lot, sometimes up to 18-20 hours a day. To do this, they are located on a tree branch, or curled up in a ball in a hollow and other shelter.
Swifts are known for their records. They are some of the fastest flying birds, and by far the longest flying birds. A swift can be in flight for up to 4 years. All this time the bird eats, drinks, sleeps and even mates on the fly. A young swift, having taken off for the first time, can fly up to 500 thousand kilometers before landing for the first time.
In order to sleep in a dream, birds gain a great height, up to three thousand meters, and then fly at an angle to the direction of the wind, changing the direction of flight every few minutes. Thanks to this rhythm, swifts continue to fly back and forth over the same place. But in a light wind, as it was noticed, swifts fly in a circle in a dream.