Alternation of the periods of wakefulness and dream very important not only for the person, but also for animals. Thanks to it the organism of living beings has a rest and gains strength for activity continuation. But unlike the person, each animal sleeps differently.
Dream of large animalsThe dream of large animals, as a rule, differs in short duration, however among them there are exceptions. Lions, tigers and other large predators of cat's breeds can sleep for 15-20 hours a day. Such long time is necessary to conduct the active life full of vigorous jumps and pursuits during hunting. They sleep on the earth or on trees that other inhabitants of fauna did not disturb.
About 13 hours gorillas sleep, settling on the earth or boughs in the most relaxed postures: on a back, a stomach and even on one side. Many lean during sleep a back against a tree. Other representatives of family of monkeys sleep less long time – from 7 to 10 hours.
And here elephants have enough 3-4 hours of a dream a day. Adult elephants usually sleep standing, putting heavy tusks on thick branches of trees or apertures of a lattice in bondage. However if desired they can sleep and as young people – lying on a stomach and even on one side, having extended legs and a trunk. As a rule, all herd never sleeps tight – somebody always remains on guards.
As much horses, goats, cows and the majority of other hoofed animals sleep.
The shortest time among large mammals is necessary for a dream for a giraffe – all a couple of hours. He sleeps only at night, having curled up in a peculiar ball and having put a neck on a back or having buried the head to the earth. At the same time duration of sound sleep at it does not exceed 20 minutes a day. Bears in the spring, in the summer and spend not enough time for a dream in the fall, but fall into long hibernation in the den in the winter. Wolves sleep very sensitively, especially lone or those which are in a den with the cubs. Seals sleep at the bottom of reservoirs, each five minutes climbing to the surface to take a sip air. And sea lions sleep in water on a back, like the person.
The share of a REM sleep at recently been born animals is higher, and in process of growing it decreases.
Dream of small animalsSmall animals usually sleep very sensitively and more long time, than large there Is it for several reasons: to existence of constant danger around, small life expectancy and fast metabolism. Many of them, by the way, prefer a daytime sleep. Among them there are, for example, porcupines, badgers, owls, bats and others. The most long dream among rodents at groundhogs. They carry out nearly 70% of the life in a dream, and their hibernation can continue from 4.5 to 9 months, depending on weather conditions in the place of residence. Only the small animal the sleepyhead which is awake only 2-3 hours a day can argue with a groundhog. Foxes always carefully prepare for sleeping, choosing a pole and turning in it long time, and then are displaced in a ball and twist themselves with a tail. Foxes in couple always sleep next to each other, gathering in one ball. For a dream they have enough 7-8 hours. Squirrels sleep for 15 hours a day, taking a break on food or care of cubs. And here moles – for 2-3 hours several times a day. More than others domestic cats and dogs sleep, they should not care for search of food. Often birds sleep, however their dream is always sensitive, and eyes are constantly slightly opened. Fishes do not sleep at all – they have a rest, being in a motionless state. Dolphins as through a certain period they need to jump out surely of water have no phase of a deep sleep and to gather air. For 5-6 hours at them has serially a rest the right and left half of a brain – this process and replaces with it a dream.