You often saw a picture when a bird without any confusion slept on a branch or wire and did not fall.
Surely, in you more than once there was a surprise or even amazement as it comes out.
In nature almost every animal takesSleep in a position in which you can relax the maximum number of muscles. After all, sleep is primarily considered a rest of the body and they, too. However, most of the birds do not like this state of affairs. They can sleep only when the muscles of the paws are tense.
The fact is that in birds the tendons are knittedMuscles and fingers. It turns out, when the bird lands, muscles contract, tendons stretch, and the fingers bend. During sleep the bird does not move, so it can not straighten the legs. As a result, she does not let go of her paws. When the bird comes to the waking state, it rises, and the fingers release the place of a recent hibernation.
Birds who sleep in the water often stand only onOne leg. It is easy to give an explanation to this. So they lose less heat and keep the necessary body temperature. For example, long-legged herons and flamingos resort to this technique of sleep.
However, there are birds that are not badIt turns out to doze on the fly. For example, storks without troubles alternately sleep during their long flights. Dark tern can fly over the sea for more than a year, without stopping for breaks.