Why Horses Sleep Standing Up?

There are mammals that sleep standing. This is due to a reflection of survival because they are usually animals that have traditionally been easy prey for other predators.

In this sense, the horses are potential prey for wolves especially, as would be the case of the Iberian Peninsula, since in other territories horses find danger in such ferocious animals like lions, tigers and other big cats in areas such as America, Asia and Africa.

Sleeping standing is especially useful for the wild horses that live in unprotected areas and for non-stabled. Just look at any report or documentary in nature to realize that the animal is usually fair game is one that does not pay attention to their surroundings or are 'clueless'.

So, to sleep standing maintain a defense mechanism against a possible attack, because in reality, in that posture, sleep is light, nothing deep, and with the advantage of standing and stalking case, would already prepared to flee.

How do you maintain the balance?

Horses, sleeping standing, the weight of a release of the hind legs only support the front of the helmet. Dejan, and the tendons and muscles in a relaxed state.

This position allowed to sleep only about four or five hours a day with this light sleep. And those hours are not continuous but spread over several times. To get a deep sleep need to lie down. And the horses reach deep sleep or on all fours either side collected lying on the ground.