This question is directly related to the problem, which has long bothered the minds of animal psychology: do animals have consciousness or is it unique to humans?
In 1970, American zoologist Gordon Gallup (Gordon G. Gallup) put an end to these disputes, putting a very simple experiment: he decided to trace the behavior of the primates in front of the mirror.
It turned out that the lower monkeys (macaques, baboons react to their reflection as if before them was another individual. They take an aggressive posture, trying to intimidate "outsider".
Highest apes (chimpanzees, gorillas and orangutans) on the contrary, recognize themselves in the mirror. They also accept his reflection for another animal. But gradually, on the fourth or fifth day, they begin to search the coat, looking in the mirror.
To dismiss all doubt, Gallup decided to hold such an experience. The animal was anestesiology and euthanized animal tinted eyebrows and the tips of the ears, then there are places that without a mirror you cannot see. For the purity of the experiment were used paint, odorless. When chimpanzees were, they did not notice that they were coloured. But being in front of the mirror, showed a genuine interest in colored places, began actively to touch their eyebrows and the tips of the ears. This experiment clearly proved that apes understand what I see in the mirror themselves: they remembered how they looked before, and was aware that their appearance has changed.
Chimpanzees kept and more complex tests with mirror. They were given any simple exercise for the hands, but the animal could not see their hands directly, but only its reflection in the mirror. Chimpanzees coped with this task, but it's not so easy for a man.
Currently, there are 5 types of animals that can recognize themselves in the mirror, is chimpanzees, orangutans, gorillas, dolphins and elephants.
Other animals either did not notice his reflection, or saw him as another animal that is perceived or as a rival or as an object for courtship. So, it turned out that fish, for example, start to attack his reflection, parrots, on the other hand, begin to care for, and cats and dogs to his reflection completely indifferent.
The birds of this quality have magpies in the test Gallup they tried to remove the sticker legs and beak, proving thereby that he had learned in the mirror reflection of yourself, not other animal*.
But the crows are renowned for their intelligence, himself in the mirror and don't recognize and relate to his reflection as to the other bird, and trying to attack. But new Caledonian crows have successfully coped with another problem associated with the mirror: the birds were offered to find boxes of food outside their field of view, focusing on the reflection of these boxes in the mirror. This task ravens decided so quickly that scientists were surprised by their success. *
In this regard, we can recall one funny incident that occurred in Canada. To the East of Vancouver, someone began methodically breaking the side mirror on a parked car. Residents were shocked - it won't start if the maniac in their area. However, it soon became clear that the mirror broke... woodpecker! Ornithologists explained to the residents that woodpecker sees in the mirror "another woodpecker", "fighting" with him and, in the end, wins. To deceive woodpecker, residents were advised to close than any mirrors in cars, which they did: the owners of the cars began to put on the side mirror of his car plastic bags from the supermarket. However, the woodpecker was astute: he guessed where hides his enemy, and began to break these packages got to the mirrors and still "won" his imaginary "enemy". Unfortunately, the fate of this battle of the birds is unknown. One of these days woodpecker suddenly ceased to break the mirror and disappeared in an unknown direction*.
And Australian ornithologists, which was necessary for the research to catch a few male lyrebird, was successfully used traps with a mirrored back wall. The bird comes there to figure out the relationship with the opponent.
By the way, the experiments with the reflection in the mirror was held with people. It was found that children begin to recognize themselves in the age of 1.5-2 years (and apes in 4-5 years, that is already at a Mature age).