Animal - Crows can remember faces

Crows are birds that are able to remember the faces of people who pose a threat to their own kind. Also they can invite other crows to join them to take revenge on the attackers.
Crows can bring their bad experience with some people to the wider population of crows, says co-author of study John Marclaf at the University of Washington. Intrigued by the behavior of the crows living on their campus in Seattle, Marclaf and two colleagues wanted to determine whether the bird will remember the person they have experienced a traumatic experience.
For their experiment the scientists with thesame masks had putted the rings on the captured birds, and then let them free. Thenthey watched the reactions of crows. The moment they saw the mask, the crows began to caw angrily, waving their wings and come together in a threatening crowd.
If, traveling to other parts of the city, the researchers placed the same mask on their faces, crows that they have never previously captured would have recognized the dangerous faces. Crow behavior demonstrates that birds learn not only fromdirect experience, but also through communication with other members of the species.
During a five years of research, scientists have extended the experiment at several locations, using the other masks. Regardless of the change of masks, there are more crows reacted to the arrival of dangerous persons.
Alert is not just spreading only to the neighborhood crows, but also a young crows, observing the reactions of their parents, began to imitate them.