United States - An experiment conducted on campus showed that some birds recognize the disturbing elements of their environment. They are ready to attack when they are approached again.
The campus of the University of Florida, United States, meets many Mockingbird (Mimus polyglottos). They build their nests in shrubs and bushes that surround it.
Based on this fact, scientists have used student volunteers to conduct a study. They asked them to approach the nests and shaking moqueurs hedges in passing, without touching the eggs or chicks.
The students replicated these movements for several days. After five experiments of this type carried out last year, scientists were able to conclude that birds act according to the same model in case of threat.
The first day, mocking leave the shrub in piaillant once the student approached the nest. But from the third day, the bird has stored the image of the individual threat and launches an alert when he is only few steps from its nest.
Every day, mocking become more aggressive toward students, even stitching on bill them for the injury to the face. These birds are even able to recognize the person if he wears clothes different from those of previous days, or if approaching the nest from other angles.
In contrast, any other unknown person approaching the nest causes no early reaction from the birds. According to the report published in the journal Proceedings of the National Academy of Sciences, the alerts issued by mocking both are less violent when they target unknown individuals.
Dr. Levey said that two passages were sufficient to recognize that mocking students. By watching for one minute, they are able to save several people and recognition among many people.
This is the first study to demonstrate that animals living in the wild can perfectly identify individuals.