It is crucial for animals that live in groups to distinguish the members of their "gang" from those of other groups. German scientists have shown that common macaques living in two groups of 46 and 57 individuals in "La Forêt des Singes" , a wildlife park in Rocamadour (France), are able to spontaneously distinguish photographs of their companions from those of the rest of macaques without having received previous training . This ability improves with age, according to experiments, led by Julia Fischer of the German Primate Center and the University of Gottingen. "At least adult monkeys memorize the facial features of a large number of individuals," the authors conclude in an article published in the journal Animal Cognition .
In the study, when adult monkeys were shown a photo of a familiar face, they quickly looked away. "Adult animals spent more time observing unfamiliar animals, suggesting that they recognized their group members from the photos," explains Fischer. The young people, however, were equally interested in all the images, and they were also the ones who when seeing them showed the most enthusiasm: they licked their lips, and touched and sniffed the image, trying to greet their portrayed fellows.
"We didn't expect them to respond that way," admits Fischer, who thought that the images would not be relevant to them, since in real life they don't have anything like a photograph.
