It is a more revealing investigation than it seems. Researchers from the universities of Bonn and Bochum undertook it. They used 58 specimens of roosters. This is how they learned that roosters recognize themselves in mirrors. The study was published in the journal PLOS ONE.
«We study the ability of animals to recognize themselves and, therefore, be aware of themselves. “It is a central question in behavioral research.” This is stated in a statement by doctoral student Sonja Hillemacher.
Warning of danger
«Roosters warn their companions with special calls if they see a predator. For example, a bird of prey or a fox. But if they are alone, they remain silent, so as not to attract the attention of the predator. “The danger signal is the perfect behavior for a test of self-identity,” the research notes.
They sought to know if the roosters would really raise the alarm if their companions were present… and if they would remain calm if they were alone. They made a testing ground. A fence separated two sections, although both sides were visible to the roosters. A bird of prey was then projected onto the ceiling of one section.
The researchers tested 58 roosters. The experiment was repeated three times with each rooster. In total, the roosters sounded 77 danger alarms when other hens were present. And only 17 when they were alone. “Most roosters warn their mates when a predator is on the loose.”
Other species
For the next step, a mirror was placed between the sections instead of a fence. How do roosters react to the combination of their own image in the mirror and a bird of prey? The test was performed again three times with each animal. Of 174 tests, only 25 alarms were issued. “This shows that roosters do not see their own reflection as someone else’s,” says Sonja Hillemacher. Roosters recognize themselves in mirrors.
“When a predator threatens them, it becomes clear that their reflection in the mirror is not another rooster, but themselves.” This approach can be used to study self-knowledge in other species.
