Research on European robins shows that the birds become aggressive due to human noise pollution. Urban robins acted more angrily towards a new bird than their rural counterparts. According to the researchers, urban birds are more aggressive because of the noise they are used to.
The scientists placed a 3D model of a chirping robin in a room with male robins. They added traffic sounds. Then the researchers looked at the robins’ reactions. They wrote their findings in the scientific journal Behavioral ecology and sociology.
Urban robots reacted more physically to 3D birds than rural robins. Researchers believe that birds coming from the city are more aggressive, because their daily communication is disrupted by construction noise and traffic noise, for example.
When the researchers played the sounds of traffic, the robins from the city began to sing more softly. Presumably they do this because they are used to the noise. They have learned to wait for the weather to calm down. Despite the quieter singing, city birds react more aggressively to intruders as standard.
On the other hand, country robins reacted more aggressively to hearing traffic noises. By waving vigorously and showing their red feathers, they probably wanted to compensate for the fact that they were less visible.
It is common for birds to interact competitively with newcomers. They tune their vocals or interact physically to mark their territory.