Traffic is pretty aggravating even on the best of days. A new study finds that it’s so frustrating, it even angers robins.
Researchers from Anglia Ruskin University in the UK and Koç University in Turkey recently studied how urban and rural European robins react to traffic noises. The animals, which are quite territorial, show another bird that it’s on their turf with movements and song. The team found that their physical aggression toward intruders increased when there was traffic noise. In a paper published in the journal Behavioral Ecology and Sociobiology, the researchers explain that this is likely due to the birds having to overcompensate when these noises drown out their territorial songs.
Dr. Caglar Akcay, the study’s senior author and senior lecturer in behavioral ecology at Anglia Ruskin University, explains, “We know that human activity can have a significant impact on the long-term social behaviour of wildlife, and our results show that human-produced noise can have a range of effects on robins, depending on the habitat they live in.”
When it comes to habitat, urban robins were found to be more physically aggressive than rural robins, but rural robins upped their aggression levels when dealing with traffic noise. In the study, the artificial noise was piped in with speakers, while a 3D model of a robin and recordings of their songs served as an “intruder.”
During the study, researchers also observed that urban robins may have learned not to make their calls when traffic noise is heavier, as they reduced their call rate at this time. The team believes that because rural robins don’t have as much experience with such noises, they haven’t learned to adjust their calls and thus compensate with more aggression.
Higher levels of aggression are harmful to this species, though.
Dr. Akcay explains, “The chronic high levels of noise that exist day and night in urban habitats, such as from traffic or construction equipment, may permanently interfere with the efficient transmission of acoustic signals and this is likely to be the key reason why urban robins are typically more aggressive than rural birds. It should be stressed that physical aggression is a risky behaviour for small birds like robins and is likely to have health consequences.”
Among those consequences are injuries and attracting the attention of predators.
Robins aren’t the only animals impacted by noise. Female frogs have been found to be less capable of responding to a male’s signal when it’s noisy, and some bats avoid hunting in areas with road noise.