Wind farm noise suppresses territorial defense behavior in a songbird

Abstract

In birds, anthropogenic noise has been linked to reduced breeding densities and success, but the mechanisms by which this occurs are currently unclear. In this study, we investigated whether wind turbine noise, an increasingly common source of anthropogenic noise in remote and rural locations, affects territory defense in a songbird, the European robin (Erithacus rubecula). We showed that robins increase low-frequency song elements in response to territorial intrusion under quiet conditions but that this response did not occur in the presence of wind turbine noise. These results are particularly interesting in light of previous work implicating low-frequency song in aggression, perhaps as a signal of body size. Thus, anthropogenic noise may affect their ability to deter an intruder, leading to expenditure of extra time and energy, to increased risks of injury and, as a consequence, reduced breeding success. Our study contributes to understanding the impact of anthropogenic noise on birds by linking disruptive noise and territorial behavior, which may be a mechanism underlying the reduction in bird breeding densities and success that has been reported in noisy areas.