The prevalence of human-generated noise is posing novel challenges to birds, by changing how they communicate or causing them to disperse away from the source of noise. We sought to understand how noise affected space-use and social connectivity in a small passerine bird, the Red-backed Fairywren (Malurus melanocephalus). As the displaced birds would likely be forced to occupy a smaller area that may already have resident individuals, we predicted that noise-affected birds would show increased social connectivity that may include new individuals. To test this, we introduced an experimental point-source of traffic noise to groups of fairywrens in an otherwise quiet habitat and compared the change in social connectivity of birds in groups exposed to noise to the changes in social connectivity in neighbouring groups unaffected by noise. Contrary to our prediction, noise-affected birds had reduced social connectivity during experimental noise treatments, as measured by weighted-degree, which was driven by a reduction of interactions with birds of neighbouring groups outside the noise zone. Additionally, we did not discern a change in space-use in response to our noise treatment. Therefore, we suggest that noise reduces the efficacy of signal transmission and detection in this species, resulting in the reduction of social connectivity between groups of this otherwise highly social songbird.
EMU - Austral Ornithology
Hawkins, Carly E.; Ritrovato, Isabel T.; and Swaddle, John P., Traffic noise alters individual social connectivity, but not space-use, of Red-backed Fairywrens (2020). EMU - Austral Ornithology.