Meeting Abstract
Anthropogenic noise, which is increasing globally, affects birds from gene expression up through alteration of community composition. At the behavioral level, noise often disperses birds away from the point source. The impacts of this dispersal on surrounding quieter areas is not well understood. Therefore, in this project, we sought to understand how noise-related dispersal affected the sociality of groups of songbirds as they moved away from the source of noise. As the displaced birds would likely be forced to occupy a smaller area that may already have resident individuals, we predicted that displaced birds would show a more clustered social network that may include new individuals, and that individuals within the flock would have more social connections overall. We tested these ideas in two songbird systems, captive domesticated zebra finches (Taeniopygia guttata) and free-living red-backed fairy wrens (Malurus melanocephalus). Preliminary results indicate that networks became more clustered during experimental sound treatments and lost connectedness in the period following a sound treatment. Free-living birds seemed to shift their territory away from the sound source, and only some individuals returned to the original territory following the sound treatment. If social networks are altered consistently, there may be implications for future breeding success, detection of communication signals, and even for pathways of disease transmission among individuals.
