Song playback increases songbird density near low to moderate use roads

Abstract

Many songbird species avoid roads. Although acoustic masking, vehicle collision, and edge effects are likely culprits, spatial avoidance also occurs along low use roads and at locations distant from the pavement. Neophobia may be one factor contributing to avoidance in these regions. In this case, playback of bird song, generally a signal of high-quality habitat, may reduce avoidance and increase territory establishment. We investigated whether playback of song from 6 migratory species increased territory establishment along low to moderate use roads in a community of songbird species. We determined whether the intensity and regularity of anthropogenic noise altered the pattern of response, and whether particular life-history traits predicted which species were responsive to playback. Territory density was significantly higher where song playback was present. Species-specific responses were variable, with 11 species increasing territory density by >30% at playback sites and 6 species decreasing in density. Noise level did not significantly impact establishment. Foraging behavior, habitat, and song frequency predicted which species were most responsive to playback. These results are similar to a companion study conducted near forest edges that did not contain roads, and suggests that song playback may be a viable method for increasing songbird use of near road habitats. Although additional work is needed to understand the variable responses of particular species and to address vital issues, such as the reproductive success of lured birds, this study highlights a behavioral management technique that may have significant conservation implications along the vast worldwide network of roads.