Behavioural responses of birds to urbanization

Abstract

Urbanization is a growing cause of habitat loss, a major driver of global biodiversity decline. Urban habitats differ from the habitats they replace, altering the ecological and selective environment for urban dwelling species. To survive and thrive in these new habitats, species need to adapt or alter their behaviour. One salient feature of urban habitats is the elevated levels of background noise relative to undisturbed ecosystems. Low frequency traffic noise in cities potentially masks animal communication signals, interrupting important functions such as mate choice and territory defence, possibly leading to decreased fitness. To avoid signal masking, species might adjust their vocal signals to higher frequencies. Alternatively birds might change the tempo of their songs, sing only selected songs of a repertoire, or even alter the timing of their singing activity (for example singing later into the night). Here I present a review of what we know about the effects of urban noise on birds, followed by results from our studies on behavioural responses to noise in urban bird species in Hong Kong. Finally, I will highlight interesting future research avenues to further our understanding on the impact of noise on urban wildlife.