Building use by urban commensal avifauna in Melbourne central business district, Australia

The foraging and perching behaviours of urban commensal birds are well studied but disproportionately focused on green spaces (e.g. parks, backyards) rather than inner city urban sites. The relationship between building use and foraging was examined in free-ranging urban birds of the central business district (CBD) of Melbourne, Victoria, Australia during 2015–2016. The presence of common birds on urban buildings was attributable both to the time of day (Feral Pigeons and Silver Gulls in the morning, and House Sparrows in the evening) and the architectural period of the building (Feral Pigeons, House Sparrows and Common Mynas were found mostly on historic buildings). The proximity of buildings to tree cover had a significant impact on the presence of House Sparrows. Silver Gulls were present in large numbers only in areas with the least disturbance from traffic and trams (and their overhead wires). Feeding behaviours constituted a small portion of time budgets for all species (mean 4.3%; range 0–11%) compared to perching (28.2; 0–60%), walking (30.4; 0–80%) and flying (23.0; 0–54%), indicating that food sources were highly abundant and requiring little effort to acquire. Management implications of this study support control of food availability rather than costly and ineffective bird deterrent systems on buildings.