Resource availability and foraging of Silvereyes (Zosterops lateralis) in urban trees

Abstract

Whereas the changes in avian community composition resulting from urban development are well described, the specific factors that allow certain species to thrive in urban areas remain poorly understood. However, the availability of arthropod prey is emerging as a potentially important factor in shaping urban bird communities. Silvereyes (Zosterops lateralis) are common in urban areas and so provide a useful study organism to test the factors that allow some birds to become urban 'winners'. We here present the results of an observational study on the foraging frequency of Silvereyes and arthropod prey availability in native and exotic urban trees in Dunedin, New Zealand. Silvereyes more frequently used individual trees, native or exotic, that supported the highest level of arthropod abundance. Silvereye foraging also varied greatly on a seasonal scale. Silvereyes were able to adjust their seasonal foraging to incorporate exotic vegetation with high arthropod abundances. We conclude that the flexibility of Silvereyes with regards to foraging and their use of exotic plant species are important factors in their success in surviving urban development. © BirdLife Australia 2013.