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. Silvereyes were able to adjust their seasonal foraging to incorporate exotic vegetation with high arthropod abundances. Silvereye foraging also varied greatly on a seasonal scale. Silvereyes more frequently used individual trees, native or exotic, that supported the highest level of arthropod abundance. 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 (Zosterops lateralis) are commonin urban areas and so provide a useful study organism to test the factors that allow somebirds to become urban 'winners'. However, the availability of arthropod prey is emerging as a potentially important factor in shaping urban bird communities. 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. We suggest that abundant, continuously available food ( seed) resources, apparently limited competition for food and the presence of suitable roosting sites are probably important in facilitating winter occupancy of parkland by red-rumped parrots in Melbourne. Mean flock size was 10 +/- 6 and, on average, males comprised 67 +/- 19% of a flock's members. Mean population density in occupied sites was 1.3 parrots ha(-1). Little aggressive interference competition occurred with other ground- feeding birds. Sites occupied by parrots had relatively more native trees, tall trees and dense canopy cover than unoccupied sites this may be important in providing suitable daytime and nocturnal roost sites. Two of these species were common turf grasses and their visible and concealed seeds provided > 50% of the diet. The predominantly ground- feeding red-rumped parrot consumed mainly seeds of exotic grass and herb species, four of which were particularly important in providing a continuous winter food resource. We investigated aspects of the parrot's ecology at six parkland sites through late autumn and winter 2006 to elucidate these factors. The factors that have facilitated this colonisation have not been evaluated. The red-rumped parrot (Psephotus haematonotus), which appears to be undergoing range expansion, started colonising metropolitan Melbourne similar to 30 years ago.
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