Foraging and Other Behavior of Birds in Subtropical and Temperate Suburban Habitats

Abstract

Observations on the use of native and exotic trees and shrubs by buds in winter were made in the suburbs of Brisbane (1985, 1986) and Melbourne (1975). Among buds using woody plants for purposes other than foraging, native buds were consistently associated with native plants. In the Brisbane winter of 1985 there was no significant difference in the use of native and exotic plants by foraging native and exotic birds. However, in the drier winter of 1986 and in Melbourne, native buds foraged proportionately more frequently on native plants than did exotic buds and, when not foraging, used artiticial structures (as opposed to woody plants) less frequently. Exotic buds foraged proportionately more on the ground than on plants relative to the native buds in Melbourne and in the Brisbane winter of 1985. Counts of foliagk invertebrates were also made in winter in both cities. There were far more invertebrates on foliage in Brisbane than in Melbourne. Insect resting stages (egg masses and pupae), lerps and scales occurred more frequently on native than on exotic plants. Invertebrate densities on native plants exceeded those on exotics in Melbourne but not in Brisbane, due to the higher proportion of insect resting stages in Melbourne. The association between native birds and plants was weaker in Brisbane than in Melbourne and this is partially explicable by the differences in invertebrate numbers.