THE INTERACTION OF BIRD COMMUNITIES WITH VEGETATION AND SEASON IN BRISBANE-FOREST-PARK

Vegetative and seasonal influences on bird community structure in wood land and open forest in Brisbane Forest Park were examined over two ye ars. The transition from woodland to open forest with open or closed u nderstorey was associated with changes from bird assemblages (Or guild s) dominated by nectarivores, vertebrate feeders, ground seed-feeders and invertebrate feeders at all levels, to ones dominated by frugivore s and invertebrate feeders from shrubs and dense understoreys. Underst orey vegetation density and eucalypt tree height correlated with the p resence of understorey invertebrate foragers and frugivores, the latte r related to fruit-producing rainforest plants in the understorey. Inv ertebrate feeders at all levels and ground seed-eaters predominated in summer movements into the park. The number of species feeding on bark invertebrates increased in winter. A severe drought in the first year affected most guilds except ground, bark or air invertebrate feeders and ground seed feeders. Vegetation density, structure and diversity a nd seasonal variation in food sources all influenced the structure of the bird communities.