Ecology of honeyeaters (Meliphagidae) in Western Australian Eucalypt Woodlands I: Resource allocation among species in the Great Western Woodland during spring

摘要

Nectar-feeding birds are commonly the most abundant birds in Australian eucalypt forests and woodlands, where they play a key role as pollinators of native plants. Among the nectar-feeders, honeyeaters (Meliphagidae) are particularly aggressive and may exclude other birds from the habitats they occupy thereby affecting the composition of avian communities and the distribution of species on a landscape scale. Such behaviour has cascading effects on ecosystems, changing the abundances and kinds of plant-eating arthropods. A comprehensive knowledge of the ecology of honeyeaters is therefore basic to the conservation management of Australia's natural environments. In this paper, we describe the foraging ecology of honeyeaters in the Great Western Woodland (GWW) during the spring, comparing the use of resources between species and locations. Species of honeyeaters in the GWW differ morphologically, and in social and dispersive behaviour, but aggregate in multi-species flocks on blossoming eucalypts (Eucalyptus spp.), the main source of nectar. There are differences among the species of honeyeaters in the eucalypts frequented as nectar sources, with these differences reflecting differences among species in habitat. Species also differ in foraging manoeuvres (the way food is taken), substrates, and heights, as well as the plant species visited when feeding on foods other than nectar (e.g., lerp, arthropods, and fruit). The use of substrates and foraging manoeuvres differed between locations. Differences in foraging ecology between locations were primarily related to differences in flowering phenology and vegetation structure (e.g., height, type of bark) and floristics, which in turn affected the food resources available to honeyeaters. Our observations support arguments that the long-term conservation of nectar-feeders cannot be achieved by relying on a fragmented system of widely dispersed conservation reserves. This is especially true in an era of accelerated climate change. Instead, a landscape scale, if not a continental scale, approach to ecosystem conservation that emphasizes habitat connectivity is required.