Foraging of Birds in Eucalypt Woodland in North-eastern New South Wales

Abstract

The foraging behaviour of 40 species of birds in eucalypt woodland near Armidale is described. The foraging method, substrate, height and plant were noted for each foraging observation. Six guilds can be recognized on the basis of the substrate on which they forage. (1) Eleven species forage on the ground. This group includes two seed-eaters, and three insectivores that pounce on terrestrial invertebrates from low perches or the air. The remainder are gleaners of in- vertebrates. (2) Four species are bark-foragers. One is a trunk specialist, while the other three feed on upper branches, exfoliating bark and horizontal boughs respectively. (3) Foliage foragers make up the largest guild, with 13 species. Four species glean from both acacias and eucalypts. Three species mostly snatch insects from leaves whereas the rest glean from eucalypt leaves. This last group of species includes pardalotes and some honeyeaters, which feed on carbohydrate foods such as manna and honeydew as well as on arthropods. (4) There is single frugivore, specializing on mistletoe fruits. (5) The six aerial feeders include species that capture prey by hawking from a perch and others that continuously sweep through the air after insects. (6) Finally five nectarivores visit the flowers of eucalypts (three species) or mistletoe (two species).

Several very similar pairs or groups of species were identified (pardalotes Pardalotus, honeyeaters Melithreptus, thornbills Acanthiza). These merit more detailed study; indeed several have already been investigated.