A comparison of the diet of three finch species in the Yinberrie Hills area, Northern Territory

The diet of three finch species, the Gouldian Finch (Erythrura gouldiae), the Long-tailed Finch (Poephila acuticauda) and the Masked Finch (Poephila personata) was studied at a site in the monsoonal tropics of northern Australia from June 1995 to May 1997. Seeds of native grasses dominated the food of all three species. There was seasonal variation in the diet of all three species, with seeds of annual grasses being important during the dry season, and seeds of perennial grasses being important during the wet season. Seed of annual spear-grass (Sorghum spp.) was important for all species during the dry season, but was especially prominent in the diet of the Gouldian Finch. Invertebrates, especially termites, were prevalent in the diet of the Long-tailed Finch in the late dry season but were not conspicuous in the diet of the other species. Relative to co-existing finches, the Gouldian Finch is a dietary specialist and thus potentially more exposed to changes in the distribution and abundance of key food resources. This may partially explain the current threatened status of this species.