The winter foraging behaviour of birds in a mixed eucalypt forest and woodland on the Southern Tablelands of New South Wales

Abstract

In this paper, I present data on the foraging behaviour of eucalypt forest and woodland birds at two sites on the Southern Tablelands of New South Wales during the non-breeding season (winter). The winter community was a subset of the summer community, with six guilds among 23 species identified by cluster analysis compared with seven guilds among 41 species in summer. Despite this difference, birds were abundant during winter, with more than 200 individuals of 29 species recorded during July censuses on the two 10 ha plots. Although a few birds fed on nectar, nectar was not abundant in winter and the nectar-foraging guild present in summer was absent in winter. Most birds that relied on large arthropods and aerial foragers left the area after summer and an aerial foraging guild was restricted to one species, the Grey Fantail. As in summer, species differed in foraging manoeuvres and substrates, as well as foraging heights and the plant species frequented to find food. The continued abundance and diversity of species/guilds through the winter is best explained by the variety of food resources available for birds; the complexity of foliage, bark, and ground substrates provided a wide range of foraging substrates over the entire vertical profile of the vegetation. Maintenance of this structural complexity is essential for the survival of eucalypt forest and woodland birds.