On the selection of tree species by Acanthizidae in open-forest near Sydney, New South Wales

Abstract

Selection between tree species as foraging substrates by four species of Acanthizidae was studied in an open eucalypt forest near Sydney, New South Wales. Weebills Smicrornis brevirostris, Striated and Little Thornbills Acanthiza lineata and A. nana foraged more often than expected on the foliage of Narrow-leaved Ironbark Eucalyptus crebra than on that of Grey Box E. rnoluccana. By contrast Gerygone olivacea used the two trees in about the same proportion as the amount of foliage of each species. Weebills and Striated Thornbills selected Narrow-leaved Ironbark foliage as a foraging substrate more often than Little Thombills in winter but not in spring. Little Thornbills foraged on Narrow-leaved Ironbark foliage more often in spring than in winter. The selection of eucalypt foliage as a foraging substrate is correlated with the abundances and kinds of invertebrates found on the two tree species. Invertebrates were generally more abundant on the foliage of Narrow-leaved Ironbark than on that of Grey Box in both winter and spring.