Abstract

Eastern rosellas, Platycercus eximius, and pale-headed rosellas, P. adscitus, fed in single-species flocks of generally less than five birds. Eastern rosellas fed in larger groups, particularly at ground level, and showed greater seasonal and daily changes in flock sizes than pale-headed rosellas. These interspecific differences are attributed to: (1) their feeding stations; (2) the social structure of each species; (3) the relative degree of aridity of the study areas.