Social behaviour and displays of the Hoary-headed Grebe Poliocephalus poliocephalus

Abstract

The Hoary-headed Grebe Poliocephalus poliocephalus specialized in feeding on an unpredictable though at times very abundant supply of tiny arthropods. It may be more gregarious than any other grebe, with less developed agonistic behaviour. A strong tendency to cluster may facilitate food-location and reduce predation. Big roosts where the individuals clump densely are formed by night. Courtship rituals are simple, and similar to those of the New Zealand Dabchick P. rufopectus. The two species form a distinct evolutionary line, with the Neotropical White-tufted Grebe Rollandia rolland and Great Grebe Podiceps major as the nearest relatives.