$Colymbus cristatus australis Peters,1931,Checklist of Birds of the World,1,p.39.
generally breeds on small,shallow,highly eutrophic water bodies,with lush vegetation & typically stretches of open water.Erratic:readily oves into nw flooded areas,but abandons many sites after few seasons.Non-breeding:open,generally saline waters
"Mainly May/Jun in Europe;season longer in N.America with laying Apr-Aug." (HBW,1,p.194)
Highly migratory & dispersive,though populations in south of range can be more or less sedentary. Highly gregarious on migration & in winter,forming concentrations of up to hundreds of thousands at certai sites in North America & Asia: at Great Salt Lake,Utah and Mono Lake,California. Sites for primary moult and staging:Salton Sea,California,with ca 500K birds in winter.also in south Caspian Sea. Much movement apparently nocturnal,although diurnal migration also recorded in Palearctic.Straggler to Hawaii; also to Aziores,Madeira & Canaries.