$Colymbus dominicus brachypterus Brewster,1902,Bulletin of the Museum of Comparative Zoology,Harvard University,41,p.13,1902 (Santiago,Lower California). Not Colymbus dominicus brachypterus Chapman,1899.
During breeding,mainly shallow,stagnant fresh waters,marshy ponds,lakes,slow-flowing stretches of rivers.Prefers water with abundant vegetation,both emergent & along shores.breeds to 3100m.On migration & outside breeding,occurs on more exposed waters.
"Mainly May-Sept in N;Sept-Dec in S.;all year round in tropical areas." (HBW,1,p.190)
Mainly sedentary. Populations of extreme north move south, wintering south to Baja California and Central America.Most movements by night,alone or in pairs.Concentrations of up to 20,000 birds occasionally recorded on Salton Sea.Vagrant to Hawaii,north Alaska,Bermuda,Azores and western Europe. Race antarcticus recorded on Grenada.