The southern form lives on lakes in Argentina and Chile, eating small aquatic animals.
It has a grey head and back with pale flanks; in breeding plumage, golden tufts extend behind the ears.
It feeds on aquatic invertebrates in vegetated steppe lakes and may gather in large groups.
In Patagonia, the southern form is mainly a summer resident, though some remain in winter. Winter birds are solitary or in small groups; breeding colonies nest on floating vegetation.
The southern form has red eyes, a fine black bill, and a black nape and hindneck. It loses its ear tufts in nonbreeding plumage; juveniles resemble that plumage but are browner, with a white throat.
An extinction-risk assessment has not been added yet.