Description: It is the largest grebe in South America, characterized by an elongated body and long neck that give it a sleek and elegant appearance. In breeding plumage, the head is dark with a distinct white stripe extending from the base of the bill along the sides of the neck, contrasting with the dark gray upperparts and pale underparts. The reddish eyes are a noticeable feature. Outside the breeding season, the plumage becomes duller, with grayish tones and reduced contrast.

Geographic distribution: It is widely distributed across the southern cone of South America, from southern Brazil, Paraguay, and Uruguay to Chile and much of Argentina, including Patagonia. Its occurrence is closely linked to large inland water bodies.

Habitat: It inhabits lakes, lagoons, reservoirs, and slow-flowing rivers, both freshwater and brackish. It favors open and extensive water bodies with areas of aquatic vegetation used for shelter and breeding, while often foraging in open water.

Feeding: The species is primarily piscivorous, feeding mainly on fish of various sizes captured during prolonged dives. Aquatic crustaceans and, occasionally, insects also form part of its diet. It is a highly skilled diver, using powerful leg strokes to chase prey underwater.

Behavior: Usually observed alone or in pairs, though small groups may form outside the breeding season. It is a wary species that typically dives rather than flies when disturbed, traveling considerable distances underwater. Vocalizations are infrequent and mostly associated with courtship and breeding activities.

Nesting: Breeding takes place in floating nests made of aquatic vegetation and anchored to emergent plants. The clutch generally consists of 2 to 4 eggs, incubated by both parents. The chicks are precocial and are often carried on the adults’ backs shortly after hatching.

Conservation status: It is classified as Least Concern, with relatively stable populations throughout most of its range, although wetland degradation and local human disturbance may negatively affect some populations.

Author of this compilation: EcoRegistros – 22/12/2025