Large high-Andean coot, 54 cm long, overall dark lead-gray with a blacker head and neck. Robust, bulky body, short wings, and a reduced tail. It is characterized by a fleshy black proboscis, like a “horn,” long and retractable at the base of the bill, which can be extended or retracted, and bears two small tufts at its base. Bill yellow with a pinkish base and black culmen, lacking the typical frontal shield of the genus. Iris red. Legs olive to yellowish, with long toes furnished with lateral lobes. In flight shows a whitish trailing edge on the wing. Sexes similar. Juvenile paler, with whitish throat and without a developed proboscis.
By shape and size it may be confused with other large coots of the region, especially the Giant Coot (F. gigantea), from which it differs by having reddish legs, a yellow frontal shield with a white center, and a mostly red bill with a pale tip, as well as two feathered lobes on both sides of the head.
Geographic distribution: Distributed in the Andes of southwestern Bolivia, northern Chile, and northwestern Argentina. In the country it inhabits puna and high-Andean environments of Jujuy, Salta, Catamarca, La Rioja, San Juan, and Tucumán. There are records in lagoons within protected areas such as Monumento Natural Laguna de los Pozuelos (Jujuy), Laguna Blanca (Catamarca), Laguna Brava (La Rioja), Parque Nacional San Guillermo (San Juan), and Laguna Huaca-Huasi in Parque Provincial Cumbres Calchaquíes (Tucumán). Its presence is local and fragmented.
Habitat: Inhabits high-Andean lagoons, both freshwater and brackish, generally open, with rocky or silty bottoms and abundant aquatic vegetation. It occurs between 3,000 and 5,200 m a.s.l., although it may descend to around 2,000 m during movements. It prefers well-preserved water bodies with good availability of submerged plants.
Diet: Mainly herbivorous, feeding on aquatic macrophytes (such as Myriophyllum, Potamogeton, and other submerged plants), as well as seeds and plant material. It feeds while swimming, partially diving, or grazing along the shores.
Behavior: Primarily aquatic species, observed alone, in pairs, or in dispersed groups. Territorial during the breeding season, it shows aggressive behaviors in defense of its territory, including short “running” displays over the water and vigorous wing-flapping toward other waterbirds. It flies little and with difficulty; movements are often nocturnal. Vocalizations are poorly known, consisting of low grunts. The function of the proboscis is not fully understood, although it has been observed to be erected during interactions and displays, likely linked to territorial or reproductive behavior.
Nesting: Builds enormous nests on mounds of stones that the birds themselves accumulate from the lagoon bottom, forming large structures. On this base they place plant material, creating an elevated platform above the water. These nests may be reused for years. The usual clutch is 3 to 5 eggs. Both adults participate in construction and chick care. It may nest in small colonies or associated with other coots.
Conservation status: Classified internationally as Near Threatened (NT) and as Threatened (AM) in Argentina. It is a scarce species with a fragmented distribution, naturally low populations, and very localized in high-Andean lagoons. In the country the population is estimated at fewer than 1,000 pairs, making it particularly vulnerable to any environmental alteration. Degradation of lagoons due to overgrazing, livestock trampling, and the resulting erosion that increases water turbidity directly affects its habitat. Additional threats include water extraction, pollution associated with various activities (including mining), and the introduction of exotic species. Predation on eggs and chicks by the Andean Gull (Chroicocephalus serranus) has also been recorded, which may impact local reproductive success.
Author of this compilation: Diego Carús y María Belén Dri – 12/04/2026