Horned Coot Fulica cornuta Scientific name definitions

Like the closely related Giant Coot (Fulica gigantea), the Horned Coot is a massive coot, although smaller than the giant. This coot has a more restricted and southern range than the Giant Coot, and it is found in lakes in more arid desert Puna. The most impressive feature of this bird is the large fleshy proboscis that lies on top of the bill, the “horn.” The role of this feature is not clearly known although it is reported that the horn can be raised during display. Another curious feature of the behavior of this little known coot is that its nest tends to be build on a large mound of stones that allow the nest to be placed away from the shore, but above the water’s surface. This mound of stones may be several feet wide at the base, and estimated to be composed of up to 1.5 tons of material! The coots themselves create the mounds, although they may be used for many years in a row.

46–53 cm; one male 2100 g, two females 1600 and 1900 g, two juveniles 1360 and 1500 g. Adult slate grey, darkest on head and neck ; undertail-coverts black with two white stripes; bill  greenish yellow with dull orange base and black ridge; long, extensible and erectile black proboscis which normally rests on ridge of bill  , and has two black tufts at base; legs and feet olive with dark joints. Shape and size like F. gigantea, but differs strikingly in bare part colours and forecrown structure. Sexes alike. Juvenile greyer, with extensively white chin and throat; bill black, tinged greenish; proboscis reduced or absent.

N Chile, SW Bolivia and NW Argentina.

Barren Andean high-altitude lakes , both freshwater and brackish, with dense submerged aquatic plants. Occurs chiefly at 3000–5200 m in desert puna.

May fly from one feeding ground to another. Local populations fluctuate greatly between periods of drought and inundation; altitudinal movements or displacements, some over long distances, may occur in harsh weather, especially in winter when food becomes locally unavailable as some lakes freeze, and at such times birds recorded as low as 2000 m. Recently recorded (Apr 2013) in SW Peru (Arequipa) (1 Ugarte, M., Angulo, F., Lane, D.F., Lloyd, H., O’Neill, J., Plenge, M., Schulenberg, T., Valqui, T., Walker, B. and Zepilli, R. (2014). Reporte del Comité de Registros de Aves Peruanas (CRAP) del periodo 27313. Bol. UNOP. 9(3): 45–54. Close ). Moves at night.

Poorly known. Eats mainly aquatic plants , especially Myriophyllum, Potamogeton and Ruppia; also grass and some seeds.

Breeds mainly Oct–Feb, although nest building recorded as early as Sept. Monogamous; may breed in colonies of up to 80 pairs. Nest enormous , resembling that of F. gigantea but usually built on conical mound of up to 1·5 t of stones, up to 4 m in basal diameter and built up from lake bed to height of c. 60 cm, ending just below water surface in platform c. 1 m² on which nest of water weed is placed. Both adults build; fresh material (usually Ruppia or Myriophyllum) constantly added to rim while nest in use; nest often used over many years, and also serves as nest-site for other waterbirds after coots have bred. Eggs 3–5; downy chick black with feathered crown, bill light grey with yellow base and tip, legs black; young fed by both parents; when adults bring fresh material to nest, seed pods are torn off and given to young. Chick mortality estimated at 25%.

Not globally threatened. Currently considered Near Threatened, and previously, Vulnerable. Probably in decline. Normally occurs at low densities: 1–10 nesting pairs at some sites with up to 70–80 at a few; concentrations of over 100 birds (up to 780) reported occasionally; 2800 birds reported on Laguna Pelada, Bolivia, in Nov 1989. Total numbers not known; Chilean population estimated at 620 birds; 180–200 birds and 70–80 nests counted at Laguna Meñique in Nov 1993, with 30–40 birds at adjacent Laguna Miscanti; little known about population trends and no definite evidence of recent decline. Lakes at which species occurs, although remote, remain vulnerable to contamination and effects of trampling by cattle, while from some, water is pumped to coastal cities and towns and to mines. Also suffers from hunting and egg-harvesting. Predation by Andean Gull (Larus serranus) reported as an occasional threat. Some lakes at which species occurs have been protected, including the important Laguna Pelada. Officially considered “vulnerable” in Chile, where census work, surveillance and other studies are being carried out.