Overview
The Slate-colored Coot (Fulica ardesiaca), also widely celebrated as the Andean Coot, is a high-altitude rail endemic to the majestic lakes and puna wetlands of the Andean mountains. Enduring freezing night temperatures and intense UV radiation above 4,000 meters, it is famous for occurring in two distinct color morphs—one with a pure white frontal shield and another with a rich chestnut-red frontal shield.
Biology and Physical Characteristics
The Slate-colored Coot has a heavy, rounded body with dark slate-grey to sooty plumage, deepening to black on the head and neck. It exhibits fascinating facial polymorphism: the common morph features a pale bluish-white bill and a large, swollen white frontal shield, while the less common ‘red-shielded’ morph displays a bright yellow bill with an intense chestnut-red frontal shield. Its legs and lobed toes are pale slate-blue to grey.
Behavior and Ecology
A superb diver, it repeatedly plunges several meters beneath the surface of cold mountain lakes like Lake Titicaca to harvest lush beds of submerged waterweeds. It is territorial when nesting, building large mounds of aquatic plants among floating reed islands, but aggregates into huge communal feeding rafts during the dry Andean winter.
Conservation and Human Impact
Assessed as Least Concern by the IUCN, the Slate-colored Coot is widespread and highly abundant across Andean high-elevation lakes throughout Peru, Bolivia, and Ecuador, though local populations are vulnerable to wetland pollution from mining operations and severe climate-induced drought.
Interesting Factoid
The Slate-colored Coot is a master of two-faced disguise: in the exact same Andean lake, some individuals sport bright ivory-white forehead shields, while their neighbors wear fiery chestnut-red shields like completely different species.