The White-winged Coot is distributed from Bolivia and southern Brazil to Tierra del Fuego in Argentina. It is found on freshwater lagoons, ponds and marshes where it prefers sandy or grassy shores.
Its bill is yellowish while its shield can vary in colour from pale yellow to bright orange. Belton speculates that this might be related to the age of the birds. It has white undertail coverts and broad white tips to the secondaries which give the bird its English name and are visible in flight.
It is smaller than Red-gartered CootF. armillata as you can see in the 3rd photo but about the same size as the other coot found in the same areas, Red-fronted CootF. rufifrons.