Widespread, rather large but “average” coot of lakes, marshes, and river mouths; mainly in Andes and adjacent Pacific coastal lowlands. Despite the name, its plumage is no more slate-colored than other coots. Adult comes in three types: most Andean birds have a dark red forehead shield and yellowish bill; elsewhere, rounded forehead shield can be white or pale yellow with a whitish bill. Legs greenish, appreciably shorter than legs of Giant Coot, which occurs alongside Slate-colored at some lakes. Juvenile has a variably grizzled whitish face and throat.