The general plumage of the Tawny Frogmouth is silver-grey, slightly paler below, streaked and mottled with black and rufous. A second plumage phase also occurs, with birds being russet-red. The eye is yellow in both forms, and the wide, heavy bill is olive-grey to blackish. South-eastern birds are larger than birds from the north. Tawny Frogmouths are nocturnal birds (night birds). During the day, they perch on tree branches, often low down, camouflaged as part of the tree.