The Broad-tailed hummingbird, Selasphorus platycercus, is a medium-sized hummingbird, nearly four inches (10 cm) in length. Male and female both have iridescent green backs and crowns and a white breast. The male has a gorget (throat patch) that shines with a brilliant red iridescence. The female is much duller with rust-colored, mottled flanks and underside. Female's tail feathers are tipped with a band of white. In flight the wings produce a distinct trilling noise diagnostic for this species.