The Southern House Wren, (Troglodytes aedon), is a very small songbird of the wren family, Troglodytidae. House Wren species occurs from Canada to southernmost South America, and is thus the most widely distributed bird in the Americas. All subspecies have blackish barring to the wings and tail, and some also to the flanks. All subspecies show a faint eye-ring and eyebrow and have a long, thin bill with a blackish upper mandible, and a black-tipped yellowish or pale grey lower mandible. The legs are pinkish or grey. The short tail is typically held cocked. This bird's rich bubbly song is commonly heard during the nesting season but rarely afterwards. There is marked geographical variation in its song, though somewhat more gradual than in the birds' outward appearance which can strikingly differ e.g. on neighboring islands in the Caribbean. Birds from far north and south of the species' range nonetheless have songs that differ markedly.