Streamertail is a spectacular hummingbird endemic to Jamaica. There are two populations of Streamertail: the "Red-billed" Streamertail (T. p. polytmus), which occurs on most of the island, and the "Black-billed" Streamertail (T. p. scitulus), which is restricted to the eastern part of the island. Each of these has been considered to be a separate species on the basis of differences in bill color, size, voice, and display, but the two populations interbreed to some extent in the John Crow Mountains. Both populations share green plumage, a black cap, and very long black tail streamers in the male. Females of both populations are green above and whitish below, and lack the ornamental tail feathers.