Other Names: none
Distribution: Pacific coastline and waters off of Central and South America.
Size: 18-20 cm in length with a 34-38 cm wingspan.
Plumage: A large white triangular patch on the rump is characteristic of the species. The top of the tail and flight feathers appear dull white because of dark feather shafts. The rest of the plumage is uniform dark brown to black with a paler diagonal bar across upper surface of the wings. The bill, legs, and eyes are dark brown to black.