Red-tailed Tropicbird on Nihoa Island

Mature birds have mostly white plumage with a conspicuous black stripe from gape, curving towards and passing through eye. Their bill is strong, decurved, and bright red. Their legs and feet are blue-gray with webs distally black. Red-tailed tropicbirds also have a white tail with long, red, central rectrices or tail plumes (36-55 cm).