slightly rosy tinge when its plumage is fresh, the bolder look of the black barring on the upper wing, and the more solid look of the black on the outer wing. The subspecies P. a. indicus can be distinguished by its smaller size, its smaller mask on the face, which often does not extend far behind the eye, and its more orange bill with a black cutting edge. When the chicks hatch, they are covered with gray down. This down is eventually cleared in about 40 to 50 days. The young chicks lack tail streamers. The juvenile looks similar to the adult with a mostly white crown. In the juvenile, the stripes above the eye usually are connected at the nape. The tail feathers usually have black tips or subterminal dots and without the tail streamers that are distinctive on the adult. Occasionally, a juvenile will have black markings on its flanks and under tail coverts. The red-billed tropicbird can be differentiated from the other tropicbirds by its red bill in combination with its white tail streamers. The slightly smaller red-tailed tropicbird has red rather than white tail streamers, and the white-tailed tropicbird can be differentiated by its smaller size, black stripe along its upper wing coverts, and its yellow-orange bill. Juvenile red-billed tropicbirds have more heavily barred upper parts than juveniles of other species. In flight, the royal tern can be confused with the adult red-billed tropicbird but can be distinguished by the former's less direct flight pattern and its lack of tail streamers. This tropicbird moults once every year as an adult, following a complex basic strategy. This is completed before courtship and lasts between 19 and 29 weeks, with most being completed in 24 weeks. Birds gain their adult plumage at two to three years of age. The red-billed tropicbird usually only calls near breeding colonies, where it joins in with groups of other adults, numbering from 2 to 20, in circling above the sea and making loud, harsh screams. If disturbed at the nest, the chicks will vocalize a loud and piercing shriek, either rasping or reeling. Distribution and habitat The red-billed tropicbird has the smallest range of the three tropicbird species, yet it still ranges across the Neotropics, as well as the tropical Atlantic, eastern Pacific, and Indian oceans. The nominate subspecies Phaethon aethereus aethereus breeds on islands in the Atlantic south of the equator,