The white-tailed tropicbird Phaethon lepturus, is a tropical pelagic seabird and the smallest of the tropicbird family measuring up to 40 cm without its tail streamers, and up to 80 cm with its tail feathers, both sexes are similar in size, males generally have longer tails. It has a wingspan of 89 to 96 centimeters, and it bears a black band on its inner wing. This bird has an orange-yellow to red bill distinguishing it from the red-billed tropicbird. Like other tropicbird species, Phaethon lepturus has a large and powerful bill, its head is large, and its neck is short and thick. It has totipalmate feet; all four digits are connected by webbing. Juvenile white-tailed tropicbirds have a yellow-greenish bill and lack the long tail streamer. Tropicbirds can be recognized by their loud, piercing, shrill, grating whistle, or crackle given in a rapid series in a display flight.
Tropicbirds frequently catch their prey by hovering and then plunge-diving, typically only into the surface-layer of the waters. The white-tailed tropicbird feeds on small fish, especially flying-fish, squid and some crustaceans with a preference for crabs.
White tailed tropicbirds live in the tropic Atlantic, western Pacific and Indian Oceans. Geographic location may affect feeding habits and breeding patterns: breeding can be seasonal in some regions while being more or less continuous in others. Tropicbirds engage in remarkable courtship displays, with groups of two to 20 birds flying simultaneously and repeatedly around one another in large vertical circles while swinging their tail streamers from side to side. Females acquiescing to the display will mate with males on prospective nest sites. Nesting in rocky crevices and inaccessible sites such as cliffs which allows them to take off more easily, the females will lay a single spotted brown egg that will incubate for 40 to 46 days. Both male and female take turns to incubate, although most of the incubation is carried out by the female while the male searches for food. Once hatched, the grey chick will stay in the nest alone for several days at a time while the parents search for food for 12 to 13 weeks. When not breeding, white-tailed tropicbirds disperse widely across the oceans.
The species is currently evaluated as “Least Concern”. The species is widespread; therefore, no immediate concern has been raised. However, human disturbance of nesting sites is thought to be part of the reason that the population of white-tailed tropicbirds has been in decline.
The legs of a tropicbird are located far back on their body, making walking impossible, so that they can only move on land by pushing themselves forward with their feet.