Phaethon lepturus Daudin, 1802

Adult Size and Body Form

The adult white-tailed tropicbird (Phaethon lepturus Daudin, 1802) is a slender, mostly white bird, measuring 71–80 cm (28–31 in) long in total. This total length includes very long central tail feathers, which double the bird's overall length. Its wingspan ranges from 89–96 cm (35–38 in).

Adult Plumage and Bill Color

This species has a black band on the inner wing, a black mask around the eye, and a bill that ranges in color from orange-yellow to orange-red. Bill color, a pure white back, and a black wing bar separate this species from the red-billed tropicbird.

Sexual Dimorphism

Male and female white-tailed tropicbirds look similar, though males on average have longer tails.

Juvenile Appearance

Juveniles do not have the long tail streamers, have a green-yellow bill, and a back marked with fine barring.

Breeding Location and Egg Laying

White-tailed tropicbirds breed on tropical islands, where they lay a single egg directly onto the ground or a cliff ledge.

Breeding Frequency

They do not follow a yearly breeding cycle; instead, breeding frequency depends on climate and the availability of suitable breeding sites. They can breed again 10 months after a previous successful breeding attempt, or 5 months after an unsuccessful one.

Non-Breeding Dispersal

When not breeding, they disperse widely across the world's oceans, and sometimes wander very far from their typical range.

Diet and Feeding Behavior

They feed on fish and squid, which they catch by plunging from the surface, but this species is a poor swimmer.

Vocalization

Its call is a high, screaming keee-keee-krrrt-krrt-krrt.