Medium-sized oceanic birds with pointed wings, highly elongate central tail-feathers, an overall white coloration with black markings on the wings, and excellent flight skills
29–40 in (74–100 cm); includes elongated tail streamers; wingspread 37–44 in (94–112 cm)
Number of genera, species
1 genus; 3 species
Coastal and offshore waters of warm-temperate and tropical oceans
Not threatened, although some populations are declining
Breed on isolated tropical islands; range widely in tropical and warm-temperate waters around the world, often far offshore
Evolution and systematics
There are only the three species of tropicbirds (genus Phaethon) in the family Phaethontidae. They are related to other waterbirds in the order Pelecaniformes, including pelicans, frigatebirds, cormorants, gannets, and anhingas. The Pelecaniformes lineage is ancient, with a fossil record extending to the Lower Eocene (54 million years ago).
Tropicbirds are medium-sized seabirds with a slightly decurved and pointed bill, long pointed wings, and highly elongate tail streamers (rectrices, the two central tail feathers). Body length is about 29–40 in (74–100 cm); this includes the tail streamers, which can be up to 21 in (53 cm) long and comprise about half the total body length. Wingspan is 37–44 in (94–112 cm), and the weight is 0.7–1.7 lb (0.30–0.75 kg). The plumage is overall white, sometimes with a pink flush, and black wing markings, a black eye-line, and sometimes a darker back (depending on the species). The bill is colored yellow to orange-red. Adults have elongate, narrow tail streamers. Young birds lack the tail streamers and have a gray-white banded back and wings. The short legs are placed far back on the body, making walking awkward. The feet are webbed as an aid in swimming. There is no obvious external physical difference between male and female tropicbirds.
Tropicbirds range widely in coastal waters of tropical and warm-temperate regions, sometimes occurring far offshore. They breed on isolated tropical islands such as Ascension Island in the Indian Ocean, Cousin Island in the Seychelles group, and Kauai in the Hawaiian Islands.
Tropicbirds breed on isolated tropical islands. When not breeding, they range widely in coastal and offshore tropical and warm-temperate waters.
Tropicbirds have a steady, pigeon-like flight, often settling on the surface of the water to rest. They use their webbed feet as rudders during flight, and sometimes hover in breeding displays. They do not walk well, and often shuffle on their belly when on land. They catch much of their food of small fish and marine invertebrates by making shallow plunge-dives, often from an impressive height. They have a tern-like voice and can be noisy around the breeding colonies, but are generally silent when at sea outside of the breeding season.
Feeding ecology and diet
Tropicbirds generally search for food singly or in pairs, but may also associate with large flocks of other seabirds. They often catch small flying-fish above the surface. They also feed on other species of small fish, squid, and larger
crustaceans caught at the water surface, or by making a shallow plunge-dive. The typical size of prey selected is determined by the size of the bill; in areas where two species of tropicbirds occur, they tend to partition food on the basis of bill size.
Tropicbirds usually nest on ledges of coastal cliffs, in cavities under rocks, or under vegetation that gives protection
from the sun and rain. On some Pacific islands, they nest in trees. Ground nests are a shallow scrape and are usually located together in colonies. The social courtship display includes groups of birds flying excitedly and noisily around the nesting site in undulating flight. During this display flight, the long tail feathers wave conspicuously up and down. Tropicbirds lay only one egg, which is initially colored mottled reddish or brown but becomes paler with time as the water-soluble pigment is lost due to moisture and rubbing. The chick hatches after an incubation period of 41–45 days. The chick has a dense, silky, gray or yellow-brownish down plumage that gives protection against intense sunlight. It is fed by both parents, beginning at an age of three days, and takes 11–15 weeks to fledge. Chicks are vulnerable to being killed by adults of the same or related species of tropicbirds that are seeking a scarce nesting site. Among the redbilled and white-tailed tropicbirds of Ascension Island, such interactions within and between the two species can result in a low survival rate of young and the evolution of complex differences in breeding timetables. Red-billed tropicbirds breed every year on Ascension Island, but white-tailed tropicbirds
breed every nine months and may do so at any time of the year.
Tropicbirds are not listed as being at risk globally by the IUCN or in the United States by the Fish and Wildlife Service. Although general population trends are not well known, some local breeding populations have declined because of disturbance and habitat loss, and perhaps because of mortality associated with commercial drift-net fishing.
Significance to humans
Tropicbirds are not of much economic importance to humans, although they are appreciated by naturalists and this can contribute to local economic benefits through ecotourism.
Formerly, tropicbird feathers were sold to the once-prominent business of millinery, or the production of women's hats and garments. The long tail feathers are still used as traditional adornments in various island cultures. The human consumption of tropicbirds, including eggs and chicks, has occurred since ancient times.
List of SpeciesWhite-tailed tropicbird
Phaeton lepturus Daudin, 1802, Mauritius.
other common names
English: Golden bosunbird, yellow-billed tropicbird; French: Phaéton à bec jaune; German: Weißchwanz-Tropikvogel; Spanish: Rabijunco Menor.
Adult body length (including streamers) is 29 in (74 cm), wingspan 37 in (94 cm), and weight 11 oz (0.30 kg). The overall body color is white, with black markings on the upper wings, a black eye-stripe, and a reddish (rarely yellow) bill. Juveniles have a pale-cream bill.
Tropical and warm-temperate oceans of the world.
Tropical and warm-temperate oceans of the world, especially in coastal waters.
An excellent flier that commonly feeds by shallow plunge-dives and by catching flying-fish on the wing. They have a rattling call in flight, and seldom glide.
feeding ecology and diet
Small fish, squid, and larger marine invertebrates, which are caught above, at, or just under the water surface. Tends to feed closer to shore than other species of tropicbirds.
Breeds on remote tropical islands. A single egg is laid and incubated by both adults. Chicks have white, buff-gray, or blue-gray down. Fledging in 70–85 days.
significance to humans
Phaethon aethereus, Linnaeus, 1758, Ascension Island.
other common names
English: Silver bosunbird; French: Phaéton à brins rouges; German: Rotschwanz-Tropikvogel; Spanish: Rabijunco Colirrojo.
Adult body length (including streamers) is 18 in (46 cm), wingspan 44 in (112 cm), and weight 1.6 lb (0.75 kg). The overall body color is white, with black markings on the upper wings, a darker back, a black eyestripe, red tail-streamers, and a bright red bill. Juveniles have a black bill.
Tropical and warm-temperate oceans of the western Pacific Ocean, especially off western Mexico and the Galápagos Islands, the tropical Atlantic Ocean, and the Red Sea region of the northwestern Indian Ocean.
Tropical and warm-temperate waters, especially in coastal areas.
An excellent flier that feeds by shallow plunge-dives and by catching flying-fish on the wing. The voice is a harsh, clanging rattle.
feeding ecology and diet
Small fish, squid, and larger marine invertebrates, which are caught above, at, or just under the water surface.
Breeds on remote tropical islands. A single egg is laid and incubated by both adults. Chicks have gray down, fledge at 80–90 days.
significance to humans
Not of much importance to humans, except for the economic benefits of ecotourism related to birdwatching.
Harrison, P. Seabirds. An Identification Guide. Beckenham, United Kingdom: Croom Helm Ltd., 1983.
Orta, J. "Family Phaethontidae (Tropicbirds)." Handbook of the Birds of the World. Vol 1, edited by J. del Hoyo, A. Elliott, and J. Sargatal. Barcelona: Lynx Edicions, 1992.
Howell, T. R., and G. A. Bartholomew. "Experiments on Nesting Behavior of the Red-tailed Tropicbird, Phaethon rubricauda." Condor 71 (1969): 113-119.
Stonehouse, B. "The Tropicbirds (Genus Phaethon) of Ascension Island." Ibis 103b (1962): 126-161.
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Bill Freedman, PhD