Tropicbird
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{{Taxobox | color = pink | name = Tropicbirds | image = Rtailedtropicbird8.jpg | image_caption = Red-tailed Tropicbird | regnum = Animalia | phylum = Chordata | classis = Aves | ordo = Pelecaniformes | familia = Phaethontidae | familia_authority = Brandt, 1840 | genus = Phaethon | subdivision_ranks = Species | subdivision = 3, see text }}
Tropicbirds are a group of three closely related pelagic seabirds of tropical oceans: The Red-Billed Tropicbird, the Red-Tailed Tropicbird, and the White-Tailed Tropicbird. The Indian Ocean subspecies of Red-billed tropicbird P. a. indicus was at one time considered a full species, the Lesser Red-billed Tropicbird. Tropicbirds are grouped in the Order Pelecaniformes. Pelecaniformes comprises six families: Pelicans, Cormorants and Shags, Darters, Gannets and Boobies, Frigatebirds, and of course, Tropicbirds. The Sibley-Ahlquist taxonomy gives a radically different scientific arrangement for this group based on DNA studies.
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Size and Appearance
Tropicbirds range in size from 76cm-102cm in length and 94cm-112cm in width. Tropicbirds are predominately white with elongated central tail feathers. The three species will have a different combination of black markings on the face, back, and wings. Their bills are large, powerful and slightly decurved. Their heads are large and their necks are short and thick. Tropicbird legs are very short and their feet are totipalmate.
Geographic Range
- The Red-billed Tropicbird Phaethon aethereus occurs in the tropical Atlantic, eastern Pacific, and Indian oceans.
- The Red-tailed Tropicbird, P. rubricauda, occurs in the Indian Ocean and the western and central tropical Pacific.
- The White-tailed Tropicbird, P. lepturus, is widespread in tropical waters, except in the eastern Pacific.
Social Structure and Mating Habits
Tropicbirds are usually solitary or in pairs away from breeding colonies. They also engage in courtship displays. For several minutes, groups of 2–20 birds simultaneously and repeatedly fly around one another in large, vertical circles, while swinging the tail streamers from side to side. If the female likes it, she will mate with the male in his prospective nest-site. Occasionally, disputes will occur between males trying to protect their mates and nesting areas.
Food and Foraging Habits
Tropicbirds frequently catch its prey by hovering and then plunge-diving, typically only into the surface-layer of the waters. They eat mostly fish, especially flying fish, and occasionally squid. Tropicbirds tend to avoid multi-species feeding flocks as opposed to their sister Frigatebirds.
Reproduction and Nesting
Tropicbirds generally nest in holes or crevices on the bare ground. The female will lay one white egg, spotted brown and incubate for 40-46 days. The incubation is performed by both parents, but mostly the female, while the male brings food to feed the female. The chick hatches with grey down. It will stay alone in nest while both parents search for food, and they will feed the chick twice every three days until fledging, about 12-13 weeks after hatching. The young are not able to fly initially, they will float on the ocean for several days to lose weight before flight.
Development
Tropicbird chicks have relatively slow growth relative to a nearshore bird and they also tend to accumulate fat deposits while young. That, along with one-egg clutches, appears to be an adaptation to a pelagic lifestyle where food is usually gathered in big, but not often, amounts.
Song-Call
The Tropicbird’s call is typically a loud, piercing, shrill, but grating whistle, or crackle. These are often given in a rapid series when they are in a display flight at the colony.
External links
- Tropicbird videos on the Internet Bird Collection
- [1] Monterey Bay Tropicbird Identification
- [2] Brian Patteson Tropicbird Photos
References
Spear, Larry B. & Ainley, David G. (2005) At-sea behaviour and habitat use by tropicbirds in the eastern Pacific. Ibis 147 (2), 391-407.doi: 10.1111/j.1474-919x.2005.00418.x
Boland, C. R. J., Double, M. C. & Baker, G. B. (2004) Assortative mating by tail streamer length in Red-tailed Tropicbirds Phaethon rubricauda breeding in the Coral Sea. Ibis 146 (4), 687-690.doi: 10.1111/j.1474-919x.2004.00310.x
Oiseaux.net http://www.oiseaux.net/oiseaux/pelecaniformes/red-billed.tropicbird.htmlda:Tropikfugle de:Tropikvögel eo:Faetontedoj fr:Phaethontidae nl:Keerkringvogels ja:ネッタイチョウ科 (Sibley) pl:Faetonowate pt:Rabo-de-palha sv:Tropikfåglar zh:鹲科