frigate bird

 

or frigate-bird, most aerial of the water birds, found in the tropic seas. The man-o'-war bird's wingspread (7¹/₂ ft/228.5 cm) is the largest in proportion to its body (3–4 lb/1.4–1.8 kg) of any bird. It can soar motionless by the hour and has been recorded in flights lasting nearly four days, spending most of that time several hundred feet or more in the air. It is awkward on land and in the sea, where the feathers quickly become water-logged.

The name derives from its grace and swiftness in the air and from its piratical tendencies; it harasses boobies, pelicans, cormorants, and gulls until they drop their catch. Man-o'-war birds feed chiefly on fish but also prey on the young of sea birds and on jellyfish, squid, and young turtles. They have long hooked beaks and forked tails; the male has an inflatable orange throat pouch that becomes red at courtship time.

The purplish black magnificent frigate-bird, Fregata magnificens, 40 in. (100 cm) long, is found from the Bahamas and Baja California S to Brazil and Ecuador; the great frigate-bird, F. minor, is found in the Indian Ocean. Other species, e.g., the Ascension and Christmas Island frigate-birds, are named for their habitats. The lesser frigate-bird, the smallest (32 in./80 cm) of the family, is found in the South Pacific and on the islands off Brazil and Madagascar.

Frigate-birds are classified in the phylum Chordata, subphylum Vertebrata, class Aves, order Pelecaniformes, family Fregatidae.

For the nuclear test codenamed Frigate Bird, see the main article Operation Dominic I and II.

Frigatebirds
Scientific classification
Kingdom: Animalia Phylum: Chordata Class: Aves Order: Pelecaniformes Family: Fregatidae Degland & Gerbe, 1867 Genus: Fregata Lacépède, 1799
Species
Fregata magnificens Fregata aquila Fregata andrewsi Fregata minor Fregata ariel

There are five species in the family Fregatidae, the frigatebirds. They are very closely related, and are all in the single genus Fregata. Frigatebirds attack other sea birds, hence the name. They are also sometimes called Man of War birds or Pirate birds. Since they are related to the pelicans, the term "frigate pelican" is also a name applied to them.

Frigatebirds are large, with iridescent black feathers (the females have a white underbelly), with long wings (male wingspan can reach 2.3 metres) and deeply-forked tails. The males have inflatable red-coloured throat pouches called "gula pouches", which they inflate to attract females during the mating season.

Frigatebirds are found over tropical oceans and ride warm updrafts. Therefore, they can often be spotted riding weather fronts and can signal changing weather patterns.

These birds do not swim and cannot walk well, and cannot take off from a flat surface. Having the largest wingspan to body weight ratio of any bird, they are essentially aerial, able to stay aloft for more than a week, landing only to roost or breed on trees or cliffs.

They lay one or two white eggs. Both parents take turns feeding for the first three months but then only the mother feeds the young for another eight months. It takes so long to rear a chick that frigatebirds cannot breed every year. It is typical to see juveniles as big as their parents waiting to be fed. When they sit waiting for endless hours in the hot sun, they assume an energy-efficient posture in which their head hangs down, and they sit so still that they seem dead. But when the parent returns, they will wake up, bob their head, and scream until the parent opens its mouth. The hungry juvenile plunges its head down the parent's throat and feeds at last.

As members of Pelecaniformes, frigatebirds have the key characteristics of all four toes being connected by the web, a gular sac (also called gular skin), and a furcula that is fused to the breastbone. Although there is definitely a web on the frigatebird foot, the webbing is reduced and part of each toe is free. Frigatebirds produce very little oil and therefore do not land in the ocean. The gular sac is used as part of a courtship display and is, perhaps, the most striking frigatebird feature.

Distribution and identifying characteristics differ among frigatebird species, and thus are addressed in species-specific articles.

Feeding

Frigatebirds' feeding habits are pelagic. Lacking the ability to take off from water, they snatch prey from the ocean surface or beach using their long, hooked bills. They catch fish, baby turtles and similar items in this way. Frigatebirds often rob other seabirds such boobies, tropicbirds, and shearwaters of their catch, using their speed and manoeuvrability to outrun and harass their victims until they regurgitate their stomach contents.

Species

• Genus Fregata
  • Magnificent Frigatebird or Man O'War, Fregata magnificens.
  • Ascension Frigatebird, Fregata aquila.
  • Christmas Island Frigatebird, Fregata andrewsi.
  • Great Frigatebird, Fregata minor.
  • Lesser Frigatebird, Fregata ariel.

See also

• Limnofregata

References

• Harrison, Seabirds ISBN 0-7470-8028-8

External links

• Frigatebird videos on the Internet Bird Collection

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