Great Frigatebird, also known as the Iwa
Wild Bird Feeders ... Wild Bird Food / Seed ... Binoculars ... Humming Bird Feeders / Feed ... Bird Houses / Bird Nests ... Woodworking Instructions to Build Bird Houses ... Recommended Books
The Great Frigatebird (Fregata minor), also known as the Iwa, is a migratory seabird in the frigatebird family. Major nesting populations are found in the Pacific (including Galapagos Islands) and Indian Oceans, as well as a population in the South Atlantic. It feeds on fish taken in flight from the ocean's surface (mostly flyingfish), and indulges in kleptoparasitism less frequently than other frigatebirds. They feed in pelagic waters within 80 km of their breeding colony or roosting areas.
Distribution and range
The Great Frigatebird has a wide distribution throughout the world’s tropical seas. In the Pacific Ocean Hawaii is the northernmost extent of their range, with around 10,000 pairs nesting mostly in the Northwestern Hawaiian Islands. In the Central and South Pacific colonies are found on most islands Groups from Wake Island to the Galapagos Islands to New Caledonia with a few pairs nesting on Australian possessions in the Coral Sea. Colonies are also found on numerous Indian Ocean islands including Aldabra, Christmas Island and Mauritius. The small populations in the Western Atlantic Ocean may still persist but are very small if they do. Great Frigatebirds undertake regular migrations across their range, both regular trips and more infrequent widespread dispersals. Birds marked with wing tags on Tern Island in French Frigate Shoals were found to regularly travel to Johnston Atoll (873 km), one was reported in Quezon City in the Philippines. Despite their far ranging birds also exhibit philopatry, breeding in their natal colony even if they travel to other colonies.
Morphology
Great Frigatebirds are large seabirds (85-105 cm) with long pointed wings (205-230 cm) and long forked tails. Frigatebirds are light, weighing between 1-1.8 kg, and have the highest ratio of wing area to body mass of any bird. Male Great Frigatebirds are smaller than females. The plumage of males is black with scapular feathers that have a purple iridescence when they refract sunlight. Females are black with a white throat and breast and have a red eye ring. Juveniles are black with a rust-tinged white face, head and throat.
Feeding
Flyingfish from the family Exocoetidae are the most common item in the diet of the Great Frigatebird; other fish species and squid may be eaten as well. Prey is snatched while in flight, either from just below the surface or from the air in the case of flyingfish flushed from the water. Great Frigatebirds will make use of schools of predatory tuna or pods of dolphins that push schooling fish to the surface. Like all frigatebirds they will not alight on the water surface and are incapable of taking off should accidentally do so.
Great Frigatebirds will also hunt seabird chicks at their breeding colonies, taking mostly the chicks of Sooty Terns, Grey-backed Terns, Brown Noddies and Black Noddies. Studies show that only females (adults and immatures) hunt in this fashion, and only a few individuals account for most of the kills.
Great Frigatebirds will attempt kleptoparasitism, chasing other nesting seabirds (boobies and tropicbirds in particular) in order to make them regurgitate their food. This behaviour is not thought to play a significant part of the diet of the species, and is instead a supplement to food obtained by hunting. A study of Great Frigatebirds stealing from Masked Boobies estimated that the frigatebirds could at most obtain 40% of the food they needed, and on average obtained only 5%.
Copyright: Wikipedia. This article is licensed under the GNU Free Documentation License. It uses material from Wikipedia.org
If you would like to add to or correct any of the above information, or would like to share with web visitors your own experiences, please e-mail the webmaster.
Photo contributions are welcome!
