(Last Updated on : 04-09-2015)
Lesser Frigatebird with a scientific name "Fregata ariel
" is a seabird of the frigatebird family Fregatidae. In Indian this bird is mostly found near the Bay of Bengal
, Indian ocean
and Pacific Ocean. This bird mainly feeds on fish from the sea.
Structure of Lesser Frigatebird
Lesser frigatebird, an Indian Bird
is at around 75 cm in length. Lesser Frigatebird is the smallest species of frigatebird. It is mainly found over tropical and subtropical waters across the Indian and Pacific Oceans as well as off the Atlantic coast of Brazil.
Sexes of Lesser Frigatebird
Lesser Frigatebird is a lightly built seabird with brownish-black plumage, long narrow wings and a deeply forked tail. The male lesser Frigatebird has a striking red gular sac which it inflates to attract a mate. The female is slightly larger than the male and has a white breast and belly.
Feedings of Lesser Frigatebird
Lesser frigatebird feeds on fish taken in flight from the ocean's surface (often flying fish), and sometimes indulge in kleptoparasitism, harassing other birds to force them to restate their food.
Naming of Lesser Frigatebird
Lesser Frigatebird was first described as Atagen ariel by the English zoologist George Gray in 1845 from a specimen collected on Raine Island, Queensland, Australia. Lesser frigatebird is one of five closely related species belonging to the genus Fregata. The other four are the great frigatebird, the Christmas frigatebird, the magnificent frigatebird and the Ascension frigatebird. The genus is the only member of the Fregatidae family.
Tails of Lesser Frigatebird
Lesser Frigatebird is the smallest species of frigatebird and measures 66-81 cm in length with a wingspan of 155-193 cm and long forked tails. The male Lesser Frigatebird has a large red sac on the front of the throat which is inflated during courtship.
Courtship of Lesser Frigatebird
The courtship of Lesser Frigatebird display also involves a variety of calls, bill rattling and spreading of the wings. The male is mostly all black save for a white patch on the flank which extends on to the underwing as a spur. Males also have a pale bar on the upper wing. Females have a black head and neck with a white collar and breast as well as a spur extending on to the under wing. The female also has a narrow red ring around the eye. Juveniles and immature birds are more difficult to differentiate but the presence of the spurs of white in the armpits is a helpful distinguishing sign.
Behaviour of Lesser Frigatebird
Lesser Frigatebirds are built for flying. Lesser Frigatebird rarely swim and cannot walk but can manage to climb around the trees and bushes in which they nest. They have very light skeleton and long narrow wings and are masters of the air. Their name probably derives from the fact that they harass other sea birds such as boobies and tropicbirds as they return to their nests from feeding, forcing them to disgorge their catch, which is then swooped upon and caught by the frigate birds before it reaches the water below. This practice seems to be more common among female frigate birds, but probably only accounts for a fairly small proportion of the diet, which mainly consists of squid and flying fish scooped up from the surface of the sea.
Breeding of Lesser Frigatebird
The breeding of Lesser Frigatebird seems to occur between May and December in the Australian region. They nest in trees and both sexes contribute to nest building and incubation and feeding of the young.
Eggs of Lesser Frigatebird
The egg of Lesser Frigatebird is laid which takes 6-7 weeks to hatch. Fledglings are not left alone for another seven weeks or so for fear that they may be attacked and eaten by other birds including other frigate birds. They remain in the nest for another 6 months or so until fledged but they are cared for and fed by their parents for quite a long time after that.
Population of Lesser Frigatebird
The total world population of Lesser Frigatebird is estimated to be several hundred thousand birds. At least 6,000 pairs breed on the Aldabra Islands in the Indian Ocean and another 15,000 pairs breed on islands off the north coast of Australia. The largest colonies are on the Phoenix Islands and Line Islands in the central Pacific Ocean.
Nests of Lesser Frigatebird
The nests of Lesser frigatebird placed on the ground are very vulnerable to predation by introduced species such as feral cats. The elimination of cats from Howland, Baker and Jarvis Islands has led to the re-establishment and growth of colonies. Baker Island had no nesting for lesser frigatebirds in 1965 but after the elimination of the feral cats on the island in around 1970 the birds returned and in 2002.