Tuesday, 25 December 2012

Christmas frigatebird

Fregata andrewsi

Photo by Jeff Blincow (Christmas Island Wildlife)

Common name:
Christmas frigatebird (en); fragata-de-Natal (pt); frégate d'Andrews (fr); fragata de la Navidad (es); weißbauch-fregattvogel (de)

Order Pelecaniformes
Family Fregatidae

The Christmas frigatebird is endemic as a breeding species to Christmas Island, located in the Indian Ocean, about 1000 km south-west of the Indonesian island of Java. Foraging birds spread along the seas around Indonesia, Malaysia and the Philippines.

These birds are 90-100 cm long and have a wingspan of 205-230 cm. They weigh around 1,5 kg.

The Christmas frigatebird is a pelagic species, foraging in the open ocean. They only visit land to breed and roost, preferring tall forests near the shoreline, especially Terminalia catappa and Celtis timorensis.

They mainly eat flying fish and squids, which they obtain either by scooping from the surface of the sea, or by harassing other seabirds, namely red-footed boobies Sula sula, and forcing them to disgorge some of their food. They also picking up carrion and offal from beaches, steal eggs and nestlings of other birds and eat grasshoppers.

Christmas frigatebirds form monogamous pairs that last a single breeding season. Egg laying takes place in February-June, but breeding process cover the whole year. They are colonial, with each pair building the nest on the top branches of a tree. There the female lays a single egg, which is incubated by both sexes for 40-54 days. The chicks are fed by both parents and grow very slowly, fledging after about 6 months but only becoming independent 7-9 months later. Due to the long period of parental care each bird only breeds once every 2 years. They reach sexual maturity at 5-7 years of age.

IUCN status - CR (Critically Endangered)
This species has a very restricted breeding range and a global population estimated at just 2.400-4.800 individuals. The population declined by 66% over the last 3 generations, owing to habitat clearance and dust fallout from phosphate mining, marine pollution, over-fishing and by-catch in fishing gear. These declines are projected to continue in the future and the introduced yellow crazy ant Anoplolepis gracilipes may represents a serious future threat.

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