The Christmas Island Frigatebird is the rarest endemic seabird on Christmas Island, Australia.
It belongs to a family of five birds, the Fregatidae, which have the largest wingspan to body weight ratio of any bird. This bird has the ability to stay airborne for more than a week at a time allowing them to have a large foraging range. It spends a large proportion of time at sea, plucking squid and fish from the surface of the water. They also employ a method of feeding called kleptoparasitism; where they steal other birds’ food by forcing them to regurgitate.
Its breeding habitat is affected by invasive yellow crazy ant, which is a key threat to many species on the island. They are also threatened by hunting, getting trapped in fishing gear, habitat destruction for phosphate mining, and the ecological fallout from the phosphate dust. Much of the breeding colony now lies within the Christmas Island National Park, but almost 10% of the population nests outside this area which does not have any formal protection. With such small numbers surviving, every individual counts and conservation measures must protect the entire population.
- Order: Suliformes
- Family: Fregatidae
- Population: 3,600-7,200
- Trend: decreasing
- Size: 89-100cm
- Weight: 1.2-1.7kg
This species is endemic to Christmas Island, Australia, which is situated in the Indian Ocean approximately 500km south of Jakarta, Indonesia. In the non-breeding season it is found foraging at low densities throughout the Indo-Malay archipelago.
Habitat and Ecology
This species spends most of its time foraging out on the open ocean, in the warm, low-salinity waters of the Indian Ocean. Their diet comprises flying fish, squid and other marine animals including seabird eggs and chicks. It feeds via surface dipping, strongly relying on aquatic predators to drive its prey to the surface.
Preferred breeding habitat is tall forest on shore terraces. They form colonies, which are divided into groups of up to 20 nests due, primarily, to the limited nesting spots in a given tree. In each tree, up to 38 adjacent nests may occur, often less than one metre apart. The nesting season occurs from March to May and parents may only raise one fledgling every two years. Both sexes take part in incubation, switching every few days.