The birds of Christmas Island form a heterogeneous group of 162 species. There is a core group of four endemics that evolved on the remote island in the eastern Indian Ocean for thousands of years; there are also regular migrants, opportunists and occasional visitors. Christmas Island was not occupied by humans until the late 19th century and is some 200 km from the nearest land, Java. It is now an Australian territory. The natural vegetation of most of the 140 km2 island is rainforest, to which the endemic landbirds are adapted, while the seabirds have taken advantage of a breeding location which had no major natural predators.
This list's taxonomic treatment (designation and sequence of orders, families and species) and nomenclature (common and scientific names) follow the conventions of The Clements Checklist of Birds of the World, 2022 edition. The family accounts at the beginning of each heading reflect this taxonomy, as do the species counts in each family account. Introduced and accidental species are included in the total counts for Christmas Island.
After over a century of human exploitation of the phosphate deposits covering much of the island, two thirds of the rainforest cover remains and is now protected as a national park. However, gaps where the forest has been cleared, and the introduction of exotic fauna, continue to destabilise the island's biological diversity. The endemic Abbott's booby is threatened when nesting by wind turbulence caused by past forest clearance. However, the biggest immediate threat is the introduction and spread of yellow crazy ants, through both direct predation and ecosystem collapse. This has led to all the island's endemic bird species and subspecies being classified as Critically Endangered.
Meanwhile, the number of species recorded from Christmas Island continues to increase as birders, especially from Australia, attracted by the island's endemics, record a variety of vagrants previously unnoticed. Some of these may in time, as with the white-breasted waterhen, establish breeding populations. Christmas Island is now seen as a birding 'hot spot', not only for its endemics but also for the chance of recording new species for the Australian bird list, something reflected in the frequency of submissions of sightings to the Birds Australia Rarities Committee.
The following tags have been used to highlight several categories. The commonly occurring native species do not fall into any of these categories.
Order: Anseriformes Family: Anatidae
Anatidae includes the ducks and most duck-like waterfowl, such as geese and swans. These birds are adapted to an aquatic existence with webbed feet, flattened bills, and feathers that are excellent at shedding water due to an oily coating.
Order: Galliformes Family: Phasianidae
The Phasianidae are a family of terrestrial birds. In general, they are plump (although they vary in size) and have broad, relatively short wings.
Order: Phoenicopteriformes Family: Phoenicopteridae
Flamingos are gregarious wading birds, usually 3 to 5 feet (0.9 to 1.5 m) tall, found in both the Western and Eastern Hemispheres. Flamingos filter-feed on shellfish and algae. Their oddly shaped beaks are specially adapted to separate mud and silt from the food they consume and, uniquely, are used upside-down.
Order: Columbiformes Family: Columbidae
Pigeons and doves are stout-bodied birds with short necks and short slender bills with a fleshy cere.
Order: Cuculiformes Family: Cuculidae
The family Cuculidae includes cuckoos, roadrunners and anis. These birds are of variable size with slender bodies, long tails and strong legs. The Old World cuckoos are brood parasites.
Order: Caprimulgiformes Family: Caprimulgidae
Nightjars are medium-sized nocturnal birds that usually nest on the ground. They have long wings, short legs and very short bills. Most have small feet, of little use for walking, and long pointed wings. Their soft plumage is camouflaged to resemble bark or leaves.
Order: Caprimulgiformes Family: Apodidae
Swifts are small birds which spend the majority of their lives flying. These birds have very short legs and never settle voluntarily on the ground, perching instead only on vertical surfaces. Many swifts have long swept-back wings which resemble a crescent or boomerang.
Order: Gruiformes Family: Rallidae
Rallidae is a large family of small to medium-sized birds which includes the rails, crakes, coots and gallinules. Typically they inhabit dense vegetation in damp environments near lakes, swamps or rivers. In general they are shy and secretive birds, making them difficult to observe. Most species have strong legs and long toes which are well adapted to soft uneven surfaces. They tend to have short, rounded wings and to be weak fliers.
Order: Charadriiformes Family: Recurvirostridae
Recurvirostridae is a family of large wading birds, which includes the avocets and stilts. The avocets have long legs and long up-curved bills. The stilts have extremely long legs and long, thin, straight bills.
Order: Charadriiformes Family: Haematopodidae
The oystercatchers are large and noisy plover-like birds, with strong bills used for smashing or prising open molluscs.
Order: Charadriiformes Family: Charadriidae
The family Charadriidae includes the plovers, dotterels and lapwings. They are small to medium-sized birds with compact bodies, short, thick necks and long, usually pointed, wings. They are found in open country worldwide, mostly in habitats near water.
Order: Charadriiformes Family: Scolopacidae
Scolopacidae is a large diverse family of small to medium-sized shorebirds including the sandpipers, curlews, godwits, shanks, tattlers, woodcocks, snipes, dowitchers and phalaropes. The majority of these species eat small invertebrates picked out of the mud or soil. Variation in length of legs and bills enables multiple species to feed in the same habitat, particularly on the coast, without direct competition for food.
Order: Charadriiformes Family: Glareolidae
Glareolidae is a family of wading birds comprising the pratincoles, which have short legs, long pointed wings and long forked tails, and the coursers, which have long legs, short wings and long, pointed bills which curve downwards.
Order: Charadriiformes Family: Stercorariidae
The family Stercorariidae are, in general, medium to large birds, typically with grey or brown plumage, often with white markings on the wings. They nest on the ground in temperate and arctic regions and are long-distance migrants.
Order: Charadriiformes Family: Laridae
Laridae is a family of medium to large seabirds, the gulls, terns and skimmers. Gulls are typically grey or white, often with black markings on the head or wings. They have stout, longish bills and webbed feet. Terns are a group of generally medium to large seabirds typically with grey or white plumage, often with black markings on the head. Most terns hunt fish by diving but some pick insects off the surface of fresh water. Terns are generally long-lived birds, with several species known to live in excess of 30 years.
Order: Phaethontiformes Family: Phaethontidae
Tropicbirds are slender white birds of tropical oceans, with exceptionally long central tail feathers. Their heads and long wings have black markings.
Order: Procellariiformes Family: Oceanitidae
The southern storm-petrels are relatives of the petrels and are the smallest seabirds. They feed on planktonic crustaceans and small fish picked from the surface, typically while hovering. The flight is fluttering and sometimes bat-like.
Order: Procellariiformes Family: Hydrobatidae
Though the members of this family are similar in many respects to the southern storm-petrels, including their general appearance and habits, there are enough genetic differences to warrant their placement in a separate family.
Order: Procellariiformes Family: Procellariidae
The procellariids are the main group of medium-sized "true petrels", characterised by united nostrils with medium septum and a long outer functional primary.
Order: Suliformes Family: Fregatidae
Frigatebirds are large seabirds usually found over tropical oceans. They are large, black-and-white or completely black, with long wings and deeply forked tails. The males have coloured inflatable throat pouches. They do not swim or walk 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.
Order: Suliformes Family: Sulidae
The sulids comprise the gannets and boobies. Both groups are medium to large coastal seabirds that plunge-dive for fish.
Order: Suliformes Family: Phalacrocoracidae
Phalacrocoracidae is a family of medium to large coastal, fish-eating seabirds that includes cormorants and shags. Plumage colouration varies, with the majority having mainly dark plumage, some species being black-and-white and a few being colourful.
Order: Pelecaniformes Family: Pelecanidae
Pelicans are large water birds with a distinctive pouch under their beak. As with other members of the order Pelecaniformes, they have webbed feet with four toes.
Order: Pelecaniformes Family: Ardeidae
The family Ardeidae contains the bitterns, herons and egrets. Herons and egrets are medium to large wading birds with long necks and legs. Bitterns tend to be shorter necked and more wary. Members of Ardeidae fly with their necks retracted, unlike other long-necked birds such as storks, ibises and spoonbills.
Order: Pelecaniformes Family: Threskiornithidae
Threskiornithidae is a family of large terrestrial and wading birds which includes the ibises and spoonbills. They have long, broad wings with 11 primary and about 20 secondary feathers. They are strong fliers and despite their size and weight, very capable soarers.
Order: Accipitriformes Family: Accipitridae
Accipitridae is a family of birds of prey, which includes hawks, eagles, kites, harriers and Old World vultures. These birds have powerful hooked beaks for tearing flesh from their prey, strong legs, powerful talons and keen eyesight.
Order: Strigiformes Family: Strigidae
The typical owls are small to large solitary nocturnal birds of prey. They have large forward-facing eyes and ears, a hawk-like beak and a conspicuous circle of feathers around each eye called a facial disk.
Order: Coraciiformes Family: Alcedinidae
Kingfishers are medium-sized birds with large heads, long, pointed bills, short legs and stubby tails.
Order: Coraciiformes Family: Coraciidae
Rollers resemble crows in size and build, but are more closely related to the kingfishers and bee-eaters. They share the colourful appearance of those groups with blues and browns predominating. The two inner front toes are connected, but the outer toe is not.
Order: Falconiformes Family: Falconidae
Falconidae is a family of diurnal birds of prey. They differ from hawks, eagles and kites in that they kill with their beaks instead of their talons.
Order: Passeriformes Family: Pittidae
Pittas are medium-sized by passerine standards and are stocky, with fairly long, strong legs, short tails and stout bills. Many are brightly coloured. They spend the majority of their time on wet forest floors, eating snails, insects and similar invertebrates.
Order: Passeriformes Family: Laniidae
Shrikes are passerine birds known for their habit of catching other birds and small animals and impaling the uneaten portions of their bodies on thorns. A typical shrike's beak is hooked, like a bird of prey.
Order: Passeriformes Family: Acrocephalidae
The members of this family are usually rather large for "warblers". Most are rather plain olivaceous brown above with much yellow to beige below. They are usually found in open woodland, reedbeds, or tall grass. The family occurs mostly in southern to western Eurasia and surroundings, but it also ranges far into the Pacific, with some species in Africa.
Order: Passeriformes Family: Locustellidae
Locustellidae are a family of small insectivorous songbirds found mainly in Eurasia, Africa, and the Australian region. They are smallish birds with tails that are usually long and pointed, and tend to be drab brownish or buffy all over.
Order: Passeriformes Family: Hirundinidae
The family Hirundinidae is adapted to aerial feeding. They have a slender streamlined body, long pointed wings and a short bill with a wide gape. The feet are adapted to perching rather than walking, and the front toes are partially joined at the base.
Order: Passeriformes Family: Phylloscopidae
Leaf warblers are a family of small insectivorous birds found mostly in Eurasia and ranging into Wallacea and Africa. The species are of various sizes, often green-plumaged above and yellow below, or more subdued with greyish-green to greyish-brown colours.
Order: Passeriformes Family: Zosteropidae
The white-eyes are small and mostly undistinguished, their plumage above being generally some dull colour like greenish-olive, but some species have a white or bright yellow throat, breast or lower parts, and several have buff flanks. As their name suggests, many species have a white ring around each eye.
Order: Passeriformes Family: Sturnidae
Starlings are small to medium-sized passerine birds. Their flight is strong and direct and they are very gregarious. Their preferred habitat is fairly open country. They eat insects and fruit. Plumage is typically dark with a metallic sheen.
Order: Passeriformes Family: Turdidae
The thrushes are a group of passerine birds that occur mainly in the Old World. They are plump, soft plumaged, small to medium-sized insectivores or sometimes omnivores, often feeding on the ground. Many have attractive songs.
Order: Passeriformes Family: Muscicapidae
Old World flycatchers are a large group of small passerine birds native to the Old World. They are mainly small arboreal insectivores. The appearance of these birds is highly varied, but they mostly have weak songs and harsh calls.
Order: Passeriformes Family: Estrildidae
The estrildid finches are small passerine birds of the Old World tropics and Australasia. They are gregarious and often colonial seed eaters with short thick but pointed bills. They are all similar in structure and habits, but have wide variation in plumage colours and patterns.
Order: Passeriformes Family: Passeridae
Old World sparrows are small passerine birds. In general, sparrows tend to be small, plump, brown or grey birds with short tails and short powerful beaks. Sparrows are seed eaters, but they also consume small insects.
Order: Passeriformes Family: Motacillidae
Motacillidae is a family of small passerine birds with medium to long tails. They include the wagtails, longclaws and pipits. They are slender, ground feeding insectivores of open country.