Terns are seabirds in the family Laridae that have a worldwide distribution and are normally found near the sea, rivers, or wetlands. Terns are treated as a subgroup of the family Laridae which includes gulls and skimmers and consists of eleven genera. They are slender, lightly built birds with long, forked tails, narrow wings, long bills, and relatively short legs. Most species are pale grey above and white below, with a contrasting black cap to the head, but the marsh terns, the Inca tern, and some noddies have dark plumage for at least part of the year. The sexes are identical in appearance, but young birds are readily distinguishable from adults. Terns have a non-breeding plumage, which usually involves a white forehead and much-reduced black cap.
The Arctic tern is a tern in the family Laridae. This bird has a circumpolar breeding distribution covering the Arctic and sub-Arctic regions of Europe, Asia, and North America. The species is strongly migratory, seeing two summers each year as it migrates along a convoluted route from its northern breeding grounds to the Antarctic coast for the southern summer and back again about six months later. Recent studies have shown average annual round-trip lengths of about 70,900 km (44,100 mi) for birds nesting in Iceland and Greenland and about 48,700 km (30,300 mi) for birds nesting in the Netherlands. These are by far the longest migrations known in the animal kingdom. The Arctic tern nests once every one to three years.
The common tern is a seabird in the family Laridae. This bird has a circumpolar distribution, its four subspecies breeding in temperate and subarctic regions of Europe, Asia and North America. It is strongly migratory, wintering in coastal tropical and subtropical regions. Breeding adults have light grey upperparts, white to very light grey underparts, a black cap, orange-red legs, and a narrow pointed bill. Depending on the subspecies, the bill may be mostly red with a black tip or all black. There are several similar species, including the partly sympatric Arctic tern, which can be separated on plumage details, leg and bill colour, or vocalisations.
The little gull, is a species of gull belonging to the family Laridae which is mainly found in the Palearctic with some colonies in North America. It breeds on freshwaters but winters at sea. It is the smallest species of gull in the world. It is the only species in the monospecific genus Hydrocoloeus.
The roseate tern is a species of tern in the family Laridae. The genus name Sterna is derived from Old English "stearn", "tern", and the specific dougallii refers to Scottish physician and collector Dr Peter McDougall (1777–1814). "Roseate" refers to the bird's pink breast in breeding plumage.
The whiskered tern is a tern in the family Laridae. The genus name is from Ancient Greek khelidonios, "swallow-like", from khelidon, "swallow". The specific hybridus is Latin for hybrid; Peter Simon Pallas thought it might be a hybrid of white-winged black tern and common tern, writing "Sterna fissipes [Chlidonias leucopterus] et Hirundine [Sterna hirundo] natam".
The gull-billed tern, formerly Sterna nilotica, is a tern in the family Laridae. It is widely distributed and breeds in scattered localities in Europe, Asia, northwest Africa, and the Americas. The Australian gull-billed tern was previously considered a subspecies.
Forster's tern is a tern in the family Laridae. The genus name Sterna is derived from Old English "stearn", "tern", and forsteri commemorates the naturalist Johann Reinhold Forster.
The Aleutian tern is a migratory bird living in the subarctic region of the globe most of the year. It is frequently associated with the Arctic tern, which it closely resembles. While both species have a black cap, the Aleutian tern may be distinguished by its white forehead. During breeding season, the Arctic terns have bright red bills, feet, and legs while those of the Aleutian terns are black.
The greater crested tern, also called crested tern or swift tern, is a tern in the family Laridae that nests in dense colonies on coastlines and islands in the tropical and subtropical Old World. Its five subspecies breed in the area from South Africa around the Indian Ocean to the central Pacific and Australia, all populations dispersing widely from the breeding range after nesting. This large tern is closely related to the royal and lesser crested terns, but can be distinguished by its size and bill colour.
The Inca tern is a Near Threatened species of bird in subfamily Sterninae of the family Laridae, the gulls, terns, and skimmers. It is found in Chile, Ecuador, and Peru and has wandered to Central America and Hawaii.
The white-fronted tern, also known as tara, sea swallow, black-billed tern, kahawai bird, southern tern, or swallow tail, was first described by Johann Friedrich Gmelin in 1789. A medium-sized tern with an all-white body including underwing and forked tail, with grey hues on the over the upper side of the wing. In breeding adults a striking black cap covers the head from forehead to nape, leaving a small white strip above the black bill.
The black skimmer is a tern-like seabird, one of three similar bird species in the skimmer genus Rynchops in the gull family Laridae. It breeds in North and South America. Northern populations winter in the warmer waters of the Caribbean and the tropical and subtropical Pacific coasts, but South American populations make only shorter movements in response to annual floods which extend their feeding areas in the river shallows.
The least tern is a species of tern that breeds in North America and locally in northern South America. It is closely related to, and was formerly often considered conspecific with, the little tern of the Old World. Other close relatives include the yellow-billed tern and Peruvian tern, both from South America.
The black-bellied tern is a tern found near large rivers in the Indian subcontinent, its range extending from Pakistan, Nepal and India to Myanmar. It has become very scarce in the eastern part of its range and the International Union for Conservation of Nature has assessed its conservation status as being endangered.
The Antarctic tern is a seabird in the family Laridae. It ranges throughout the southern oceans and is found on small islands around Antarctica as well as on the shores of the mainland. Its diet consists primarily of small fish and crustaceans. It is very similar in appearance to the closely related Arctic tern, but it is stockier, and it is in its breeding plumage in the southern summer, when the Arctic tern has shed old feathers to get its non-breeding plumage. The Antarctic tern does not migrate like the Arctic tern does, but it can still be found on a very large range. This tern species is actually more closely related to the South American tern.
The black-fronted tern, also known as sea martin, ploughboy, inland tern, riverbed tern or tarapiroe, is a small tern generally found in or near bodies of fresh water in New Zealand, where it forages for freshwater fish, arthropods and worms. It has a predominantly grey plumage. Restricted to breeding in the eastern regions of the South Island, it is declining and threatened by introduced mammals and birds. It is rated as endangered on the International Union for Conservation of Nature (IUCN)'s Red List of Threatened Species.
The Andean gull is a species in subfamily Larinae of the family Laridae, the gulls, terns, and skimmers. It is found in Argentina, Bolivia, Chile, Colombia, Ecuador, and Peru.
Cabot's tern is a species of bird in subfamily Sterninae of the family Laridae, the gulls, terns, and skimmers. It is found in the eastern U.S. and Middle America, the Caribbean, Trinidad and Tobago, and in every mainland South American country except Boliva and Paraguay.
