page_title: Tern
section_title: Conservation status
hierarchical_section_title: Tern / Conservation status
caption_attribution_description: English: Ranganathittu Birds Sterna acuticauda
context_page_description: 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 consist 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 terns are birds of open habitats that typically breed in noisy colonies and lay their eggs on bare ground with little or no nest material. Marsh terns construct floating nests from the vegetation in their wetland habitats, and a few species build simple nests in trees, on cliffs or in crevices. The white tern, uniquely, lays its single egg on a bare tree branch. Depending on the species, one to three eggs make up the clutch.
context_section_description: A number of terns face serious threats, and the Chinese crested tern is classed as "critically endangered" by BirdLife International. It has a population of fewer than 50 birds and a breeding range of just 9 km² (3.5 mi²). It is declining due to egg collection, human disturbance and the loss of coastal wetlands in China. Three other species are categorised as "endangered", with declining populations of less than 10,000 birds. The South Asian black-bellied tern is threatened by habitat loss, egg collecting for food, pollution and predation. In New Zealand, the black-fronted tern is facing a rapid fall in numbers due to predation by introduced mammals and Australian magpies. Disturbance by cattle and sheep and by human activities is also a factor. The Peruvian tern was initially damaged by the collapse of anchoveta stocks in 1972, but breeding colonies have subsequently been lost due to building, disturbance and pollution in their coastal wetlands.
  The Australasian fairy tern is described as "vulnerable". Disturbance by humans, dogs and vehicles, predation by introduced species and inappropriate water level management in South Australia are the main reasons for its decline. Five species are "near threatened", indicating less severe concerns or only potential vulnerability. The elegant tern is so categorised because 95% of the population breeds on one island, Isla Rasa in the Gulf of California, and the Kerguelen tern has a population of less than 5,000 adults breeding on small and often stormy Pacific islands. Three species, the Inca, Damara, and river terns, are expected to decline in the future due to habitat loss and disturbance. Some tern subspecies are endangered, including the California least tern and the Easter Island race of the grey noddy.
  Most tern species are declining in numbers due to the loss or disturbance of breeding habitat, pollution and increased predation. Gull populations have increased over the last century because of reduced persecution and the availability of food from human activities, and terns have been forced out of many traditional nesting areas by the larger birds. A few species are defying the trend and showing local increases, including the Arctic tern in Scandinavia, Forster's tern around the Great Lakes, the Sandwich tern in eastern North America and its yellow-billed subspecies, the Cayenne tern, in the Caribbean.
  Terns are protected by international legislation such as the Agreement on the Conservation of African-Eurasian Migratory Waterbirds (AEWA) and the US-Canada Migratory Bird Treaty Act of 1918. Parties to the AWEA agreement are required to engage in a wide range of conservation strategies described in a detailed action plan. The plan is intended to address key issues such as species and habitat conservation, management of human activities, research, education, and implementation. The North American legislation is similar, although there is a greater emphasis on protection.
caption: The black-bellied tern is endangered by human activities.
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