
Appearance
This is a large tern, similar in size to the Sandwich tern at 33–36 cm long with an 82–94 cm wingspan. The wings and deeply forked tail are long, and it has dark black upperparts and white underparts. It has black legs and bill. The average life span is 32 years. Juvenile Sooty Terns are scaly grey above and below. The Sooty Tern is unlikely to be confused with any tern apart from the similarly dark-backed but smaller bridled tern . It is darker-backed than that species, and has a broader white forehead and no pale neck collar.The call is a loud piercing ''ker-wack-a-wack'' or ''kvaark''.

Habitat
Sooty terns breed in colonies on rocky or coral islands. It nests in a ground scrape or hole and lays one to three eggs. It feeds by picking fish from the surface in marine environments, often in large flocks, and rarely comes to land except to breed, and can stay out to sea for 3 to 10 years.This bird is migratory and dispersive, wintering more widely through the tropical oceans. It has very marine habits compared to most terns; sooty terns are generally found inland only after severe storms. The Field Museum, for example, has a male specimen which was found exhausted on August 2, 1933 on the slopes of Mount Cameroon above Buea, about 1,000 m ASL, after foul weather had hit the Gulf of Guinea. This species is a rare vagrant to western Europe, although a bird was present at Cemlyn Bay, Wales for 11 days in July 2005.
It is also not normally found on the Pacific coasts of the Americas due to its pelagic habits. At Baja California, where several nesting locations are offshore, it can be seen more frequently, whereas for example only two individuals have ever been recorded on the coast of El Salvador - one ring recovered in 1972, and a bird photographed on October 10, 2001 at Lake Olomega which was probably blown there by a storm . Hurricanes can also devastate small breeding colonies, as has been surmised for example for the sooty tern nesting sites on cays off the San Andrés Islands of Colombia.
An exceptionally common bird, the sooty tern is not considered threatened by the IUCN.
Cultural
On Easter Island, this species and the spectacled tern are collectively known as ''manutara''. The ''manutara'' played an important role in the ''tangata manu'' ritual: whichever ''hopu'' could retrieve the first ''manutara'' egg from Motu Nui islet would become that year's ''tangata manu''; his clan would receive prime access to resources, especially seabird eggs.References:
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