Sterna fuscata
The wings and deeply forked tail are long, and it has dark grey upperparts and white underparts. It has black legs and bill. 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 (O. anaethetus). It is darker-backed than that species, and has a broader white forehead and no pale neck collar. Bill and legs black, iris dark brown. Non-breeding adult has variable white feather with fringes above. The call is a loud piercing ker-wack-a-wack or kvaark.
Not Threatened.
The wings and deeply forked tail are long, and it has dark grey upperparts and white underparts. It has black legs and bill. 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 (O. anaethetus). It is darker-backed than that species, and has a broader white forehead and no pale neck collar. Bill and legs black, iris dark brown. Non-breeding adult has variable white feather with fringes above. The call is a loud piercing ker-wack-a-wack or kvaark.
36 - 45 cm, 147-240 g, average 173 g in Australia
Taxonomy:
- Sterna fuscata Linnaeus, 1766, Santo Domingo. Formerly united with S. anaethetus and S. lunata in separate genus Haliplana or Onychoprion. Geographical variation subtle: separation of races crissalis, infuscata and serrata probably not warranted; validity of proposed form somaliensis, possibly endemic to Mait I (Gulf of Aden), requires study. Eight subspecies currently recognized. (source: Handbook of the Birds of World)
Subspecies and Distribution:
- * fuscata Linnaeus, 1766 - Gulf of Mexico, including West Indies and E Mexico, with sporadic isolated nesting attempts in the Carolinas and Florida, more regularly in Louisiana and Texas; also islands in Gulf of Guinea and in S Atlantic. * nubilosa Sparrman, 1788 - S Red Sea, Gulf of Aden and Indian Ocean E to Ryukyu Is and Philippines. * infuscata Lichtenstein, 1823 - C Indonesia (range uncertain). * serrata Wagler, 1830 - New Guinea, Australia and New Caledonia. * kermadeci (Mathews, 1916) - Kermadec Is. * oahuensis Bloxham, 1826 - Bonin Is to Hawaii and S through Pacific. * crissalis (Lawrence, 1872) - islands off W Mexico and Central America S to Galapagos. * luctuosa Philippi & Landbeck, 1866 - Juan Fernández Is (Chile).
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.
Mainly fish and squid, also crustaceans, ocassionaly insect and offal. During nonbreeding periods, flocks of Sooty Terns follow large schools of migratory tuna. However, in the breeding season, the species forages close to breeding islands in association with smaller species of tuna.
Breeding occurs in small to large colonies, often mixed with other seabirds. The locality may determine the time of breeding and the breeding cycle. Populations have been recorded breeding every twelve months, every nine and a half months and every six months.