Long-tailed jaeger | |
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Scientific classification | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Chordata |
Clade: | Dinosauria |
Class: | Aves |
Order: | Charadriiformes |
Family: | Stercorariidae |
Genus: | Stercorarius |
Species: | S. longicaudus |
Binomial name | |
Stercorarius longicaudus Vieillot, 1819 | |
The long-tailed skua or long-tailed jaeger (Stercorarius longicaudus) is a seabird in the skua family Stercorariidae.
The word "jaeger" is derived from the German word Jäger, meaning "hunter". [2] The English word "skua" comes from the Faroese name skúgvur [ˈskɪkvʊər] for the great skua, with the island of Skúvoy known for its colony of that bird. The general Faroese term for skuas is kjógvi [ˈtʃɛkvə] . [3] The genus name Stercorarius is Latin and means "of dung"; the food disgorged by other birds when pursued by skuas was once thought to be excrement. The specific longicaudus is from Latin longus, "long", and cauda, "tail". [4]
This species is unmistakable as an adult, with grey back, dark primary wing feathers without a white "flash", black cap and very long tail. Adults often hover over their breeding territories. Juveniles are much more problematic, and are difficult to separate from parasitic jaeger over the sea. They are slimmer, longer-winged and more tern-like than that species, but show the same wide range of plumage variation. However, they are usually colder toned than Arctic, with greyer shades, rather than brown.
This is the smallest of the skua family at 38–58 cm (15–23 in), depending on season and age. However up to 29 cm (11 in) of its length can be made up by the tail which may include the 15 cm (5.9 in) tail streamers of the summer adult. The wingspan of this species ranges from 102 to 117 cm (40 to 46 in) and the body mass is 230–444 g (8.1–15.7 oz). [5] [6]
Two subspecies are described: [7]
This species breeds in the high Arctic of Eurasia and North America, with major populations in Russia, Alaska and Canada and smaller populations around the rest of the Arctic. It is a migrant, wintering in the south Atlantic and Pacific. Passage juvenile birds sometimes hunt small prey in ploughed fields or golf-courses, and are typically quite fearless of humans.
They nest on dry tundra or higher fells laying two spotted olive-brown eggs. On the breeding grounds they can be heard making yelping and rattling sounds. Outside of the breeding season they spend most of their time over open ocean and have a harsh kreeah cry. This bird feeds on fish (mainly caught from other seabirds), smaller birds, food scraps, small mammals, fruit and carrion. On migration, long-tailed jaegers are more likely to catch their own food, and less likely to steal from gulls and terns than larger species.
The skuas are a group of predatory seabirds with seven species forming the genus Stercorarius, the only genus in the family Stercorariidae. The three smaller skuas, the Arctic skua, the long-tailed skua, and the pomarine skua, are called jaegers in North American English.
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 parasitic jaeger or Arctic skua (Europe), is a seabird in the skua family Stercorariidae. It is a migratory species that breeds in Northern Scandinavia, Scotland, Iceland, Greenland, Northern Canada, Alaska, and Siberia and winters across the southern hemisphere. Kleptoparasitism is a major source of food for this species during migration and winter, and is where the name is derived from.
The pomarine jaeger, pomarine skua, or pomatorhine skua, is a seabird in the skua family Stercorariidae. It is a migrant, wintering at sea in the tropical oceans.
The great skua, sometimes known by the name bonxie in Britain, is a large seabird in the skua family Stercorariidae. It is roughly the size of a herring gull. It mainly eats fish caught at the sea surface or taken from other birds.
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.
Sabine's gull also known as the fork-tailed gull or xeme, is a small gull. It is the only species placed in the genus Xema. It breeds in colonies on coasts and tundra, laying two or three spotted olive-brown eggs in a ground nest lined with grass. Sabine's gull is pelagic outside the breeding season. It takes a wide variety of mainly animal food, and will eat any suitable small prey.
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 south polar skua is a large seabird in the skua family, Stercorariidae. An older name for the bird is MacCormick's skua, after explorer and naval surgeon Robert McCormick, who first collected the type specimen. This species and the other large skuas, such as the great skua, are sometimes placed in a separate genus Catharacta.
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.