Skua
Arctic Skua ( Stercorarius parasiticus )
The skuas ( Stercorariidae ) are a family of birds in the order Charadriiformes. Sometimes they are eingeordneta also in the family of gulls ( Laridae ). The name Skua, which is used for the major representative of the family, is one of the very few loanwords from Faroese, where the bird skúgvur [ sgɪgvʊɹ ] is called and the island Skúgvoy its name.
Appearance
The short but rough beak is provided with a skin. At the top it is slightly compressed and the transition to head almost round. The upper part of the beak is hook-shaped and bent downward, the lower part constituting a trough fitted into the former. The nostrils are located far forward and are small and narrow. The claws are sharp, sharp and curved. The wings are long and narrow and pointed at the end. The arc-shaped tail composed of 12 medium length springs. Skuas have a dark - gray or brown plumage, which looks the same in summer and winter.
Circulation area and way of life
Most species live in polar regions, and then in the vicinity of salt water. Skuas live in pairs or individually. During the mating period, groups or colonies can form. Skuas can fly very fast and perform this sudden turns. You can only go well mediocre, and their resting places on rocky islands. They frequently rob other birds, mostly gulls and terns, their prey. As soon as one of these birds has caught a fish, he is attacked by the Skua with beak, claws and wings until he gives up the sometimes almost swallowed prey. Even before the fish hits the ground or water surface, it is absorbed by the skua. Since skuas can only dive in shallow depths, they even catch only fish that float on the water surface. Furthermore, skuas of eggs, young birds, small rodents and molluscs feed.
Skuas breed on sea coasts and place two speckled eggs. The eggs and young birds, which are long cared for by the parents, are defended with heavy use against real and suspected enemies.
System
The skuas are sometimes divided into two genera, with the smaller species are in the genus Stercorarius and the larger species (the " skuas " ) in the genus Catharacta. However, this division has no biological basis: in fact, either the Great or the Pomarine from a hybridization between a " Catharacta " are - and a Stercorarius - type emerged. Some authors also proposed to give the three subspecies of Subantarktikskuas species status.
Species
- Antarktikskua (syn. Südpolarskua ) Stercorarius maccormicki (syn. Catharacta maccormicki )
- Chileskua Stercorarius chilensis (syn. Catharacta chilensis )
- Skua Stercorarius longicaudus
- Arctic Skua Stercorarius parasiticus
- Pomarine Stercorarius pomarinus
- Subantarktikskua Stercorarius antarcticus (syn. Catharacta antarctica)
- Great Skua Stercorarius skua (syn. Catharacta skua )