Caspian Tern
Caspian Tern ( Hydroprogne caspia, syn. Sterna caspia )
The Caspian Tern ( Hydroprogne caspia, syn. Sterna caspia ) is a species of bird in the order of the Charadriiformes. It is the largest species of the tern family.
Systematic position
By comparing mitochondrial DNA showed that the terns are not monophyletic group, so do not have the same origin. Accordingly, the Caspian Tern is now classified in a separate genus.
Appearance
Caspian tern are slightly larger than gulls with a length of 48 to 55cm. They fly with slower wing beats than other terns. As a special mark they have a strong red bill, dark brown feet and a little forked tail. The primaries appear dark on the lower wing surface. In breeding plumage they have a deep black headstock, which is interspersed in plumage with white feathers.
Young birds and females have identical plumage. The head plate and the back feathers are mixed here with dark brown feathers. Your beak is orange just dull.
Habitat
Caspian tern nests in colonies on sandy sea- coasts and on islands. On their train, they are occasionally observed in small numbers also in inland waters.
Caspian tern have a very large area of distribution. They are spread from North America to Europe to Asia and includes the fauna of Australia. The Nordic Caspian tern breeding colonies have priority to the northeastern Baltic Sea coasts and wintering mainly in West Africa and on the shores of the Mediterranean.
Reproduction
Caspian tern have only one years young. The nest is a shallow depression in the sand. The nest consists of two to three yellowish gray eggs with dark brown spots. The eggs are incubated by both parents birds 22 to 24 days.
Food and foraging
Caspian tern live fish, which they capture by impact dives. They are often observed previously in Rüttelflug. Even young birds of other species are eaten occasionally by Caspian tern.
Protection status
The Caspian tern is in Germany Endangered ( Red List category 1 ). It is a kind of Annex I of the EU Birds Directive ( 79/409/EEC RL ).