Roseate Tern
Roseate Tern
The roseate tern (Sterna dougallii ) is a seabird of the tern family ( Sternidae ).
Appearance
The roseate tern is similar to both their size and the shape. Also the rest, breeding, and the plumage of the young birds is like these related Art In the roseate tern, however, is the beak slightly slimmer, it is of black color and only on the beak-root red. The outermost tail feathers are remarkably long and protrude in a sitting position far beyond the wing tips also. In breeding plumage roseate tern often show a pink to reddish tinge on the underparts.
Better of the Common Tern and Arctic Tern also similar looking to identify the roseate tern over her voice. She calls kriii screeching and a soft choo - ick.
Area of distribution and subspecies
The roseate tern is in Europe a rare and occasional breeding birds of coastal areas. In the subspecies that can be observed here is the meaning of dougallii. This also breeds on the Atlantic coast of North America. The birds spend the winter in the Caribbean and in West Africa. The population figures both in Europe and in North America take off for a long time. Active protection measures have been unable to stop the decline in some breeding colonies.
Two other subspecies S. d korustes and S. d Bangsi are breeding birds in eastern Africa to Japan. This subspecies, which are characterized by a stronger red on the beak, are resident birds. The subspecies S. d gracilis, which is characterized by a particularly long beak and in comparison to the other subspecies short wings, belongs to the fauna of Australia and also breeds in New Caledonia.
Reproduction
The roseate tern breeds in Europe in the period from June to July. For mating ritual of the birds heard a handing over of fish by the male to the female.
A nest is not built into the rule. The two rahmfarbenen and brown spotted eggs are simply stored on sand, where it prefers nesting areas that are hidden under tufts of grass. Incubation period is 21 days. At the breeding birds both parents are involved. The nest and the young birds are defended by the roseate tern significantly less intense than is the case with the Common Tern and Arctic Tern. Often, the Roseate Tern breeds in colonies with these types together.
Food and foraging
Roseate tern live mainly on small fish. This they capture by impact dives. There are almost exclusively eaten marine fish. Only very rarely the roseate tern is also observed in inland waters. There, they will not find, however, to purchase a food, but only bathes there.
Unusually for roseate tern terns show occasionally a kleptoparasitisches behavior. In breeding colonies in Britain they hunt other birds from a share of the spoils. Affected by this behavior are especially puffins. This behavior extends their ability to purchase food, especially during bad weather, when the prey of the roseate tern swim in deeper water layers and thus are beyond the reach of terns, but are still within the range of diving puffins.
Others
In the late 19th century, the roseate tern were hunted for their plumage. It was mainly processed by milliners for the jewelry of hats. Lately, the number of birds has in some regions, in particular be removed because they were more exposed to competition from gulls, whose population numbers have increased greatly in recent decades. It has also shown that roseate tern nesting boxes willingly accept and that it can thereby stabilizing the population numbers and even increased. Roseate tern, who prefer places -hidden under tufts of grass, also accept Nistboxen. These protect the chicks from predators such as the herring gull. In one located on the Coquet Island, Northumberland breeding colony thus could the population numbers of 25 breeding pairs increased in 1997 to 92 breeding pairs in 2005.