Rose tern
| Rose tern | ||||||||||
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Rose tern |
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| Sterna dougallii | ||||||||||
| Montagu , 1813 |
The rose tern ( Sterna dougallii ) is a species of bird in the family of the tern (Sternidae).
Appearance
The rose tern resembles the common tern in both size and shape. The resting, breeding and plumage of the young birds resembles this related species. However, the beak of the rose tern is somewhat slimmer, it is black in color and only red at the base of the beak. The outermost tail feathers are noticeably long and protrude far beyond the wing tips when sitting. When brooding, rose terns often show a pink to reddish sheen on the underside of the body.
It is better to identify the common tern as well as the arctic tern, which also looks similar, to the rose tern through their voice. She screams loudly Krii and a soft Tschu-ick .
Distribution area and subspecies
The rose tern is a rare and only occasional breeding bird of the coastal areas in Europe. The subspecies that can be observed here is S. d. dougallii . This also breeds on the Atlantic coast of North America . The birds winter in the Caribbean as well as in western Africa . The population numbers in both Europe and North America have been decreasing for a long time. However, active protective measures have been able to stop the decline in some breeding colonies.
Two more subspecies S. d. korustes and S. d. bangsi are breeding birds in eastern Africa as far as Japan. These 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 short wings compared to the other subspecies, belongs to the fauna of Australia and also breeds in New Caledonia .
Reproduction
The rose tern breeds in Europe from June to July. The mating ritual of the birds includes the handing of fish by the male to the female.
As a rule, a nest is not built. The two cream-colored and red-brown spotted eggs are simply laid on sand, preferring breeding sites that are hidden under tufts of grass. The incubation period is 21 days. Both parent birds are involved in the brood. The nest and the young birds are defended much less intensively by the rose tern than is the case with the common tern and the arctic tern. The rose tern often breeds in colonies with these species.
Food and subsistence
Rose terns mostly live on small fish. They prey on them through shock dives. Almost exclusively marine fish are eaten. The rose tern can only be seen very rarely in inland waters. There she does not come to eat, however, but only bathes there.
Unusually for terns , rose terns occasionally show kleptoparasitic behavior. In the breeding colonies in Great Britain they hunt off part of the prey from other birds. Affected by this behavior are especially puffins . This behavior expands their ability to acquire food, especially during bad weather, when the prey of the rose tern swim in deeper water layers and are therefore out of reach of the tern, but are still within the diving range of the puffin.
Others
In the late 19th century, the rose terns were hunted for their plumage. It was mainly used by milliners to make hats . Lately, the number of birds in some regions has decreased mainly because they have been exposed to increased competitive pressure from seagulls , whose populations have risen sharply in recent decades. It has also been shown that rose terns willingly accept nesting aids and that this can stabilize and even increase population numbers. Rose terns, who prefer hidden spots under tufts of grass, also accept nesting boxes. These protect the young birds from predators such as the black-backed gull . In a breeding colony on Coquet Island , Northumberland , the population increased from 25 breeding pairs in 1997 to 92 breeding pairs in 2005.
Web links
- Sterna dougallii in the endangered Red List species the IUCN 2008. Posted by: BirdLife International, 2008. Accessed January 31 of 2009.
- Videos, photos and sound recordings of Sterna dougallii in the Internet Bird Collection
- Distinction between common and arctic tern with notes on the forest and rose tern, technical article by Peter H. Barthel from Limicola, volume 5 (1991), page 1 (PDF file; 5.7 MB)