Ringed Gull-billed Terns on the coast of the Northern Sea

LachseeschwalbeIn the only colony in North Western Europe, in Schleswig-Holstein on the Dithmarsch Elbe estuary in the Neufeld polder, Gull-billed Terns (Gelochelidon nilotica) had a good breeding success in 2014 and about 30 breeding pairs in the colony in Neufeld / Schleswig-Holstein and the one in Lower Saxony probably get roughly 40 young birds fledge. In the last two years the Gull-billed Tern had already raised each 20-30 fledged young birds. In 2014 the first young birds from the year 2012 returned to the breeding colony. This was clearly visible by the color rings.

About 100 years ago, the Gull-billed Tern was widespread in Central Europe. Breeding population consisted of semi-natural, dynamic rivers in the Alpine foothills of Bavaria and Baden-Württemberg and on the Danube in Austria. There were colonies of up to 200 pairs on non-vegetated gravel banks. Human activities have led to the populations decline. The channeling of rivers destroyed the former breeding grounds. Changes and destruction of food-rich wet meadows, heathland and farm land near the breeding colonies, intensification of agriculture, obstruction and over-fertilization led to the loss of habitats. Today, the Gull-billed Tern (Gelochelidon nilotica) is very rare, and the breeding areas are almost exclusively in south-eastern and southern Europe, as in the Camargue in France and in the Ebro Delta in Spain. Since 1995 a breeding colony of 30-40 pairs at the mouth of the Elbe in Schleswig-Holstein is established.

To ensure the survival of this colony, the Artenhilfsprojekt Lachseeschwalbe (Species conservation project Gull-billed Tern) was founded in 2010. It is coordinated by several nature conservation associations. The Schleswig-Holstein Ministry of Environment and the county Dithmarschen finance the project. A support team monitors the colony of Gull-billed Tern around the clock.

In addition to direct observations webcam also provide live images from the colony, so that the wardens can respond quickly to any disturbance. Disturbance ranges from harassment against nest robbers and other predators to the fencing of the colony site with electric wires. The young birds are ringed after breeding. They get color rings that make them individually identified. The intensive conservation efforts are successful.

Towards the end of the breeding season nature conservationists try to ring all the nearly fledged young birds to learn about their migration routes and their survival success. After the breeding season in July / August the Gull-billed Terns migrate in the family groups through the Wadden Sea. The pair from the Lower Saxony flew with its two ringed young birds to Sylt. Referring to the website observation platform for the Netherlands, Gull-billed Terns also like stay in Holland, where there are traditionally found e.g. on the Balgzand. In September, most birds have left Holland however and move along the coast or even across the inland south / southwest to winter probably in West Africa. On the tidal flats of the Banc d’Arguin (Mauritania) or Bissagos archipelago (Guinea Bissau) they specialize in catching fiddler crabs. Even in winter, the families still hold together and the young birds are still fed by the parents.

On the coast along the Elbe estuary Common Terns (Sterna hirundo) breed, too. Here is the largest Terns colony of the Wadden Sea with almost 2,000 breeding pairs. Obviously the Gull-billed Tern is decisively looking for the protection by the large colony of Common Terns for their own breeding grounds.

If the North Sea summer visitors make sightings of Gull-billed Terns on the German coasts, he / she should please always try to pay attention to color rings, the age of the birds and possible family affiliations. Photos are always welcome and help to better see the color rings.

Ring messages are welcome at the conservation station in the Wadden Sea of Schleswig-Holstein. Please send an e-mail to k.guenther@schutzstation-wattenmeer.de at the hands of Klaus Günther.

This image of a Gull-billed Tern is just a taste of what you will find in the gallery “Picture-Shop“. Just enter bird-lens.com know if you can serve with an additional image. Not only traveling to remote places but also detailed knowledge of the nearby home was very helpful to take pictures of the birds of the Western Palearctic.

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