Aquatic warbler held by Djoudj National Park ornithologist, Indega Binda.

© Martin Flade/BirdLife/afrol News

afrol News, 22 February - After years of investigations, an "expedition" has tracked down one of the last great mysteries of Europe's migratory birds, the wintering grounds of the threatened aquatic warbler. Thousands of the birds were found spending the winter in Senegal's Djoudj National Park - ironically a bird conservation area supervised by ornithologists.

The aquatic warbler mainly breeds in lowland marsh habitats in Eastern Europe, and it is estimated that its population has dropped to about one tenth as an estimated 95 percent of habitat has been lost in the last century. Its global population is now down to 15,000 pairs – largely because of drainage of its wetland nesting sites.

Therefore, bird conservationists have now spent five years of investigations to track down the bird's wintering grounds, hoping to extend protection measures to both summer and winter habitats of the threatened species. In Poland, Belarus and Hungary, great conservation schemes are already underway.

Great was the surprise when an "expedition" of birdwatchers found immense numbers of the bird species in one of Africa's most well-known bird sanctuaries, the Djoudj National Park of north-western Senegal, on the Mauritanian border. For decades, the Djoudj has been "mainly visited by keen bird-watchers," as even regional travel guides ('Rough Guide') inform.

Even more embarrassing to conservationists, the national park employs its own ornithologist, Indega Binda, who could assist the European "expedition" in pointing out the large settlement of wintering aquatic warblers. Mr Binda showed the Europeans large populations in an area of about 100 square kilometres within the park.

Based on the "discovery", the conservationists - mostly from the UK-based international organisation BirdLife - were thrilled to publish a report. "Preliminary estimates range from 5-10,000 birds at this single site," the group said - meaning that roughly a quarter of the species' global population had been found in Djoudj.

Not embarrassed at all over the previous lack of knowledge, BirdLife was of course happy to find that this great part of aquatic warblers already was well protected while passing winter holidays in Africa. Also the Djoudj park administration was happy about the "discovery", which could mean more European investments in the active management of the important habitat.

"Knowing where they are in winter now provides a starting point to mirror the successful European conservation efforts in Africa," noted Lars Lachmann of BirdLife UK, who co-organised the "expedition" to Senegal. "Thankfully, substantial parts of the bird's wintering range fall within protected areas, with the Djoudj National Park alone possibly holding up to a third of the world population," he added.

Despite records by West African ornithologists, the European researchers had to use advanced science to reveal "the mystery" of the birds' winter location. The team analysed feathers from warblers caught in Europe to help narrow their search. Knowing that the feathers would have been grown on African wintering grounds, they looked for patterns of isotopes and compared these alongside isotope maps of West Africa. This was combined with a computer modelling of potentially suitable climatic conditions, leading researchers to likely areas bordering the Senegal River.

Research is now going to be continued to find further wintering sites of the aquatic warbler in the West African region. "Future work in the field and with satellite maps will help identify other potential sites in southern Mauritania and elsewhere in western Africa," BirdLife announced. It seemed the organisation still had no plans asking ornithologists at famous neighbouring bird sanctuaries in Senegal and Mauritania for help.

By staff writer

© afrol News

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