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Several factors support the theory that the whinchat population may be declining because of problems the birds face on their annual odysseys to and from Africa south of the Sahara. One is that the whinchat's nearest relative, the stonechat, has more than trebled its numbers since 1995, while the migratory whinchat has decreased by 43 per cent over the same period. The stonechat occupies similar habitats of heathland, gorse and bracken-covered hillsides, but stays in Britain all year.
A second factor is that several other sub-Saharan migrant species are showing similar substantial declines. These species range from the turtle dove (66 per cent decline since 1995) and the wood warbler (60 per cent), to the pied flycatcher (51 per cent), the nightingale (41 per cent) and the cuckoo (37 per cent). The migrant declines have prompted the BTO to begin research on these species' wintering habitats to see if they are running into trouble during the times they spend in Africa.
The whinchat is much appreciated by birdwatchers. "It's a lovely species, and its song is part of the filigree background sound of spring," said Mark Cocker, author of Birds Britannica.
"Its disappearance is deeply saddening, and further evidence that something truly disturbing is happening to our summer migrants," said Graham Madge, conservation spokesman of the Royal Society for the Protection of Birds.
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http://www.independent.co.uk/environment/nature/going-for-a-song-a-mysterious-vanishing-act-1876401.html