Distribution and Habitat
The Sedge Warbler has a large range and an estimated Global Extent of Occurrence of 10 million square kilometres, with a large global population including between 8.8 million and 15 million birds in Europe. Data analysis by the British Trust for Ornithology has shown that fluctuations in the Sedge Warbler population stem from the adult survival rate, due to changes in rainfall on the birds' wintering grounds. Global changes in population have not been measured, but the Sedge Warbler's status is designated 'of Least Concern' by BirdLife International.
It breeds across Europe and western and central Asia and is migratory. After feeding up post-breeding, they migrate quickly across southern Europe and the Sahara from August to September. Studies in Nigeria and Uganda suggest that Sedge Warblers return to spend winter at the same sites, year after year.
All Sedge Warblers spend winter in sub-Saharan Africa, from Senegal in the west to Ethiopia in the east, and as far south as the eastern Cape Province of South Africa and northern Namibia. The route taken on the southward migration, and eventual wintering grounds, correspond to the birds' breeding grounds. Birds ringed in the United Kingdom and Netherlands are later found from south-west Iberia to Italy; birds from Sweden are recovered in central Europe and Italy; while Finnish birds are found in north-east Italy and Malta east to the Aegean region. Sedge Warblers from the former Soviet Union take routes via the eastern Mediterranean Sea and Middle East.
Loss of wetland areas for feeding on migration, and the expansion of the Sahara desert, pose threats to the Sedge Warbler's breeding population. Birds begin leaving Africa in late February, fatten up at wetlands before and probably after crossing the Sahara, and arrive in Europe from March onwards.
Unlike other members of the Acrocephalus genus, the Sedge Warbler's range stretches from the Arctic to mid-latitudes. It is adapted to cool, cloudy and moist conditions. Though it is often found in wetlands, it can breed 500 metres or more away from water. During the breeding season, this is a species found in reedbeds, often with scrub, ditches and habitats away from water including hedgerows, patches of Stinging Nettles, and arable crops. On the African wintering grounds, habitats such as reeds at wetlands, papyrus, grass, sedge and reedmace and tall elephant grass are used. It can be found at altitudes of 1,800–2,400 metres above sea level in Ethiopia.
Read more about this topic: Sedge Warbler
Famous quotes containing the words distribution and/or habitat:
“The man who pretends that the distribution of income in this country reflects the distribution of ability or character is an ignoramus. The man who says that it could by any possible political device be made to do so is an unpractical visionary. But the man who says that it ought to do so is something worse than an ignoramous and more disastrous than a visionary: he is, in the profoundest Scriptural sense of the word, a fool.”
—George Bernard Shaw (1856–1950)
“Neither moral relations nor the moral law can swing in vacuo. Their only habitat can be a mind which feels them; and no world composed of merely physical facts can possibly be a world to which ethical propositions apply.”
—William James (1842–1910)