The importance of arable habitat for farmland birds in grassland landscapes

摘要: Summary 1 Over the last 25 years, populations of seed-eating birds have declined severely over most western Europe. Local extinctions occurred in grassland-dominated areas Britain, which may be influenced by loss habitat diversity and a decline amount arable cultivation. 2 We used large-scale British Breeding Bird Survey 1998 to investigate importance within grassland landscapes for 11 common four similar sized insectivores. Generalized linear models were model number recorded agricultural survey squares as function present. 3 Numbers grey partridge Perdix perdix, skylark Alauda arvensis, tree sparrow Passer montanus, corn Miliaria calandra reed buntings Emberiza schoeniclus, yellowhammer citrinella whitethroat Sylvia communis increased with present square; numbers house domesticus, finch species, dunnock Prunella modularis, robin Erithacus rubecula blackcap atricapilla did not. 4 The positive association between some species 1-km was strongest where rare surrounding area, weakest or even reversed when common. These results demonstrate scale-dependence bird–habitat associations landscapes, only demonstrable data are available at fine grain large geographical areas. 5 These support hypothesis that range contractions (i.e. local extinctions) granivorous because contraction cultivation. The it is scarce causing declines areas, though intensification management thought main cause elsewhere. Agri-environment schemes need vary regions, example encourage cultivation pastoral areas.