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Evidence for declines in populations of grassland-associated birds in marginal upland areas of Britain
Authors:Ian G Henderson  Robert J Fuller  Greg J Conway  Susan J Gough
Institution:1. 'Belmont', Berwyn, Llangollen , Clwyd , LL20 8AL;2. 128A North View Road, London , N8
Abstract:Capsule We report large declines among summer populations between 1968–80 and 2000.

Aim To assess changes in the status of breeding populations of birds in pastoral uplands.

Methods Volunteer observers revisited 13 areas of marginal upland in Britain where Common Birds Census data were collected during 1968–80. This allowed the status of 35 bird species to be examined over about 20 years and to make a comparison between grassland-based and woodland-based species.

Results For 12 species the decline in abundance was significant, particularly among passerines, such as Skylark Alauda arvensis, Wheatear Oenanthe oenanthe, Whinchat Saxicola rubetra, Yellow Wagtail Motacilla flava and Yellowhammer Emberiza citrinella, each of which declined by over 80%. Redshank Tringa totanus, Yellow Wagtail, Dipper Cinclus cinclus, Whinchat, Wheatear, Ring Ouzel Turdus torquatus and Yellowhammer were found on less than half the number of plots on which they were originally recorded. Most declining species were associated with grassland for nesting and foraging, compared to those species that increased (Wood Pigeon Columba palumbus, Pied Wagtail Motacilla alba, Carrion Crow Corvus corone, Jackdaw C. monedula and Goldfinch Carduelis carduelis) that were less specialized in their habitat requirements. Woodland or woodland edge species showed no significant change in status, suggesting that population declines among grassland species were not due to lower observer effort between recording periods.

Conclusion Long-term changes to grassland ecosystems in marginal upland areas of Britain may have influenced the status of bird populations.
Keywords:Alauda  Oenanthe  Saxicola  Motacilla  Emberiza  Turdus  Tringa  Cinclus  Columba  Motacilla  Corvus  Carduelis  Numenius  Vanellus  Curlew  Lapwing  Skylark  Wheatear  Whinchat  Yellow Wagtail  Yellowhammer  Redshank  Dipper  Ring Ouzel  Wood Pigeon  Pied Wagtail  Carrion Crow  Jackdaw  Goldfinch  pastoral farmland ecology  waders  passerines  gamebirds  Common Birds Census
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