Recent changes in the abundance of British upland breeding birds

Abstract

Capsule: Breeding wader populations have more often shown declines than passerine populations during the last 10-20 years. Aims: To determine abundance changes in British upland breeding birds during the last 10-20 years. Methods: We re-surveyed 1348 km2, in nine study areas, of the British uplands in 2000 and 2002, which had been previously surveyed between 1980 and 1991. In addition, we included data from recent repeat surveys in four other upland areas, covering approximately 365 km2, to broaden the scope of our study. Results: We found evidence of widespread population declines in three species of breeding waders, Lapwing Vanellus vanellus, Dunlin Calidris alpina and Curlew Numenius arquata. Among the passerines, some species declined, including Twite Carduelis flavirostris and Ring Ouzel Turdus torquatus, while others showed strong gains, including Stonechat Saxicola torquata and Raven Corvus corax. Conclusion: Overall, abundance changes were characterized by a high degree of variability across study areas, even when close together. This variability may have been partly due to the different time intervals between the original and repeat surveys. Improved upland breeding bird population monitoring is needed to allow better detection of trends. Action is needed to restore upland breeding bird populations in areas where they have declined. © 2005 British Trust for Ornithology.