The history of eagles in Britain and Ireland: an ecological review of placename and documentary evidence from the last 1500 years

Capsule The loss of eagles from large tracts of lowland and upland habitat in Britain and Ireland over the last 1500 years is attributed to human activity. Aim To estimate changes in past distribution and population size of Britain and Ireland's two native eagle species. Methods Placenames suggesting the past presence of eagles were categorized according to modern knowledge of the species' ecology. Together with documented historical locations, these sites were mapped to derive approximate former ranges. Population estimates were made for each species at about 500 and 1800 CE. Results Estimated range at about 500 CE was 110 250 km(2) for White-tailed Eagles Haliaeetus albicilla and 98 500 km(2) for Golden Eagles Aquila chrysaetos, with 44 600 km(2) of overlap. Population sizes were 800-1400 pairs of White-tailed Eagles and 1000-1500 pairs of Golden Eagles, declining to 150 and 300-500 pairs, respectively, by 1800. Conclusion Our results provide evidence for the presence within the last 1500 years of one or other species of eagle throughout much of Britain and Ireland. The influence of climate change on eagle habitat has been subsumed by the effects of habitat destruction and persecution as primary causes of absence from much of their former range.