An evidence-based assessment of the past distribution of Golden and White-tailed Eagles across Wales

Abstract

Two species of eagles (Golden and White-tailed) bred in Wales during prehistoric and historic times and became regionally extinct as breeding species in the mid-1800s. They are iconic and charismatic, and discussions about reintroducing them back into the Welsh landscape have been ongoing for years. Reintroductions, however, can be risky, costly and/or contentious. To address these concerns, and to judge whether it is appropriate to reintroduce a regionally extinct species; the “International Union for Conservation of Nature (IUCN)” have produced criteria by which a proposed reintroduction can be assessed. A key criterion is that the potential reintroduction location lies within the former range of the species. In this study, we addressed this criterion by assessing the past distributions of Golden and White-tailed Eagles within Wales. Using historic observational data, fossil/archaeological records and evidence from place-names in the Welsh language, we demonstrated strong evidence for the presence of both of these eagle species in Wales in pre-historic and historic times. We used kernel density functions to model the likely core distributions of each species within Wales. The resulting core distributions encompassed much of central and west-north Wales for both species, with the White-tailed Eagle exhibiting a wider core distribution extending into south Wales. Our results fill knowledge gaps regarding the historic ranges of both species in Britain, and support the future restoration of either or both species to Wales.