A new study has revealed that eagles were once evenly distributed throughout the UK.
White-tailed eagles and golden eagles can be found in Scotland at present and are only occasional visitors to England.
The white-tailed eagle faced extinction in the UK in the early years of the 20th century but has made a limited recovery through re-introduction. Both species are thriving in Scotland although now only occupying a fraction of their previous territory.
According to the research, published in the journal Bird Study, human persecution and habitat destruction were the causes for the drop in numbers in Britain and Ireland.
The white-tailed eagles were thought to have ranged the English uplands such as the Peak District National Park and North York Moors. The golden eagles may have been dispersed across lowlands in coastal and wetland areas.
Researchers have estimated the population of the eagles between 500 AD and the present day by using historic records, place-name analysis and modern knowledge of the species' ecology.
Richard Evans of RSPB Scotland and lead author of the study said: "The results of this study are striking as they provide compelling evidence that eagles were widespread throughout most of Britain and Ireland in the Dark Ages. Between 500 and 1800AD we see massive loss of eagle range in the south, which is consistent with the effects of habitat loss and killing by humans, rather than the influence of climate change on habitat, or competitive exclusion, as some have suggested.”
Sue Armstrong-Brown of the RSPB said: “There have been many changes in our countryside over the last few centuries, but we believe there is ample potential for eagles to return to skies where they have been absent for centuries. We’re not talking about a return to the Dark Ages, but we are asking for more enlightened attitudes to eradicate illegal persecution, which is still a major reason why these birds can’t return to England.”
In 2008, Scottish Natural Heritage suggested that illegal persecution in parts of Scotland may be a reason why golden eagles have not been able to recolonise England successfully as a nesting species.
Commenting on Richard Evans’ study, Scotland’s Environment Minister Stewart Stevenson said: "Birds of prey are an important part of Scotland's biodiversity and our eagles are hugely popular with locals and visitors alike. The recent marked increase in sea eagles demonstrates how conservation and management efforts are beginning to make a real difference for these beautiful and iconic birds. The Scottish Government is also committed to working with our partners to tackle eagle persecution, with 2011 figures showing a welcome reduction in poisoning incidents for birds of prey."
For more information, please visit the RSPB and BTO websites.