Their conclusions are the same as the paper linked on page 1...............the British Birds article Phil has kindly linked concludes: -
"This shows that the Eagle Owl (as defined above) has probably been a native species in Britain for a long time and possibly through different climatic regimes with different habitats. It may be that this native status was not continuous and was punctuated by the extreme conditions of the most severe glacial periods. However, at most other times the climate would probably have been suitable for the species. The finds from the Late Glacial, if they represent Eagle Owl, may well be part of the same population as the earlier Holocene find. There is no climatic reason why these birds may not be part of a continuous occupation by the species. It is the view of the author that the fossil and archaeological record suggest strongly that the Eagle Owl is part of the natural, native British fauna".
The World Owl Trust report, from 2010, concludes: -
"We believe that in this report we have given sufficient evidence to suggest that the European Eagle Owl Bubo bubo bubo is a legitimate candidate for listing as a native British species. The BOU’s arbitrary interpretation of what does or does not constitute a native species, is at odds with archaeologists, palaeontologists and mammal scientists’ interpretations (see Stewart 2007 and Yalden 2003), and also that published by DEFRA. Furthermore, their claim that the European Eagle Owl is an invasive alien originating solely from escapes or deliberate releases is unsubstantiated. We therefore now call on DEFRA, FERA, the RSPB, BTO and Natural England to scrap the Risk Assessment document and it’s conclusions until first-hand accurate data is collected from pairs nesting or present in Britain. We also call on the British Ornithologist’s Union to remove the Eurasian Eagle Owl from Category E* of the British List and place this species in Category A unless they can validate their claim that all Eagle Owls currently in Britain originate from captive stock."
Is it of any relevance that both investigations concur?