In a previous forum (now archived) it was suggested that farmers might have been responsible for the poisoning of birds of prey.
http://www.ukclimbing.com/forums/t.php?t=582698
One farmer has commented on the deaths.
'Mr Macdonald's three farms, including his home, have been searched by police who found nothing which linked him to the deaths. Officers examined his sheds, barns and even his bedroom.
He said the reputation of the local farming community, which has actively encouraged the reintroduction of red kites in the area, is being tarnished.'
http://www.bbc.co.uk/news/uk-scotland-highlands-islands-27074309 
