Conservationists are pressing for tougher laws to combat wildlife crime on Scottish grouse moors after a rise in poisoning cases against birds of prey such as golden eagles and red kites last year.

The Royal Society for the Protection of Birds (RSPB) in Scotland said ministers should make grouse moor owners legally responsible for attacks on birds of prey on their estates because existing laws and voluntary codes had failed.

The conservation charity said the latest official figures showed there were 46 proven poisoning incidents targeting birds of prey last year - the most in two decades - and another seven cases where illegal poisons were found on shooting estates. The cases included the deaths of two rare golden eagles, four red kites, 21 buzzards and a sea eagle. As well as poisoned baits such as rabbits and eggs, the RSPB included cases where cats, magpies and ravens had been poisoned by pesticides laid to kill birds of prey.

Some gamekeepers on grouse moors and pheasant shooting estates target birds of prey because they eat game birds kept for commercial and private shooting.

The record level of incidents is a significant setback to efforts by the Scottish government to tackle wildlife crime and an embarrassment to Highland estate owners who claim to abhor such attacks.

Duncan Orr-Ewing, head of species for RSPB Scotland, said the legal and voluntary approaches were not working and prosecutions of gamekeepers were rare.

Copyright: Guardian News & Media 2010