Landowners and gamekeepers who kill Scotland's rare birds of prey to protect their livestock should be "named and shamed" by Scottish ministers.
Sarah Boyack, Scottish Labour MSP, said taking steps to reduce incidents of wild raptors being shot and poisoned was "a matter of urgency".
Deliberate killing birds such as sea eagles, buzzards, red kites and hen harriers have reached "unacceptably high" levels, according to an RSPB report published last month.
The bird charity's year-long study into wildlife crimes found 28 cases in which pesticides were used to illegally kill or threaten birds of prey in 2008.
Another four cases involved the discovery of pesticides suspected to be used for illegal purposes, and 42 poisoned baits, also illegal, were found in the Scottish countryside.
The killings were concentrated around so-called hotspots on the east coast, where much of the land is given over to grouse and pheasant rearing.
Ms Boyack, the Shadow Cabinet Secretary for Rural Affairs and Environment, said "unscrupulous" Scottish estates should be publicly named to try and reduce the number of birds of prey being illegally killed in the country.
"Authorities need to take action against unscrupulous estates in Scotland where bird killings have taken place," she said.
"We want to see thorough investigations where there have been a higher number of incidents. If foul play is involved then these estates should be named and shamed to publicly condemn their actions.
"It is clear that something must be done to tackle the high number of poisonings. Birds of prey are spectacular creatures and we must protect them and ensure their survival.
"It goes without saying that there are estates where there are good management practices in place and these must be recognised and spread out across the country.
"The Scottish Government needs to take more robust action on wildlife crime."
