Crimes against wild birds in the UK increased by more than 50% last year, a leading wildlife charity has reported.
Hen harriers are struggling to recover from years of persecution
The Royal Society for the Protection of Birds (RSPB) said there were 1,109 incidents in 2006, up from 726 in 2005.
Its Birdcrime report says threatened species suffered shooting, poisoning, trapping and nest destruction.
The RSPB is particularly worried about the killings of birds of prey, and named Derbyshire, North Yorkshire and Northumberland as the worst hotspots.
There were 12 reported cases of persecution against birds of prey in Derbyshire, 11 in North Yorkshire and 10 in Northumberland in 2006.
RSPB conservation director Dr Mark Avery said: "Data from the report identifies these three counties as the worst in England for reported persecution of birds.
"Worryingly, these counties are important for a number of birds of prey - such as red kite, goshawk and hen harrier - that are struggling to recover from many years of deliberate persecution."
Because of the importance of northern England for threatened species and the high levels of wildlife crime, the RSPB has employed a full-time investigations officer based in the region.
Dr Avery said: "After 25 years of legal protection, we should be seeing dramatic cuts in wildlife crime.
"Thankfully, some birds of prey are heading towards recovery in the UK, but let us not forget that illegal slaughter of birds of prey that caused their extirpation and extinction in the first place.
"We mustn't allow age-old attitudes towards birds of prey to once more put these magnificent birds under threat."
Of the 1,109 reported wildlife crime incidents, 627 were in England, 300 in Scotland, 142 in Wales and 12 in Northern Ireland. Another 28 crimes were not allocated to any single country.