However, figures from the Partnership for Action Against Wildlife Crime (Paw) Scotland still showed the number of illegal poisonings in Scotland doubled in the past year – there were three in 2012 and six in 2013.
A red kite, a golden eagle and four buzzards were poisoned in 2013 but the number remains well below a peak of 30 in 2009.
In a bid to curb the increase in killings, Paw has published a set of maps which show the location of all recorded crimes against birds of prey last year.
There were two poisoning cases discovered in Perthshire, two near Stirling, one in Angus and another south of Edinburgh.
The RSPB said the figures were “very worrying” and showed birds continued to be persecuted in the countryside.
Environment minister and chair of Paw Scotland, Paul Wheelhouse, said: “I was disturbed to learn of the unfolding number of raptor persecution incidents as the year progressed, and the publication of the new map confirms a larger number of other reported crimes that is nearly three times the level of poisoning.”
The maps have been unveiled at the end of a month when 11 birds of prey have been found dead in the Highlands, though these figures are not included in the maps, which only cover up until the end of last year.
This month, a total of seven red kites and four buzzards were found dead in an area between Conon Bridge and Muir of Ord in Ross-shire. The birds were found at various places but police have yet to confirm how they died or whether a crime had been committed.
Conservationists say the problem of illegal killings is mainly linked to managed grouse moors, with raptors being culled to protect birds for sport.
Duncan Orr-Ewing, RSPB Scotland’s head of species and land management, said: “It is very worrying the number of detected illegal poisoning incidents has shown an increase on the previous year. The other reported criminal incidents show the deliberate targeting of vulnerable raptor species including hen harriers, red kites and both golden and sea eagles.
“We acknowledge Scottish Government efforts to tackle these appalling crimes and agree the production of these annual raptor crime maps makes a significant contribution to public awareness.”
He said wildlife criminals were switching from poisoning towards less easily detectable methods of killing the protected birds. There have been incidents where chicks and eggs of ground-nesting species such as the hen harrier have been stamped on, and a case last year when a tree where sea eagles were building a nest was deliberately felled.
It is an offence in the European Union to possess carbofuran, a pesticide designed to control insects in crops such as potatoes. It is particularly toxic to birds and has been linked with criminal raptor poisonings.
Douglas McAdam, chief executive of Scottish Land & Estates, said: “We have supported the publication of these poisoning maps because robust facts and evidence are an essential part of resolving this problem. With good progress having been made on reducing illegal poisoning incidents since the high double-figure numbers of a few years ago, it is helpful to extend the same approach to show other types of illegal killing.”