Six birds of prey have been found dead in the Highlands over the last week.
Police investigating the discovery of five red kites and a buzzard in Ross-shire suspect criminal behaviour.
The birds were found in the area around Conon Bridge and Muir of Ord over the period 17 to 24 March.
Gamekeepers appealed for anyone with information to assist officers following the “disappointing” discovery.
Detective Inspector Scott McDonald, who is leading the investigation, said: “At this time we are unclear as to what has caused the death of these birds, but given all the circumstances and the close proximity to each other in which they were found, we must assume at this stage some form of criminality.
“I would ask anyone who has been working on the land or using the area for recreational purposes to contact us if they have seen anything suspicious that may be linked to this incident.”
Police advised anyone who finds a dead bird of prey to note its location and inform officers, without attempting to recover it.
Scottish Gamekeepers Association (SGA) chairman Alex Hogg said: “This is a hugely disappointing discovery and we would ask anyone who knows anything about this mindless act to contact Police Scotland and to assist with the investigation.
“Clearly, until the post-mortem and toxicology reports are known, there is little information to go on.
“However, the SGA condemns wildlife crime and advocates only legal means to solving conflicts.”