A satellite-tracked bird of prey has vanished in the Highlands for the fifth time this year.
The young hen harrier's tag stopped responding on the western border of the Cairngorms National Park last month.
Brian, who went missing on August 22, was last seen a few miles from Kingussie and his body has not been found.
The Royal Society for the Protection of Birds said there was no sign of any problems with his tracker before it went silent.
A spokeswoman for the animal charity said: "Brian was tagged on July 4 on an estate in Perthshire within the Cairngorms National Park.
"He fledged from the nest and stayed close to the nest site until the beginning of August when he moved north into southern Inverness-shire.
"Brian then spent the next few weeks over various areas of managed grouse moor within the National Park with frequent strong, clear transmissions from his tag providing detailed information about his daily travels.
"Suddenly and without warning, these transmissions stopped on August 22.
"His last recorded position was a few miles from Kingussie, though he may have travelled some distance before his satellite tag stopped. Despite a thorough search of the area with landowner cooperation, his body could not be found."
A young hen harrier, known as Lad, was shot dead within the Cairngorms National Park near Kingussie earlier this year.
The Scottish Government has ordered a review of satellite tracking data in Scotland.
Environment secretary Roseanna Cunningham described the disappearances as "clearly suspicious".
She said: "I take this issue very seriously and it shows the need to establish whether the disappearance of these birds is indicative of criminal activity.
"It is clearly suspicious, but we must ensure that a robust statistical analysis of all the data from over 200 tagged birds supports any conclusion.
"I will consider what action to take in the light of the full evidence and I am not ruling out any options."
Grant Moir, chief executive of the Cairngorms National Park Authority added: "We are working with Police Scotland, Scottish Natural Heritage and Scottish Government to look at next steps around wildlife crime in the Cairngorms National Park."