Conservationists are appealing for information after a satellite-tagged bird of prey vanished in the Cairngorms National Park last month.
The female hen harrier, named Marci, was tagged as a chick in 2018 as part of a conservation project headed by nature charity RSPB.
The young bird fledged from a nest on Mar Lodge estate, near Braemar in Aberdeenshire, and the Hen Harrier LIFE team had been tracking her movements until transmissions stopped on 22 April.
Searches by Police Scotland and RSPB Scotland have uncovered no trace of the bird or the tag.
RSPB Scotland has raised concerns for the hen harrier, which disappeared in an area where other birds of prey have gone missing, near managed grouse moors.
“This is the latest in a string of similar incidents in western Aberdeenshire, and is further strong evidence of the systematic targeting of protected birds of prey on Scotland’s driven grouse moors,” said Ian Thomson, head of investigations for RSPB Scotland.
“It is abundantly clear that current legislation is completely failing to protect our birds of prey.”
The last known whereabouts of the bird was near Strathdon, west Aberdeenshire, within the Cairngorms National Park.
Another young satellite-tagged hen harrier went missing in the same area last year.
However, the owners of the sporting estate at the centre of the inquiry have reacted angrily to suggestions the bird has been a victim of persecution.
Solicitors acting for the estate accused RSPB Scotland of “a grave and unwarranted attack” and said the owners “categorically” deny any part in Marci’s disappearance.
“My clients have fully co-operated with the inquiry and will continue to help in any way that they can,” said David McKie, partner at the firm Levy & McRae.
“The estate has a long and proud history of conservation and operates a zero-tolerance approach to any form of persecution. The estate supports fully any inquiry to establish what has happened to the bird but it completely respects the process of law and keeps a completely open mind on a range of possible alternative explanations.”
Hen harriers nest on the ground on upland moors, with a diet that can include red grouse.
Scotland is the UK stronghold for hen harriers, with 460 of an estimated 545 pairs.