Police are investigating after a female hen harrier was shot dead in South Lanarkshire.
Officers said a man on a quad bike was reported to have shot the raptor at about 17:15 on 4 May.
He was driving on moorland close to the B7040 at Elvanfoot when he fired the weapon. Witnesses reported that he drove off before the police arrived.
Landowners Leadhills Estate appealed for "information and clarity" over the reports.
Hen harriers are considered rare and are protected under the Wildlife and Countryside Act.
The man on the quad bike had his face covered at the time of the shooting, according to RSPB Scotland.
Sgt Craig Smith said: "Police Scotland is committed to tackling wildlife crime and reducing the number of crimes against our iconic birds of prey.
"We will continue to work with partners and the public to protect Scotland's wildlife.
"At this time I am asking for anyone who witnessed a man on a quad bike between Elvanfoot and Leadhills on the evening of Thursday 4 May to please contact police. You may hold valuable information which could assist our inquiry."
RSPB Scotland's head of investigations, Ian Thomson, said: "This latest incident shows very clearly how protected birds of prey continue to be treated in some areas of our uplands, particularly where there is intensive grouse moor management.
"The hen harrier is an increasingly rare bird in southern and eastern Scotland, with illegal killing the main driver of this long-term decline.
"This incident occurred only a few miles from where a satellite-tagged harrier, known as Annie, was found shot a couple of years ago, and is close to where another tagged bird, Chance, disappeared mysteriously last spring."
A spokesman for Leadhills Estate said: "The first we knew of this incident was a newspaper report and we contacted police immediately with a view to assisting them.
"At this stage we do not know the details of the incident but if a hen harrier has been shot we wholeheartedly support the police investigation and have launched our own internal inquiry.
"We want to make clear our condemnation of all forms of wildlife crime."
The estate said Leadhills was not currently an active grouse moor.
The spokesman added: "The estate acknowledges that 13 years ago and nine years ago gamekeepers were convicted of wildlife crime offences while employed by sporting tenants who had sole responsibility for sporting operations.
"Since October 2013, the estate has directly been responsible for sporting operations. We, and our staff, are wholly committed to the highest standards of moorland management."