The "best breeding female" in a crane project has been shot dead on the Somerset Levels.
The bird, nicknamed Swampy, was found in a field near Ilchester by a farmer, who handed it to the Great Crane Project team.
The RSPB said the shooting had been reported to police and offered a £1,000 reward for information leading to a conviction.
It is illegal to shoot cranes in the UK.
'Tragic and upsetting'
The project said a post-mortem examination "identified four round metal objects identified as gun shot".
Great Crane Project manager Damon Bridge said: "This is tragic and upsetting and what is particularly galling is that Swampy was the project's best breeding female, having successfully raised two chicks in Somerset in 2015, and another this year.
"She would have been highly likely to go on and make more successful breeding attempts.
"Her mate Alexander has been seen continuing to raise their 2016 chick.
"Alexander is likely to find a new mate for the 2017 breeding season but whether the new pair will go on to have the success Alexander and Swampy did remains to be seen."
The Great Crane Project team said it was working with the police "to raise awareness of the presence of cranes with the shooting community in Somerset, and the bird's legal status".
The project is a partnership between the Wildfowl and Wetlands Trust, the RSPB and the Pensthorpe Conservation Trust, with funding from the Viridor Credits Environmental Company.
Its aim is to "restore healthy populations of wild cranes throughout the UK".