The project to boost golden eagle numbers across southern Scotland is led by the charity Restoring Upland Nature (RUN) and has seen the birds flourish.
However, there have been a number of setbacks with shootings and disappearances.
Dumfriesshire farmer Michael Clarke, who chairs the group, said: "While we are relieved that Squeagle has survived, and is soaring high in southern skies thanks to the efforts of the rescuing gamekeepers, the Scottish SPCA and our eagle officer, John, we utterly condemn this act of persecution.
"This abhorrent wildlife crime was clearly committed by an individual or individuals who consider themselves above the law.
"Whoever is responsible for this, and anyone who seeks to excuse or conceal it, should reflect on the immense damage their actions cause to wildlife, the efforts of land managers, farmers, conservationists and local communities, and the future of golden eagles in the UK."
