Cock feather in a bonnet for civilian attire.

[ThistleDown]

We must also keep in mind that the eagle feather business is not 'Scots' tradition, but 'Highland Scots' tradition. Even if it is only 150 years old that is certainly enough time under the belt for a tradition to be established. About that long ago was the Crimean War, the US Civil War, Chinese rebellions, the Austro-Prussian War, the French were in Mexico, Russia sold Alaska to the US, and Highland aristos were wearing eagle feathers. A sign of their self-importance, perhaps, and a bit like the pre-dandy of seventy-five years earlier who stuck a feather in his cap and called it macaroni. Today dandies don't usually wear feathers, but it has become traditional for Highland chiefs and other armigers to. (There are a few dandy chiefs, mind you.)

As others have said, best to leave your feathers on the bird.