[LittleRedHen]

AND if I would clip one of the wings, would this stop it?   

[Roughlee Handled]

I would say that they can not fly over a 5ft fence with one wing clipped.  Just make sure that there is nothing near the fence that they can jump onto and then over!!
Clipping just one wing unbalances the bird in flight but gives it enough feathers to "wing assisted run away".