Clipping a pheasant's wings is painless and serves an important purpose.
Before the pheasant poults go out to their pen for the first time, it is important to clip their. Since it doesn't have a roof, the theory is that the pheasants will be able to fly out of the pen once they are ready to do so, but they do need a certain amount of training before this can happen. They need to learn that the pen is a safe and comfortable environment which is always worth returning to. Releasing them into the pen without their wings having been clipped would mean that they could just fly straight out, feeling no allegiance to the pen and losing themselves in the wilderness. Wing clipping is an easy and temporary way of keeping the poults together inside the pen for about two weeks, after which stage they will be able to leave with the understanding that the pen is where they will be fed.
At seven or eight weeks old, pheasant poults will have developed some flight feathers, but these are soon to be moulted out into adult feathers. By clipping the juvenile primary flight feathers on one side, any attempt by the bird to fly will result in little more than a toppling motion as one wing out-powers the other. Within a fortnight, the adult flight feathers will have grown sufficiently to allow flight, and the process of wing clipping will have achieved its end. Painless, straightforward and temporary, clipping a pheasant's wings may be slightly annoying for the bird, but it is surely for the best in the long run.