I wouldn't use a cold smoker unless the meat has been cured.
The problem you are going to have is keeping the bird from drying out. I am assuming wild pheasant has very little fat in it. Since the skin is off that makes it even harder to keep it moist. I don't know anything about pheasant but I would make a butter/garlic marinade, inject into the bird and smoke to the proper internal temp. Smoke over a pan so yo can keep the bird basted. Just guessing here but I hope this sends you in the right direction.