The "wishbone" you might save from your roasted chicken or turkey has an interesting function for the bird. It has nothing to do with granting wishes.
The bone is called the furcula. Its ends are attached to the humerus bone in the wing, the bone between the elbow and the shoulder. It has spring to it. When the wings are on the downstroke the "wishbone" is pulled open. It is compressed on the upstroke. It is believed to function in conjunction with the sternum (breastbone) as a pump. The springing/pump action draws air into the lungs, supplementing the bird's normal breathing mechanisms.
This can be important because birds, unlike mammals, do not have diaphragm muscles. For mammals, those muscles work to draw air into our lungs.