It is probably to dificult to get the bird bck to them. Pigeons can lose alot of weight on a long flight. It may have been blown over with a storm. Keep it away from the chickens you can feed it some of your phesant feed as it is higher in protien if I remember right. Homing pigeons bounce back pretty fast. If you like him and can't find the owner I don't see a problem with you keeping him they are easy to care for.