RE: non electronic calling and shotgun loads?
This may sound crazy but I have had great success with a glass jar or bottle and a piece of styrofoam. You lighlty wet the bottle and rub it with the styrofoam. It makes a terrible high pitched squeal and red foxes will charge in. Have used it for 2 years and have taken 5 foxes. Numerous others have been called in while driving around in a car just experimenting. Live in Maryland and have only had fox come to it but I guess it would work on differant predators.