i have had a lot of sucsasewith an american turkey caller. it emits a very ralistic sound of a crow call. male gobblers hate crows as much as famrers do and won't tolertate thhem getting near the females, so the sound of a crow calling is often the best way of drwaing a gobbler out of cover. the "cawlin' crow" is also good. its a lifesize decoys wich emits the sound of crows mobbing frantically in 60 second loops. its about 35 quid though.