I hope that magpies aren't considered songbirds where you live ,
some states protect songbirds , even irritating ones .

If you try to draw them with a call and shoot them they will quickly learn this trick too . Bait will have the same result , magpies aren't stupid . If you want to keep them away long term your best bet is to attract a predator to the area that they fear such as a hawk or owl . Having a cat or two can also help reduce their numbers .