Things may be a little different up here, but we don't fool with decoys or owls. We have lots of both but we found it too time consuming to set up, and besides crows are too dam smart and once thier on to you , you have to move. Because of that we use the " run and gun" meathod. We use an electronic call and tapes with lots of owl and hawk fights. We set up in heavy cover so the crows can't see where the rukus is coming from but when they hear it they can't resist the low swoop for a look, and that's when we blast them. Pick a spot where the tree tops are no more than 30 yards high with some decent shooting holes. The crows will head directly to the speaker so set up accordingly. We don't shoot a spot for more than 10 to 15 minutes because once there onto you the game is over. It's also important to kill the first crow in range because if you miss he'll sit in a tree and tell every crow in the area. If there is the slightess brease , before you leave the spot rotate the speaker 360 deg. just hold it above you head and slowly point it in all directions. Its surprising how many crows don't hear it the first time if thier up wind. Take lots of shells and a full choke and we can use lead on crows. They are actually pretty feeble birds and one pellot will bring them down so nothing heavier than #6 shot will do. It's a blast and I can't wait for spring for the action to start, especially since I just learned how devistating they are on breeding ducks.
And remember " If men were birds there would be few wise enough to be crows". Full camo is a must. Give it a try , you will be helping the ducks and sharpening the shooting skills while your at it.
I'm not as good as I once was, but I'm as good once as I ever was.