I voted 12 gauge cause it's usually what I got with me when I see them...But I will use whatever I got handy at the time when I see them in my front or back yard 12 gauge, 20 gauge, 17hmr, 22lr ( pick your ammo they're like pennies layin around in every nook and cranny ) so yeah, whichever of those guns I have sit up against the corner of the wall in the kitchen or livin room when I see them is what I use. But I use 12 gauge most often with #3 kent fasteel goin to or from duck ponds, bonus birds in the bag!
My bad, shot one tonight in my back yard with a #6 lead imperial out my kitchen window.