Some of my bird pens can be reached by coyotes, and I use 2 x 4 wire to keep the coyotes or dogs out! Then a finer wire to keep the birds in, even chicken wire works. I have bite marks on the 2x4 stuff from coyotes, but the only birds they killed were some pheasants that panicked and jump up and stuck there heads out and got chomped that way, that's when I started using a finer mesh inside the pen. Also I now keep the pens next to another fence or 2 or 3 together so the birds "hide" on the inside wall if the coyotes circle the pens trying to flush them. Lesson learned! I use 6 ft tall chain link dog runs (because I had them) around my layer flocks to also deter the coyotes from a daytime attempt.