Your three four top predators are:

Coyote, bobcat, fox or panther. We would believe that the coyote or bobcat would be your major predators, especially if panthers are not known to run in your area. Alligators and snapping/soft-shelled turtles could decapitate, but they usually drag the carcass into the water, not woodline areas.

You need to bring the birds inside or in a secure pen so that the predator cannot reach through the fencing, climb or dig over. Even if you have to first bring them indoors for several days, you will still need to eventually keep them securely penned from long paws, climbing or digging. By bringing them indoors for several days, the predator may keep coming back to check on the prey and if he does not see anything, may leave the area. Again, this is only a temporary fix and a secured night/dusk/dawn pen is required to protect your waterfowl.