Around here, it's the squirrels and chipmunks who eat the corn. They love the stuff. Never tried it, but if it's a real concern, I've heard about this to stop squirrels from eating edible bulbs: plant, then put down chicken wire. Squirrels can't dig through it, but the plants can grow up through it. When they're big enough, you can remove it.

I had a mole eat my first planting of sweet corn seeds once....went right down the row. Yes, it was a mole. It had a run near the garden since the fall before. I liberally "planted" field corn seeds in a row across the end of the garden before the mole got in the garden. This worked as he had plenty to eat and I assume I later trapped him with an old time Victor Mole trap...not one of the flimsy new models.

Flea beetles is another possibility as are slugs tho not likely in containers. It all depends on the pests you have there as they are different from those on the mainland. But either way it isn't any real threat to the corn. Leaves can get all kinds of holes and damage and still function fine. Dave

How deep are you planting the seed? Never had the problem and have assumed that the normal planting depth of 2 inches would make it difficult for birds to get at it. Dave