...and having read the answers above, I have nothing to add.
@Ridgerunner and
@3KillerBs have hit the highpoints. If
@aart were here, they'd share the message about putting your location into your profile, so we would have that information when trying to assist with your question.
14x16 is a good sized area for three birds, I suspect that - during some seasons - they will be able to stay in that space "a while" before they need to be moved on so the ground can recover. Other times of the year, that may be completely untrue, based on climate and growing season.
You will, likely, want a mix of vegetation to help avoid dietary imbalance, and likely what that mix is will vary seasonally, with cool season plantings late summer/early fall through the start of winter, an overwintering cover, and then transition to warm season plantings in the spring, after first frost. A diverse landscape will help plant recovery too, though you will need to be careful that no particular crop crowds all the others out.