I enjoy a group of Muscovies that visit my backyard daily. A week ago one female came with a bad right leg that she couldn't put weight on. A few days later a second female showed up with a bad right leg. I thought it was odd. But then a day later, a third female showed up with the exact same problem. Same leg. What could be happening to them? Just yesterday, the last one with the problem flew in with two injured legs and now she can't get around on land at all. The males are all fine. I'm puzzled.