American Coots, to be exact. They've been haunt the area recently. There were FOUR of them here that I caught on camera. Three hung together more, but one seemed more prone to roam off on its own at times. They're small, they're black, they have little white beaks, and they're very shy.
Here are all four, with one off by itself ahead of the others. That one liked to roam a lot on its own.