This gull was walking around with its bill slightly ajar. It seemed almost as if it was trying to cough something up, or perhaps swallow something big. Either way, I never saw what went in or came out of its bill.
Birds leave evidence of their presence in any patches of fresh or dried mud around Donaldson Park. Based on the size, this appears to be the work of a Canada Goose, though I suppose one of the larger gulls could have left it.