Well, at least I can be thankful the passenger pigeon is extinct

From the Stanford University website, Essays on Birds.  In all probability, the Passenger Pigeon was once the most abundant bird on the planet. Accounts of its numbers sound like something out of Alfred Hitchcock's The Birds and strain our credulity today. Alexander Wilson, the father of scientific ornithology in America, estimated that one flock consisted of two billion birds. Wilson's rival, John James Audubon, watched a flock pass overhead for three days and estimated that at times more than 300 million pigeons flew by him each hour. Elongated nesting colonies several miles wide could reach a length of forty miles. In these colonies, droppings were thick enough to kill the forest understory.