Male Harlequin Duck, Harlequin Duck, Harlequin Ducks, Harlequin Duck drake, Histrionicus histrionicus, duck, ducks, Sea Ducks, sea duck, waterfowl, bird, birds, wildlife, fauna, River, stream, water, colorful, North America, Western U.S., Wyoming, Yellowstone National Park, Yellowstone River, mountain, mountains, horizontal, male, males, drakes, drake, fast moving, fast flowing. leesonphoto