Female common merganser on a rock by Walnut Canyon Lakes in Flagstaff, Arizona, USA

Well-traveled waterfowl

Most ducks’ quacks are worse than their bites, but a nip from this toothy beak could be a major ouch – just ask a fish. The common merganser is a diving duck found all over the Northern Hemisphere, snaring freshwater and saltwater swimmers alike in its sawtooth maw. To give an idea of the merganser’s massive migratory range: The birds’ breeding grounds extend well north of the Arctic Circle, while this specimen was spotted deep within the American Southwest in Flagstaff, Arizona.