The Common Loon swims underwater to catch fish, propelling itself with its feet. It swallows most of its prey underwater. The loon has sharp, rearward-pointing projections on the roof of its mouth and tongue that help it keep a firm hold on slippery fish. Migrating Common Loons occasionally land on wet highways or parking lots, mistaking them for rivers and lakes. They become stranded without a considerable amount of open water for a long takeoff. A loon may also get stranded on a pond that is too small. Loons are water birds, only going ashore to mate and incubate eggs. Their legs are placed far back on their bodies, allowing efficient swimming but only awkward movement on land. The Common Loon is flightless for a few weeks after molting all of its wing feathers at the same time in midwinter. Description Size: 66-91 cm (26-36 in) Wingspan: 104-131 cm (41-52 in) Weight: 2500-6100 g (88.25-215.33 ounces) Large waterbird. Long pointed bill. Long body slopes to rear. Sits low on water. Breeding adult (Alternate Plumage): Head, neck, wings, and sides black. Back has large white checkered markings. Chest white. White neck ring with vertical black bars; patch of smaller stripes below throat. Stripes on side of chest. Bill black. Eyes red. Nonbreeding adult (Basic Plumage): Upperparts gray to gray-brown. Underparts and throat white. Irregular border of dark and light along neck. Wedge of white extending from throat to back of neck. White crescents around eye. Bill silvery-gray with black upper edge. Eyes dark. Sex Differences Sexes alike in plumage, male larger. Immature Juvenile similar to nonbreeding adult, but head more uniformly dark with more distinct edge between light underparts and dark upperparts. Back feathers edged with light, giving a scaled appearance. Bill paler, but still with dark upper edge. Similar Species Cormorants have longer necks and blunt-tipped or slightly hooked bills and are not white on chest or throat. Yellow-billed Loon has ivory-yellow bill with dark only at the base of the upper edge. In winter, neck is paler with dark ear patch. Red-throated Loon has more slender bill usually held more upward, paler face in winter, and neck without pale collar. Pacific Loon is smaller with even division between gray and white on side of neck, lacks pale collar. Lacks the Common Loon\'s white around the eye. Sound Call a tremulous wail. Summer Range Breeds across Alaska and Canada, southward to northern United States and Yellowstone region. Also in Greenland, Iceland, and rarely in Scotland. Winter Range Winters along both coasts and inland on large lakes from Alaska to southern Mexico, and Newfoundland to eastern Mexico. Also winters in Europe from Iceland to the Mediterranean. Habitat Breeds on clear freshwater lakes with rocky shorelines surrounded by forest; also on subarctic tundra lakes. Stages for migration on large lakes and rivers. Winters primarily in coastal marine areas near shore; also in large freshwater lakes. Food Fish; some other aquatic vertebrates and invertebrates. Behavior Foraging Pursues fish underwater, grabs with bill. Reproduction Nest Type A large wet mass of plant material near the surface of the lake, sometimes on top of muskrat mound. Placed along shoreline or on floating island. Egg Description Brown with dark splotches. Clutch Size Usually 2 eggs. Range: 2-4. Condition at Hatching Downy and active; leaves nest within one day. Conservation Status Numbers decreased across the south part of the range in the early to mid-20th century, but increased in the last third of the century. Poisoning by mercury in aquatic ecosystems and by lead from fishing sinkers can be significant caues of death.The North American Loon Fund is a nonprofit conservation organization that sponsors research, management, and educational programs throughout North America in an effort to check the population decline of the Common Loon and other loon species. Other Names Plongeon huard (French) Colimbo mayor, Colimbo común (Spanish) Great Northern Diver (British) (English) Sources used to construct this page: McIntyre, J. W., and J. F. Barr. 1997. Common Loon (Gavia immer). In The Birds of North America, No. 313 (A. Poole and F. Gill, eds.). The Academy of Natural Sciences, Philadelphia, PA, and The American Ornithologists\' Union, Washington, D.C.