The red-throated loon or red-throated diver (Gavia stellata) is a migratory aquatic bird found in the northern hemisphere. The most widely distributed member of the loon or diver family, it breeds primarily in Arctic regions, and winters in northern coastal waters. Ranging from 55–67 centimetres (22–26 in) in length, the red-throated loon is the smallest and lightest of the world's loons. In winter, it is a nondescript bird, greyish above fading to white below. During the breeding season, it acquires the distinctive reddish throat patch which is the basis for its common name. Fish form the bulk of its diet, though amphibians, invertebrates and plant material are sometimes eaten as well. A **** species, the red-throated loon forms long-term pair bonds. Both members of the pair help to build the nest, incubate the eggs (generally two per clutch) and feed the hatched young.