Tern sea terns have light grey or white body plumage as adults, with a black cap to the head. The legs and bill are various combinations of red, orange, yellow, or black depending on species. The pale plumage is conspicuous from a distance at sea, and may attract other birds to a good feeding area for these fish-eating species. When seen against the sky, the white underparts also help to hide the hunting bird from its intended prey. The Inca tern has mainly dark plumage, and three species that mainly eat insects, the black tern, white-winged tern, and black-bellied tern, have
Forster's tern nests are usually located deep within the marsh, either on tidal islands or evaporation pond islands, but also on manmade dikes. Nests are composed of adjacent marsh vegetation. Many nests are considered floating and are made of marsh grasses, then can be set on top of the vegetation or deposited on floating rafts of vegetation. In Manitoba, there is a strong association between Forster's tern nests and muskrat houses. They are, in fact, highly solicited nesting grounds. Also in Manitoba, Scirpus and often Typha are the main plants used for nest building. In the case of large colonies, nesting area