Shorebirds, Gulls, and Auks, and Their Relatives

Few bird orders contain more species than the diverse order Charadriiformes. This order includes such groups as plovers, sandpipers, gulls, terns, and auks -- some of our most familiar coastal and waterside birds.

The family Alcidae (auks, murres, puffins, and their relatives) consists of highly specialized diving birds. They are compact in shape, with relatively small. thin wings. The wings propel them in flight with rapid, whirring wingbeats and also propel them through the water in their pursuit of fish, squid, and crustaceans. Birds of this family, often called alcids, live only in northern oceans. Penguins and diving-petrels, unrelated to the Alcidae, fill a similar ecological role in the southern oceans.

Gulls and terns are united in the family Laridae. Gulls are opportunistic and abundant coastal birds, scarce only in tropical regions. Gregarious by nature, they feed by scavenging and by exploiting abundant prey such as fish, insects, and -- on occasion -- bird eggs and nestlings. Terns resemble slender gulls. Most species capture prey such as small fish by plunge-diving or by picking prey from the surface of the water while the terns are in flight. Terns are widespread even on tropical coasts and seas.

Related to the gulls and terns is a small group of predatory birds known as jaegers and skuas. Breeding at high latitudes in both the Northern and Southern Hemispheres, these birds habitually pirate prey captured by gulls or terns. They are also scavengers, and voracious predators within colonies of birds such as penguins. Arctic-breeding jaegers feed mostly on rodents during the nesting season. Related to terns and somewhat similar in appearance are three species of skimmers. These species possess a remarkable knife-like bill that birds skim over the surface of the water to capture prey.

Of the various families of wading birds within the order Charadriiformes, the most familiar are the Sandpiper family (Scolopacidae) and the Plover family (Charadriidae). The 85 or so species of sandpipers are distributed worldwide, although the greatest diversity of breeding species inhabits the higher northern latitudes. Many species undertake long annual migrations. The legs of sandpipers may be short to quite long, and the wide variety of bill shapes and lengths reflect a corresponding diversity in feeding habits. A subfamily within Scolopacidae includes the three species of phalaropes, which have evolved lobed toes and are excellent buoyant swimmers. The Plover family, with over 60 species consists of compact, short-billed sandpiper-like birds that inhabit shorelines, grasslands, and other open areas. The distribution of plovers is nearly worldwide. Other families of shorebirds include stilts and avocets, oystercatchers, jacanas, and thick-knees.