Birds are warm blooded (endotherms) vertebrates with feathers. Their bones are lightweight yet strong. Birds have poor taste and smell, but good hearing and sight. They also have a high body temperature and high metabolism as well as a rapid heart rate. Aquatic birds show a variety of adaptations in the structure and function of their beaks, wings, and feet, for feeding in and around the sea. They have waterproof feathers that help insulate their bodies and salt glands to deal with the excess salt from their environment.
There are several species of birds which linger around the shores, but do not swim. Collectively, these birds are referred to as shorebirds. All shorebirds look alike with similar countershading. Shorebirds have darker color feathers on their backs and lighter color feather on their bellies. However, the bills, legs, and behavior of these birds reflect their feeding behavior and make them distinct. Some examples include the Least sand piper, Greater yellowlegs, Ruddy turnstone and the American oystercatcher.
Wading birds are bird with long legs, long necks, and long bills. They use their necks to make sudden thrusts in the water or to probe in the mud. They have widespread toes to keep them stable while walking on the mud or wet sand. Examples of wading birds include the White ibis, Great blue heron, and the Snowy egret.
Seaducks are found in bays, estuaries and the open shore. They are typically divers and may dive 15-20 feet below the surface. Examples of sea ducks include the red-breasted merganser, white-winged scotor, and the common eider.
Gulls are long-winged birds with slightly hooked bills. They are typically scavengers although they are fully capable of swimming. In fact, many gulls make a home near garbage dumps for easy access to their food source. Terns on the other hand, dive into the water to catch prey. Skimmers use their lower mandible to skim the surface of the water for food. Pelicans use their pouches to scoop up fish and crustaceans.