SeabirdSeabirds (also known as marine birds) are birds that are adapted to life within the marine environment. While seabirds vary greatly in lifestyle, behaviour and physiology, they often exhibit striking convergent evolution, as the same environmental problems and feeding niches have resulted in similar adaptations. The first seabirds evolved in the Cretaceous period, and modern seabird families emerged in the Paleogene. Seabirds generally live longer, breed later and have fewer young than other birds, but they invest a great deal of time in their young.
AlbatrossAlbatrosses, of the biological family Diomedeidae, are large seabirds related to the procellariids, storm petrels, and diving petrels in the order Procellariiformes (the tubenoses). They range widely in the Southern Ocean and the North Pacific. They are absent from the North Atlantic, although fossil remains show they once occurred there and occasional vagrants are found. Albatrosses are among the largest of flying birds, and species of the genus Diomedea (great albatrosses) have the longest wingspans of any extant birds, reaching up to .
ProcellariidaeThe family Procellariidae is a group of seabirds that comprises the fulmarine petrels, the gadfly petrels, the diving petrels, the prions, and the shearwaters. This family is part of the bird order Procellariiformes (or tubenoses), which also includes the albatrosses and the storm petrels. The procellariids are the most numerous family of tubenoses, and the most diverse. They range in size from the giant petrels with a wingspan of around , that are almost as large as the albatrosses, to the diving petrels with a wingspan of around that are similar in size to the little auks or dovekies in the family Alcidae.
Bird migrationBird migration is the regular seasonal movement, often north and south, along a flyway, between breeding and wintering grounds. Many species of bird migrate. Migration carries high costs in predation and mortality, including from hunting by humans, and is driven primarily by the availability of food. It occurs mainly in the northern hemisphere, where birds are funnelled onto specific routes by natural barriers such as the Mediterranean Sea or the Caribbean Sea.
PenguinPenguins are a group of aquatic flightless birds from the order Sphenisciformes (sfᵻˈnɪs@fɔrmiːz) of the family Spheniscidae (sfᵻˈnɪsᵻdiː,_-daI). They live almost exclusively in the Southern Hemisphere: only one species, the Galápagos penguin, is found north of the Equator. Highly adapted for life in the ocean water, penguins have countershaded dark and white plumage and flippers for swimming. Most penguins feed on krill, fish, squid and other forms of sea life which they catch with their bills and swallow whole while swimming.
