northern seabird
While seabirds vary greatly in lifestyle, behavior and physiology, they often exhibit striking convergent evolution, as the same environmental problems and feeding niches have resulted in similar adaptations. [1]
Any of several diving sea birds (family Alcidae) of northern regions, such as the razor-billed auk, having a chunky body, short wings, and webbed feet. [2]
Many species are famous for undertaking long annual migrations, crossing the equator or circumnavigating the Earth in some cases. [3]
In general, seabirds live longer, breed later and have fewer young than other birds do, but they invest a great deal of time in their young. [1]
Most species nest in colonies, which can vary in size from a few dozen birds to millions. [...] Seabirds can be highly pelagic, coastal, or in some cases spend a part of the year away from the sea entirely. [3]
The Sooty Tern is highly aerial and marine and will spend years flying at sea without returning to land. [...] Prions have special bills with filters called lamellae to filter out plankton from mouthfuls of water, and many albatrosses and petrels have hooked bills to snatch fast-moving prey. [1]
Loons and grebes, which nest on lakes but winter at sea, are usually categorized as water birds, not seabirds. [3]
With the exception of the cormorants and some terns, and in common with most other birds, all seabirds have waterproof plumage. [...] Cormorants, like this Double-crested Cormorant, have plumage that is partly wettable, allowing them to dive without fighting buoyancy. [...] Surface feeders in flight include some of the most acrobatic of seabirds, which either snatch morsels from the water (as do frigate-birds and some terns), or “walk”, pattering and hovering on the water’s surface, as some of the storm-petrels do. [1]
With their poor flying ability, many wing-propelled pursuit divers are more limited in their foraging range than other guilds, especially during the breeding season when hungry chicks need regular feeding. [3]
Alcidae, family Alcidae - web-footed diving seabirds of northern seas: auks; puffins; guillemots; murres; etc. [2]
Gannets, boobies, tropicbirds, some terns and Brown Pelicans all engage in plunge diving, taking fast moving prey by diving into the water from flight. [1]
Sources:
[1] sea bird: Definition from Answers.com
[2] auk - definition of auk by the Free Online Dictionary, Thesaurus and …
[3] Seabird - Wikipedia, the free encyclopedia