With the end of the long polar winter comes the arrival of millions of seabirds to breed. First to arrive are the Adelie penguins who have walked as much as 50 kilometers across the sea ice to reach their nesting grounds. They are followed soon after by the petrels and skuas, flying in from the open sea. Of the 35 species of seabirds that live south of the Antarctic Convergence, only 19 species breed on the Antarctic continent itself. Probably 100 million or more birds breed along the coast and offshore islands of Antarctica. These include the pelagic or free-ranging species such as the albatrosses and petrels. Coastal species, by contrast, forage close to the shore, and among them are found skuas, cormorants, terns and sheathbills.
Most of the sea birds belong to the species Procellariiformes, which include the albatross (largest flying sea bird, with the wingspan of some species exceeding 4 meters), the fulmars, petrels, and shearwaters. The remaining regular sea bird species encompass shore birds-- skuas, gulls, terns, and the penguin--doubtless the bird most popularly associated with the Antarctic.
Most sea birds breed in large concentrations, owing to the scarcity of snow-free ground used for nesting. During the long austral summer, the birds have virtually an unlimited food supply in the nearby sea-zooplankton, cephalopods, and fish. The chicks develop quickly and soon fend for themselves until the approach of winter, when most species migrate north in pack ice or the open sea--some even to Arctic waters--in which they spend most of their lives.
The Antarctic sea birds have evolved to gain features that help conserve body heat--waterproof plumage, a layer of subcutaneous fat, and large, compact bodies.
Most of the sea birds belong to the species Procellariiformes, which include the albatross (largest flying sea bird, with the wingspan of some species exceeding 4 meters), the fulmars, petrels, and shearwaters. The remaining regular sea bird species encompass shore birds-- skuas, gulls, terns, and the penguin--doubtless the bird most popularly associated with the Antarctic.
Most sea birds breed in large concentrations, owing to the scarcity of snow-free ground used for nesting. During the long austral summer, the birds have virtually an unlimited food supply in the nearby sea-zooplankton, cephalopods, and fish. The chicks develop quickly and soon fend for themselves until the approach of winter, when most species migrate north in pack ice or the open sea--some even to Arctic waters--in which they spend most of their lives.
The Antarctic sea birds have evolved to gain features that help conserve body heat--waterproof plumage, a layer of subcutaneous fat, and large, compact bodies.
