I read something several days ago that stated that only three species of birds breed exclusively on the Antarctic Continent. I never thought about that before and did a little research regarding that statement. It set my imagination at work, though I have no intention of visiting Antarctica, even during its chilly summer.
Snow petrels, emperor penguins and south polar skuas are the three kinds of birds that nest nowhere but on the sea coasts of Antarctica. These are hardy, adaptable birds that exploited different niches, mostly free of competition from other bird species. And each species is well adapted to its role in life. Snow petrels and skuas have even been spotted flying over the South Pole.
Snow petrels are tube-nosed birds that are pigeon-sized and have a fluttering flight. Elegant, dainty birds, they have white feathering all over, with black beaks, legs and eyes. Their white plumage hides them when their little flocks rest on icebergs, pack ice and ice floes.
Snow petrels fly low over the Southern Ocean, close to the shores of Antarctica, to ingest krill, which is a kind of shrimp, and small fish. They also scavenge seal placentas, washed-up whale carcasses and dead penguin chicks. And they are able to drink ocean water because they excrete a high-saline solution from their tubed nostrils.
It's estimated that 4,000,000 adult snow petrels nest in colonies on rocky cliffs, usually near the ocean. Each pair's nursery is deep in a rock crevice, away from skuas.
The majestic, handsome emperor penguins are also masters of Antarctica. Thousands of them nest in colonies on pack ice many miles back from the Southern Ocean. This is the only bird species in the world that does not lay eggs on some kind of soil or rock. Emperors lay on frozen water- ice.
Male and female emperors court on the Antarctic ice shelf in autumn of the southern hemisphere. Each female lays one egg, which her mate puts in a flap of feathery skin and on top of his feet so the egg doesn't touch the life-stealing ice. Through the cold, sunless winter the males huddle together for warmth as each one incubates his mate's egg. Female emperors, meanwhile, went back to the sea to fatten up on fish and krill.
After two months at sea, surviving females return to their rookeries to relieve their starving mates of incubating duties. Each chick has hatched and is hungry for food stored in its mother's stomach. Each female repeatedly feeds her youngster and broods it on her feet. Meanwhile, the emaciated males march to the sea to feed up and come back later to feed their progeny. This routine goes on while the ice shelf melts until the young emperors are almost right at the ocean to dive in and do their own hunting of fish and krill. The habit of incubating eggs during the southern hemisphere winter insures that emperor chicks are on their own in the southern summer when the living is easier.
Emperors are adapted to their rigorous lifestyle. They have layers of fat and dense feathering that keeps them warm. They live off much of that fat when not feeding, and store food in their stomachs for their young.
The robust, eagle-like south polar skuas are related to gulls, but have strongly-hooked beaks for killing and tearing off chunks of meat and massive, barrel-shaped chests packed with powerful flight muscles for swift flight to pursue panicky prey. These web-footed, tawny-feathered gull relatives seem to be eagles in the making.
The aggressive south polar skuas are scavengers, feeding on unattended bird eggs, dead whales, penguins and other critters they find on ice and ocean water. They are also fierce predators, quickly killing and eating penguin chicks, and any other hapless critters they happen to come across on the sea or ice. They do what they must to survive and reproduce in a harsh habitat.
Snow petrels, emperor penguins and south polar skuas are the only birds in the world endemic to the Antarctic continent, where they live, feed and breed. Most people will never see them in their Antarctic habitats, but it's intriguing to know they are there.
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