Because of the long Antarctic night, the 800 varieties of plants—lichens, mosses, freshwater algae, bacteria, molds, yeasts and fungi living on the land area are dormant for long periods. But they become almost instantly photosynthetic during short summer bursts of only a few days, weeks or a month or two.
On the other hand, though plant life is sparse, animals abound; but both the number and the size of the land species are few. Nearly all the animals are seen near the edge of the ice sheet or in the water, either living in the ocean or getting their sustenance from it. The animals relying on the land for food and shelter are some microscopic species along with tiny insects and spiders. The largest of these is a fly, a relative of the common housefly, about one tenth of an inch (c. 3 millimetres) long. Besides the non-flying penguins, there are the South Polar skua and the Antarctic petrel. In the Antarctic and in the sub-Antarctic island regions there are terns, albatrosses, cormorants, gulls and other birds. Some birds at times penetrate toward the continent's interior.
The Arctic tern is the world's greatest navigator. It spends six months of the year in the Antarctic and six months in the Arctic, flying 11,000 miles (17,700 kilometres) from the north to enjoy the Antarctic summer. Thus it manages to live in almost perpetual daylight.
Five of the world's seventeen varieties of penguin are to be found here. The Adélie penguin and the Emperor penguin are the only two that breed on the continent. The Adélie penguin, averaging about fifteen inches (38 centimetres) in height and weighing ten to fifteen pounds (4.5 to 6.8 kilograms), appears to get its direction from a sun-related orientation and a biological clock mechanism.
On the other hand, though plant life is sparse, animals abound; but both the number and the size of the land species are few. Nearly all the animals are seen near the edge of the ice sheet or in the water, either living in the ocean or getting their sustenance from it. The animals relying on the land for food and shelter are some microscopic species along with tiny insects and spiders. The largest of these is a fly, a relative of the common housefly, about one tenth of an inch (c. 3 millimetres) long. Besides the non-flying penguins, there are the South Polar skua and the Antarctic petrel. In the Antarctic and in the sub-Antarctic island regions there are terns, albatrosses, cormorants, gulls and other birds. Some birds at times penetrate toward the continent's interior.
The Arctic tern is the world's greatest navigator. It spends six months of the year in the Antarctic and six months in the Arctic, flying 11,000 miles (17,700 kilometres) from the north to enjoy the Antarctic summer. Thus it manages to live in almost perpetual daylight.
Five of the world's seventeen varieties of penguin are to be found here. The Adélie penguin and the Emperor penguin are the only two that breed on the continent. The Adélie penguin, averaging about fifteen inches (38 centimetres) in height and weighing ten to fifteen pounds (4.5 to 6.8 kilograms), appears to get its direction from a sun-related orientation and a biological clock mechanism.