South America is home to approximately 40 percent of the world's birds, and most of them live in its rain forest. Two groups of rain forest birds are among the most colorful in the world — the hummingbirds and parrots.
Known as "living jewels," hummingbirds are found only in the New World, where they live from southern Alaska to Tierra del Fuego. However, they are primarily tropical birds. There are 319 known species which range in size from the world's smallest bird, the 57 mm (2 1/2 in) long Cuban bee hummer, to the giant hummingbird of the high Andes, measuring 216 mm (8 1/2 in) in length.
A second group of colorful rain forest birds, the parrots, are distributed worldwide in the tropics and on all lands in the southern hemisphere excepting the southern tip of Africa and some of the more remote Pacific islands. In the New World, they reach northward into southern Arizona and New Mexico, where they are represented by occasional visits of the endangered thick-billed parrot.
The only parrot native to the United States is now extinct. In the early 19th century, the Carolina parakeet ranged from North Dakota and central New York south to eastern Texas and Florida. It was especially abundant in the Mississippi River bottoms and along the Atlantic seaboard The little bird was slaughtered for sport and to control its depredations on fruit crops The last one was sighted m the Florida Everglades m the early 1920 s
In addition to its wealth of birds, the South Amen can rain forest is the home of a wide variety of other animals The world s slowest mammal, the sloth which spends long periods hanging upside down from tree branches, is a forest dweller So are opossums, anteaters, poisonous frogs, jaguars, tapirs, and several snakes, among them the anaconda, the world s largest An anaconda can measure more than 9 m (30 ft) in length Its prev includes the world s largest rodent, the hog sized capybara, and the caiman, South America s counterpart of the alligator
To the west, the rain forest terminates at the Andes, the mountain ranges stretching the length of South America The highest point m the western hemi sphere, 7,000 m (22,834 ft) tall Mt Aconcagua, is m the Andes
America s smallest deer, the pudu, and one of the world s largest flying birds, the Andean condor, live in these mountains Probably the best known of Andean animals are the guanacos, vicunas, llamas, and alpacas, New World relatives of camels, which are found at high elevations. Llamas have been domesticated as beasts of burden since pre-Columbian times; vicunas and alpacas are prized for their high-quality wool.
The cold water off South America's west coast is rich with plankton, a link in a food chain which reaches up through fish and ends with the millions of sea birds living on the South American coast and nearby islands. Among them, the guanay cormorant breeds in enormous numbers. Cormorant rookeries are not particularly pleasant places for humans. They reek of droppings, dead birds and regurgitated food, and there are flies everywhere. The droppings, called guano, make a superb fertilizer and are harvested commercially in Peru and Chile.
South America's grassland is called the pampas. Although similar to the Great Plains of North America, the pampas never was home to the vast herds of wild animals which once roamed North America.
One of the world's large, nonflying birds, the common rhea, lives on the pampas. It was once hunted by gauchos on horseback for its tail plumes, which were used as dusters. A second species, Darwin's rhea, roams the Andean foothills from Peru to Bolivia and south to the Straits of Magellan. It is an endangered species.
The pampas' predators include foxes, skunks, rattlesnakes, hawks, and one which is found only in South America, the rare maned wolf. This mammal looks more like a fox than like a wolf. It is solitary, nocturnal, and wide-ranging. It hunts small mammals, birds, and reptiles and also eats fruits and other plant material.
Реферат опубликован: 21/12/2008