They usually occur in their familiar black color phase, but also have been
known to be a cinnamon color, brown, and even blue. The rare blue or
glacier bear occurs only in southeastern Alaska, where there are about 500
left.
South of North America's taiga is the immense grassland known as the
Great Plains. This covers most of the continent's interior and stretches
3,900 km (2,400 mi) from southern Canada deep into Mexico. It is prairie
country, a seemingly flat land, devoid of trees excepting along the river
courses. Almost all of the original grasses were plowed under for the
raising of crops, and of the tremendous number of wild animals which once
lived there, practically nothing remains. As the naturalist Peter Farb
wrote, "Not even the eastern forests have suffered the almost complete
destruction that European man has brought to the grassland."
The story of the American pronghorn, the only "antelope" native to the
New World, illustrates his point. When Europeans first settled in the
Western Hemisphere, there were an estimated 50 to 100 million pronghorn on
the plains. Four centuries later by the turn of the 20th century, only
20,000 were left. Today, through strenuous conservation efforts, the prong-
horn is safe, although consigned to a small fraction of its former range.
Another example of what happened to the plains' wildlife concerns a
"dog." Before the Europeans came, hundreds of millions of rodents, called
prairie dogs because of their dog-like call, lived in underground "towns"
from southern Canada to Mexico. One such system of burrows in Texas covered
more than 65,000 sq km (25,000 sq mi) and contained approximately 400
million animals. With the coming of civilization, the burrows were plowed
under and the animals poisoned. Few prairie dog towns still exist.
As the prairie dogs disappear, they are taking with them at least one
of their predators, the black-footed ferret. This member of the weasel
family has prairie dogs as its prime food. It has become overspecialized
and is caught in an evolutionary trap.
North America's arid areas occur in the southwestern United States and
parts of Mexico. Large grazers and browsers include bighorn sheep, mule
deer and javelinas, also called peccaries. Hawks, foxes, owls, coyotes, and
several species of reptiles are among the carnivores. Among them, the
coyote is one of the few which has thrived in the face of human intrusion
into its habitat. Not only has it maintained its former range; it has
expanded it.
One of the resident birds of the North American southwest is the
roadrunner, a member of the cuckoo family. Primarily a ground bird, it can
run at speeds of up to 24 kmph (15 mph). Its diet consists of lizards and
other reptiles which it kills by repeated blows from its heavy beak. If
prey proves too large to swallow, the roadrunner ingests a bit at a time.
The birds can be seen dashing along the desert with snakes or lizards
hanging from their mouths.
The world's smallest owl, the 14 cm (5 1/2 in) high elf owl, also is a
resident of the American desert. This tiny predator uses the hollowed-out
nests of woodpeckers, located in cactuses, as its home.
The desert also has its reptiles, including many species of lizards,
plus two of the four poisonous snakes of North America — the rattlesnake
and coral snake.
Rattlesnakes are pit vipers, a group of reptiles which also includes
the fer-de-lance, bushmaster, water moccasin, and the copperhead The pit is
an opening below the snake's eyes which contains a heat-sensing organ.
Only two of North America's lizards are poisonous — the gila monster
and Mexican beaded lizard. Unlike poisonous snakes which inject their venom
through hollow fangs, these lizards bite their victims, hold on, and allow
poison to flow into the open wound from fangs which are grooved at the
rear.
The coastlands and adjacent lands of the United States are the habitat
of a wide variety of reptiles, birds and mammals. Water moccasins and
copperheads are found in the warmer portions, and the largest of all North
American reptiles, the alligator, lives in the rivers and bayous of the
southeast.
Alligators can be distinguished from the closely related crocodiles by
their broader heads and the lower teeth which are out of sight when the
mouth is closed. A crocodile's teeth are visible at all times.
There are no authenticated cases of wild alligators attacking humans.
Crocodiles, on the other hand, can attack people.
Many species of shorebirds live in North America. One of them, the
brown pelican, came close to extinction on the continent because of DOT.
The pesticide was sprayed and dusted on croplands, then percolated into the
ground water and was carried to sea where it entered the ocean's food
chain. The pelicans, being ultimate consumers, got heavy doses. Although
the chemical didn't kill them, it did weaken the shells of their eggs. The
result was few pelican hatchlings. After DDT was banned the pelican
population began to grow again. In 1979, 1,200 nests were counted in
California, a remarkable comeback.
Marine mammals of the U.S. Pacific coast include four species of
pinnipeds — members of the seal group. They are elephant seals, harbor
seals, Steller sea lions and California sea lions.
South of the United States and northern Mexico, the character of the
land and its wildlife changes. Desert, chaparral, and plains give way to
tropical forest. In places rainfall exceeds 500 cm (200 in) annually, and a
mild average temperature of 27°C (81°F) prevails.
As in most rain forests, primates dominate. In America they consist of
dozens of species of monkeys and marmosets. New World monkeys are only
distantly related to those of the Old World. Many species have prehensile
tails, a feaure lacking in the Old World monkeys. This "fifth hand" is
especially well developed in the spider monkey.
Not all of the rain forest's primates have prehensile tails. Marmosets
of the forests of Panama and the Amazon basin lack it. And the uakari has a
mere stub of a tail, making it the only short-tailed New World monkey.
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.
