domesticated for centuries — for riding, war, and as beasts of burden.

The Asian elephant's only natural enemy is the tiger. Although this

cat attacks elephants, especially calves, it also preys on just about

anything it can catch, including the crocodiles that live in the forest's

sluggish rivers. One of its chief prey is the Malay tapir.

Tapirs originated in the New World, crossed on the land bridge into

Asia and now exist on both continents. The obvious difference between Old

World and New World tapirs is the large, white saddle-shaped patch of hair

on the Malay tapir's body. American tapirs are a solid brown color.

Of the many species of birds in the tropical forest, among the most

bizarre are the hornbills. There are 45 species, distributed throughout

tropical and subtropical Africa and Asia. One of the bird's more

fascinating behavioral habits is the manner of nesting. In most species of

hornbills, when the female is pregnant and ready to lay, she enters a

natural cavity in a tree. She and the male plaster over the cavity's

opening with a mixture of droppings, mud and regurgitated food. They leave

a narrow opening just wide enough for the female to poke her beak through,

but too small for predators to enter. The plastered wall hardens, and the

female, her eggs, and later the chicks, are safe. The male spends the time

feeding his mate. When the nestlings are half-grown, both parents chip away

the wall and the female emerges. She then helps her mate feed the baby

birds, which remain in the nest until they are fledged. During the time the

nest is occupied, it is kept clean and disease-free by insects and

microscopic scavengers.

THE ANIMALS OF THE AMERICAS

North and South America comprise the only continuous land mass that

reaches from the north to south polar regions, a distance of more than

14,500 km (9,000 mi). The combined area of the two continents is 41.4

million sq km (16 million sq mi), in which are found all terrestrial

biomes.

The two continents have been joined for the past two or three million

years. Earlier South America was an island, set apart from the northern

land mass for at least 60 million years. This gave time for animal species

unique to the continent to evolve. After the Isthmus of Panama emerged,

there was an interchange of animals between North and South America, much

as that experienced by Eurasia and America during the Ice Ages. One of the

animals found in both Eurasia and America is the polar bear. Its habitat is

along the entire Arctic coast. It has even been sighted hunting seals on

ice floes hundreds of miles at sea. The polar bear's heavy coat insulates

it from the icy water and air. Thick hair growing between its toes keep it

from slipping on the ice. The thick, white pelt made the animal a prized

trophy and reduced its population. The bear is now protected throughout its

range.

The musk ox, resident of the far north, also has had to be protected

from excessive hunting. At one time it came very close to extinction. A

member of the cow family, the musk ox has adapted to the bitter cold by

developing a heavy, shaggy coat consisting of two parts — a coarse outer

covering of long guard hairs and a soft inner coat so dense that neither

cold nor moisture can penetrate.

Musk oxen form a defensive ring when threatened. Adults stand along

the perimeter, heads and horns pointing out, and the calves cluster

together inside. This defensive posture works well against the ox's chief

enemy, wolves, but is of little avail when high-powered rifles are the

enemy.

Wolves prey on many species in the north — musk ox, caribou, moose,

deer, hares, and even rodents. These carnivores are among the most maligned

of all animals, victims of false myths and legends and systematic programs

of extermination. They are accused of attacking humans and destroying

entire herds of domestic animals. But their depredations of livestock are

less severe than often claimed. And unprovoked attacks by healthy wolves in

North America on humans are unknown. Those recorded from Europe's Middle

Ages are thought to have been made by rabid animals or hybrids.

The world will be a far lonelier place if the last wolf dies. As

biologist Ernest P. Walker wrote in his book, Mammals of the World, "The

howl of the wolf and coyote, which to some people is of more enduring

significance than superhighways and skyscrapers, should always remain a

part of our heritage."

Some Arctic wolves remain snow white year round, an adoption to their

environment. Three other predators of the far north— the snowy owl, Arctic

fox, and weasel— are white at least part of the year.

The life cycle of the snowy owl demonstrates the close relationship

which can exist between predator and prey. This owl hunts hares and

lemmings. When these mammals are plentiful, female owls lay clutches of

seven to ten eggs. When the food supply drops, only one to three eggs are

laid.

Lemmings are among the most plentiful animals of the far north. These

tiny rodents, found throughout the Arctic, are characterized by wide

fluctuations in population. When vegetation is plentiful, the lemmings'

numbers skyrocket. This population density seems to trigger a drive to

migrate. Hordes of lemmings move out. Nothing deters them — swamps,

forests, lakes, rivers. Eventually some reach the sea, which seems just one

more obstacle. They plunge in, swim out, and drown.

Each summer the far north comes alive with the millions of birds which

have migrated from the south to mate, build nests and raise their young.

Waterfowl make up the majority of these migrants. Shore birds, pelagic

birds, geese and ducks abound in the short Arctic summer. Some have come

thousands of miles. The champion migrant is the Arctic tern, which flies •

16,000 km (10,000 mi) from the Antarctic, and in autumn flies back again.

When the birds leave the Arctic at the end of summer, they follow

ancient flyways south. One of the flyways follows the Pacific coastline

from Alaska to California. Small ponds and estuaries along the coast

resound to the gabbling of hundreds of ducks.

The southern edge of North America's tundra borders on the taiga. Here

wildlife tends to stay on the forest's edge, in meadows, along streams, on

lakes and in old burns. Grass, sedges, and willows grow most profusely in

these openings.

The lakes of Wood Buffalo Park in Canada's taiga are the summer

nesting sites of the whooping crane, the rarest of all cranes and the

object of a decades-long conservation effort. In 1949 there were only 21

left out of a population which once ranged from the East Coast to the Rocky

Mountains. With complete protection, the population rose to 109 birds by

1979. Eighty-three lived in the wilderness; the others were captives.

Twice a year the wild birds migrate a hazardous 4,000 km (2,500 mi)

from their nesting grounds in Wood Buffalo Park to the Aransas Wildlife

Refuge on the Texas coast. The possibility of a major storm or devastating

disease striking this flock is a threat which makes biologists shudder. One

of the basic rules in the management of an endangered species is to spread

the risk. A daring experiment was undertaken with the whooping cranes. Eggs

were removed from nests in Wood Buffalo Park for artificial incubation and

placement under setting sandhill cranes, a related, more plentiful species.

The artificially incubated eggs are hatching and producing birds that are

raised in captivity. Several whooping cranes have been hatched and are

being raised by their foster parent sandhills in Idaho. If the experiment

succeeds, a new flock of whooping cranes will have been produced, one which

migrates a much smaller distance, over a different route, than the original

group. A fringe benefit of taking eggs is that it stimulates the female

bird to continue laying, thus generating more than the usual number of

clutches per year. The most common grazing animal of the American

coniferous and deciduous forests is the white-tailed deer. In the far West,

it is replaced by the mule deer. There are actually more deer now in North

America than when Europeans first arrived, because of the clearing of

forest land, plus game management.

Bears once occurred throughout the forests of America north of Mexico.

The world's largest is a brown bear, the Alaskan or Kodiak. The grizzly,

also a brown bear, has been known to launch unprovoked attacks against

humans.

American black bears are quite common in much of their range —

practically all the wooded areas of North America north of central Mexico.

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.

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