Aardvark (Afrikaans for "earth pig"), common name for a burrowing, ant-eating mammal. The aardvark is found throughout much of Africa, from the southern part of Egypt to the Cape of Good Hope. A primarily nocturnal animal, it lives in burrows and feeds on ants and termites, occasionally eating other insects, the fat mouse, and a species of wild ground cucumber.
The aardvark is up to 2.3 m (7.5 ft) long, including the fleshy, tapering tail, which it uses to throw earth backward when it burrows. It has an arched back, a tubular snout, and large, upright ears. The aardvark uses its specialized, chisel-shaped claws to break open the hard clay of termite nests; then it uses its sticky tongue to capture the insects in the nest. Unlike the animals known as anteaters, which are toothless, the aardvark has 20 cylindrical, rootless teeth that grow continually throughout its lifetime.
The female gives birth to one or occasionally two offspring, which can dig their own burrows at the age of six months. Although timid, the aardvark will fight when it cannot flee or burrow to safety; it defends itself with its powerful claws or by striking with its tail or shoulders.
Scientific classification: The aardvark makes up the order Tubulidentata. It is classified as Orycteropus afer
Ape, any of 13 species of large, highly intelligent primates, including chimpanzees, gorillas, gibbons, and orangutans. Apes are sometimes confused with monkeys, but unlike their smaller primate counterparts, apes do not have tails and their arms are usually longer than their legs. Apes live in tropical woodlands and forests of Africa and Asia. Despite sharing similar habitats, different ape species show striking differences in behaviors and ways of life.
At one time, apes were classified as a single group of primates, but today most zoologists divide them into two distinct families: the lesser apes, or gibbons, and the great apes. Gibbons are similar to monkeys, with lithe, slender bodies and extremely agile movements. Gibbons spend all of their lives in trees, using their hands like hooks to swing arm-over-arm between branches. Known as brachiation, this method of locomotion is so fast that gibbons can easily overtake a person running on the forest floor.
The great apes include the gorilla, the orangutan, and two species of chimpanzee: the common chimp and the bonobo (sometimes called the pygmy chimpanzee). Great apes are bigger than gibbons and also much less acrobatic. However, they are still good climbers. While orangutans spend most of their life in trees, where they use their long arms and dexterous hands and feet to grasp branches and vines, chimpanzees frequently come to the ground to feed. Gorillas are primarily terrestrial, but even fully grown adult males have been observed clambering among tree branches more than 15 m (49 ft) high. Chimpanzees and gorillas—the apes that spend the most time on the ground—normally walk on all fours, clenching their hands so that their knuckles take their weight.
From physical and fossil evidence, biologists know that apes and humans share a common ancestry. In recent years, biochemical analysis has shown just how close this link is—chimpanzees and humans differ significantly in only 2 percent of their genes. This evidence suggests that they diverged from a common ancestor around five to seven million years ago.
RANGE AND HABITAT
The gorilla, the common chimpanzee, and the bonobo live in dense tropical forests on the African continent. Chimpanzees also inhabit wooded savanna, where there are more opportunities for foraging out in the open. Most gorillas live in the hot, lowland forests of west and central Africa, but a subspecies called the mountain gorilla lives in a very different habitat. Its range extends as high as 3400 m (11,200 ft) on the cool, mist-covered slopes of the Virunga Mountains.
The gibbons and orangutans inhabit Southeast Asia. Gibbons live in rain forests and seasonal forests of India, Indochina, and the Malay Archipelago. The orangutan is purely a rain forest animal. Today its range is restricted to two large islands—Sumatra and Borneo—but fossils show that it once had a far greater range, reaching as far north as China.
With their long limbs and opposable thumbs, apes are well adapted to a tree-climbing life. The smallest gibbons stand just 44 cm (17 in) tall and weigh just 4.5 kg (10 lb)—light enough to swing from the highest, smallest branches. Great apes are considerably larger, particularly male gorillas, which can be as tall as 1.8 m (about 6 ft) and weigh up to a quarter ton, making them by far the largest apes alive today. Male and female gibbons are usually similar in size, but in great apes, the ******es can differ greatly. Male orangutans, for example, often weigh more than twice as much as females.
Most apes are covered with thick fur. Gibbons have long fur of one color on the body and short fur of a contrasting color surrounding the face. A diverse range of colors distinguishes the different species and subspecies of gibbons, and there is frequently a difference in coloring between the ******es. The coloring of the great apes is drab by comparison. Orangutans have reddish brown fur, while the fur of chimpanzees and gorillas is black. Mature male gorillas are called silverbacks because the fur on their backs turns silvery gray.
Ape skulls and skeletons share the same underlying structure as those of humans, allowing for large brains and forward-pointing eyes. Like humans, apes also have bare skin on their faces, which enables them to communicate by making different facial expressions.
Great apes are exceptionally long-lived. Wild gorillas may survive to age 35, and wild chimps live about 50 years. Great apes in captivity have been known to survive into their late fifties. The life span of gibbons is considerably shorter, probably lasting about 25 years.
Great apes have well-developed brains and are among the most intelligent of all animals. In the wild, chimpanzees and orangutans are known to make simple tools, such as sharpened sticks used to extract insects from holes in tree trunks. Toolmaking involves a preconceived image of what the tool will look like, a visualization ability that is only possible with an advanced brain. Orangutans have even been observed untying knots, working out for themselves the steps necessary to achieve this complex task. Some scientists believe that apes have the capability to learn and use ********, and considerable success has been achieved in training chimps and gorillas to communicate with humans using symbols or sign ********.
With the exception of orangutans, which spend most of their lives alone, apes live in social groups. These groups range from 3 or 4 animals in the case of some gibbons, an average of about 10 in gorillas, and often more than 50 in chimpanzees. In general, the larger the group size, the looser the social structure is. Gorilla groups are generally close-knit, and may be led by the same dominant male for many years. By contrast, chimpanzee social life is marked by constantly shifting alliances and sometimes by violent confrontations between neighboring groups. Gibbons are also strongly territorial, but they are not as aggressive. They lay claim to patches of forest with extraordinarily loud hooting calls that can be heard up to 3 km (2 mi) away.
Some of these behavioral differences are related to the way apes feed. Chimpanzees eat a wide variety of foods, including fruit, leaves, honey, and insects, and they sometimes hunt and eat other mammals. During the course of a day's foraging, they may travel nearly 18 km (11 mi). By banding together they improve their chances of finding food and also of spotting danger. Gorillas, on the other hand, are vegetarians, eating leaves, plant stems, and roots. This kind of food is comparatively easy to find, and although gorillas also move about, they rarely travel more than 2 km (1 mi) a day. Their great size also means that they are less vulnerable to attack. Consequently, gorillas would gain few advantages from living in larger groups.
Most apes breed throughout the year. Male and female orangutans come together only for a brief courtship and return to their solitary lifestyle immediately after mating. Other apes follow very different patterns: gibbons, for example, pair up for life. In these social species, long-term bonds develop between the adults, as well as between the adults and their young.
Female apes usually give birth to just a single young after a gestation period ranging from seven to nine months. Succeeding births normally occur only after the previous infant has been weaned. This process—like all aspects of ape development—takes a remarkable length of time. A gibbon is weaned by the age of about 2 years, while chimps take more than 4 years. Like young monkeys, young apes are carried by their mothers. They either cling to the mother's belly or, in the case of older chimps, ride on her back. In great apes, infant care is largely the job of the females, while in some gibbons the mother hands over responsibility to the father when the infant gibbon's first year is complete.
Like nearly all rain forest animals, ape populations have been harmed by deforestation. Some also face additional threats. Most vulnerable of all is the mountain gorilla, which has recently been extensively hunted by starving people ravaged by war. Today just a few hundred of these animals are left, and their future looks uncertain.
In Asia, five of the nine species of gibbons are listed as endangered, as is the orangutan. Despite a ban on their export, young orangutans are sometimes captured and sold as pets after their mothers have been killed. The massive forest fires on Sumatra and Borneo in 1997 and 1998 killed thousands of orangutans and destroyed the habitat of thousands more, further endangering the survival of the species.
Scientific classification: The gibbons make up the family Hylobatidae and the great apes make up the family Hominidae. The gorilla is classified as Gorilla gorilla, the common chimpanzee as Pan troglodytes, the bonobo as Pan paniscus, and the orangutan as Pongo pygmaeus.
Black Bear, common name for a medium-sized bear of North America. The American black bear often has a white, star-shaped mark on its chest, and its color ranges from black to brown, cinnamon, beige, and even pure white. Its habitat ranges from the Tropics of Florida to the Arctic.
Female American black bears commonly weigh about 70 kg (about 155 lb); males usually weigh about 130 kg (about 285 lb), although some may weigh 250 kg (550 lb) or more. The cubs weigh only about 0.5 kg (about 1 lb) at birth. In the northern mountains, both males and females weigh less. The American black bear has plantigrade feet (heel and sole touching the ground) and five short, curved, sharp claws on each foot for climbing trees. It is generally solitary, except during the breeding season, or in family groups of mother and young. The American black bear lives in a wide range of habitats, including forest, scrub forests of the subarctic, and near jungle. It also ranges onto the open tundra and plains along streams. A unique behavioral and physiological adaptation allows American black bears to remain dormant without eating for as long as seven months when food is scarce. When active, they are omnivorous, feeding mostly on berries, acorns, succulent herbs, fish, carrion, and insects. When food is abundant, they may eat as much as 20 kg (45 lb) of food per day and gain up to 2.5 kg (5 lb) a day in preparation for winter.
Female American black bears often do not give birth to their first young until they are five or six years old, and they usually do not have more than two cubs every second or third year. They may bear young until they are about 25 years of age. Because most American black bears do not live beyond ten years of age, and because juvenile mortality is rather high, many females barely replace themselves in the population. The cubs purr when fed and cry when hungry or cold. Adults huff and growl, roar, and chomp their teeth as warnings to other bears or to people. American black bears do not prey on humans, but sometimes they hurt or kill people in conflicts over space or food or while protecting their young. In most areas, American black bear populations are stable. Black bears are the most abundant of the species of bears.
Scientific classification: The American black bear belongs to the family Ursidae in the order Carnivora. It is classified as Ursus americanus
Brown Bear, any member of a species of northern bear, the widest ranging of all bear species. Several subspecies range throughout wilderness areas in North America, Europe, and Asia.
Although the name grizzly bear is sometimes used to refer to all brown bears, grizzly actually refers to one subspecies in the northwestern interior of North America. Members of the subspecies that range throughout coastal Alaska and western Canada are known as Kodiak bears; those on Alaska’s Kodiak Archipelago are also called Kodiak bears. On the Eurasian land mass, brown bears extend from Norway to the Siberian peninsula and as far south as Greece and Iraq.
Brown bears have large, plantigrade feet (heel and sole touching the ground) and five long claws on their front paws to aid in digging. They may be almost black or very light beige; a few brown bears are pure white. The grizzly bear has deep chocolate brown fur with silver tips. The Kodiak bear is uniformly brown and usually has a ruff of longer hair that makes the head look larger.
Brown bears, along with polar bears, are the largest of the bear species. Brown bears range in weight from 95 to 780 kg (209 to 1716 lb), and adult males generally weigh more than adult females. Kodiak bears, which often feed on salmon, weigh more than 440 kg (970 lb); many males weigh more than 700 kg (1540 lb). Grizzly bears, with a diet of berries, vegetation, and small mammals, are smaller than Kodiak bears. Depending on habitat, the average weight of grizzlies varies from 150 to 360 kg (330 to 794 lb) in Alaska and British Columbia, 95 to 139 kg (209 to 306 lb) in the Yukon Territory, and 102 to 324 kg (224 to 714 lb) in Yellowstone National Park.
Males and females are together only during the breeding season (May to June), but family groups may stay together for two to three years. Brown bears generally inhabit open areas, including the plains and the tundra. They may remain dormant without eating for up to seven months, usually at high elevations in dens or caves. During this dormant period, they are lethargic and less sensitive to danger. Their temperature declines only slightly, but their respiration and heart rate drop dramatically. When active, they eat enormous amounts of fish, berries, and succulent plants, sometimes consuming 40 kg (90 lb) of food per day.
Females have their first young at five to seven years old. They normally give birth to two cubs, skipping three to four years between litters. They can reproduce until almost 30 years of age, but few survive beyond the age of 20.
Brown bears make a loud roar when injured, but normally warn other bears and people by huffing, or making chomping or clacking sounds with their teeth. They almost always avoid confrontations with people. In most of their range, brown bears are relatively secure, although habitat losses pose a threat.
Scientific classification: Brown bears belong to the family Ursidae in the order Carnivora. They are classified as Ursus arctos. The grizzly bear is classified as Ursus arctos horribilis and the Kodiak bear as Ursus arctos middendorfii