The pongids are the four great apes: orangutan, gorilla, chimpanzee, and bonobo. Rigorous primate-behavior field research during the last fifty years has clearly demonstrated that these apes are closer to the human species than Thomas Huxley, Ernst Haeckel, or even Charles Darwin had anticipated in the nineteenth century. Today, scientific evidence, ranging from biochemistry and genetics to morphology and psychology, confirms those striking similarities between these wild pongids and the human species in terms of organic evolution.
The wild orangutan or “man of the woods” (Pongo pygmaeus) is the only great ape of Asia; like the two lesser apes or hylobates (gibbon and siamang), this elusive pongid now faces extinction. This rare but fascinating red ape of Indonesia is found only on the islands of Borneo and Sumatra. Most orangutans live in the upper tropical rain-forest canopy; adult females and juveniles swing among the vines and creepers of this arboreal world, while huge adult males may leisurely forage on the damp jungle floor below.
The wild mountain gorilla of central East Africa (Gorilla gorilla beringei) is the largest of the four great apes. It is an introverted but intelligent and powerful pongid. In remote highlands, scattered groups of gorillas freely roam through the lush, wet forests. A social unit is dominated by the magnificent adult silverback male: Such a mature gorilla may reach a height of six feet and weigh up to 600 pounds. Yet, this gentle giant of the primate world is shy and acts somewhat like a recluse.
The gorilla and chimpanzee (as well as the bonobo) are found in Africa. Their striking similarities to the human animal led Darwin to write that the origin and early evolution of humankind had taken place on the so-called “Dark Continent,” a hypothesis that is now supported by both molecular and paleontological evidence. The common chimpanzee (Pan troglodytes) is the most curious, intelligent, and extroverted of the four pongids inhabiting the earth today. In the forests and on the woodlands, the African chimpanzees generally exhibit a free-ranging and harmonious existence. Whether in the trees or on the ground, small groups of these apes spend much time searching for food when not playing, grooming, or merely resting in their nests.
The bonobo (Pan paniscus) also inhabits Central Africa, but it has remained elusive to anthropologists until the last twenty years. Both in terms of biology and behavior, it remarkably resembles the human species. Unfortunately, this pongid is also an endangered species threatened with extinction.
Each of the four great apes has no tail, and is both larger and more intelligent than any monkey. The pongid adult dental formula is 2-1-2-3 (also shared by all of the Old World monkeys and humankind). With arms longer than their legs, these apes brachiate through the trees but usually take a quadruped position when terrestrial. Their thumbs and big toes, both opposable, are favorable adaptations for an arboreal life. However, because of their large size, adult great apes spend considerable time on the ground during the day.
Today, these four wild pongids need to be both saved by and protected from the human species, the most dangerous animal of all. To do so, since the middle of the twentieth century, there has been a concerted effort by primatologists to study the great apes in their natural habitats. Such close-range, long-term pongid research supplements those scientific findings as a result of research in laboratories and zoos.
In prehistoric times, giant orangutans probably inhabited much of Southeast Asia (the hominoid fossils Ramapithecus and Gigantopithecus are now considered to be ancestral to this red ape). Today, the orangutan is the largest of the three Asian apes but it is restricted to the dense tropical jungles on the islands of Borneo and Sumatra. In the nineteenth century, the naturalist and evolutionist Alfred Russel Wallace spent several years investigating the flora and fauna of Indonesia. In his 1869 book The Malay
Archipelago, dedicated to Charles Darwin, Wallace related his encounters with the wild orangutan in the swampy dense forests of Borneo. It is now very disconcerting to read how casually this biologist hunted and killed this very rare pongid in order to obtain specimens for scientific study; nevertheless, Wallace was one of the first naturalists to observe the orangutan’s general habits in its natural environment. His report includes physical descriptions of this ape as well as information on its diet, nestbuilding activity, and arboreal loco-motion. Apparently, the orangutan’s only past enemies were the leopard, the cobra, the python, and the crocodile; yet, it is now an endangered species because of the encroachment of human civilization, with the resultant destruction of its habitat and disruption of its activity.
In the twentieth century, zoologist John MacKinnon presented a popular account of his three-year behavior study of the elusive orangutan in both Borneo and Sumatra. In his 1974 book, In Search of the Red Ape, MacKinnon gives a vivid picture of this wild pongid’s general environment: the endless and inhospitable green jungles of these two islands in which only deep grunts, smacking lips, and crashing branches betray the presence of the shy orangutan. He describes this ape’s typical day of feeding, traveling leisurely, and resting in tree nests.
Since 1971, anthropologist Birute Mary F. Galdikas has rigorously undertaken the first intensive, longrange study of the wild orangutan (Pongo pygmaeus) of interior Borneo in its own environment. The late anthropologist Louis S.B. Leakey had inspired her to study this red ape of Indonesia, a project never before attempted by a female scientist. This “man of the woods” is the rarest and least social of the four great apes. Its natural habitat is now restricted to diminishing forests on the islands of Borneo and Sumatra. At present, there are fewer than 4,000 free-ranging orangutans existing in their own ecological niche. Operating from three research campsites within the lowland jungle of the Tanjung Puting Nature Reserve (Indonesian Borneo), Galdikas has devoted herself to two major objectives: the rehabilitation of orphaned orangutans and the ethological study of this great ape in its own environment.
Young, orphaned orangutans usually die from neglect, disease, or malnutrition. At her remote rehabilitation center in Kalimantan, Galdikas prepares these tame animals so that they may eventually adjust to the wild woods. After camp life, the successfully rehabilitated juveniles are returned to their natural habitat to be free and magnificent in the trees. Hopefully, this undertaking will help to increase the number of wild orangutans in their own environment.
The wild orangutan is now an endangered species for two major reasons: Hunters needlessly slaughter many adult pongids in order to obtain infants and juveniles for the “black market” sale to zoos, circuses, museums, or individuals (illegally held apes are confiscated), while farmers continue to destroy this pongid’s natural habitat by cutting timber and clearing cropland, thereby depriving the red ape of forest area, food supply, natural protection, and normal social activity (including sexual behavior). Obviously, there is an urgent need to understand and appreciate the wild orangutan if this unique primate is to be protected from human encroachment and saved from imminent extinction.
Since 1974, Galdikas has followed an adult male orangutan through the Borneo jungle to observe his behavior in the wild. This task has required her venturing through swamps with leeches, mosquitoes, crocodiles, and poisonous snakes. She discovered that this large ape spends much of its time walking on the ground. However, most orangutans are generally arboreal; they move slowly and deliberately through the trees by using their hook-like hands and prehensile feet. The adult orangutan is essentially asocial: There are no problems to be solved in a day-to-day life that demands little cooperation, other than mating and minimal infant care by a mother. Adult males and females are usually solitary or found in loose social organizations. The only temporary social unit is an adult female with her infant or juvenile.
Adult social interaction is infrequent. Two males may engage in combat over a female at mating time; however, there is only sporadic male/female companionship for sexual purposes. Females prefer the larger males as partners in consort relationships. Since orangutans are usually arboreal, there is no group structure or social discipline. They build simple nests in the forest trees or on the jungle ground; during heavy rain, they make a “roof” of leaves. Orangutans rarely groom each other. Their diet is primarily frugivorous and includes buds; shoots; seeds; young leaves; wild, unripe and ripe fruits; flowers; soft bark; wood pith; honey; termites; birds’ eggs; and insects. In fact, the orangutan uses a stick to extract honey from a tree.
Caged in zoos, the shaggy red ape is lethargic and very prone to both obesity and erotic behavior. It suffers the same diseases humans do, from malaria to the common cold. This pongid may even identify with humans (thereby contributing to problems of sexual reproduction in captivity).
At about the age of 12, an adult male orangutan will exhibit these characteristics: a large-domed head, pronounced cheek pads (flares of tissue), a throat sack (gular pouch), and a beard, as well as at times the making of a long, shrill call. There is marked sexual dimorphism, with the adult male being about twice as large as the adult female. The male may reach a height of nearly five feet, weigh over 200 pounds, and have a cranial capacity of about 200 cc.
The wild orangutan is an independent and gentle creature, living a rather lonely existence and acting viciously only when provoked. Leaving the primeval rain-forest canopy during the day, an adult male spends time on the ground and may even venture out of the tropical jungle. Such an isolated ape may forage for as long as six hours while walking awkwardly for long distances through the rain forest on all fours, and perhaps even nap on the damp, humus-covered floor of the jungle. Although free-ranging, adult females never leave their home area throughout their lives. As there is clearly an urgent need to protect and preserve the wild orangutan, which is sometimes referred to as a “missing link,” the serious research of Galdikas (among others) is a major step to understanding and appreciating this endangered great ape of Borneo and Sumatra.
The wild gorilla of central East Africa is the largest of the four great apes; this mountain subspecies was discovered in 1847. Until recently, this primate was thought to be a vicious animal of the jungle; in sharp contrast to this view, however, field studies have revealed that this huge pongid is actually shy, gentle and basically introverted, but curious, intelligent, and very powerful.
In prehistoric times, wild gorillas were abundant and ranged freely throughout central Africa. Today this great ape is represented by only three geographically isolated subspecies: the lowland or valley gorilla of central West Africa (Gorilla gorilla gorilla), the highland or mountain gorilla of central East Africa (Gorilla gorilla beringei), and a third subspecies also found in central East Africa (Gorilla gorilla gmveri). The differences among these three subspecies are minor: the mountain gorilla is larger and has thicker hair (an adaptive advantage), shorter arms, a narrower skull, a longer palate, and does not share its forest with wild chimpanzees.
Now an endangered species, the vanishing wild gorilla needs to be understood and appreciated in order to ensure both its protection and survival in captivity as well as in its natural environment. It is estimated that only about 240 mountain gorillas now inhabit the lush, wet, tropical jungle areas of central East Africa. Their ecological niche is gravely threatened by hunters, farmers, and poachers; thus the desperate plight of this mountain pongid.
George B. Schaller, a zoologist, was the first scientist to seriously study the wild mountain gorillas (Gorilla gorilla beringei) in their own habitat. His pioneering, twenty-month research project (1959-1960) remains a classic contribution to primate ethology. He presented his important findings in two books: The Mountain Gorilla and The Year of the Gorilla.
Gorillas are primarily quadrupedal and terrestrial, living in the humid rain forests of Africa. In his extensive study of the mountain subspecies, Schaller concentrated on the ecology and general behavior of this remarkable great ape. His 466 hours of direct observation were made from the viewing advantage and safety of trees. He was able to watch free-living gorillas wander through the dense jungle, forage on succulent herbs and vines (they prefer young, secondary forest growth), groom and play, defend territory, and build nests in the trees or on the ground. The zoologist observed no tool use, no meat eating, and no drinking of water; furthermore, gorillas do not like to get wet. Both vocalizations and sexual behavior are infrequent. Of particular interest, however, is the wild gorilla’s chest-slapping behavior, an elaborate sequence of nine distinct acts to relieve frustration.
Despite his dedicated study of this great ape for nearly two years, Schaller never made physical contact with the mountain gorilla; this incredible feat was first accomplished by a remarkable primatologist, Dian Fossey (to date, the other two gorilla subspecies have not been seriously studied in their own habitats).
In 1967, the late anthropologist Dian Fossey began living among the wild highland gorillas of the Virunga Volcanoes in central East Africa. Her research—camp, Karisoke, is located in the ancient rain forest of Mt. Vasokie; it is a tropical jungle world of fog and mist in Rwanda near Zaire.
Encouraged by the late Louis S.B. Leakey and following in the footsteps of Schaller, Fossey undertook to investigate the mountain gorilla in its natural habitat with only notebook, camera, and binoculars. Her courageous and intensive years of observations between 1967 and 1985 in the ancient rain forests resulted in an invaluable scientific as well as compassionate contribution to the understanding of and appreciation for this giant of the primate world. Like the orangutan, chimpanzee, and bonobo, the free-living mountain gorilla is an endangered species. Because of the ongoing encroachment of human beings with civilization, this largest of the four great apes is now a vanishing animal threatened with extinction.
In 1984, Fossey published Gorillas in the Mist, in which she gave a personal account of her thirteen-year study of four family groups of this rare pongid among the dense and remote rain forests of those dormant Virunga Volcanoes in central East Africa (Rwanda, Uganda, and Zaire). She followed gorilla groups on the ground in order to observe them at close range during their leisurely day-long search for food and shelter. Fossey was very successful in establishing a rapport with the mountain gorillas. Habituation required her patiently learning to imitate their feeding methods, general sounds, basic gestures, submissive postures, and vocalizations of contentment. This led to her being gradually accepted by these wild pongids, which are usually timid despite their size and power. Her book focused on various group dynamics and behavioral patterns: social range, kinship bonds, nest building, group structure, play and grooming, sexual habits, ritual displays, inter-group and intra-group interactions, cannibalism, and even infanticide. Fossey also wrote about the gorilla’s vegetarian diet, mountainous ecosystem, territoriality, and diseases.
As a result of Fossey’s relentless efforts, she was able to examine the uninhibited behavior of mountain gorillas under normal conditions in their natural range. Her close-range, long-term, intimate study of this highland pongid was a rich and rewarding experience for science. Unlike Schaller, and only after a long period of slow habituation, Fossey was able to actually make physical contact with several of these apes; the first time a scientist has touched this primate in its own habitat.
In the glorious rain forests, this magnificent great ape is primarily a ground-dweller and usually a peaceful vegetarian. Yet a nervous adult gorilla will hoot, mouth a stick or leaf, rise bipedally, thrash branches and vegetation, slap its chest, kick its legs, run sideways, and finally thump the ground with its palms. It may even bluff a roaring “charge” as protective action if necessary, doing so only when provoked (this fierce-looking and very powerful ape will try to avoid physical contact with intruders). In truth, this pongid’s alleged savagery toward human beings is grossly exaggerated. However, gorilla brutality does exist. This ape is capable of aggressive behavior and even murder, including infanticide.
A mountain gorilla’s staple diet consists of fruit, bark, roots, thistles, nettles, wild celery, blackberry leaves, galium vines, and other such succulents. Primarily folivorous, this ape has never been observed eating meat, insects, or even birds’ eggs in its natural environment (the lowland gorilla is both frugivorous and folivorous).
Most gorillas live in small, scattered groups which usually consist of about ten individuals (there are even both peripheral and loner blackbacks as well as silverbacks). These stable social units roam through the rain forests of central West Africa and wander on and below the slopes of the Virunga Volcanoes. A social group is dominated by the adult, alpha silver-back male. Other members include a hierarchy of subordinate blackback males, adult females, juveniles, and infants.
The fearsome adult silverback male gorilla is characterized by nuchal and sagittal crests, a prominent supraorbital torus, marked prognathism, long arms and powerful shoulders for modified arboreal brachiation, and a quadrupedal stance on the ground with the weight of the body supported on clenched knuckles and plantigrade feet (the presence of silvery grey hair on his back, rump, and hind legs clearly indicates a dominant adult male). Fossey discovered adult males to be unusually protective and tolerant toward the young; she once saw an old male tickle an infant with a flower, as might a kindly grandfather. Protected by the dense jungle foliage and with the advantage of its huge size, an adult, male mountain gorilla may even live as a loner (apparently the leopard, buffalo, and elephant are no serious threat to this great ape).
Each gorilla has a unique personality as well as a distinct nose print and voice print. These gorillas com-municate by using at least twenty-two distinct sounds.
The gorilla is an intelligent animal; in the rain and bamboo forests of mountainous central East Africa, more fully developed mental capabilities would not have increased its fitness. In the safety of the tropical jungle, there is no need for this ape to tax its brain (this had resulted in an early underestimation of this pongid’s true intelligence when compared to the extroverted behavior of the chimpanzee and bonobo). Because of its awesome size as well as brute strength and placid nature, it is extremely difficult for a human being to train and manage the mountain gorilla in captivity.
Until recently, captive gorillas were displayed as prisoners in small, sterile cages which cruelly removed them from their normal biome and essential troop behavior. Fortunately, growing numbers of concerned biologists and anthropologists are becoming involved with the survival of this great ape in captivity. In zoos, the gorilla is prone to fatal pneumonia and tuberculosis; therefore, all artificial environments must be carefully watched and controlled. Unfortunately, it is also very difficult to mate this huge pongid in captivity; gorillas require privacy and conditions similar to their natural habitat for successful sexual activity (in fact, a gorilla may even identify itself with a human being).
The mountain gorilla is in grave danger of extinction. This pongid’s precarious existence is threatened by human encroachment and ongoing neglect. Civilization is slowly engulfing the shrinking domain of this magnificent ape. If serious measures are not taken immediately, this unique, giant anthropoid of the natural primate world will soon vanish from the earth forever.
Concerning extinction, several factors are determined by the evolutionary history of a particular primate and its own genetic information, for example, such species-specific factors as: size of the original geographic range, natural habitat requirements (ecosystem), population density limits, body size and weight, and behavioral traits. Other contributing factors include habitat alteration or destruction and human predation (i.e., hunting, collecting, and killing). Of course, humankind still remains the greatest danger to the survival of the wild gorilla in its own environment (and to the survival of other threatened primates). One alarming point: for the survival of this impressive animal, prompt and strict conservation measures are necessary, or else the impressive mountain gorilla will soon disappear. There is an urgent need for both the short-term preservation and the long-range conservation of this giant ape so that future generations may benefit from understanding and appreciating this remarkable pongid.
The gorilla is a key species in the scientific study of primate evolution, biology, psychology, and behavior. Fossey’s pioneering research was both an intimate portrait of and an accurate report about this imperiled mountain pongid, dispelling legends and myths surrounding this majestic rare ape while bringing its plight to the consciousness of both naturalists and general readers. Her steadfast dedication to, and deep concern for, these precarious creatures represented primate ethology at its best.
Ongoing research in Gabon, central West Africa, is providing needed information on the ecology and behavior of both lowland gorillas and chimpanzees (sympatric apes in the lush, tropical rain forest of Lope).
Since 1960, anthropologist Jane Goodall has been studying the wild chimpanzee (Pan troglodytes schwe-infurthi) in its natural environment. She has lived among chimpanzees in the tropical rain forests and woodlands of central East Africa; her patient, sustained, and courageous efforts for over forty years have resulted in remarkable discoveries about the behavior of this great ape. Goodall had been inspired to observe the wild chimpanzee in its own habitat by Louis S. B. Leakey. Her dedicated and pioneering research is now recognized as a milestone in primate ethology. Her two books, In the Shadow of Man and The Chimpanzees of Gombe: Patterns of Behavior, are major contributions to the scientific literature on pongid behavior.
Among the primates, as well as in terms of biological evolution, the chimpanzee is closest to the human species. Goodall has studied this wild ape at close range in the Gombe Stream Research Center on the shore of Lake Tanganyika in Tanzania. Established in 1943, this natural park remains a sanctuary for approximately 100 chimpanzees. With only her camera and binoculars, Goodall followed these trusting pongids into their own habitat. This unique, long-term, scientific study of a wild chimpanzee community yielded incredible new findings of inestimable value about this human-like ape of Africa. As a direct result of her impressive field research, she is now the preeminent authority on this endangered species.
The chimpanzee is found throughout tropical Africa and is both arboreal and terrestrial. When in the trees, it is capable of modified brachiation, but while on the ground it will walk quadrupedally on the knuckles of its hands and on the outsides of its feet. Occasionally, it does stand erect in order to move about in bipedal locomotion for short distances.
Unlike the orangutan and gorilla, the chimpanzee is an extroverted pongid (like the bonobo). In captivity, chimpanzees are easily trained for circuses and zoos. In the wild, they live in open, poorly defined, temporary, and unstable nomadic groups. A shifting band of 60-80 members consists of a hierarchy: adult males with a temporary male leader, young males, females with babies, and females without babies. There is no nuclear family unit; the only temporary bonding relationship is the parental care of an adult female for her infant or juvenile. Play and mutual grooming seem to ensure a state of well-being among the members of this pongid society.
Chimpanzee sexual behavior is grounded in biochemistry. Mating habits are normatively promiscuous, but only when the adult female is in estrus. Presenting and mounting are typical social behavior patterns among the adult males, representing subordinate and dominant actions, respectively.
In nature, chimpanzees live a casual life within constantly shifting groups (these societies meander within a home range). They may even defend their territory against other intruding chimpanzee units.
Chimpanzees build nests and dislike getting wet. Whether living in dense trees or on the jungle ground, these apes apparently fear only large cats (especially the lion and leopard) and the human species. In fact, human civilization is the major threat to this pongid’s existence in the wild. Chimpanzees show much individuality, differing in their facial expressions and mannerisms. They are very intelligent and highly emotional; their temperament ranges from violent aggression to gentle playfulness. Actually, one may even speak of chimpanzee personalities.
Chimpanzees communicate and control behavior through a variety of calls as well as by touch, gesture, and cooperative behavior patterns (especially play and grooming). A chimpanzee group is dominated by the top-ranking or alpha male, and each sex has its own fluctuating dominance hierarchy.
The bulk of chimpanzee food consists of fruits, leaves, and blossoms, as well as seeds, stems, bark, and nuts. Occasionally, this ape will add ants and termites to an otherwise basically frugivorous and vegetarian diet. Goodall’s major discovery is that wild chimpanzees make, use, and transport simple tools. They deliberately modify stems, twigs, sticks, or blades of grass for the specific purpose of probing insect mounds at certain times in order to extract and eat ants or termites (thereby challenging our species as the only tool-making animal). They seem to consider such insects as delectable morsels. Chimpanzees also crumple and chew leaves to make a “sponge” for obtaining water from notches in trees or for sopping up the soft brains from inside a monkey’s skull cavity. They even use large leaves as containers for carrying water, and also use sticks and stones as weapons. These activities clearly demonstrate intelligent, learned behavior in a social environment. In short, wild chimpanzees have a technology—albeit a very simple one. Wild chimpanzees are not only tool-makers, but also meat-eaters, occasionally adding raw flesh to their general diet. They will hunt, kill, and eat small red colobus, redtail, and blue monkeys (including infant baboons), as well as young bush-bucks and young bushpigs.
Goodall was the first primatologist to observe the frenzied “rain dance” ritual of this great ape, a stylized display of apparent nervous behavior. During a thun-der-and-lightning storm, excited male chimpanzees stage a unique pattern of activity: They leap to the jungle floor and careen through the grass, then charge downhill while bellowing and brandishing boughs; this activity is followed by the act of slapping the ground or swatting at trees. This activity may last up to thirty minutes. Females and their young are merely arboreal spectators.
Goodall also discovered that wild chimpanzees can display aggressive behavior and extreme brutality; they are capable of murderous violence and primitive warfare. At times, these apes are savage killers and ruthless cannibals. Between 1974 and 1977, she observed the clash between two neighboring chimpanzee groups that resulted in the gradual extermination of the small southern Kahama society by the apes of the northern Kasakela region. It had not been known previously that wild chimpanzees would systematically and deliberately attack and kill one another. Slaughterous behavior may be grounded in territoriality, as one ape group defends its home range against unwanted intruders. Goodall also witnessed adult chimpanzees killing and eating their infants. Perhaps such primate aggression is biologically inherited, an innate aspect independent of social and environmental forces.
Goodall’s pioneering research has resulted in original information on wild chimpanzee vocal communication, sexual activity, social hierarchies, facial expressions, greeting gestures, parental care, nest building, diseases, diet, grooming, and play. In general, chimpanzee behavior bears uncanny similarities to human behavior.
Since the publications of Huxley, Haeckel, and Darwin in the nineteenth century, naturalists have become increasingly convinced that the human species does share a common prehistoric ancestor with both the chimpanzee and the gorilla. Fossil and genetic evidence suggests that a momentous split in primate evolution occurred about five million years ago, resulting in one route leading to the three living apes of Africa and another to the human animal itself.
The anthropologist Adrienne Zihlman argues that the common ancestor shared by the chimpanzee, bonobo, and the human species was probably a hominoid that looked and behaved very much like the contemporary pygmy chimpanzee (Pan paniscus), that rare and intriguing great ape of equatorial Africa. If her hypothesis should prove to be true, the pygmy chimpanzee of today represents a living link with our remote evolutionary past.
Chimpanzees are fascinating creatures with advanced brains and complex behavior. They demonstrate mental capacity for foresight, learning, symbolizing, problem-solving, and even self-awareness. As a result of rigorous research in biochemistry and ethology, one fact has been clearly established: The human animal is closer to the chimpanzee and bonobo than to any other living species. Jane Goodall’s impressive field work supports this conclusion and contributes to those efforts in preventing the extinction of wild chimpanzees.
The wild bonobo (Pan paniscus) is found only in the forests of the Democratic Republic of the Congo, Central Africa, where about 15,000 members of this species now live. Although known as the pygmy chimpanzee, this great ape differs from the common chimpanzee. Compared to the chimpanzee, the bonobo has a smaller head, a darker face with tufts of hair on each side, and is taller with a more slender build (narrower shoulders, and legs longer relative to arms). It is a peaceful and gentle pongid.
Bonobos have been scientifically studied only during the last two decades. They are more arboreal than chimpanzees, but less aggressive and less excitable, with violent behavior being very infrequent. Bonobos live in female-dominated, fluid social groups that are headed by an adult alpha female. Their sexual behavior is frequent, promiscuous, and inventive (bonobos literally “make love, not war” in order to reduce tension and resolve conflict).
Bonobos use objects (for example, stones and branches) as tools, stand erect, and walk upright for short distances more often than chimpanzees and gorillas, and they display a range of emotions and activities that suggest an eerie resemblance to how our remote ancestors probably looked and behaved. One bonobo has even figured out, by himself, how to make a simple stone implement like those made by our own remote hominid ancestors in Africa 2.5 million years ago.
Significant bonobo research is being done by Frans B. M. de Waal, whose unique book, Bonobo: The Forgotten Ape, which released in 1997, is particularly important to understanding and appreciating this pongid. Ongoing field studies of the wild bonobos by biologists and anthropologists will shed more light on the bio-social origin and evolution of the human species.
The gap between modern humans and the four great apes is very narrow, indeed (demonstrating how remarkable were the original insights of Huxley, Haeckel, and finally Darwin himself). Even so, only the human species is capable of sustained bipedality, using symbolic language as articulate speech (not to mention the complexity of its abstract thoughts and intricate behaviors), and creating an extraordinarily multifaceted socio-cultural milieu in which simple implements are used for the manufacturing of far more complex tools, weapons, and other objects.
If the human species journeys to other planets and beyond, then it will carry with it those indelible biosocial marks of its primate origin and evolution on earth. Even as the future cosmic ape, humankind will always remain akin to the four living pongids on earth.
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