Introduction to Ape Culture and Conservation
I'm sitting on a grassy hillside, surrounded by 20 close relatives. No, it's not a family picnic. I'm in the East African nation of Tanzania, and I am watching an extended family of wild chimpanzees. As I sit quietly taking notes and shooting video, the chimpanzees go about their day. Three males sit side by side grooming one another, their long fingers combing through one another's black hair. A mother lies on her back, using her legs to dangle her infant above her. A few yards away, several females groom the alpha (top-ranking) male, whom researchers have named Frodo. Frodo has ruled this family group for three years. He has successfully fought off several challenges to his leadership, although some day another male chimpanzee will likely overthrow him.
Suddenly we hear a pant-hoot—a loud, wailing call—from the next valley. Everyone in the group leaps up and replies with the same call. Another group of chimpanzees is announcing its approach. When the newcomers arrive, they exchange excited greetings with members of the first group before settling down to more grooming.
Among the arrivals is Freud, Frodo's older brother, a lifelong ally and occasional rival. Freud is as different from Frodo as night is from day. Frodo is aggressive and macho. Freud is laid back, easygoing, and good-natured. I have nearly stepped on Freud a few times as I walked through thickets where he lay dozing in the shade. Getting that close to Frodo would be a mistake that he would punish with a hard slap on my leg. This difference in personalities is one reason chimpanzees are so fascinating to study. Their personalities influence the way they live their life, just as ours do.
I have spent about one-fourth of my adult life in remote forests of Africa and Asia studying primates (the group of mammals including apes, monkeys, and human beings). On my 35 research trips into the wild, I have usually focused on chimpanzees, which are, to me, the most fascinating of all the apes.
According to the theory of evolution, apes are our closest relatives in the animal kingdom. I think of them as my evolutionary cousins. Most scientists, including me, believe that human beings and apes developed from a common ancestor. We believe that if you went back in time 7 million to 10 million years ago, you would find this so-called missing link. Studies beginning in the 1960's have found that human and chimpanzee DNA (deoxyribonucleic acid, the molecule that directs the development of all living things) is nearly identical.
This close genetic relationship alone makes apes intriguing to scientists. We have learned a great deal about our early apelike human ancestors from the many fossils we have found. For clues to how these early ancestors probably lived, however, we often study the behavior of modern apes. My own special area of research, for example, is the meat-eating habits of chimpanzees. This subject is of great interest to primatologists (scientists who study primates) because it helps us understand the origins of the modern human diet.
Another vitally important reason we study apes is their uncertain future. Without stepped-up local and international efforts to protect them, the apes will disappear from the wild within the next 50 years. Destruction of their forest habitat, poaching (illegal hunting), and disease are all taking a terrible toll on these creatures.
Which Primates Are Known As the Great Apes?
About 250 species of primates live in the world today. However, there are only five main types of apes. Scientists divide these five into two categories, based chiefly on size. Great apes include gorillas, chimpanzees, bonobos, and orangutans. Three of the great apes—the bonobo, chimpanzee, and gorilla—live in the tropical equatorial forests of Africa, while the fourth—the orangutan—lives in Indonesia on the islands of Sumatra and Borneo. The gibbon, which lives in Southeast Asia, is the only lesser ape.
Although apes and monkeys appear similar, apes share certain characteristics that set them apart. Apes lack tails, which most monkeys possess. Apes have rotating shoulder joints that allow them to hang or swing by their arms. (You have the same kind of rotating shoulder, which allows you to throw a football or swing from a gymnastics high bar.) Apes also have a specialized way of walking, placing the weight of their forearms on their knuckles.
The most important trait shared by all great apes, however, is a large brain. Great apes top the list of brainy creatures, exceeded only by human beings. For this reason, ape intelligence has become an important focus for scientists seeking to understand the evolution of human intelligence. Some scientists study apes' intellectual abilities in laboratories, giving them tests similar to the intelligence tests given in school. My approach, however, is to try to understand ape intelligence in nature, by studying apes' strategies for using tools, finding mates, or hunting. Some primatologists also try to understand whether the emotions apes display—such as guilt, shame, fear, and anger—are the same as human emotions.
Among the great apes, the chimpanzee is probably the best known. An estimated 150,000 to 200,000 chimpanzees live in the wild—more than all the other great apes combined. Chimpanzees live in a variety of habitats, from lowland tropical rain forests to open grasslands with only patches of trees. These habitats range across equatorial Africa from Gambia in the west to Lake Victoria in the east.
In some ways, chimpanzees strongly resemble people in their behavior, anatomy, and ways of life. For example, infant chimpanzees spend many years with their mother. Chimpanzees reach sexual maturity at about age 11. Females usually give birth for the first time in their midteen-age years and have a baby every four years for the rest of their life. Chimpanzees may live to about age 45 in the wild and may reach 60 in captivity.
Chimpanzees live in complex social groupings called communities. Males spend their entire life in the community in which they were born, while females typically immigrate at maturity to a neighboring group. Males of a community have strong social bonds, and they act together to defend their community boundaries against all outsiders. They attack and even kill chimpanzees from neighboring communities that wander into their area. Male chimpanzees spend a great deal of energy intimidating and fighting other males in an attempt to move up the chain of command, so to speak, in their community.
Males and females form temporary subgroups called parties that come together when trees are laden with ripe fruit or when females are ready to mate. Chimpanzees seem to relish the meat of other mammals and spend much time and energy hunting. However, they often get less energy from the meat they catch than the amount of energy they spend hunting. Most of the chimpanzee diet consists of ripe fruit.
Bonobos, also sometimes called pygmy chimpanzees, live in the rain forest south of the Congo River in the Democratic Republic of the Congo, often called Congo (Kinshasa). Bonobos look like chimpanzees, but their social behavior differs greatly. Although males dominate chimpanzee social life, female bonobos form alliances with other females to intimidate males and so try to prevent the males from dominating them. In addition, like human beings, bonobos do not use sexual contact solely for reproduction. Bonobos engage in sexual activity with members of their own gender as well as with members of the opposite sex as a way of reducing tensions, settling conflicts, and strengthening the bonds among members of a group.
The gorilla is the world's largest primate. Like chimpanzees and bonobos, gorillas live in tropical forests near the equator. Because of their size, gorillas spend more time on the ground and less time climbing trees than chimpanzees or bonobos do.
The name gorilla actually refers to two similar species. Western gorillas live in western and central Africa, primarily in lowland rain forests. Eastern gorillas live higher in mountain ranges. One race (subspecies) of eastern gorilla, the mountain gorilla, lives at elevations up to 4,000 meters (13,000 feet) in two small patches of forest near the border between Uganda, Rwanda, and Congo (Kinshasa). As males reach their midteen-age years, the hair on their backs becomes silvery, earning them the common name of silverback. At about the same age, females tend to leave their home groups and join another group.
The orangutan is the only Asian great ape, and is, perhaps, still the least understood of the four great apes. These large red apes, which live in the tropical rain forests of the Indonesian islands of Sumatra and Borneo, are mostly solitary. As a result, scientific studies of orangutans have been able to produce only limited amounts of information. Adult male orangutans spend their lives alone, while adult females live in the company of their infants. Considering that all other great apes are highly social, this is strange behavior, which scientists have not been able to explain.
Like all the other great apes, orangutans grow slowly and reproduce infrequently; a female may go more than five years between the births of offspring. Orangutans spend most of their life high in trees, where they feed on ripe fruits. These apes live in complex societies that, when mapped out, resemble overlapping rings. Several females live alone or with their offspring on overlapping areas. One resident male, meanwhile, tries to control a territory that encompasses the areas of all his females. He constantly patrols his area in an attempt to keep other males away. At the same time, younger, “bachelor” males wander the forest hoping to find females when the resident male is not nearby.
Studying the Great Apes
Primatology emerged as a field of study in the early 1960's. Perhaps the best-known primatologist is Jane Goodall, a British chimpanzee researcher whose pioneering work opened the door to the in-depth study of great apes in the wild. In 1960, Goodall traveled to Africa and landed a job as assistant to famed fossil hunter Louis Leakey. The following year, Leakey sent her to Gombe, a forest along the Tanzanian shore of Lake Tanganyika that was home to a population of wild chimpanzees. At the time, scientists knew little about the lives of chimpanzees, and Leakey wondered whether scientists could learn something about the behavior of ancient human ancestors by studying modern living apes in the wild. Goodall spent months patiently working to make the chimpanzees comfortable in her presence. She would clear a patch of forest and lay out bananas to attract them. Then she would sit quietly near them. Eventually, the chimpanzees neither fled from her nor expected handouts of food, and Goodall could follow and observe them for hours.
By the mid-to-late 1960's, Goodall's discoveries about chimpanzee behavior had blurred the lines that, scientists thought, separated people from all other animals. She described the long and intense bond between chimpanzee mothers, their babies, and other relatives. She became the first to discover that chimpanzees fashion simple tools from sticks and blades of grass. Most amazing of all, she watched chimpanzees hunt and kill monkeys, antelope, and other animals, and share the meat. This discovery particularly shocked the public and the scientific world, which had long thought of all apes as vegetarians (nonmeat-eaters), chiefly because scientists had not witnessed chimpanzees killing other animals.
Goodall also documented that chimpanzee society values intelligence as much as it does physical strength. Members of a community remember the debts and favors they owe to other group members, as well as those owed to them. For example, if Frodo gives meat to Freud after a hunt, Freud will remember the favor and later repay Frodo by giving him meat from another hunt.
In the 1960's, Louis Leakey also sent other students off to study gorillas and orangutans. Dian Fossey, an American woman, became the pioneering researcher for gorillas. She conducted her research in the Virunga Volcanoes region of east-central Africa. There she documented the gentle nature of these giant apes, which, at that time, had a reputation for ferocity and aggression. She also opened the public's eyes to the threats to gorillas from poaching and loss of habitat.
In the early 1970's, Biruté Galdikas, a student from the University of California at Los Angeles, traveled to the rain forests of Indonesia and undertook the first long-term study of orangutans in the wild. She became the first scientist to document the unusual solitary nature of these apes and the often-violent relationships among males of the species.
Bonobos, which were unknown to scientists until the 1920's, were not studied in the wild until the 1980's, when Japanese primatologist Takayoshi Kano from Kyoto University established a research station in central Africa. Before Kano began studying bonobos, they were known mainly from studies carried out in zoos, where they appeared to be completely nonviolent. In the wild, however, female bonobos have less power, and males are more aggressive. Occasionally they even hunt and eat meat. Today, despite the work of Kano and others, the inaccessibility of the bonobos' habitat and the many political troubles in that part of the world have seriously interfered with primatologists' efforts to learn more about these fascinating apes.
Learning About Apes
When I am in the field, I study particular aspects of great ape behavior that I have spent years reading about and preparing to observe. I follow chimpanzees, as well as some of the prey animals the chimpanzees like to hunt, and record the apes' behavior using notebooks, video, and still photography. Only by spending long periods in the field can one hope to see the amazing things chimpanzees and other primates do with their lives.
You might think that studying a particular group of animals for more than 30 years would be long enough to tell us all we need to know about it. But consider this. If extraterrestrial scientists came to Earth to study people, how long would they have to observe you and your family before they could say they had learned everything of importance about the whole human species? The answer is, of course, a very long time, and even then they would need to observe a variety of societies in a variety of places.
Each decade since the 1960's has brought new and exciting discoveries about the great apes. In the 1970's, after 15 years of closely observing wild chimpanzees, Goodall and her students first reported one of the most astonishing of all her discoveries about chimpanzee behavior—murder and warfare. Indeed, among primates, only chimpanzees and human beings engage in such brutal acts.
Field studies in the late 1970's—starting with those of Caroline Tutin of the Centre International de Recherches Médicales, a primate research center in Franceville, Gabon—revealed that gorilla social groups often have more than one male. This was a surprising development, as primatologists had previously thought that gorillas lived only in “harems” made up of one male and several females. Primatologists such as Tutin also witnessed gorillas in parts of Africa eating fruit rather than leaves, traveling long distances, and otherwise behaving quite differently from the gorillas Fossey had studied.
In the 1980's, scientists realized that chimpanzees in some parts of Africa use stone tools to crack open nuts. In the 1990's, researchers learned how frequent and intense chimpanzee hunting and meat-eating can be. And only in the early 2000's have we begun to appreciate the differences in culture in great ape societies. Culture is the learned beliefs and practices of a society.
One of the most fascinating examples of cultural diversity (differences) among chimpanzees involves their choice and use of tools. For example, in a forest in East Africa, a chimpanzee sits by a gigantic termite mound. He pokes a hole in the mound with his finger, then inserts a thin stick. Hundreds of huge-jawed soldier termites swarm over the stick to protect their nest. The chimpanzee gently withdraws his tool and swipes it through his mouth, licking off and chewing the insects. He endures the many termite bites he receives for the sake of a tasty snack rich in protein and fat.
Meanwhile, in a forest 3,200 kilometers (2,000 miles) away in western Africa, another chimpanzee sits under a nut tree pounding walnut-sized nuts open with a stone hammer. The meat inside is fatty and delicious. He has learned to do this by watching his mother and is now an expert nutcracker himself.
The termite-fishing chimpanzee in eastern Africa does not use stone tools, even though there are plenty of rocks and nuts in his forest. The stone-hammering chimp in western Africa does not fish for termites, even though there are many of the insects' huge mounds in his habitat. These behaviors are not, as far as we know, determined by the chimps' environment. If they were, then we would expect to see similar tools in similar forests, which we do not. These preferences for certain tools represent differences in chimpanzee culture, similar to the differences in styles of human homes, for example. Scientists have found some evidence for cultural diversity in the other three groups of great apes, though it appears to be much less common than among chimpanzees.
Apes Under Threat
Despite all the exciting recent discoveries about great apes, many dangers still threaten these amazing animals. The greatest threat to apes, as well as to all other tropical creatures, is deforestation, the destruction of their forest habitats. Faced with the intense pressure of a rapidly growing human population, many developing countries are doing little to protect what remains of their natural forests. People need land for farms and villages, and governments and companies want profits from timber sales.
All wild great apes live in poor nations—some of them among the poorest on Earth—where the populations are growing rapidly and governments have little incentive to protect wildlife or its habitats. For example, primatologist Carel van Schaik from Duke University in Durham, North Carolina, and his colleagues have estimated that since the early 1990's, timber-cutting operations have destroyed up to 80 percent of the orangutan habitat on Sumatra.
The trade in bushmeat (meat from wild animals) poses a second major threat to the survival of apes. People have been hunting and eating wild animals for hundreds of thousands of years. In Africa, the meat of chimpanzees, gorillas, and bonobos is considered a delicacy. This may sound gruesome, but it is no more strange than the popularity of turkey, lobster, or frogs' legs as food in many cultures. In March 2001, the United Nations Food and Agriculture Organization reported that the bushmeat trade was becoming an increasingly profitable industry. As logging roads are cut into the forests, local businesspeople capitalize on the frequent truck traffic by setting up hunting businesses. Hunters ship the ape carcasses on trucks to nearby towns, where they are sold in the market at prices up to five times as high as that for beef. In addition, the logging companies sometimes provide their workers with shotguns to hunt for meat for themselves rather than supplying them with food.
In forests all across Africa, people set snares (leg traps) to catch antelope, wild pigs, and other animals for food. These snares also entrap great apes as they walk across the forest floor. Poachers used to make snares from natural fibers. If a chimpanzee stepped into one, the material usually rotted quickly and the snare would fall off, causing no major damage. However, metal wires have replaced fiber snares. These tighten around the ape's limb and continue to cut into the flesh until the hand or foot develops gangrene (a condition in which body tissues die from lack of oxygen), which can kill or maim the ape. More than one-third of all the chimpanzees living in some forests today, including Uganda's Budongo Forest, are either amputees or carry severe injuries from snares. In some parks, rangers collect snares—sometimes finding hundreds in a given area—but in unprotected areas, the danger from these traps is extremely high.
Because of their genetic similarity to us, great apes can catch nearly all infectious human diseases. And like us, apes lack any immunity (resistance) to diseases to which they have never been exposed. So when a chimpanzee contracts the common cold or other respiratory infection, the disease is often fatal. In particular danger are apes that come in contact with people, for example, in areas where farms and forests sit side by side.
Primatologists believe that thousands of gorillas and chimpanzees have died across Africa since the early 2000's in epidemics of the deadly Ebola virus, which may be transmitted between apes and human beings. A study published in 2004 by Eric M. Leroy of the Research Institute for Development in Gabon, Africa, linked five Ebola outbreaks in central Africa in the early 2000's to a 60-percent drop in gorilla populations and a 90-percent drop in chimpanzee populations. In 2004, Heinz Ellerbrock of the Robert Koch Institute in Berlin and Fabian Leendertz of the Max Planck Institute for Evolutionary Anthropology in Leipzig announced that they had discovered anthrax bacteria in chimpanzees that had died at Tai National Park in Côte d'Ivoire. Their findings represent the first time the disease had been identified in a wild ape population.
Can They Survive?
The survival of the great apes, like that of all wildlife, is a human issue. When the living standards of people improve, their ability to preserve the natural environment and the creatures in it also increases. The question is, given the slow reproductive rate of the apes, whether they will be decimated before conservation efforts can succeed.
One of the most important steps is protecting their forest homes. Many African and Asian countries have set aside land as national parks and nature preserves. Unfortunately, that strategy is not always simple. Protecting the land costs money and takes many dedicated people. Governments of poor countries are not eager to lock up natural resources, such as oil, gas, minerals, and timber, in national parks, when these areas could be exploited, at least in the short term, for profit. Developing nations must have economic incentives to set aside valuable land and protect its wildlife.
One such incentive, at least for gorillas and chimpanzees, is ecotourism (visiting rare and endangered species in their natural habitat). Dian Fossey felt the only way she could protect her gorillas was by threatening to shoot poachers. Today, ecotourism has dramatically reduced poaching of mountain gorillas. Tourists pay hundreds of dollars per hour to sit and watch a group of wild chimpanzees or gorillas. Revenue from such ecotourism goes mainly to the local government, giving it a strong economic incentive to protect the forest and its apes. Some ecotourism revenue also goes to local people, in the form of health clinics and dispensaries in villages near the forest.
Helping local people feel they have a stake in the future of the animals in their area goes a long way toward protecting them. Unfortunately, many of the countries where great apes live are not only poor but also politically unstable. Civil wars and terrorism can destroy a thriving tourist industry overnight. For example, in 1999, Rwandan rebels attacked an ecotourism center in Uganda's Bwindi Impenetrable National Park, taking 14 people hostage. Eight of the hostages were murdered, though the rest were released unharmed. Tourism plummeted for months as a result.
Ultimately, the fate of the great apes depends on the people of the nations where these magnificent and fascinating animals live. These days, as I work with scientists from African nations, I am impressed by their determination to save the natural heritage of their society, the apes with whom they share their land. We sit in tropical forests, watching gorillas and chimpanzees a few yards away as they go about their lives, unaware of the dangers they face from human beings. At the same time, only human beings can save them from extinction.