Given that they are not very proficient swimmers, around two million years ago, the formation of the Congo River forced a population of chimpanzees to separate into chimps and pygmy chimps, after many generations of being isolated from each other. This led to the speciation of the more gracile version which is commonly known as bonobos. They live south of the river while their chimpanzee ancestors remained in the north. To be even more precise, bonobos are only found south of the Congo River and north of the Kasai River, in the humid forests of what is now the Democratic Republic of Congo. As a result of this, the bonobos went down a very different evolutionary path from all the other apes. This means that bonobos (Pan paniscus) are not a subspecies of chimpanzees (Pan troglodytes), but rather a distinct species in their own right.
Still, the bonobo genome is only about 0.4% divergent from the chimpanzee genome. Plus, DNA evidence suggests the bonobos and chimpanzees genetically diverged approximately 880,000 years ago, much later than when they diverged geographically. During that period of prehistory, they were confronted by acidification and the spread of savannas. As a result of this, and other factors, wild bonobos are exclusively found in a 190,000 square mile area of the Congo Basin, in the politically unstable Democratic Republic of the Congo, Central Africa. Deep in the heart of the continent, they typically inhabit primary and secondary forests, including seasonally inundated swamps.
In line with this, the species is omnivorous. This is very important because, in the Congolese tropical rainforest, the vast majority of plants need animals to reproduce and disperse their seeds. More to the point, bonobos are the largest fruit-eating animals in this region, after elephants. In fact, each bonobo will ingest and disperse nine tons of seeds, from more nearly 100 different species of plants. These seeds will travel 24 hours in the bonobo digestive tract, which will transfer them over several miles, where they will be deposited intact in their feces. This means that the disappearance of the bonobos, which disperse seeds of 65% of the tree species in those all-important oxygen-producing forests, would have severe consequences for the conservation of the Congo rain forest and the overall future of the planet in general.
To give you a sense of what they’re like, bonobos are distinguishable from chimpanzees because their heads are relatively smaller than that of the common chimpanzee with less prominent brow ridges above the eyes. Bonobos also have a black face with pink lips, small ears, wide nostrils, and long hair that forms a part down the middle. The bonobo also has a slim upper body, narrow shoulders, thin neck, and long legs when compared to the common chimpanzee. In general, male bonobos average nearly 4 feet when standing upright, compared to 3 and a half in females. Plus, their body mass ranges from about 70 to 130 pounds, with an average weight of 100 pounds in males against an average of 75 pounds in females.
With that being said, the real difference between bonobos and chimpanzees is in their behavior, not so much their appearance. The key to all of this is found in the way that these two different species resolve their problems with one another. According to Frans de Waal, an expert primatologist and one of the few people in the world to actually study bonobos, “Physical violence almost never occurs in bonobos, yet is common in chimpanzees.” He also asserts that “The use of sex to promote sharing, to negotiate favors, to smooth ruffled feathers, and to make up after fights is enough to make it the magic key to bonobo society.”
According to Jane Goodall, who is by far the world’s leading expert in the field, among chimpanzees “aggressive or avoidance behaviors outweigh friendly affiliative ones.” Jennifer Lindsey, who serves as a director at the Jane Goodall Institute, has stated that “Bonobos are an intensely peace-loving and gregarious species, avoiding social discord with a warm touch, embrace, or even sexual intercourse.” Similarly, Frans de Waal describes bonobos as being “a close relative of ours in which female alliances intimidate males, sexual behavior is as rich as ours, different groups do not fight but mingle, mothers take on a central role, and the greatest intellectual achievement is not tool use but sensitivity to others”. Of course, this is completely at variance with the other great apes.
In these hyper-sexual primates, clitorises are larger and more externalized than in most mammals. So, while the weight of a young adolescent female bonobo is about half that of a human teenager, she has a clitoris that is according to Frans de Waal “three times bigger than the human equivalent, and visible enough to waggle unmistakably as she walks.” As part of this, tribbing often happens within the immediate female bonobo community and sometimes even outside of it. The ethologist Jonathan Balcombe stated that female bonobos rub their clitorises together rapidly for ten to twenty seconds, and this behavior, “which may be repeated in rapid succession, is usually accompanied by grinding, shrieking, and clitoral engorgement.” He estimated that they engage in this lesbian practice “about once every two hours”. Along with having a deeply bonding effect, this functions as a means for female bonobos to evaluate their intrasocial relationships.
Along with this, bonobos have highly individuated facial features. As a result of this, one individual may look significantly different from another. More to the point, bonobos are the only non-human animal to have been observed engaging in tongue kissing. Also, bonobos often have face-to-face intercourse. So, the level of intimacy in their society is off the charts, even compared to us. This is because bonobos have sex for every imaginable reason, in every possible combination of ways. They fornicate for reconciliation and to bond and even as a means of greeting each other. This is also important because female bonobos spend much more time in estrus than female chimpanzees. Again though, sex is all done with the permission of their females.
Moreover, bonobos don’t seem to discriminate in their sexual behavior by sex or age, with the possible exception of abstaining from sexual activity between mothers and their sons. So, the males often engage in frotting while the females engage in tribbing. Male bonobos also like to do a lot of rump rubbing with each other. Adult male bonobos even have sex with infants, although without penetration. As part of this, when bonobos come upon a new food source or feeding ground, the increased excitement will lead to a communal orgy. Granted, female bonobos engage in mutual genital-rubbing behavior, more often than the males, in order to bond socially with each other, thus forming a female nucleus of society. The bonding among females then enables them to dominate most of the males.
Plus, adolescent females tend to leave their native communities. This migration then mixes the bonobo gene pools, providing genetic diversity. Then, sexual bonding with other females establishes these new females as members of a group. I cannot emphasize this enough. The most important thing to understand in all of this is that while chimpanzees and even humans became male-based societies, the bonobo adopted matriarchy instead. This has given rise to the only anthropic beings on Earth that don’t kill each other. There is no infanticide or plots for genocide or anything of the sort among their society. Instead, they have found peace through female guidance. This is because warmongering patriarchal societies like chimpanzees tend to have significantly larger males, while the peace-loving bonobo is far more egalitarian due to significantly reduced sexual dimorphism.
Plus, there are more males than females in chimpanzee societies, whereas there are more females than males in bonobo societies. So, it really all just comes down to strength in numbers, in two radically different ways. That is to say, chimpanzees have male leaders who exist to compete with each other and bonobos have female leaders who exist to cooperate with one another. Put another way, chimpanzees sustain antisocial discord with hate, whereas bonobos seem to sustain social harmony with love. Therefore, in having to constantly contend with the stress and conflict of their violent world, chimpanzees often experience misfortune through things like murder, rape, and child neglect. Meanwhile, the bonobos live in peace and harmony, where none of these wicked things happen.
The thing is that a male bonobo derives his status from the social standing of his mother. So, bonobo society is based on matrifocal egalitarianism. As such, the bond between a mother and her son often stays strong and continues throughout life. Therefore, while social hierarchies do exist, and although the son of a high-ranking female may outrank a lower female, rank plays a less prominent role among bonobos than it does in other primate societies. Typically speaking, relationships between different communities are often affiliative, and bonobos are not very territorial. They will even share food with unrelated strangers. Granted, female bonobos more often than not secure feeding privileges and feed before males do. This is because although they are rarely successful in one-on-one confrontations with males, a female bonobo with several allies supporting her has extremely high success in monopolizing food sources.
Undoubtedly, the most important aspect of bonobo society is the ability of their females to form strong alliances with other unrelated females to live in a sisterhood of trust. Contrary to this maternal alliance, chimpanzees prefer the politics of treachery among their patriarchs. Like chimpanzees, the males in our own societies intentionally seek to approach and compete with each other, even taking their rivalry to the point of wars. In sharp contrast to this, females in bonobo societies often intentionally avoid interacting with each other at the boundaries of their neighboring territories. Thus, the bonobos have figured out how to live in peace by letting their mother’s opinion matter more than their father’s and that has made all the difference in the world. Simply put, they are utopian-based apes, while we are dystopian-based. Granted, Frans de Waal warns of the danger of romanticizing bonobos, stating that “There would obviously be no need for peacemaking if they lived in perfect harmony.”
Still, unlike orangutans, gorillas, chimpanzees, and humans, bonobos are not known to kill each other. Granted, even though they are generally less violent than chimpanzees, aggression still manifests itself among bonobos at times. Of course, among males, bonobos are half as aggressive as chimpanzees, while female bonobos are far more aggressive than female chimpanzees. Furthermore, both bonobos and chimpanzees exhibit physical aggression more than 100 times as often as humans. Thus, males are unable to dominate females. Instead, the most chivalrous males enjoy more success in attaining high rank and fathering large amounts of young. In fact, male bonobos are known to attack each other and inflict serious injuries such as missing digits, damaged eyes, and torn ears. Some of these injuries may also occur when a male threatens the high-ranking females and is injured by them, as the larger male is swarmed and outnumbered by a mob of females.
To sum up their society, at the top of the hierarchy is a coalition of high-ranking females and males typically headed by an old, experienced matriarch who acts as the decision-maker and leader of the entire group. Of course, bonobo party size tends to vary because the group exhibits a fission-fusion pattern. Thus, a community of approximately 100 members will split into small groups during the day while looking for food and then will come back together to sleep in nests that they construct in trees. Meanwhile, female bonobos typically earn their rank through age, rather than physical intimidation, and top-ranking females will often protect immigrant females from male harassment.
As part of this, bonobos live in a male philopatric society where the females immigrate to new communities while males remain in their natal troop. So, a mother bonobo will support her son in conflicts with other males and help him secure better ties with other females, enhancing her chance of gaining grandchildren from him. She will even take measures such as physical intervention to prevent other males from breeding with certain females she wants her son to mate with. Furthermore, male bonobos engage in lengthy friendships with females and, in turn, female bonobos prefer to associate with and breed with males who are respectful of them. So, because female bonobos can use their sorority alliances to rebuff coercive and domineering males and select males at their leisure, they enjoy a higher position in their group compared to the females of other simian societies.
Presumably, the strategy of bonobo females mating with many males may be a counterstrategy to infanticide because it confuses paternity. That is to say, if male bonobos cannot distinguish their own offspring from others, the incentive for infanticide essentially disappears. However, due to the promiscuous mating behavior of female bonobos, a male cannot be sure which offspring are his, so the entirety of parental care in bonobos is assumed by the mothers. To make matters worse, one of the reasons that bonobos are so endangered is because for one thing female bonobo oestrus periods are longer. The gestation period is on average about 240 days. On top of that, an absence of menstruation lasts less than one year and a female may resume external signs of oestrus within a year of giving birth, though the female is probably not fertile at that point. More to the point, female bonobos carry and nurse their young for four years. So they can only give birth every five years.
This is why bonobos desperately need our help in order to protect their dwindling population. That’s why, starting in 2003, the American government began investing millions of dollars in the Congo Basin Forest Partnership. Thankfully, this investment triggered the involvement of international NGOs to establish bases in the region and work to develop bonobo conservation programs. Hopefully, this initiative should improve the likelihood of bonobo survival, but its success will depend upon far greater involvement and capability in local and indigenous communities. With that in mind, the World Wide Fund for Nature, the African Wildlife Foundation, and other organizations are trying to raise awareness and focus attention on the extreme risks facing the bonobos in the 21st century. Some of those involved have even suggested that a reserve be established in a more stable part of Africa, or on an island in a place such as Indonesia.
Part of the problem is that there are no concrete data on population numbers, although the rough estimate is between 30,000 and 60,000 individuals. With that being said, the bonobo population is believed to have declined sharply in the last few decades, though surveys have been hard to carry out in the war-ravaged region. According to the World Wildlife Fund, there are less than 50,000 bonobos living in Africa. As such, bonobos are listed as endangered on the IUCN Red List. In the end, this species is most threatened by habitat destruction and the spread of human populations. Tragically, to prevent the starvation of humans, many bonobos are captured and eaten in the African bushmeat trade, like the unlucky bonobo who had his head put in a bucket, in the picture below. Without a doubt, this is by far the most immediate threat to the survival of bonobos in the wild. Furthermore, as a result of this, and ecological factors resulting from the climate crisis, the only civilized anthropic beings in the world may all soon be dead and gone. Only time will tell…