Chimpanzees and bonobos are our closest living relatives. Humans (Homo sapien) share not only a common ancestor with both these primates, but we also share over 95% of our genome. But while these two great ape species have many similarities, they are actually quite different animals.
Physically, chimpanzees and bonobos are quite similar, and together, they make up the sole members of the genus Pan. Their genus shares the family Hominidae with the other tailless great apes like gorillas and orangutans. Originally, researchers assumed bonobos were just a subspecies of chimpanzees. In fact, until 1954, scientists called them pygmy chimpanzees. Eventually, the two ape species were seen as distinct. Over the years, research has continued to reveal differences between chimpanzees (Pan troglodytes) and bonobos (Pan paniscus). Keep reading to learn more about the ecology of these two primates along with some of their key differences.
Both chimpanzees and bonobos live in the tropical jungles of central Africa. However, bonobos have a much smaller range. In fact, bonobos are endemic to a small region of the Congo River Basin in the Democratic Republic of the Congo. On the other hand, chimpanzees are found across twelve countries in east, central, and west Africa. Though both species can be found in the Congo River Basin, bonobos stay south of the river while chimpanzees can be found to the north.
At first glance, it might be hard to tell the two primates apart, but, in fact, chimpanzees and bonobos have a few key differences in appearance. To start, they have quite different body shapes. Bonobos are slender with long lanky limbs. Chimps, on the other hand, are much burlier. Additionally, chimpanzees display sexual dimorphism as the males are significantly larger than the females. In contrast, bonobo females and males are much closer in size. Their coloration differs slightly as well. Bonobos have dark black faces from birth, while baby chimps have pale pink faces that darken with maturation. You can always tell a bonobo from a chimp by their lips! Bonobos have bright pink lips while chimpanzees have dark lips.
|Lip Color||Bright Pink Lips||Dark Lips|
|Face Color||Black||Darkens with age|
Both chimps and bonobos are primarily frugivores, preferring to munch on the wide variety of fruit available in the tropical forests of central Africa. However, bonobos are more likely to add vegetables to their diets by grazing on stems, leaves, and flowers. Additionally, while bonobos won’t shy away from a protein source like worms or ants or the occasional duiker (small antelope), chimps tend to be a bit more carnivorous. Seemingly tied to competition for status and mates, male chimpanzees will go on violent hunting sprees, mostly targeted at the smaller colobus monkeys. Bonobo communities tend to hunt for meat about twice per month, and they share their prey generously with the group.
The most dramatic differences between chimps and bonobos lie in their social behaviors. Not only fascinating from an ecological perspective, but primate behavior can also give us clues to human evolution. In the field of evolutionary anthropology, scientists use primate studies to answer questions. Chimpanzee and bonobo behavior can help us understand if certain human behaviors are part of our genome or learned through societal pressures.
Both primates live in social groups of mixed males and females, with bonobos generally occupying larger groups. Both groups use a fission-fusion structure in which smaller foraging teams reunite at night to sleep. However, there are several key divergences in how the primates interact between ages and genders. Chimpanzee communities have a clear hierarchy of males that defend clearly marked territories. On the other hand, wild bonobos are less strict with their territory borders and operate under a more matriarchal society. These trends in social structure are built on the social bonds between individuals.
For chimpanzees, the relationships between males define the group structure. A classic example of natural selection, chimps compete for power in the group which translates to more chances to mate and pass on their offspring. The more dominant alpha males intimidate younger chimps and have more offspring. However, this fierce competition comes at a violent cost. Chimps are known to commit both infanticide and cannibalism to increase their chances of fathering offspring.
In contrast, female bonobos run the show south of the Congo River. In general, bonobo society has much more interaction between genders and ages, and female bonds are critical. While young males stay with their natal groups, adolescent females disperse to find a new group. In the quest to become accepted, the new female will pamper the higher-ranking females. Sexual behavior between females is extremely common, and this new female will use socio-sexual behaviors to eventually bond with all the non-related female bonobos.
Both species of great ape have complex communication with several similarities. However, their vocalizations sound quite different. Chimpanzees have lower-pitched voices, letting out barks and grunts. Bonobos are higher-pitched, and their vocalizations sound like squeals and yelps.
One of the most well-known fun facts about these two primates is their creative tool use! Chimpanzees have been observed using a plethora of tools from absorbant drinking sticks to makeshift shovels. To help with foraging, chimp mothers intentionally teach their young to use specific herbs like a spoon in a termite mound. Bonobos have also been seen to use tools including rocks and sticks. Due to the nature of their habitat, wild bonobo populations are understudied, and most of the tool observations have been made in captivity. Who knows what else they could be up to in the jungle?!
Unfortunately, the IUCN red list lists both chimpanzees and bonobos as endangered. Most of their population declines come as a result of human action. Whether deforestation, poaching, urban development, or the impending threat of climate change, these primate populations are at risk.
While all species deserve protection, certainly we owe it to our closest living relatives to treat our shared planet with a bit more thoughtfulness. Conservation efforts to protect both these species have garnered attention since Jane Goodall made her first observations. However, slowing the devastating effects of climate change and habitat destruction is critical to the survival of these two amazing apes!