Bonobos: Our Lesser-Known Cousins

Most people know that chimpanzees (Pan troglodytes) are considered to be our closest living relatives. However, what comes as a shock to many is learning that they’re not our only closest relative. Now I’m not talking about gorillas and orangutangs, although they are our next closest relatives, I’m actually referring to the bonobo (Pan paniscus). English pronunciation is usually either boh-noh-boh or boh-noh-boh.

If you’re surprised to learn that there is a great ape you hadn’t heard of, you’re definitely not the only one. Despite our close relation and the wide popularisation of the Great Apes, the Hominidae family or hominids, the bonobo seems to have been largely overlooked. To best understand where bonobos fit in, its best to look at the Hominid family as a whole. This includes all of the aforementioned species along with us humans (Homo sapiens) for a total of eight extant or living species. The genus Pongo, orangutans, includes three species, the Sumatran, Tapanuli and Bornean Orangutans. The genus Gorilla, gorillas, includes two species, the Eastern and Western Gorillas. The Genus Pan includes two species, chimpanzees and bonobos. And finally, we humans are the last living members of the Homo genus.

Bonobos are endemic (only found in) the Democratic Republic of Congo (DRC) whilst chimps can be found in the DRC and numerous other countries. Although both chimps and bonobos are found in the Congo, their ranges are separated by Congo River. The formation of the Congo River is one explanation as to why the ancestor of chimps and bonobos was able to evolve into the two species.

Bonobos and chimps are very similar in appearance with the main differences between them being their behaviour. Bonobos are found to the south of the Congo River where there is more edible ground vegetation compared to chimps which are found north of the Congo River where there is less edible ground vegetation and what is available is also a food source for gorillas. It is believed that these differences in their habitat may have been partially responsible for chimpanzees evolving more aggressive and violent behaviours as fighting for access to food, territory and mates becomes more important. Bonobos on the other hand have evolved to be much less aggressive and more selfless. For Bonobos, acting aggressively over resources would not only be unnecessary but would likely lead to an individual becoming an outcast and having a reduced likelihood of mating.

Not only are bonobo generally less aggressive they also have a unique way of resolving conflicts and reducing stress of individuals in the group, Sex. Referred to as ‘The Bonobo Handshake’, Bonobos use non-reproductive or social sexual contact as a way of strengthening relationships and diffusing tension, whether it’s two individuals having a ‘handshake’ instead of fighting over some food or an individual trying to help another who is stressed or irritated. Bonobos also aren’t inhibited by the sex of the individual, with female-female and male-male ‘handshakes’ being just as common. This behaviour makes them one of the very few species that are known to have sex for pleasure rather than simply to reproduce. It’s this behaviour that has earned them the nickname ‘The Love Not War Apes’ and why World Bonobo Day occurs on Valentine’s Day.

The ‘Bonobo Handshake’ is not the only behaviour that makes them stand out from other mammals. Bonobo groups are matriarchal with the dominant bonobo of a group always being female. Even though they are smaller than the males they work with other females to maintain order within the group, using their strength in numbers to prevent any males showing aggression from hurting others. Bonobos are very playful apes and like humans they can laugh, smile and they put on a ‘play face’ when having fun. They are also very altruistic, even welcoming and sharing food with strangers to their group. This compared with chimpanzees where it is not uncommon for individuals to be killed in fights between males from different groups. However, it is still important to note that much, though not all, of what we know about Bonobo behaviour is observed in captive groups and although they are certainly less aggressive bonobos are still wild animals and can be aggressive and violent under certain circumstances which can be incredibly dangerous given their strength which much like chimpanzees is much greater than that of humans.

Unfortunately, bonobos are classified as Endangered by the IUCN. This is primarily due to poaching for bushmeat which is putting a huge pressure on the species. Habitat loss for logging and agriculture as well as disease from humans are also threatening their populations. Their population has never been accurately surveyed because of their patchy distribution and difficult habitat but estimates based on surveys of small, protected areas suggests a minimum population of 15,000 to 20,000.

Lolo Ya Bonobo, paradise for bonobos, is the first and only sanctuary for orphaned bonobos. It was founded by Claudine André in 1994. Bonobos usually arrive as young infants who have been captured to be sold as pets after their groups have been poached for bushmeat. They are taken in by the sanctuary and looked after and when they are able to are placed in peer groups. Lolo Ya Bonobo were also part of the first re-introduction of bonobos into the wild.

Claudine André with a baby bonobo.

Unfortunately, bonobos aren’t the only Great Apes that are Endangered. In fact, all species of Great Apes, except for humans, are either Endangered or Critically Endangered almost solely due to human activity. I certainly doubt this makes us the favourites of the family. But amazing places like Lolo Ya Bonobo provide hope for these species it a world that is yet to find a way to live in harmony with them.