Title Bonobo: The Forgotten Ape
Author Frans De Waal
Year Published 1997
Kind of Book Science/Evolution
How strongly I recommend it 9/10
My Impressions I'm sure there has been much more research and observation of Bononbos since this book was written in the late 90s, but I thought De Waal did a great job explaining their behavior and how their societies work. The photos were also incredible and often adorable.
Date Read January 2022
What question is the author trying to answer?
What do we know about Bonobos and how they live and behave socially?
Big Ideas
Bonobos were studied much later than Chimpanzees
Therefore
Most of our theories about our early human ancestors point towards a hostile species similar to a chimpanzee rather than the docile species like a bonobo
Our understanding/discovery of bonobos changes our understanding of human evolution
We always compare what is new to what is common/known
Advantages to bipedalism
Look over the tall grass
Free…hands to carry weapons
Reduce the heat absorbed from the burning sun by exposing less of their bodies
Increase locomotion efficiency
Walking on two legs takes less energy than walking on all fours
Pg.26
During our transition from walking on all fours to being bipedal, we likely had an intermediary stage where we walked on two legs but also climbed trees
Chimpanzees and Bonobos have culture
Because
Chimps and Bonobos are able to pass "technology" on from one generation to the next (eg. Using rocks to crack open nuts)
Bonobo and Chimpanzee Grins sometimes indicate pleasure
Bonobo and Chimpanzee Grins/baring of teeth sometimes indicate anxiety and fear
Bonobo and Chimpanzee grins are used to appease a threatening dominant (in which case they indicate anxiety as well as 'everything okay here don't hurt me')
Many animals guess what we mean when we talk to them by paying attention to our tone of voice, gaze, and the context of the interaction
The more violence-prone a species is the more likely they may be to share food
Because
Sharing food is a way for the Alpha of the group to maintain peace and order in the group
Prostitution exists amongst Bonobos. There is evidence of female Bonobos having sex for bribes
Infanticide amongst chimpanzees causes the female who bore the chimp to start her reproductive cycle over again
Therefore
The Male chimpanzee who kills the female chimpanzees baby (who is not his) stands a better chance of fathering her child (and passing on his genes)
Humans are more like Chimpanzees than Bonobos
Because
Humans evolved in a savannah Habitat
It is unlikely Bonobos could have maintained their egalitarian female led societies on the Savanah
Because
Female and young bonobos could not have survived on the plains without male assistance and protection
Both Humans and Chimpanzee males compete with others in their tribe while also uniting with them to fight other tribes
The nuclear family (where Father sticks around to raise the children) may have started for two reasons
so that the Father could protect his offspring from infanticide from other males
Because The Mother may have allowed the Father sexual access for longer in order to prevent the Father from abandoning her for other Females
Surprising Facts
Bonobos sometimes lose their hair from grooming each other too much
There are only about one hundred captive bonobos in the world, compared to thousands of captive chimpanzees. (1997)
We share a common ancestor with both chimpanzees and bonobos. Neither can be considered closer to us than the other. We share 98% of our genetic material with both chimps and bonobos
Male bonobos are twice the size as females and have sharp canine teeth which the females lack
Bonobos engage in sex in virtually every partner combination: male-male, male-female, female-female, male-juvenile, female-juvenile
Sexual frequency is higher in bonobos than any other primate
Bonobos often have sex face to face. (something that was once thought to be uniquely human)
Female bonobos vulva is situated between their legs rather than oriented to the back (like chimpanzees)
Orangutangs live solitary lives expect for the occasional consortship between a male and a female
Gorillas travel in permanent groups of fewer than 10 individuals (one adult male, several adult females, and their offspring) They are polygynous
Gorilla aggression only occurs when another male challenges the Alpha male of the group to try to take over.
"Australopithecus afarensis lived about 3.5 million years ago. This diminutive hominid had a chimp-sized brain but already walked upright, which indicates that in the course of human evolution bipedal locomotion came before brain expansion." pg.24
Orangutans are the best tool users in the animal kingdom (aside from humans)
Bonobos often walk on two legs when they are carrying food
Female rank order in Bonobos is based on seniority rather than physical features
When a male Bonobo tries to attack a female Bonobo the females will band together and chase him off (the males do not work together like this)
Bonobos sleep in nests/hammocks they make in trees by weaving branches together
Bonobo groups do not attack other groups of bonobos (First they bark and chase each other, then the females groom and have sex with each other, sometimes the males even engage in scrotal rub with one another)
Copulation between males and females of different Bonobo groups are common during the first 15 minutes of an encounter
Missionary Position is termed that because missionaries believed that "uncivilized" men and women would greatly benefit from face to face sex, which was thought to fundamentally alter the relationship between men and women.
Bonobos have sex in almost every position that humans do
Bonobos open mouth kiss (sim. To a French Kiss) (Chimpanzees do not do this)
Bonobos engage in oral sex (blow jobs)
Male Bonobos rarely ejaculate when they masturbate
Intercourse between Bonobos typically lasts between 13-15 seconds
Female Chimpanzees are receptive to sex 5% of their adult lives. Female Bonobos are receptive to sex 50% of their adult lives.
Around 3/4 of all sexual encounters in a Bonobo colony have nothing to do with reproduction (reconciliation, bonding, etc.)
Adolescent female bonobos often leave their mother and siblings to join a neighboring community and have sex with unrelated males. (This allows them to avoid inbreeding) They are not chased out of their group or kidnapped by the other group. They simply become vagabonds
We are the only creatures on earth to know the connection between sex and procreation.
When a male langur monkey takes over a harem of females after having defeated the original leader, the first thing he does is kill the infants in the troop. (this ensures that he is not wasting parental investment on another monkey's offspring)
Infanticide is practiced amongst Gorillas and Chimpanzees, but not Bonobos
It is highly unlikely that a male Bonobo can distinguish his offspring from another Male's offspring
Bonobo parents play the "airplane game" with their young where they hold them up high above them with their hands or feet while laying on the ground
Unknown Terms
Sexual Dimorphism: the condition where the sexes of the same species exhibit different characteristics, particularly characteristics not directly involved in reproduction. The condition occurs in most animals and some plants. Differences may include secondary sex characteristics, size, weight, color, markings, or behavioral or cognitive traits.
Neoteny: The retention of juvenile characteristics into adulthood
Scrotal Rub: When two Bonobos but their buttocks together and allow their scrota to rub together. This serves as a gesture of goodwill on conciliation.
Dates/Timeline
1929 Bonobos are first recognized as being a distinct species from Chimpanzees