Chimpanzees and Bonobos Flashcards
What is the scientific name for chimpanzees?
Pan troglodytes
What is the scientific name for bonobos?
Pan paniscus
Where do gibbons and orangutans originate?
Asia
Where do gorillas, pan, and humans originate?
Africa
Where are chimpanzees located?
Chimpanzees live in a broad but discontinuous distribution across equatorial Africa
Where are bonobos located?
Their habitat is restricted in the Democratic Republic of Congo (south of the Congo river)
What is the chimpanzee diet composed of?
Mainly fruit (ripe-fruit specialists) but also eat young leaves, insects, and colobus monkeys
What are preferred foods?
High quality foods eaten in proportion to availability
What are fallback foods?
Always available but only eaten when preferred foods are scarce
What are the preferred foods of chimpanzees?
Non-fig fruits (NFF)
What are the fallback foods of chimpanzees?
Fig fruits
What does chimpanzee social organization look like?
The community is a fission-fusion system, with some parties big in size and some small - variation due to distribution of fruits through space and time
What philopatry are chimpanzees?
Male philopatry
How are females distributed in chimpanzee society?
Relatively solitary (due to scarce food sources) and utilize core areas
What are core areas?
Smallest area within which an individual spends most of their time
Why are core areas used by females?
Beneficial in terms of accessibility to high-quality resources = more energy toward reproduction
What is female reproductive success correlated with?
Rank, where higher-ranking females show greater fidelity to core areas (competition for high-quality core areas)
What does having better core areas result in?
Shorter IBIs and higher infant survival
How are IBIs measured?
Using the age of the daughter’s first swelling where the sooner they are reproductively active = better
How are males distributed in chimpanzee societies?
Males encompass core areas of many females, defending both food sources and the females
What are the bonds between chimpanzee males like?
1) patrol
2) coalitions (lethal raids)
3) share food
4) groom
5) competition for dominance rank within their groups
How do lower-ranking male chimpanzees reproduce?
Through consortship
What is the diet of bonobos composed of?
Similar to chimpanzees, but more leaves in comparison
What does bonobo social organization look like?
Fission-fusion system that also assemble in parties BUT 2 differences:
1) larger because of more food availability and no gorillas
2) remain relatively stable
What does more food for bonobos allow for in terms of relationships?
Females can form more social bonds
What philopatry are bonobos?
Male philopatry
What is the main difference between chimpanzees and bonobos in terms of societal organization?
Females play a more prominent role and there are female-female bonds
How are chimpanzees and bonobos different in terms of female sexual receptivity?
1) Chimps are sexually receptive once every few years - rarity = more male competition
2) Bonobos are sexually receptive during fertile and infertile parts of their cycle = less pressure for male competition
What does strong female-female bonds in bonobo society entail?
1) Females form strong coalitions against males
2) Older female bonobos determine group movement
How do bonobo mothers help their sons (4)?
1) Bring them close to females in estrus
2) Protect sons’ mating from interference
3) Interfere in mating attempts of other males
4) Form coalitions with sons to establish/maintain high rank
How do females compare to males in chimpanzee society?
All females have lower dominance than any male in chimpanzee society
Why are chimpanzees better models for the LCA?
Bonobos are more specialized and evolved in a distinct setting
How are bonobos more egalitarian than chimpanzees (4)?
1) Males maintain strong bonds with their mothers
2) Communities overlap and aggressive patrolling is rare
3) Females control feeding resources
4) Females exert social dominance over males
How do chimpanzees resolve conflict?
Mainly through grooming
How do bonobos resolve conflict?
Sex and grooming
What is a “Kohler moment”
When chimpanzees are struck with a solution after encountering problems
Bonobo Kanzi
learned keyboard-assisted communication
Is monkey a monophyletic term?
It is a paraphyletic term because OWMs and NWMs have different recent common ancestors
What are differences between chimpanzees and bonobos in terms of aggression, hunting, tool-use, and feeding tolerance?
1) Within-group and between-group aggression is low in bonobos, high and frequent in chimpanzees
2) Hunting is rare in bonobos, common in chimpanzees
3) Tool use is frequent in chimpanzees
4) Feeding tolerance is high in bonobos, low for chimpanzees
