Anthropology Discussion 4

Lecture # 13 Bonobo and Chimpanzee Behavior Closest Living Relatives • Bonobos and chimpanzees are our closest living relatives. • We share over 98% of our DNA with them. • We split from our last common ancestor (LCA) with them about 6 million years ago ( mya ). • Since we are so closely related, we can learn a lot about ourselves by studying their behavior. Bonobos Pan paniscus http://www.bonoboconservation.com/images/maps/RangeMap.jpg Chimpanzee Pan troglodytes http://www.bonoboconservation.com/images/maps/RangeMap.jpg Bonobos and Chimpanzees are very similar • Both live in multimale -multifemale groups of about 50 with a fission -fusion distribution. – Fission -fusion — the entire community splits into smaller daily foraging parties. • Males are philopatric (stay in the group they are born into) and females transfer to a new group at sexual maturity. – Males have life long relationships with their mothers. • Both are primarily frugivorous (prefer ripe fruit). Bonobos and Chimpanzees are very different Pan paniscus • Less likely to fission • Less dramatic seasonality • Not sympatric with gorillas • Greater reliance on THV – Terrestrial Herbaceous Vegetation • Female coalitions • Alpha females and males • Continuous female receptivity • Less aggression Pan troglodytes • More likely to fission • Dramatic seasonality • Sympatric with gorillas – Who also like to eat Terrestrial Herbaceous Vegetation • Strong preference for ripe fruit • Male coalitions • Alpha males • Cyclical female receptivity • Frequent aggression Why are the different? • One of the questions from behavioral ecology asks, “How do ecological factors help explain differences between species?” Why are the different? • Bonobos live in an area with less dramatic seasonal variation in the availability of ripe fruit. • Bonobos are more willing to eat leaves and THV than chimpanzees when fruit is scarce.  Less feeding competition between bonobos facilitates stronger relationships between females and more relaxed social interactions overall. Some Websites about Bonobos • http://www.arkive.org/bonobo/pan -paniscus/ – Take a look around, watch some of the videos • Bonobos at the San Diego Zoo – These are the bonobos I study. • The Left Bank Ape • Bonobo Conservation Initiative • Lola Ya Bonobo Sanctuary Some Websites about Chimpanzees • http://www.arkive.org/chimpanzee/pan - troglodytes/ – Take a look around, watch some of the videos. • Jane Goodall Institute • Ugalla Primate Project – This is my advisor’s site and currently run by one of my grad school colleagues. • Kibale Chimpanzee Project • Primate Research Institute at Kyoto University