June 2009

KCP Co-Directors Edit Book on Sexual Coercion in Primates

Sexual Coercion in Primates and Humans: An Evolutionary Perspective on Male Aggression Against Females (Harvard University Press). Edited by Martin Muller & Richard Wrangham (2009).
Conflict between males and females over reproduction is ubiquitous in nature due to fundamental differences between the sexes in reproductive rates and investment in offspring. In only a few species, however, do males strategically employ violence to control female sexuality. Why are so many of these primates? Why are females routinely abused in some species, but never in others? And can the study of such unpleasant behavior by our closest relatives help us to understand the evolution of men’s violence against women? In the first systematic attempt to assess and understand primate male aggression as an expression of sexual conflict, the contributors to this volume consider coercion in direct and indirect forms: direct, in overcoming female resistance to mating; indirect, in decreasing the chance the female will mate with other males. The book presents extensive field research and analysis to evaluate the form of sexual coercion in a range of species—including all of the great apes and humans—and to clarify its role in shaping social relationships among males, among females, and between the sexes.

May 2009

New Book on Cooking and Human Evolution by KCP Co-Director Wrangham

Catching Fire: How Cooking Made Us Human (Basic Books). By Richard Wrangham (2009).
Ever since Darwin and The Descent of Man, the existence of humans has been attributed to our intelligence and adaptability. But in Catching Fire, renowned primatologist Richard Wrangham presents a startling alternative: our evolutionary success is the result of cooking. In a groundbreaking theory of our origins, Wrangham shows that the shift from raw to cooked foods was the key factor in human evolution. Once our hominid ancestors began cooking their food, the human digestive tract shrank and the brain grew. Time once spent chewing tough raw food could be used instead to hunt and to tend camp. Cooking became the basis for pair bonding and marriage, created the household, and even led to a sexual division of labor. A pathbreaking new theory of human evolution, Catching Fire will provoke controversy and fascinate anyone interested in our ancient origins - or in our modern eating habits.

• NY Times Review of "Catching Fire"
• Dr. Wrangham on NPR's "All Things Considered"
• Dr. Wrangham in "The Economist"

April 2009

Kanyawara Alpha Male Survives Life-Threatening Poaching Injury

On April 5th a group of Kanyawara chimpanzees travelled deep into the southern part of their range, past the National Park boundary, and into a field near the village of Rurama, where they fed on maize. Three armed poachers and a pack of their hunting dogs pursued the chimpanzees into the forest, spearing the alpha male, Imoso, in his left arm. Doctoral student Paco Bertolani and field assistants from the Kibale Chimpanzee Project arrived in time to drive off the poachers and save Imoso from further injury. However, he was severely wounded, with the bone in his arm visible to observers (Photos: P. Bertolani). Thanks to quick action by KCP staff, the Uganda Wildlife Authority, and a team of veterinarians from the Jane Goodall Institute, Imoso was successfully darted on April 7th, and his wound was cleaned and stitched. He has now almost healed, and is again able to use his left arm. This has been an unsettling reminder of how vulnerable chimpanzees are - even in a national park - and underscores the importance of research in protecting wild chimpanzees.

March 2009

KCP Research on Chimpanzee Dispersal

The context of female dispersal in Kanyawara chimpanzees. RM Stumpf, M Emery Thompson, MN Muller, and RM Wrangham. Behaviour 146: 629-656.
Contribution to the special issue on Dispersal in Primates: Advancing an Individualized Approach.
Chimpanzees are unusual among Old World primates in that dispersal is almost exclusively by females. It is thought that, as in other species, sex-biased dispersal in chimpanzees evolved as a means to avoid the genetic detriments of inbreeding, yet very little is known about the proximate forces that lead individual females to disperse. Our data suggest that females mate actively in their natal communities, and that inbreeding avoidance is unlikely to affect individual decisions about when (or whether) to emigrate. Additionally, neither age, maturational state, nor urinary stress hormone levels predicted the highly-variable timing of dispersal by adolescent Kanyawara chimpanzees. Instead, female emigration was predicted by dietary quality, suggesting that females wait to have sufficient energy reserves to buffer the high costs of dispersal.

February 2009

2008 In Review

2008 was a fertile year for Kanyawara females. We registered 4 births: Moon, Wallace, Quiver, and Obama (pictured at 1 day old, photo by P. Bertolani). In addition, two new immigrant females, Michelle and Rwanda, joined the community. A third - Leona - made preliminary visits, but has not definitely settled. We are happy to report that no Kanyawara chimpanzees died in 2008, so the total community size is ~50 -- holding steady from its size in 1998.

Distinguished human visitors to Kibale in 2008 included L.S.B. Leakey Foundation President Bill Wirthlin and his family. Uncharacteristically, a trek to Ngogo yielded observations of only a lone male chimpanzee, whereas the Kanyawara community turned out in force for the event. The Wirthlins also had the opportunity of meeting one of the Leakey Foundation's Baldwin Fellows-- Kanyawara field manager Dr. Emily Otali.

Pictured (L-R): Whit, Lisa, Meriel, Will, and Bill Wirthlin, Richard Wrangham, Martin Muller, Emily Otali

Kibale C-peptide research in Hormones and Behavior

Urinary C-peptide tracks seasonal and individual variation in energy balance in wild chimpanzees. M Emery Thompson, MN Muller, RW Wrangham, JS Lwanga, KB Potts. Hormones and Behavior 55: 299-305. This paper validates a new method for non-invasive assessment of energetic condition in wild animals. We found that urinary C-peptide of insulin correlated well with behavioral measures of dietary quality and revealed the energetic deficit imposed by severe illness. We also collaborated with our colleagues at the Ngogo Chimpanzee Project to demonstrate that known differences in habitat quality were reflected in differing C-peptide levels in male chimpanzees at Kanyawara and Ngogo. C-peptide is a powerful new tool that will help us answer questions about the impact of ecological variation on individual condition and behavior.

October 2008

New book highlights research-conservation link at Kibale

Science and Conservation in African Forests: The Benefits of Longterm Research (Cambridge University Press). Edited by Richard Wrangham and Elizabeth Ross (2008). In 2007, to celebrate the 20th anniversary of the Kibale Chimpanzee Project, Richard Wrangham and Elizabeth Ross organized a unique conference on the long-term benefits of research for forest conservation. The resulting text addresses the diverse consequences of biological research for conservation, including effects on habitat management, community relations, ecotourism, and training. Features contributions from long-term African and Western researchers, as well as managers, in Kibale National Park and other major ape research sites.

September 2008

Special volume on Reproductive Strategies and Competition in Female Apes

New Kibale Chimpanzee Project research is featured in a special issue of the International Journal of Primatology. The volume, co-organized by Kibale scientists, features 5 papers by KCP researchers: "Female Reproductive Strategies and Competition in Apes: An Introduction" (M. Emery Thompson, R.M. Stumpf, and A.E. Pusey); "Female Mate Preferences Among Pan troglodytes schweinfurthii of Kanyawara, Kibale National Park, Uganda" (K. Pieta); "A Comparison of Female Mating Strategies in Pan troglodytes and Pongo spp." (R.M. Stumpf, M. Emery Thompson, and C.D. Knott); "Male Mating Interest Varies with Female Fecundity in Pan troglodytes schweinfurthii of Kibale National Park" (M. Emery Thompson and R.W. Wrangham); "Female Competition over Core Areas in Pan troglodytes schweinfurthii, Kibale National Park, Uganda" (S.M. Kahlenberg, M. Emery Thompson, and R.W. Wrangham).