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PrIME | Primate Immunogenetics and Molecular Ecology Research Group

Fiona A. Stewart, PhDfiona 1


 Current positions

Post doctoral research associate, PrIME research group
Co-Director, Ugalla Primate Project, Tanzania
President, Anthropogeny Research Group, California, USA


I completed my PhD on chimpanzee nest building behaviour in the Division of Biological Anthropology at the University of Cambridge in 2011.  My first degree is in Zoology from the University of Glasgow in Scotland, where I developed initial interests in tropical biology studying dominance interactions of wild hummingbirds in Ecuador.  My M. Sci research took me to Fongoli, Senegal, where I managed the study site and conducted research into savanna chimpanzee nest-building behaviour.  I then began work in Ugalla, western Tanzania, surveyed new areas and provided the nest decay rate data necessary to calculate chimpanzee density in the region. 

fiona 2My PhD investigated variation in, and the shelter function of chimpanzee nests across two communities of savanna chimpanzees; the Fongoli community in Senegal, and the Issa valley community in Ugalla, western Tanzania. Throughout a lifetime each great ape builds a nest, or bed, at least once a day, which is a notable investment of time and effort. I investigated how nests are made, how techniques vary across individuals and communities, and through observation and experimental tests I investigated the functions of these ubiquitous shelters.

 Research interests

My research interests surround the behavioural variation of chimpanzees, from nest building behaviour to social structure and the intersection of each with conservation.

Specifically, I am interested in the use of genetics as a tool to understand behavioural variation. Firstly, by identifying individual nest builders through DNA fingerprinting of faeces collected beneath night nests I am studying variation in nest building across individuals, lineages, and groups. Secondly, genetics can help to identify where and with whom individuals are associating across the landscape. In dry habitats chimpanzees live at extremely low densities and are hypothesized to range across areas 4-100 times larger than forest-dwelling chimpanzees. Through genetic identification of individuals, and use of sex-specific markers of dispersals, I aim to understand how or if chimpanzees maintain typical fission-fusion,territorial defense, and male patriarchy, whilst living at such low densities.

My current research uses genetics to improve a chimpanzee survey across the Greater Mahale Ecosystem of fiona 3western Tanzania. In Tanzania, 75% of chimpanzees are found outside of the protected areas. In collaboration with Alex Piel, The Nature Conservancy, Frankfurt Zoological Society, and the Jane Goodall Institute, we aim to prioritize key areas across the Greater Mahale Ecosystem for conservation through the use of technology, genetic census and investigation of gene flow. We also provide information and assistance to local and regional governments to coordinate village land use plans with conservation strategies.

Current Projects

I recently completed a survey of the Greater Mahale Ecosystem in order to prioritize areas for chimpanzee conservation. Specific projects under this survey include:

  • Population genetics of chimpanzees in the Greater Mahale Ecosystem: determining gene flow and priority conservation areas (with A. Piel, L. Knapp, The Nature Conservancy, Frankfurt Zoological Society, the Jane Goodall Institute)
  • Presence and distribution of SIVcpz across the Greater Mahale Ecosystem, and the prevalence and impact of SIVcpz on the Issa chimpanzees (with A. Piel, L. Knapp, and B. Hahn of the University of Pennsylvania)

Since 2008 I have co-directed research of the Ugalla Primate Project, where we focus on research of chimpanzees, but also baboons, red-tails, and overall community ecology. Specific projects include:

  • Parasite diversity of Issa primates, and specifically co-infection of SIVcpz with other pathogens in Issa chimpanzees (with K. Petrzelkova of the Academy of Sciences of the Czech Republic)
  • Issa chimpanzee behavioural ecology and adaptation to a dry, open, savanna woodland (with Ugalla Primate Project) investigated through the use of motion-triggered cameras (with the Max Planck Institute), genetics (with L. Knapp and B. Hahn), and acoustics (with A. Piel)
  • Inter-specific competition between Issa chimpanzees and large mammals, specifically primates (with Ugalla Primate Project)
  • Issa baboon and red-tail monkey diet, ranging, and inter-specific competition (with C. Johnson and S. Tapper)


Stewart, F.A. and A.K. Piel. (accepted) Termite fishing by wild chimpanzees: new data from Ugalla, western Tanzania. Primates.

Stewart, F.A. and J.D. Pruetz. 2013. Do chimpanzee nests serve an anti-predatory function? American Journal of Primatology. 75:593-604

Piel, A.K., F.A. Stewart, L. Pintea, Y. Li, M.A. Ramirez, D.E Loy, P.A. Crystal, G.H. Learn, L.A. Knapp, P.M. Sharp, and B.H. Hahn. 2013. The Malagarasi River does not form an absolute barrier to chimpanzee movement in western Tanzania. PLoS ONE. 8(3):e58965

Piel, A.K. and F.A. Stewart. (submitted) Non-human animal responses towards the dead and death: a comparative approach to understanding the evolution of human mortuary practices. In Death Shall Have no Dominion: The Archaeology of Mortality and Immortality, edited volume.

Rudicell, R. S., A.K. Piel, F.A. Stewart, G.Learn, Y. Li, J.Robertson, J. J. Moore. and B. Hahn. 2011. High prevalence of SIVcpz infection in a community of savanna chimpanzees. Journal of Virology. 19:9918-28

Stewart, F. A. 2011. Why sleep in a nest? Empirical testing of the function of simple shelters made by wild chimpanzees. American Journal of Physical Anthropology. 146:313-318.

Stewart, F. A., A.K. Piel, W.C. McGrew. 2011. Living archaeology: Artefacts of specific nest site fidelity in chimpanzees. Journal of Human Evolution. 61:388-95.

Stewart, F. A., A.K. Piel, R. O’Malley. 2011. Responses of chimpanzees to a dead community member at Gombe National Park, Tanzania. American Journal of Primatology. 74:1-7.

Stewart, F. A., Pruetz, J. D., and Hansell, M. H. 2007. Do Chimpanzees build comfortable nests? American Journal of Primatology. 69(8):930-939.

Plumptre, A. J., R. Rose, G. Nangendo, E.A. Williamson, K. Didier, J. Hart, F. Mulindahabi, C. Hicks, B. Griffin, H. Ogawa, S. Nixon, L. Pintea, A. Vosper, M. McLennan, F. Amsini, A. McNeilage, J. R. Makana, M. Kanamori, R. A. Hernandez, A.K. Piel, F. Stewart, J. Moore, K. Zamma, M. Nakamura, S. Kamenya, G. Idani, T. Sakamaki, M. Yoshikawa, D. Greer, S. Tranquilli, R. Beyers, C. Hashimoto, T. Furuichi, and E. Bennett. 2006. Eastern Chimpanzee (Pan troglodytes schweinfurthii): Status Survey and Conservation Action Plan 2010-2020. Gland, Switzerland: IUCN. 52pp.

Funding and Support

Research at Issa is made possible in part by support from the UCSD/Salk Center for Academic Research and Training in Anthropogeny (CARTA).

Research and survey of the Greater Mahale Ecosystem chimpanzees has been made possible by generous support and funding from the ARCUS Foundation, the United States Fish & Wildlife Service, Great Ape Program, The Nature Conservancy, Frankfurt Zoological Society, and the Jane Goodall Institute.

Other research has been generously supported by; The Carnegie Trust for Universities of Scotland, The Harold Hyam Wingate Foundation, LSB Leakey Foundation, Wenner Gren Foundation, International Primatological Society, and Corpus Christi College.

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Last Updated: 11/28/16