From 1996 through 2005, I conducted field research on the ecological relationship between chimpanzees and mountain gorillas in Bwindi Impenetrable National Park, Uganda. Bwindi is a rugged, mountainous 300+ sq. km. forest tract in southwestern, and the only forest in Africa in which chimpanzees and mountain gorillas co-occur. I conducted field research on the behavior and ecology of chimpanzees in Bwindi, while my Ph.D. student John Bosco Nkurunungi carried out simultaneous research on the gorillas sharing the same habitat. Together we were able to test hypotheses about the ecological influences of a tropical forest on the behavior of each species, and on the effects of co-existence of each species on the other. We found that Bwindi chimpanzees and gorillas rarely interact, occasionally feed or nest in the same or adjacent trees, and on very rare occasions do exhibit aggression toward one another at feeding trees. I also studied the use of bipedal posture by chimpanzees, and their use of tools for extracting food such as honey and insects. Nkurunungi and I made extensive use of GIS/GPS technology to make digital maps of the movements of both ape species, and of their food resources.
The study also had a human evolutionary aspect. We know that at several times and places in the past, multiple hominid species shared habitats and therefore resources. Studying sympatric modern apes was an opportunity to gain some insights into how early humans might have shared a habitat.This work was conducted with the support of the Institute of Tropical Forest Conservation, the Ugandan government, and the L.S.B. Leakey Foundation, National Geographic Society, Fulbright Foundation, and Jane Goodall Research Center of the University of Southern California.
Selected publications on sympatric ecology of chimpanzees and mountain gorillas.
Stanford, C.
Apes of the Impenetrable Forest. Prentice Hall (Primate Field Studies Series). (in 2007)
Stanford, C.B.
The sympatric ecology of African great apes, with implications for the hominoid divergence. Primates 47: 91-101 (published online 10/05).(in 2006)[pdf]
Stanford, C.B.
Arboreal bipedalism in wild chimpanzees: implications for models of the evolution of hominid posture and locomotion. American Journal of Physical Anthropology 129: 225-231.(in 2006)[pdf]
Nkurunungi, J.B. and C.B. Stanford.
GIS analysis of range use by sympatric mountain gorillas and chimpanzees in Bwindi Impenetrable National Park, Uganda. In Primates of Western Uganda (J. Paterson, V. Reynolds and H. Notman, eds.), pp. 193-205. Kluwer-Plenum Publ. Co.(in 2006)
Nkurunungi, J.B., J. Ganas, M. Robbins and C.B. Stanford.
A. comparison of two mountain gorilla habitats in Bwindi Impenetrable National Park-Uganda. African Journal of Ecology 42: 289-297.(in 2004)
Stanford, C.B. and J.B. Nkurunungi.
Sympatric ecology of chimpanzees and gorillas in Bwindi Impenetrable National Park, Uganda. Diet. International Journal of Primatology 24: 901-918.(in 2003)[pdf]
Stanford, C.B.
Arboreal bipedalism in Bwindi chimpanzees. American Journal of Physical Anhropology 119: 87-91.(in 2002)
Stanford, C.B.
The subspecies concept in primatology: the case of mountain gorillas. Primates 42 (3): 309-318. (in 2001)[pdf]
Stanford, C.B. , C. Gambaneza, J.B. Nkurunungi and M. Goldsmith.
Chimpanzees in Bwindi Impenetrable National Park, Uganda, use different tools to obtain different types of honey. Primates 41: 335-339.(in 2000)[pdf]
Stanford, C.B. and R.C. O’Malley.
Nesting tree choice in Bwindi chimpanzees(manuscript)