Gombe National Park, Tanzania currently hosts the longest continuous study of wild chimpanzees. Studies at Gombe have spanned 43 yr and represent the only studies with nearly complete lifespan data on adult chimpanzees.2,3 The length and scope of the Gombe study make this population of the highest scientific importance to our understanding of ape behavior, ecology, and conservation. Loss and even precipitous decline of this population would be a major setback for primate conservation efforts.
Disease outbreaks, either in isolation or in concert with other risk factors such as environmental variations, demographic stochasticity, or loss of genetic diversity, can pose serious threats to the long-term persistence of mammal populations; these risks are elevated as population size decreases and/or population isolation increases.1 Many chimpanzee study sites are increasingly isolated by loss of habitat due to human encroachment and managers in parks containing chimpanzees perceive that disease outbreaks have been and continue to be significant causes of mortality for chimpanzees. The total population at Gombe has declined from perhaps as many as 150 in the 1960s to near 100 in 2003, with death from disease as the leading cause of mortality (J.M. Williams, 2002. An analysis of mortality factors in the wild chimpanzees of Gombe National Park, Tanzania, unpublished report). Major epidemics at Gombe include suspected polio in 1966, respiratory diseases in 1968, 1987, 1996, 1999 and 2000 and sarcoptic mange in 1997.3,7,9,10 Mahale National Park has been struck by “flu-like” illnesses and an “AIDS-like” epidemic.8 Other chimpanzee study sites have also reportedly been affected by epidemic disease (e.g., Ebola in the Tai Forest, Ivory Coast and Lossi in Gabon). Many of these disease outbreaks are suspected to be the result of close contact with humans,5,11 and similar issues surrounding human-ape disease transmission are currently under investigation in mountain gorillas4,6. These outbreaks have led park managers and researchers working in Gombe National Park to conclude that diseases originating from and/or spread by humans pose a substantial risk to the long-term survival of Gombe’s chimpanzee population.
A comprehensive ecosystem health program is currently being implemented in Gombe National Park. The purpose of this program is to standardize collection of long-term, longitudinal surveillance data on chimpanzees, baboons and humans that may be used for disease risk assessment and ecological modelling. Results of this project will be incorporated into the Tanzanian Park Authorities (TANAPA) strategic planning process for Gombe National Park.
This work was partially funded by the United States Fish & Wildlife Service Great Ape Fund, the Tanzanian Park Authority, the Jane Goodall Institute, and Lincoln Park Zoo’s Davee Center for Veterinary Epidemiology. Special thanks goes to Dr. Titus Mlengeya of TANAPA for providing vital support and advice throughout the project. We are also grateful to the following people for assistance and advice: J. Bakuza, A. Collins, M. Cranfield, J. Fouser, L. Gaffikin, I. Gilby, B. Hahn, K. John, S. Kamenya, I. Lejora, M. Lukasik, C. Murray, M. Msafiri, F. Nutter, J. Schumacher-Stankey, C. Simon, M. Smith, W. Wallauer, C. Whittier and M. Wilson. Permission and support to carry out research at Gombe was granted by the Government of Tanzania, Tanzania National Parks, Tanzania Commission for Science and Technology and Tanzania Wildlife Research Institute.
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