Impact of human disturbance on stress, disease and conservation of chimpanzees, Pan troglodytes, in Budongo Forest, Uganda
Across Africa, chimpanzee populations are endangered by habitat loss and hunting. However, little is known about the mechanisms by which chimpanzees respond to human disturbance. While chimpanzees may adapt to changes through the stress response, chronic elevation of stress hormones results in reproductive failure and disease. This research project examines the impact of human disturbance on chimpanzees in Budongo Forest, Uganda. It attempts to identify whether disturbance results in increased stress and disease. Behavioural data are being collected from chimpanzee communities at four sites, each with different disturbance regimes. Feces and urine samples will be used to assess cortisol levels, parasite load, viral and bacteriological pathogens. Interviews with villagers will elucidate variation in human activity. Research will increase understanding of wildlife endocrinology and disease ecology. By exploring both the needs of humans and chimpanzees, this project will help identify critical areas for conservation, and contribute to more effective conservation programs.
This research applies a multidisciplinary framework to examine human activity in Budongo Forest, Uganda, and the impact of anthropogenic disturbance on four communities of chimpanzees (Pan troglodytes schweinfurthii). Uganda is one of the world’s most biodiverse countries, but also one of the world’s poorest. It was ranked 145th out of 177 on the 2006 human development index. A growing population and developing economy are placing increasing pressure on remaining forest reserves.
Budongo Forest is the largest mahogany forest in East Africa, with diverse flora and fauna. Approximately 500 chimpanzees are thought to live within the forest. While the area has been designated a priority area for chimpanzee conservation in Uganda, it faces a variety of human threats including hunting, logging, pit-sawing and charcoal burning (Plumptree et al. 2003). The forest is also under increasing pressure from agricultural expansion by Kinyara Sugar Works, one of Uganda’s largest producers of sugar. This is an area of human environmental conflict that needs urgent attention!
Chimpanzees are listed as endangered on the IUCN red list, threatened by human activities such as habitat loss and by hunting. For conservation to succeed, it is critical to determine how chimpanzees adapt to human and environmental stressors. Living in territorial communities, chimpanzee populations are dependent on, and restricted to, their local environment. They should therefore be vulnerable to human disturbance. Yet, little is known about how disturbance impacts chimpanzees physiologically in terms of stress and disease. Chimpanzee population numbers have declined drastically as a result of infectious disease (Leendertz et al. 2006). Causes of disease outbreaks are unclear. Limited research exists on pathogens affecting wild ape populations. Systematic screening and the identification of pathogens is necessary to elucidate both the agents of mortality and the transmission dynamics (Leendertz et al. 2005).
At the same time, to help mitigate environmental change, greater understanding is required of local community use of and dependence on ecosystem services. While natural capital accounts for only 4% of total wealth worldwide, it accounts for 26% of the wealth of low-income countries (World Bank 2006). The world’s poorest people depend primarily on environmental goods and services for their livelihoods. This makes them particularly sensitive and vulnerable to environmental changes (World Resources Institute 2005). Only by applying a multidisciplinary perspective will we be able to fully understand both the drivers and the consequences of human environmental disturbance.
The project therefore has the following objectives:
1. To describe human use of ecosystem services and drivers which influence human use of the forest.
2. To describe the distribution of human disturbance across the forest.
3. To compare the behaviour of the four chimpanzee communities.
4. To compare differences in stress levels, measured by glucocorticoid (GC) levels among the four communities and among the individuals within each community.
5. To compare difference in disease levels, both micro and macroparasites, among the four communities and among the individuals within each community.
6. To evaluate whether heightened stress levels contribute to increased disease burden.
During the past two years data has been collected at four sites in Budongo Forest, each facing different human pressures:
1. Sonso, a former logging site that is currently protected and suffers little encroachment, logging or other forms of human activity.
2. Busingiro, a site on the southern edge of the main forest block, which experiences significant levels of illegal logging.
3. Kaniyo-Pabidi, a site in the northern part of the forest that has never been logged. As part of Murchison Falls National Park, it does not suffer from snaring or encroachment, but is subject to ecotourism.
4. Kasokwa, a forest fragment to the south of the main forest body, surrounded by sugar cane fields.
Over 1,000 feces and urine samples have been collected and will be used to assess cortisol levels, parasite load, viral and bacteriological pathogens. Over 800 interviews have been collected from local villagers elucidate variation in human livelihoods and forest use. This project brings together a strong research team from around the world. It involves collaborations between WildCRU, the Max Planck Institute for Evolutionary Anthropology and the Robert Koch Institute, in Germany, Conservation Through Public Health, The Jane Goodall Institute and the Budongo Conservation Field Station in Uganda. It is hoped that research will increase understanding of wildlife endocrinology and disease ecology. By exploring both the needs of humans and chimpanzees, this project will help identify critical areas for conservation, and contribute to more effective conservation programs.