Sex differences in the movement patterns of free-ranging chimpanzees (Pan troglodytes schweinfurthii): foraging and border checking
- 429 Downloads
Most social primates live in cohesive groups, so travel paths inevitably reflect compromise: decision processes of individuals are obscured. The fission–fusion social organisation of the chimpanzee, however, allows an individual's movements to be investigated independently. We followed 15 chimpanzees (eight male and seven female) through the relatively flat forest of Budongo, Uganda, plotting the path of each individual over periods of 1–3 days. Chimpanzee movement was parsed into phases ending with halts of more than 20 min, during which individuals fed, rested or engaged in social activities. Males, lactating or pregnant females and sexually receptive females all travelled similar average distances between halts, at similar speeds and along similarly direct beeline paths. Compared to lactating or pregnant females, males did travel for a significantly longer time each day and halted more often, but the most striking sex differences appeared in the organisation of movement phases into a day's path. After a halt, males tended to continue in the same direction as before. Lactating or pregnant females showed no such strategy and often retraced the preceding phase, returning to previously visited food patches. We suggest that female chimpanzee movements approximate an optimal solution to feeding requirements, whereas the paths of males allow integration of foraging with territorial defence. The ‘continually moving forwards’ strategy of males enables them to monitor their territory boundaries—border checking—whilst foraging, generally avoiding the explicit boundary patrols observed at other chimpanzee study sites.
KeywordsChimpanzees (Pan troglodytes) Range use Sex differences Fission–fusion Individual movement patterns Border checking
We thank all the staff of the Budongo Forest Project, especially Kakura James, Fred Babweteera and Vernon Reynolds. For permission to work in Uganda, we thank the Uganda National Council for Science and Technology, the President's Office, the Uganda Wildlife Authority and the Uganda Forest Authority. This research was supported by a studentship from the Biotechnology and Biological Sciences Research Council (01/A1/S/07457). The paper has benefited from helpful comments from two anonymous referees.
Conflict of interest
The authors declare that they have no conflict of interest.
- Batschelet E (1981) Circular statistics in biology. Academic, LondonGoogle Scholar
- Boesch C, Boesch-Achermann H (2000) The chimpanzees of the Taï forest: behavioural ecology and evolution. Oxford University Press, OxfordGoogle Scholar
- Chapman C, White F, Wrangham R (1994) Party size in chimpanzees and bonobos: A re-evaluation of theory based on two similarly forested sites. In: Wrangham RW, McGrew WC, de Waal FBM, Heltne PG (eds) Chimpanzee cultures. Harvard University Press, Cambridge, pp 41–58Google Scholar
- Dunbar RIM (1988) Primate social systems. Croom Helm, LondonGoogle Scholar
- Goodall J (1986) The chimpanzees of Gombe: patterns of behavior. Harvard University Press, CambridgeGoogle Scholar
- Krebs JR, Davies N (1997) Behavioural Ecology: an evolutionary approach, 4th edn. Blackwell Scientific, OxfordGoogle Scholar
- Kummer H (1968) Social organisation of Hamadryas baboons. University of Chicago Press, ChicagoGoogle Scholar
- Moss CJ (1988) Elephant memories: thirteen years in the life of an elephant family. Elm Tree Books, LondonGoogle Scholar
- Newton-Fisher N (2000) Male chimpanzee core areas: ranging in Budongo Forest chimpanzees. Pan African News 7:10–12Google Scholar
- Nishida T (1990) The chimpanzees of the Mahale mountains. Sexual and life-history strategies. University of Tokyo Press, TokyoGoogle Scholar
- Nishida T, Hiraiwa-Hasegawa M (1987) Chimpanzees and Bonobos: Cooperative relationships among males. In: Smuts B, Cheney D, Seyfarth RM, Wrangham RW, Struhsaker T (eds) Primate societies. University of Chicago Press, London, pp 165–177Google Scholar
- Plumptre AJ, Cox D, Mugume S (2003) The status of chimpanzees in Uganda. Wildlife Conservation Society, New YorkGoogle Scholar
- Prins HHT (1996) Ecology and behaviour of the African buffalo. Chapman and Hall, LondonGoogle Scholar
- Strier KB (2000) Primate behavioural ecology. Allyn & Bacon, BostonGoogle Scholar
- van Schaik CP (1989) The social ecology of social relationships amongst female primates. In: Standen V, Foley RA (eds) Comparative socioecology. The behavioural ecology among humans and other animals. Blackwell Scientific, Oxford, pp 195–218Google Scholar
- Wrangham R, Smuts B (1980) Sex differences in the behavioural ecology of chimpanzees in the Gombe National Park, Tanzania. Journal of Reproductive Fertility 28:13–31Google Scholar
- Wrangham RW (1979) Sex differences in chimpanzee dispersion. In: Hamburg DA, McCown E (eds) The great apes. Addison-Wesley, Menlo Park, pp 481–489Google Scholar