The Demography and Reproductive Parameters of Bossou Chimpanzees
Ecological and behavioral research on chimpanzees at Bossou has been ongoing for more than 30 years, ever since 1976. This community exhibits quite unique life history variables, including demographic and reproductive parameters. The chimpanzees of Bossou develop and mature faster than do those in other chimpanzee populations. The interbirth interval is shorter, and females continue to give birth at least until 45 years of age. Perhaps Bossou provides an excellent habitat for chimpanzees. However, community size has never exceeded 23 and has remained stable for nearly three decades, numbering about 20 individuals. A flu-like epidemic in 2003, however, led to the loss of five individuals; the community has numbered between 12 and 14 members since 2006. Most offspring, males as well as females, disappear from Bossou during their adolescence. Patterns of emigration and immigration are discussed here. It is argued that although the habitat of the Bossou chimpanzees may be limited in its carrying capacity, it has nevertheless favored reproductive development in the females.
KeywordsReproductive Parameter Wild Chimpanzee Party Size Female Immigration Interbirth Interval
We would like to thank all the researchers and students, as well as the local assistants, who have worked at Bossou and who have provided us with demographic and life history data. We are particularly grateful to Professor T. Matsuzawa and Dr. T. Humle for their editorial help with this chapter. Finally, we would like to thank the Ministère de l’Enseignement Supérieur et de la Recherche Scientifique, in particular the Direction Nationale de la Recherche Scientifique et Technologique (DNRST) and the Institut de Recherche Environnementale de Bossou (IREB), for granting us over the years the permission to carry out research at Bossou.