Basabose / Poster

Influence of sympatric gorillas on chimpanzee's nesting behavior in the Kahuzi-Biega national park, democratic republic of Congo

Kanyunyi A. Basabose, Centre de Recherche en Sciences Naturelles, Lwiro, D.S. Bukavu, Democratic Republic of Congo

     Influence of sympatric gorillas on nesting site choice by a unit group of chimpanzees have been surveyed in the montane forest of Kahuzi-Biega National Park. A total of 310 fresh night nests were recorded at 72 nest sites. Chimpanzees did not use trees for nesting according to their abundance, but tended to nest in trees which fruits were eaten by them. However, they seemed to avoid nesting in trees which fruits were also eaten by gorillas. The degree of avoidance may vary with their nesting group size and type of vegetation. When they nested as a small group in the secondary forest, they nested in trees bearing ripen fruits eaten by themselves more frequently than those eaten by both gorillas and chimpanzees. Where as, no significant difference was found between them when the group size was large. In primary forest, they consistently nested in trees bearing fruits preferred by both apes, irrespective the group size. These observation may reflect the contest competition over fruit foods between gorillas and chimpanzees, which may have stimulated chimpanzee's avoidance and have promoted niche separation in the past.