Feeding behaviour and diet of chimpanzees (Pan troglodytes troglodytes) in the Okorobikó Mountains of Rio Muni (West Africa).

Some aspects of the nutritional behaviour of the Okorobikó-Matama (Rio Muni, West Africa) chimpanzees have been studied over two periods--from June 1963 to September 1964 and from July 1966 to February 1969. This research totaled 640 h, 119 of which were in sustained contact with the animals. We have complied a list of 43 plant and two termite species consumed by the chimpanzees. We studied the relative importance of the plants consumed in terms of the four principal biotopes and seasonal cycles, the feeding behavior, the rhythm of activity and chimpanzees' vertical stratification during feeding. We also took into accout group dynamics as a function of feeding, communication and polyspecific associations with other primates. We finally compared some aspects of the nutrition of these chimpanzees with that of gorillas living in nearby zones.