Population structure and group composition of western lowland gorillas in north-western Republic of Congo

Population studies are an essential part of conservation actions. Under exc eptional observation conditions we studied a western lowland gorilla popula tion visiting the Maya salt-clearing (north of the Pare national d'Odzala, P.N.O., Congo) over an 8 month period; 36 groups and 18 solitary individual s (a total of 420 individuals) have been identified visiting the clearing, which suggests a high gorilla density in the region. Ninety-six percent of the gorillas entered the clearing in groups. One-male groups had a mean siz e of 11.2. Ninety percent of solitary individuals were silver-back males. C ompared with other populations of both lowland gorillas and mountain gorill as, the Maya population had the highest immature rate and the highest numbe r of infants per female. Ecological correlates that could explain the attra ctiveness of the Maya clearing are discussed. The present status and the re newal rate of the Maya population indicate the need for further studies and confirm the importance of developing eco-tourism in this region as part of the sustainable park management activities developed by the ECOFAC program me (European Union). The results also provide arguments to support the prop osal for extending the P.N.O. to include this region, which is rich in salt -clearings and attracts many other key-species of mammal such as forest ele phants. Am. J. Primatol. 48:1-14, 1999. (C) 1999 Wiley-Liss, Inc.