BIOMASS OF RAIN-FOREST MAMMALS IN THE LOPE RESERVE, GABON

1. Densities of mammals in five sites in lowland semi-evergreen tropical rain forest in the Lope Reserve, central Gabon, were estimated using standard line-transect methods. Biomass was calculated using weights taken from the literature. 2. The total estimated biomass of diurnal primates, ruminants, pigs, elephants and squirrels in the five sites varied between 998 and 5866 kg km-2. Forest elephants (Loxodonta africana cyclotis Matschie) dominated the biomass in all sites, making up 52-89% and primates accounted for 6-30%. 3. Statistically significant differences in density were detected for most species in at least two of the sites. Some of these differences could be related to vegetation structure and composition, but the reasons for others were unclear. 4. Total biomass was high. However, this was due to high elephant densities, emphasizing their importance in the African rain forest. Primate and duiker biomasses were lower than figures reported for some African rain forests. 5. If the reasons for differences in mammalian biomass in rain forests are to be understood there is a need for data of the sort presented here from more sites around the world. Such studies should be considered a priority considering the current rate of habitat loss, as the survival of many rain forest species may depend upon our being able to evaluate the carrying capacity of limited protected areas in the near future.