Effects of hunting on western Amazonian primate communities

Transect surveys were carried out in seven western Amazonian upland forest sites and compared with four additional sites to examine effects of hunting by humans on the structure of species-rich primate communities. Primate body mass was a strong positive correlate of its crude and metabolic population biomass in non-hunted but not in hunted sites. Primate body mass was a good negative correlate of population density in hunted but not in non-hunted sites. Group density was not clearly affected by hunting activity. Large primates had significantly lower group densities than small primates in both hunted and non-hunted sites. These trends are largely a consequence of differences in abundance of large-bodied genera (i.e.Alouatta, Ateles and Lagothrix), accounting for the bulk of the primate biomass in non-hunted sites, but being over-harvested or becoming extinct in sites hunted by man.