Primate Population Densities in Three

Protected areas We censused primate populations at three non-hunted ‘terra firme ’ forests of south-eastern Colombian Amazonia. The aggregate biomass densities of diur-nal primates at all sites were amongst the lowest recorded for any non-hunted forest in western Amazonia and elsewhere in the Neotropics. Densities of red howler monkeys were low, as is typical in Amazonian terra firme forests far re-moved from white-water rivers, and densities of woolly monkeys were 1.5–3.5 times lower than those estimated for this species in central-western Brazilian Amazonia. Densities of small to mid-sized primates except for brown capuchins (Cebus apella) and white-faced capuchins (Cebus albifrons) were similar to those of other oligotrophic Amazonian forest sites. Our results are in agreement with other studies showing that terra firme forests of lowland Amazonia typically sustain a low biomass density of primates and other mid-sized to large verte-brates. Large reserves are therefore required to assure the viability of primat