Environmental determinants of primate abundance in Maraca Island, Roraima,Brazilian Amazonia

A primate community was studied in a fluvial tropical rain forest island, i n the northernmost part of Brazilian Amazonia, in the State of Roraima. Den sity and biomass were determined, and the differences between the forest ty pes were assessed. The line-transect method was used from the east towards the centre of the island. No previous studies had been carried out in this remote undisturbed area. Density and biomass varied between the forest type s, as well as between frugivorous primates; the smaller-bodied species were more abundant in the forest that was richer in fruiting trees, while they were absent from a monodominant forest. The folivorous, or partly folivorou s, primates were abundant in those forests with less fruiting trees. The ab undance of the primates in the different forest types was shown to be a fun ction of food availability.