Patterns of habitat use by primates in eastern Ecuador

Lowland tropical rain forests of western Amazonia are characterized by the most speciose primate communities in the Neotropics, immediately leading to the question of to what extent does niche partitioning by primate species serve as a mechanism to promote species co-existence. Because the primate assemblages that we observe today reflect a combination of ecological and evolutionary processes, this study examines habitat occupancy and its relationship to phylogeny and space in a diverse diurnal primate community in an undisturbed lowland rain forest of Amazonian Ecuador. Specifically, the following null hypotheses are explored as potential factors that shape community structure: (1) mean height in the forest strata does not differ among species; (2) species occupy habitat types at frequencies proportional to their overall availability; (3) species do not segregate in ecological space; (4) there is no relationship between phylogenetic distance and ecological distance among species; and (5) there is no relationship between ecological distance and geographic distance among species.; The results of this study reveal that ecological differences among the species in this primate community facilitate their coexistence. Larger species generally occupied higher strata than smaller ones. Furthermore, although they generally tended to occupy habitat types at frequencies proportional to their availability in the study area, species segregated in ecological space defined by dissimilarity in habitat occupancy. Finally, in this community, a clear relationship was not observed between phylogenetic and ecological distances or ecological and geographic distances. This study elucidates the spatial distribution and the habitat partitioning of the diurnal primate community at the Tiputini Biodiversity Station in Ecuadorian Amazonia.