Filtering Effect of Large Rivers on Primate Distribution in the Brazilian Amazonia

Over a century after Wallace’s proposition of the riverine barrier hypothesis, role rivers in diversification species remains matter interest Amazon biogeography. Amazonian rivers, particular those large and fast flowing are widely recognized to act as barriers dispersal some organisms. However, extent which primate changes across interfluves (β-diversity) response river features be explicitly tested. In this study, we examine how characteristics affect variation taxonomic phylogenetic β-diversity elucidate ecological processes behind differences assemblages between neighboring Brazilian Amazonia. We compiled International Union for Conservation Nature (IUCN) distribution maps 80 river-bounded 10 separated by major throughout assessed both (disregarding relationships species) β-diversities. applied multiple linear models evaluate whether annual discharge, sinuosity, reflectance (as proxy amount sediments) each or section that separates make effective primates. found mean discharge has positive effect, while sinuosity sediments have negative effects on β-diversity. These variables significant total interfluves, their turnover components. River features, however, no effect richness differences. Genera capable traversing almost all but replaced others opposite interfluves. Discharge affected small- large-sized β-diversity, only Our results indicate although many species, seems limited short/medium time scales, lineages able cross them over long-time scales.