Fine‐scale patterns of genetic structure in three species of forest birds reveal dynamic Pleistocene history within an Amazonian interfluve

Phylogeographical studies of Amazonian birds have revealed large intraspecific diversity, even within recognized areas of endemism. To understand the origin and organization of Amazonian diversity, including the influence of current and historical landscapes, we need to evaluate fine‐scale patterns of genetic diversity in relation to detailed information on environmental heterogeneity. We investigated the phylogeography and demographic history of three understorey bird species, the White‐throated Antbird Oneillornis salvini , the Common Scale‐backed Antbird Willisornis poecilonotus and the Blue‐capped Manakin Lepidothrix coronata , with dense sampling within the Purus–Madeira interfluve, which is part of the Inambari area of endemism. Analysis of sequence data of one mitochondrial (mt)DNA marker and two nuclear markers indicates that species went through recent population expansion and have no genetic structure within the interfluve, even though it includes distinct ecoregions and geological formations. These results suggest a recent occupation of the landscape by current populations, in agreement with geological reconstructions that indicate a dynamic Pleistocene history. For the studied understorey bird populations, biogeographical history is a better predictor of genetic diversity than current environmental heterogeneity within the Purus–Madeira interfluve.