Patterns of understorey bird diversity across Amazonian forests: survey effort and range maps predict local species richness

Species diversity typically increases from higher to lower latitudes, but the regional-scale variation along this geographic gradient remains unclear. It has been suggested that species diversity throughout Amazonia generally increases westward toward the Andes, but this pattern and its environmental determinants require further investigation for most taxa. Using mist-net data on understorey birds, we evaluated patterns of species richness using two approaches by addressing methodological issues that influence local species richness and the determinants of species richness across Pan-Amazonia. Specifically, we examined (i) the disparity between observed and expected species richness obtained from geographic range maps; (ii) how species' eco-morphological traits influence their detection and relative abundance; (iii) the spatial variation in estimated local species richness after controlling for sampling effort; and (iv) the environmental determinants of estimated richness. We found no e..., , # Data from: Patterns of understorey bird diversity across Amazonian forests: survey effort and range maps predict local species richness

Dataset DOI: [10.5061/dryad.2ngf1vj33](https://doi.org/10.5061/dryad.2ngf1vj33)

## Description of the data and file structure

We compiled data on understorey bird captures using mist-nets at 67 Amazonian forest sites, including 716 plots (86,278 individuals captured representing 646 species) incorporating information from published articles, MSc and PhD theses, unpublished data from collaborating researchers, environmental licensing data generated by major infrastructure projects, and the avian ecology sampling conducted by the Amazon Biodiversity and Carbon (ABC) Expeditions Project. Filtering our data excluded 23 sites, 484 plots, 415 species, and 51,556 individuals, which amounted to a total of 232 plots retained in our analyses of eco-morphological traits (including non-*terra firme* plots). We excluded 24 sites, 505 plots, 456 species, and 56...,