DOI: 10.5061/dryad.p8cz8w9rv
title: Connecting Amazonian historical biogeography and local assemblages of understorey birds: recurrent guild proportionality within areas of endemism.

description: Aim: Current diversity patterns in local communities result from
 historical and contemporary events that operate at distinct spatial and
 temporal scales. ​However, the contribution of local and large-scale
 processes in structuring species diversity remain a contentious topic in
 ecology. We investigated diversity patterns (species richness, composition
 and number of captures) of understorey bird assemblages in Amazonian
 unflooded (terra firme) forests. We sought to understand whether
 understorey bird assemblages in distinct areas of endemism show distinct
 patterns of diversity, and whether species replacements among areas of
 endemism occur while the proportion of species within guilds remains
 stable. Location: Amazonia. Taxon: Understorey birds. Methods: To
 investigate diversity patterns, we compiled studies that mist-netted birds
 at 11 regions across seven Amazonian areas of endemism. We used
 coverage-based rarefaction curves, non-metric multidimensional scaling
 (NMDS) and created a heatmap based on the proportion of captures in each
 area of endemism to access patterns of richness, composition and captures
 of understorey birds, respectively. The relative variance (RVgp index) was
 calculated to investigate the existence of guild proportionality within
 each area of endemism. Results: Bird assemblages diverged across the seven
 areas of endemism, in terms of species richness, composition and captures.
 However, the proportion of species and individuals within guilds was
 similar among areas of endemism, indicating that species replacements
 across areas of endemism occur while maintaining the same ecological
 functions. Guild proportionality suggests that interspecific competition
 and resource availability are more important than environmental
 heterogeneity in structuring understorey bird assemblages. Main
 conclusions: The similar proportion of species within guilds suggest that
 interspecific competition and resource availability are more important
 than environmental heterogeneity in structuring local assemblages,
 possibly via a process of limiting similarity in morphological and
 functional traits. The observed congruent structure in understorey bird
 assemblages across areas of endemism shows that coupled historical and
 ecological processes, operating at local to large scales, have led to
 current patterns of diversity and composition in Amazonian bird
 communities.
description: We compiled data from 11 studies that used mist-nets to sample
 birds within different areas of endemism across Amazonian <i>terra
 firme</i> forests. Mist-net studies used here were implemented with
 distinct designs, goals and contexts (see Appendix S1 in Supporting
 Information), resulting in large variation in the number of captured
 individuals per landscape (between 389 and 3,582 captures for long
 temporal sampling). We focused on understorey
 <i>terra firme</i> species and removed species that fit at
 least one of the following three criteria: i) species that are not
 typically found in the understorey (i.e. species that preferably inhabit
 the midstorey and canopy); ii) species that inhabit mainly open-habitat
 areas (e.g. <i>campinas</i>); and iii) species that inhabit
 flooded areas but that may occasionally also occur in the understorey of
 <i>terra firme</i> forest (see Appendix S2 in Supporting
 Information). Species selection was based on two databases (Stotz et al.,
 1997; Wilman et al., 2014) that contain information on habitat use and
 foraging stratum (understorey, midstorey and canopy). The list was
 subsequently revised by two ornithologists with extensive field experience
 in Amazonia. We also excluded recaptures from all analyses as we were
 interested in the number of individuals per species. 
description: There are 2 different datasets: 1.
 "Capture data.csv": Capture data of understorey birds, sampled
 in seven Amazonian areas of endemism. Each line corresponds to a species
 and the number of individuals captured in each sampling area, with the
 respective information on food guild and body size, sociability and
 foraging substratum. 2. "Metadata.csv":
 Metadata of the items 'sociability' and 'foraging
 substratum'.