ABSTRACT Aim The study of the structure of species assemblages has typically assumed that similar environments share common species; however, interacting biogeographic and phylogenetic processes are equally important. The understanding that ecological processes operate at different spatial scales to shape species assemblages led to the concept of metacommunity, bridging studies from large (distributional patterns) to smaller scales (synecological approaches). Recent autoecological approaches using ecological niche modelling have addressed the issue, yet indirectly. Still, the assumption of similar ecological requirements persists, although both their understanding and its historical relationship remain elusive. We investigated processes shaping the assembly of a metacommunity of endemic birds in acrobiont forests. Location Mesoamerican mountains north of the Isthmus of Tehuantepec. Methods We tested the assumption of similar ecological requirements by assessing ecological niche overlap in bird species in two distributional categories. We also reconstructed their evolutionary history and modelled past distributions to assess changes in range, connectivity and persistence since the Late Pleistocene, and identified climatically stable areas. Results Niche comparisons revealed low overlap among widespread and restricted species. Most widespread species showed equivalent niches, suggesting that niche tracking may have promoted broader ranges. In contrast, restricted species appear to occupy more specialised niches. We found that bird metacommunity assembled through at least three historical events since the Miocene. Overall, species exhibited contrasting responses to past climate shifts, and climatically stable areas were mainly located in the southern highlands. Main Conclusions Overall, we found that ecological niches in the metacommunity differ, suggesting that codistributed species may occupy different parts of the habitat. Widespread species tracked suitable conditions through time, while restricted species may occupy parts of the habitat not used by widespread species. The assembly of the metacommunity in these forests reflects asynchronous evolutionary and ecological dynamics shaped by climate shifts, dispersal ability and extinction.
Sánchez‐González et al. (Thu,) studied this question.