Elevational distribution of birds in an Eastern African montane environment as governed by temperature, precipitation, and habitat availability

We conducted annual point counts of birds between 2013 and 2018 at 297 plots across habitats and elevations (2,416-4,303 m) in Volcanoes National Park, Rwanda. These data were subsequently used to determine elevational and habitat preferences via indicator analyses, and to model abundance distributions as a function of temperature, precipitation, habitat availability, and congeneric competition. Of 35 focal species, we found 20 species to be particularly associated with narrow elevational range (<300 m) and 24 species to have a strong associated with one to three habitat types. Abiotic conditions, estimated for each plot location, significantly correlated with the abundance distributions of 33 species (temperature 33, precipitation 17), and biotic factors with distributions of 31 species (habitat 30, competition 7). Temperature and habitat availability were particularly associated with upper elevational limits (31 and 26 species respectively vs. 10 and 6 at lower limits), whereas pre...