Abstract Background: Tropical montane cloud forests are one of the most important hotspots on Earth and show presence of relict-endemic and endangered species, representing about 14% of the total tropical forest worldwide. Synchronous seed production or masting in tropical montane cloud tree species is a widespread reproductive strategy of decidu‐ ous and evergreen broad-leaved tree associations to decrease costs of reproduction and ensure ofspring. Masting event maintains a high avian diversity, which can be modifed by phenological process (seed production and non- seed production). Methods: The main aim of this study was to assess alpha and beta avian diversity and whether the composition of the trophic guild modifes among phenological processes and between two fragmented relict-endangered Mexican Beech (Fagus grandifolia subsp. mexicana) forests (Medio Monte and El Gosco) in the Mex...