These data represent functional traits relevant to the foraging ecology and habitat preferences of mixed-species flock joining bird species from the Western Andes of Colombia. We collected these data based on published data for the species from the Handbook of the Birds Alive online database (del Hoyo et al. 2020), supplemented with additional natural history references were available, with the objective of calculating the functional richness contained in mixed-species flock compositions sampled across a patch size gradient of subtropical forest fragments in the Serriania de los Paraguas, Valle del Cauca department, Colombia. We tabulated foraging data from 99 bird species observed at least once in a mixed-species flock, including body mass, nest type and clutch size, relative use of four different diet categories, use of different foraging attack maneuvers, foraging substrates, and elevational strata within the forest. We used these data in Jones and Robinson (2020) to calculate the Functional Richness and Functional Dispersion indices for each flock composition.

These data were collected from the Handbook of the Birds Alive online database, based on published material. We supplemented this with taxon-specific natural history resources where possible; references for each species are listed in the last column of the data set. Formal references for each source are listed in the supplementary materials to Jones and Robinson (2020). For each species, we recorded the largest body mass available where multiple body masses were listed. We classified the nest type into cavity, cup, and dome. Relative dietary preferences were quantified on a scale from 0 (no consumption) to 3 (major portion of the diet); these categories were not mutually exclusive. Use of foraging attack maneuvers, foraging substrates, vegetation stratum within the forest, and habitat category (forest interior, forest edge, secondary forest, open habitat) were classified as used (1) or not used (0). Foraging attack maneuver use classifications follow the Robinson and Remsen (1990) categorization scheme.

We removed the nest type and clutch size data prior to calculating functional diversity indices for the Jones and Robinson (2020) publication.