Nectar-feeding bird and bat niches in two worlds: pantropical comparisons of vertebrate pollination systems

Methods An extensive literature review was conducted to compile data bases on the regional and local species richness of nectar-feeding birds and bats, pollinator sizes, morphology, and diets. Coefficients of variation (CVs) were used to quantify the morphospace occupied by the various families of pollinators. The extent to which plants have become evolutionarily specialized for vertebrate pollination was explored using several criteria: number and diversity of growth forms of plant families providing food for all the considered pollinator families; the most common flower morphologies visited by all the considered pollinator families; and the number of plant families that contain genera with both birdand bat-specialized species.