Fig. 1. The EDi is a combination of the ED of the interacting species that can be used to characterize the evolutionary history of the seed dispersal interactions.

The ED of each species, calculated by equally dividing the phylogenetic distance of a branch among its daughter branches, is shown at the tips of the phylogenies. The size of the bird and plant fruit silhouettes is proportional to their ED. The ED magnitude of a bird–seed dispersal interaction ranges from very high when distinct plants are dispersed by distinct birds to very low when the opposite is true. The asymmetry can be bird-skewed, when a bird disperses a plant with lower distinctness than its own (orange circles), or plant-skewed otherwise (green circles). Defaunation is expected to have stronger impacts on interactions that involve bird species with a high ED (dashed line, highlighted bird silhouette).