The Frugivores: Evolution, Functional Traits, and Their Role in Seed Dispersal

Romeo A. Saldaña-Vázquez and Theodore H. Fleming

Frugivory is a hallmark of the Phyllostomidae, and frugivorous species in subfamilies Carolliinae and Stenodermatinae are among the most common mammals throughout the Neotropics. In this chapter we discuss the coevolution of fruits and phyllostomid frugivores; the morphological and other traits that these bats use to detect and process fruit; their foraging behavior and its consequences for seed dispersal; and the network structure of this coevolved mutualism and its conservation implications. Frugivorous phyllostomids have been interacting with fleshy-fruited angiosperms for about 20 Ma and currently disperse the seeds of hundreds of species of plants found throughout angiosperm phylogeny. They are especially important dispersers of early successional plants. Collectively, the feeding and foraging behavior of these bats creates strongly leptokurtic seed dispersal curves, but whose long tails can sometimes lead to the colonization of new habitats. Two foraging guilds (or modules in network parlance) have evolved: an understory guild of carolliines and Sturnira bats and a canopy guild of mostly stenodermatine bats. Ecological redundancy likely exists within these two guilds, but it is threatened whenever bat diversity is reduced by natural or anthropogenic factors. Climate change is one such factor, and its effects warrant careful monitoring.