Evolutionary History of Bats: Molecular time scale of diversification of feeding strategy and morphology in New World Leaf-Nosed Bats (Phyllostomidae): a phylogenetic perspective

Department of Biological Sciences and Museum of Texas Tech University, Lubbock, TX 79409, USA AG Systematik und Evolutionsbiologie, IBU Fakultat V, Carl von Ossietzky Universitat Oldenburg, 26111 Oldenburg, Germany Department of Biology, Xavier University of Louisiana, New Orleans, LA 70125, USA Depatment of Zoology, Oklahoma State University, Stillwater, OK 74078, USA INTRODUCTION Diversification of feeding strategies within each of the 19 Chiropteran families (Simmons 2005, Hoofer and Van Den Bussche 2003, Van Den Bussche and Hoofer 2004) typically is limited to one (13 families) or two (5 families) food sources. The family Phyllostomidae, however, represents an exception to this pattern with 6 distinct feeding strategies: sanguivory, insectivory, frugivory, nectivory, carnivory (feeding on vertebrates), and omnivory. Among families of bats, phyllostomids comprise the largest number of genera (56) and the third largest number of species (160+) (Simmons 2005). They are distributed throughout tropical and subtropical regions of North and South America and have been highly successful in exploiting a diverse array of life-history strategies. Included among its members are 3 species of obligate sanguivores, a feeding strategy unknown in vertebrates other than fish (Fig. 1). Among phyllostomids additional examples of feeding specialization exist, including subsisting exclusively on insects, as well as primarily on fruit, nectar, frogs, rodents, and other vertebrates. Such specializations are remarkable when viewed in the context of the concomitant suite of adaptations associated with the sensory apparatus, locomotion, digestion, dentition, kidney function, and reproduction, among others (Fleming et al. 2005, Greenhall and Schmidt 1988, Griffiths 1982) that must be favored by directional natural selection for successful exploitation of new ecological opportunities. No other clade of mammals with roots in the Eocene displays such radical evolutionary modifications.