Evolutionary relationships and population genetic structure of North American big-eared bats, genus Corynorhinus

Using molecular techniques, I have analyzed phylogenetic relationships of the three species within the North American big-eared bats, genus Corynorhinus: C. townsendii, C. rafinesquii, and C. mexicanus . I have also examined population genetic structure, connectivity, and dispersal patterns among populations of three subspecies of C. townsendii, and among five populations of C. rafinesquii . A molecular phylogeny was inferred from mitochondrial and nuclear DNA, and evolutionary relationships within the genus Corynorhinus were compared to Handley's (1959) taxonomy. Cryptic lineages were hypothesized within Corynorhinus based on phenotypic similarity of these bats and limited dispersal abilities with apparent widespread distributions. My work supports Handley's (1959) designation of three species, with no cryptic lineages detected. However, my results indicate a need for revision of the geographic ranges of two subspecies of C. townsendii. Further, various hypotheses of C. townsendii population contraction and expansion during the Pleistocene were explored.; There is considerable concern over the conservation status of C. townsendii and C. rafinesquii based on recorded declines and habitat fragmentation. In fact, two subspecies of C. townsendii, C. t. ingens and C. t. virginianus, are listed as endangered under the Endangered Species Act. A conservation genetics methodology using mitochondrial and microsatellite DNA was employed to compare two western subspecies, C. t. pallescens and C. t. townsendii, with the endangered subspecies, C. t. virginianus . Results suggest that males mediate gene flow among populations within C. townsendii. Further, populations of C. t. virginianus are isolated and have significantly lower genetic diversity than the western subspecies. Five roosts of C. rafinesquii in Arkansas were also examined in a conservation genetics framework. Although these populations still experience some connectivity, they are all extremely inbred and suffer from low genetic diversity and low effective population sizes. Results may confirm the hypothesis of Jones and Suttkus (1975) that C. rafinesquii populations experience dispersal mediated by female movement, rather than male as is typical for most mammalian taxa. Conservation implications for both C. townsendii and C. rafinesquii populations are discussed.