M.J. Hamilton | Geology Reports

USGS2008

Subspecific affinities and conservation genetics of western big-eared bats (Corynorhinus townsendii pallescens) at the edge of their distributional range

Subspecific affinities, determination of population boundaries, and levels of population connectedness are of critical importance for the development of management and conservation planning. We used variation at a mitochondrial locus and 5 biparentally inherited nuclear loci to determine partitioning of genetic variation of western big-eared bats (Corynorhinus townsendii) within and among caves occurring in a fragmented landscape of gypsum deposits in western Oklahoma. To accomplish this objective, we first performed a phylogenetic analysis based on the mitochondrial locus of western big-eared bats from a large portion of their range. This analysis indicated that western big-eared bats at the periphery of the distribution in western Oklahoma share phylogenetic affinities with the most geographically restricted subspecies, C. t. pallescens. Because C. townsendii is rare in Oklahoma and is listed as a species of special concern, this finding provides additional support for the continued protection of this species in Oklahoma. Within western Oklahoma, we failed to detect significant differentiation among any caves for the biparentally inherited microsatellite data. However, the mitochondrial locus exhibited significant levels of genetic differentiation among caves, with the highest level of differentiation occurring between caves within the disjunct distributions of gypsum (??ST = 38.76%). Although a significant amount of genetic differentiation was detected between populations on the 2 disjunct distributions of gypsum deposits, Analysis with the program Migrate suggested high levels of asymmetric gene flow among some populations. Our results provide a greater understanding of the population dynamics of western big-eared bats on the periphery of their range and highlight the importance of continued monitoring and study of this taxon. ?? 2008 American Society of Mammalogists.

Journal of Mammalogy↗

USGS2005

Unraveling the effects of sex and dispersal: Ozark big-eared bat (Corynorhinus townsendii ingens) conservation genetics

The Ozark big-eared bat (Corynorhinus townsendii ingens) is federally listed as endangered and is found in only a small number of caves in eastern Oklahoma and northwestern Arkansas. Previous studies suggested site fidelity of females to maternity caves; however, males are solitary most of the year, and thus specific information on their behavior and roosting patterns is lacking. Population genetic variation often provides the necessary data to make inferences about gene flow or mating behavior within that population. We used 2 types of molecular data: DNA sequences from the mitochondrial D loop and alleles at 5 microsatellite loci. Approximately 5% of the population, 24 males and 39 females (63 individuals), were sampled. No significant differentiation between 5 sites was present in nuclear microsatellite variation, but distribution of variation in maternally inherited markers differed among sites. This suggests limited dispersal of female Ozark big-eared bats and natal philopatry. Areas that experience local extinctions are unlikely to be recolonized by species that show strong site fidelity. These results provide a greater understanding of the population dynamics of Ozark big-eared bats and highlight the importance of cave protection relative to maintaining genetic integrity during recovery activities for this listed species. ?? 2005 American Society of Mammalogists.

Journal of Mammalogy↗