Ecology and Population Genetics of Townsend's Big-Eared Bats

Abstract

Species conservation requires broad, multidisciplinary knowledge over topics such as habitat and climate preferences, reproduction cycles, and factors that may put a species at risk such as anthropogenic disturbances. Species that live in groups may be more prone to decline from anthropogenic factors. Understanding factors driving group-living is critical, as there is evidence that degradation of groups and social relationships can have negative fitness consequences and subsequent species decline. Here, I use multiple-lines of evidence to understand the evolution and ecology of group-living Townsend’s big-eared bats (Corynorhinus townsendii townsendii) populations in California and relate these data to conservation actions. Corynorhinus t. townsendii live in seasonal colonies – in the summer, female bats and their offspring live in maternity colonies. In the fall, these colonies dissolve as bats travel to hibernacula where they hibernate for the winter. To first understand factors driving the location and persistence of seasonal colonies of C. t. townsendii, I created species distribution models for maternity colonies, hibernacula, and the transition roosts in between. I found that the distribution of suitable habitat is different for seasonal colonies but amount of precipitation generally determines suitable habitat. My results also indicate a decrease in suitable habitat for C. t. townsendii in California by 2080. Additionally, I used mark-recapture data to analyze roost fidelity in C. t. townsendii in the Inyo-White Mountains. I used genetic data to understand if bats associate more often with related individuals in seasonal colonies. My data do not indicate that group-membership in maternity colonies or hibernacula are driven by kinship; however, further research is needed to determine if cooperative behavior among non-related individuals is occurring within colonies. My results indicate this species has high roost fidelity to both maternity colonies and hibernacula, but adult males do not often return to natal maternity colonies. Finally, survival analyses from mark-recapture data of females indicates drought negatively impacts C. t. townsendii, and first-year survival is generally lower in this species. Overall, this work will be useful as land managers continue to determine areas of conservation focus for C. t. townsendii and provide baseline data for assessment of management actions.