Date of Award
Master of Science
Integrated Environmental Sciences
Alix D. Fink, Ph.D.
Mark L. Fink, Ph.D.
Edward L. Kinman, Ph.D
Bat habitat in the southeastern U.S. is being threatened by rapid deforestation and degradation, yet conservation and management strategies are limited by the paucity of accurate bat demographic and habitat-use data. I conducted summer mist-net surveys to determine species richness, relative abundance, reproductive condition, and sex ratios of the bat species occurring in the Appomattox-Buckingham State Forest in the Piedmont physiographic region of central Virginia. I captured 8 species: red bat (Lasiurus borealis), eastern pipistrelle (Pipistrellus subflavus) , little brown myotis (Myotis lucifugus) , northern myotis (M septentrionalis ), big brown bat (Eptesicusfascus), evening bat (Nycticeius humeralis), hoary bat (L. cinereus), and gray myotis (M grisescens ). Red bats were captured more than other species (72% of total captures), and pipistrelles were the next most frequently captured species (11% of total captures).
To aid in understanding how Lasiurus borealis, a forest-dwelling bat, uses the forests of the Virginia Piedmont, I located roost sites of lactating females and quantified roost-site and roost-patch characteristics. Using 0.6-gram radio transmitters, I tracked 27 bats in June and July 2003 and 2004 to 98 unique roost trees of 13 different species; 94% of which were hardwood species. I used an information-theoretic approach to evaluate my hypotheses regarding the effects of roost site, patch, and landscape on red bat habitat use. The best model supported by the data for the roost-site effects subset was the null model (w; = 0.44). Within the patch effects subset, the tree composition model (including mean DBH of all stems > 0.5 cm, number of trees in DBH class > 15cm and S 30 cm, and number of trees in DBH class > 30 cm) was best supported (wi = 0.75). The best model supported by the data for landscape effects subset was the hardwood effects model that included area of hardwood cover (wi = 0.42).
My results indicate that the Appomattox-Buckingham State Forest supports a diversity of bat species during the summer months. However, additional research is needed to identify the species that occur on the Appomattox-Buckingham State Forest in other seasons. Future surveys also should incorporate acoustic sampling to better identify species that might be missed with mist-net surveys. I determined that red bats in the Virginia Piedmont utilize hardwood trees with diameters greater than 34 cm. I also found that large diameter trees within a site positively affect habitat use. Based on my results, populations of red bats in the Piedmont are potentially at risk as the habitat they are using is being threatened by deforestation. Additional information on the habitat requirements of red bats and other tree-roosting species will aid in developing effective, data-driven conservation and management plans.
Durkee, Kathryn A., "RED BAT (LASIURUS BOREALIS) HABITAT USE IN ACTIVELY MANAGED FORESTED LANDSCAPES OF THE VIRGINIA PIEDMONT" (2005). Theses, Dissertations & Honors Papers. 84.