Date of Award

12-2009

Document Type

Thesis

Degree Name

Master of Science (MS)

Legacy Department

Wildlife and Fisheries Biology

Advisor

Jodice, Patrick

Committee Member

Brown , Bryan

Abstract

Little is known about natural roost selection of Rafinesque's big-eared bats, Corynorhinus rafinesquii , throughout their range. The objectives of this study were to determine roost use and selection of big-eared bats in the Upper Coastal Plain of South Carolina at multiple spatial scales and test whether roost use and selection differed between maternity colonies and solitary individuals. The study was conducted May-August 2006 and 2007 in Congaree National Park which contains extensive areas of old-growth bottomland forest. Roost trees were located via tree searches and radio-telemetry and I used univariate tests and multiple logistic regression to compare tree, stand, and landscape characteristics of roosts to those of randomly selected trees in similar habitats.
I located 43 big-eared bat roosts (12 maternity roosts, 29 solitary roosts, and 2 that were used by both group types). The logistic regression analysis indicated that tree characteristics were the most important factors determining roost selection by maternity groups and solitary individuals. The majority of roosts (75% of maternity roosts and 62% of solitary roosts) were in water tupelo (Nyssa aquatica) and bats selected this species over other species. Maternity and solitary roost trees were significantly larger in diameter than random trees and maternity roosts were significantly taller than random trees. There were no differences between roosts used by maternity groups and solitary individuals although 50% of maternity roosts were in upper bole cavities compared to 26% of solitary roosts. Most roosts (90.7 %) were in live-damaged trees; the rest were in snags. Although stand and landscape characteristics were not as important as tree characteristics, we found that basal area was significantly greater around roost trees than random trees and bats were more likely to use trees in the baldcypress-water tupelo-Carolina ash vegetation class than other habitat types. My results suggest that although stand and landscape characteristics may be important, conservation of large water tupelo with cavities is the most critical factor for Rafinesque's big-eared bats in the Coastal Plain.

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