Date of Award
Master of Science (MS)
Forestry and Environmental Conservation
David S Jachowski
Susan C Loeb
Catherine B Jachowski
Loss of forest habitat used for roosting and nocturnal activity by bats is a conservation concern in the southeastern United States. The northern long-eared bat (Myotis septentrionalis), southeastern myotis (Myotis austroriparius), tri-colored bat (Perimyotis subflavus), and northern yellow bat (Lasiurus intermedius) all occur within the Coastal Plain of South Carolina, where their greatest conservation threat is loss of critical roosting and foraging habitats. However, little research has been conducted on these species of conservation concern in this region, leaving gaps in information about habitat associations that would inform conservation and management as forest loss continues due to logging, agriculture, urban development, and intense storm events. To address this concern, we used radio telemetry and acoustic bat detectors to understand habitat associations of these species in southern coastal South Carolina. Our specific objectives were to 1) determine habitat characteristics associated with third order summer roost selection for the northern long-eared bat, tri-colored bat, and northern yellow bat, and 2) determine habitat characteristics associated with summer and winter nocturnal habitat use for Myotis spp., the tri-colored bat, and the northern yellow bat.
To understand summer roost selection, we radio-tracked individuals to roost trees May-August 2018 and 2019. We characterized roosts, roost sites, and associated available trees and used discrete choice models to analyze our data. Although we did not capture enough northern long-eared bats for resource selection analysis, we determined that one northern long-eared bat used bark roosts in slash pine (Pinus taeda) and one used basal cavities in water tupelo (Nyssa aquatica). Tri-colored bats and northern yellow bats switched roosts frequently (every 1.3 days). Tri-colored bats used foliage and Spanish moss (Tillandsia usneoides) in hardwood trees and selected hardwood trees with high densities of Spanish moss. Northern yellow bats used dead palm fronds in cabbage palm trees (Sabal palmetto) or Spanish moss in hardwood trees and selected cabbage palm trees and trees with high densities of Spanish moss or dead palm fronds. Our results suggest that conservation of maritime and bottomland forests with trees that have high densities of roost structures would benefit all three species.
To investigate nocturnal habitat use we conducted acoustic surveys in summer (May-August) and winter (December-March) 2018 and 2019. We surveyed 125 sites in 5 habitat categories (upland forest, bottomland forest, fields, ponds, and salt marsh) in summer and 121 of these same sites in winter. We used occupancy models to analyze our data and interpreted results as habitat use. Myotis spp. used sites that were closer to hardwood stands and freshwater year-round, and sites closer to pine stands during winter. During summer, tri-colored bats were present at most sites (85%) and use was not dependent on any characteristics we measured, but during winter they used bottomland forests, fields, and ponds more than salt marsh and upland forests. During summer, northern yellow bats used sites close to freshwater and salt marsh, and used fields, ponds, and salt marsh more than upland and bottomland forests. During winter, they continued to use sites close to salt marsh and freshwater, but used bottomland forests, fields, and ponds more than upland forest and salt marsh. Our results highlight the importance of specific forest stands and features like freshwater, salt marsh, ponds, and bottomland forests, while also highlighting that habitat use changes between seasons in response to resource and changes in vegetation structure.
Shute, Kyle Edward, "Habitat Relationships of Bat Species of Conservation Concern in Coastal South Carolina" (2020). All Theses. 3374.