Support Bat Research, Management, and Monitoring in Great Smoky Mountains National Park
PI: Bill Stiver (Great Smoky Mountains National Park Supervisory Wildlife Biologist)
Great Smoky Mountains National Park (GRSM) has been very responsive to the management and monitoring of bats and white-nose syndrome (WNS) including implementing cave and area closures; development of educational materials; population and acoustic monitoring; and collaboration with researchers, as well as state and federal biologists. The 2016 National Park Service WNS funds were used to hire a seasonal technician to continue supporting bat monitoring and management efforts in GRSM and to provide financial support for qualified personnel to assist with bat hibernacula surveys. We also provided administrative and logistical support and equipment for five bat research projects in GRSM and purchased miscellaneous supplies needed for GRSM bat monitoring.
Four caves in GRSM were surveyed in 2016, none of which had been surveyed since 2011. All of the caves showed significant decreases in the total number of cave-dwelling bats, including a 94.4% decline of endangered Indiana bats in a cave that historically housed more than 2,400 individuals. Acoustic driving transect surveys were also completed, and based on the number of calls there was an increase in big brown bats, eastern red bats, evening bats, tri-colored bats and a decrease in hoary bats, silver-haired bats and Myotis species. Data collected from this monitoring effort, as well as other bat research projects in GRSM will provide management staff with the information needed to make informed decisions about closures and other management actions that may affect park visitors and resources. Information will also be used to enhance the development of a GRSM action plan for Indiana and northern long-eared bats.
Long-Term Monitoring of Endangered Bats After Declines from WNS in Great Smoky Mountains National Park
PI: Bill Stiver (GRSM Supervisory Wildlife Biologist), Dr. Joy O'keefe (Assistant Professor Indiana State University)GRSM established a cooperative agreement with Indiana State University to investigate the summer roost ecology of northern long-eared bats and Indiana bats and to conduct acoustic surveys across the park. Objectives of the study were to assess the impacts of WNS on capture rates and roosting ecology of these species and to use acoustics to obtain data on the distribution of Indiana bats, northern long-eared bats, and other WNS-affected species.
During 2016, researchers conducted 24 nights of netting and captured 254 bats of 9 species. They captured only 1 Indiana bat and did not capture any northern long-eared bats or little brown bats, once two of the most commonly captured species in GRSM. They detected substantial declines for Indiana bats (-97%), tri-colored bats (-87%), and Rafinesque’s big-eared bats (-52%). Interestingly, capture rates for big brown bats and eastern small-footed bats were higher than pre-WNS surveys. Researchers also conducted acoustic surveys at 42 sites on trails or in early successional areas across GRSM for a total of 204 detector-nights. Preliminary analyses indicate that bat activity was highest at sites in early successional areas, followed by conifer-mixed sites, northern hardwoods, and spruce fir. Overall, activity was greatest for bats in the low phonic group, followed by the Myotis group, and then the mid-phonic group. Capture data contrasted somewhat with acoustic data, as researchers captured more mid-frequency bats than Myotis groups, but low frequency bats still dominated the capture sample. Results of this study suggests that WNS has caused significant declines in 4 (31%) of the bat species in GRSM.
Year 2—Survey of Buildings Used as Summer Roosts by Bats in Great Smoky Mountains National Park
PI: Bill Stiver (GRSM Supervisory Wildlife Biologist), Kirsten Fagan (Graduate Student, The University of Tennessee)GRSM established a cooperative agreement with the University of Tennessee for a second year to investigate the use of historic and non-historic anthropogenic structures as summer roosts by bats in the park. The objectives of the study were to establish a standard protocol for inspection of structures, identify buildings used by bats as summer roosts, determine building characteristics that influence roost selection, and develop management recommendations regarding bat presence in buildings.
During 2015 and 2016, researchers visited 145 buildings in GRSM and found 44 active roost structures. Of these, 29 structures are accessed regularly by park visitors, 30 are managed for cultural significance, and 14 are listed on the National Register of Historic Places. Researchers documented five species, either directly or through genetic analysis of guano: big brown bat, Rafinesque’s big-eared bat, eastern small-footed bat, little brown bat, and northern long-eared bat. Only big brown bats, Rafinesque’s big-eared bats, and eastern small-footed bats were observed directly. For each roost structure, researchers assessed site attributes that will later be analyzed to identify variables most influential in roost selection.
These results will help researchers develop a predictive model to assist in identifying buildings most likely to be used by bats and therefore the highest priority for management decisions. Researchers are also developing standard protocols for future building inspections and surveys as well as management recommendations regarding bat presence, including the timing of maintenance activities, restriction of human use and public access, and bat exclusion. As many GRSM buildings are culturally significant and accessed by the public, these data are critical for both wildlife and cultural resource management.
Year 2—Tricolored Bat Roost Tree and Cave Hibernacula Management in Great Smoky Mountains National Park
GRSM established a cooperative agreement with the University of Tennessee for a second year of research to investigate the ecology of tri-colored bats. The objectives of the study were to assess the current status of tri-colored bats in GRSM, identify and characterize roost trees used by tri-colored bats, and develop management recommendations. During summer 2016, researchers surveyed 24 sites across GRSM for bats that were previously surveyed by Dr. Eric Britzke in 2000-2004, before white-nose syndrome (WNS) was detected in North America. Researchers captured 191 bats representing 12 species. Most notable were two eastern small-footed bats and three endangered gray bats; two species that were not captured by Dr. Britzke. The gray bat captures represent the first records of the species in GRSM. Based on comparisons with data collected by Dr. Britzke, capture rates declined for tri-colored bats, little brown bats, northern long-eared bats, Indiana bats, hoary bats, big brown bats, red bats, and silver-haired bats. Declines for most species are likely due to WNS; however, drops in capture rates for silver-haired and hoary bats could be an effect of small sample size as WNS has never been seen on these species. Researchers also successfully radio-tracked and located 10 tri-colored bats to 45 tree roosts. Bats were located in several tree species including tulip poplar, oak, magnolia, maple, sweet gum, and yellow buckeye. All roost trees were alive, and bats were located in heavily clustered foliage.
PI: Bill Stiver (GRSM Supervisory Wildlife Biologist), Grace Carpenter (Graduate Student - The University of Tennessee)