A survey of resident bats at the Wequiock Creek Natural Area in Brown County, WI

Author / Creator

Boulanger, Nicholas, author

Available as

Physical

Summary

Despite increasing evidence that bat populations are seriously threatened, foraging habitat preferences among different species is still poorly understood. In this study, I used stationary ultrasou...

Despite increasing evidence that bat populations are seriously threatened, foraging habitat preferences among different species is still poorly understood. In this study, I used stationary ultrasound bat detectors to compare bat activity in a riparian floodplain corridor with nearby upland forest edge habitat at the recently acquired Wequiock Creek Natural Area (WCNA) in Brown County, WI. Bat activity at the WCNA was also compared to several other natural areas along the eastern shore of Green Bay using walked transects with a handheld bat detector. Bat activity was modelled with a low-frequency species group including larger species, and a high-frequency group with smaller species. Results showed highly significant differences among sites in addition to statistically significant effects of air temperature and time since sunset. The strongest models also included interaction terms between these factors, with the most complex models being the best fit according to Akaike Information Criteria (AIC). Overall bat activity was highest in the riparian zone, and the high-frequency group, in particular, showed a dramatic preference for the floodplain forest. The low-frequency group exhibited slightly higher activity at the forest edge compared with paired floodplain forest sites. All seven of Wisconsin's common bat species are present at WCNA according to acoustic analysis of vocalizations with Kaleidoscope Pro Analysis Software. In addition, the federally endangered Indiana Bat (Myotis sodalis) is potentially present at several of the forest sites, an unexpected finding. The baseline survey presented here can be used to document population declines due to emergent diseases such as white-nose syndrome or to evaluate the success of future restoration efforts at the WCNA and other protected forests along the east shore of lower Green Bay.

Show More