Document Type

Honors Thesis

Publication Date

Spring 5-2016

Abstract

Bat populations in the eastern U.S. continue to decline due to white-nose syndrome (WNS), a fungal pathogen known to produce abnormal behavior and tissue damage in bats. As a result, the composition of bat communities has changed significantly, in part due to the dramatic decrease of cave hibernating bat species. These species rely on forests for summer roosting sites and foraging. Maine is a heavily forested state where timber harvesting is a large source of revenue; therefore it is necessary to understand the factors influencing the presence of vulnerable bat species. However, little is currently known about suitable habitat for these species in Maine. This study had two main objectives: (1) to identify habitat features that influence Myotis bat presence across a range of environmental conditions; and (2) to document bat species present at our study site, the Penobscot Experimental Forest (PEF) in Bradley Maine. During the summer of 2015, we placed ten AnaBatTM acoustic detectors at a total of 46 locations throughout the PEF, stratified by four cover types: open, closed canopy, small canopy gaps, and large canopy gaps. Detectors were moved to new locations on a weekly basis. We analyzed nine potential predictor variables, creating a separate logistic regression model for each. The models were evaluated using Akaike’s corrected information criterion (AICc), assuming that the model with the lowest AICc score was the most influential. We found that the number of trees per hectare (in quadratic form) was the best predictor of Myotis species presence, with proportion of canopy openness and gap size also contributing to variation among sites. In total, we detected eight bat species at the PEF representing the full set of species occurring in Maine. Our expectation is that findings from this study will provide a foundation for future investigations into forest use by threatened bats in this region.

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