Effects of variations in tree canopy openness, prey abundance, and abiotic factors on bat activity in the Nantahala National Forest

WCU Author/Contributor (non-WCU co-authors, if there are any, appear on document)
Thomas Granger (Creator)
Institution
Western Carolina University (WCU )
Web Site: http://library.wcu.edu/
Advisor
Beverly Collins

Abstract: Early successional habitat is known to be a source of foraging habitat for bats, and studies have shown that bat activity is higher in disturbed and open vegetation structures. This study analyzed the importance of early successional habitat, created by forest management activities, on bat foraging behavior in the mixed hardwood forest of the Nantahala National Forest Cheoah Ranger District, Graham County, North Carolina. The objective was to determine the effects of variations in forest canopy opening aggregation (aggregated or dispersed) on bat foraging habitat selection. I hypothesized that 1) bat activity would be higher in dispersed canopy openings, 2) open-adapted bats would be more active in opening interior, while clutter-adapted bats would be more active in forest interior between openings, 3) bat activity would be positively correlated with prey abundance, 4) bat activity would be higher above the tree canopy than below at site centers, and 5) bat activity would be negatively correlated with elevation. Simultaneous samples were collected via Anabat SD2 (Titley Scientific, Columbia, MO) acoustical bat detectors from half of two canopy opening treatments, one aggregated and one dispersed, over three consecutive nights. Results suggest that 1) both clutter and open adapted bats were more active in dispersed openings and within openings compared to the forest corridors between them; 2) bats are equally active above and below the canopy; 3) activity is positively correlated with prey abundance, specifically with Lepidoptera, Diptera, and Coleoptera; and 4) activity is negatively correlated with increasing elevation. These results provide information for better forest management applications to improve bat foraging habitat. For example, this study demonstrates that dispersed canopy openings may provide better foraging habitat than aggregated openings for both open-adapted and clutter-adapted bat species.

Additional Information

Publication
Thesis
Language: English
Date: 2018
Keywords
Bat, Canopy, Forest, Nantahala, Openning

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