Meeting Abstract

51.1  Tuesday, Jan. 5  The effects of White Nose Syndrome (WNS) on bat hibernation FRANK, CRAIG L.*; REEDER, DEEANN; HICKS, ALAN; RUDD, ROBERT; Fordham Univ., Armonk, NY; Bucknell Univ., Lewisburg, PA; NY DEC, Albany; NY Rabies Lab., Albany frank@fordham.edu

Six bat species found in the Northeast hibernate during winter. Hibernation consists of multi-day periods of torpor. The energy source during hibernation is stored body fat, increasing from 7% to 27% in early fall. White Nose Syndrome (WNS) greatly increases bat mortality during winter. It was first observed in New York during the winter of 2006-07, and has since been found at 65 different sites located in 9 states. Bats with WNS cluster near the entrances of cave/mines during hibernation, and fly outside during daylight in January. Bats with WNS have a white fungal growth on their muzzles and wings. WNS affects 5 hibernating bat species. We predicted that the increased mortality associated with WNS is due to: a) more frequent arousals from torpor during hibernation, which produces, b) a premature depletion of body fat. We tested these hypotheses by analyzing the carcasses of Myotis lucifugus collected throughout the winter in New York, and measuring the torpor patterns of free-ranging M. lucifugus at these sites during hibernation via radio telemetry. The mean torpor bout length for M. lucifugus hibernating in WNS sites was 7.5 d, less than the 12.4-19.7 d periods previously reported for this species. Bats with WNS also had a mean body fat level of 11.0 % by 31 Jan., and it further decreased to 7.5 % by 26 Feb. Mean body fat levels of bats without WNS, in contrast, did not decrease to 7.5 % until late April. Our results thus support the hypotheses that bats with WNS prematurely deplete body fat reserves by arousing from torpor more frequently.