Journal of
Ecology and The Natural Environment

  • Abbreviation: J. Ecol. Nat. Environ.
  • Language: English
  • ISSN: 2006-9847
  • DOI: 10.5897/JENE
  • Start Year: 2009
  • Published Articles: 360

Full Length Research Paper

Post-White-nose syndrome trends in Virginia’s cave bats, 2008-2013

Karen E. Powers
  • Karen E. Powers
  • Biology Department, Radford University, Radford, VA 24142, United States
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Richard J. Reynolds
  • Richard J. Reynolds
  • Virginia Department of Game and Inland Fisheries, Verona, VA 24482, United States
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Wil Orndorff
  • Wil Orndorff
  • Virginia Department of Conservation and Recreation, Natural Heritage Program, Christiansburg, VA, United States
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W. Mark Ford
  • W. Mark Ford
  • U. S. Geological Survey, Virginia Cooperative Fish and Wildlife Research Unit, Blacksburg, VA, United States
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Christopher S. Hobson
  • Christopher S. Hobson
  • Virginia Department of Conservation and Recreation, Natural Heritage Program, Richmond, VA, United States
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  •  Received: 24 February 2015
  •  Accepted: 27 March 2015
  •  Published: 15 April 2015

Abstract

Since its 2009 detection in Virginia hibernacula, the fungal pathogen Pseudogymnoascus destructans causing White-nose Syndrome (WNS) has had a marked impact on cave bats locally. From 2008-2013, we documented numeric and physiologic changes in cave bats through fall swarm (FS), early hibernation (EH), and late hibernation (LH) capture and banding surveys at 18 hibernacula in western Virginia. We coupled active surveys with passive biennial winter counts in 2009, 2011, and 2013. We compared individual body mass index (BMI) across years for FS, EH, and LH hibernation to determine if WNS impacts on extant bats would be manifested by changes in body condition (as anecdotally observed elsewhere for WNS-impacted bats) as well as a population reduction. To estimate percent declines in bat presence or relative activity, we used FS capture per-unit-effort data, and the winter hibernacula absolute counts. We captured 4,524 bats of eight species, with species-specific capture success declining by 75-100% post-WNS. Little brown bats (Myotis lucifugus) exhibited the greatest declines in winter hibernacula counts (AVG. = 99.0% decline), followed by tri-colored bats (Perimyotis subflavus; 89.5% decline) and Indiana bats (M. sodalis; 33.5% decline). Graphical analyses of captures-per-trap-hour in FS showed declines for little brown bats, tri-colored bats, and northern long-eared bats (M. septentrionalis), but suggest a modest rebound of Indiana bat numbers. Fall swarm trends in BMI suggested some drops post-WNS exposure, but these trends were not consistent across sexes or seasonal time blocks. Our inconclusive BMI metrics and little brown bat band recapture data suggest little competitive advantage or selection for surviving bats. Lesser (but apparent) declines in Indiana bat numbers mirrors trends seen elsewhere regionally, and band recoveries do show that some individuals are persisting. Additional surveys will determine if bats in Virginia will persist or face extirpation due to presumed low recruitment and survivorship.
 
Key words: Bat, hibernaculum, Pseudogymnoascus destructans, Virginia, white-nose syndrome.