Access

You are not currently logged in.

Access your personal account or get JSTOR access through your library or other institution:

login

Log in to your personal account or through your institution.

If you need an accessible version of this item please contact JSTOR User Support

Modified Cave Entrances: Thermal Effect on Body Mass and Resulting Decline of Endangered Indiana Bats (Myotis sodalis)

Andreas R. Richter, Stephen R. Humphrey, James B. Cope and Virgil Brack, Jr.
Conservation Biology
Vol. 7, No. 2 (Jun., 1993), pp. 407-415
Stable URL: http://www.jstor.org/stable/2386439
Page Count: 9
  • Download ($42.00)
  • Cite this Item
If you need an accessible version of this item please contact JSTOR User Support
Modified Cave Entrances: Thermal Effect on Body Mass and Resulting Decline of Endangered Indiana Bats (Myotis sodalis)
Preview not available

Abstract

Entrances to many caves occupied by the endangered Indiana bat (Myotis sodalis) have been modified to control human access. We show that modifying cave entrances can degrade the bats' winter habitat, we demonstrate one mechanism by which this damage occurs, and we document a restoration experiment. We compared a large bat population in an unmodified cave with a small, reduced bat population in a cave with warm winter temperatures resulting from an entrance wall that impeded air exchange. In the modified cave, mean winter temperature at the hibernation site was 5.0circ C higher than in the unmodified cave, bats entered hibernation at a 5% higher body mass, bats lost 42% more mass, and the frequency distribution of late-winter mass was truncated, with no bats weighing less than 5.4 g. The results describe unacceptable extremes for hibernation: subfreezing temperatures and warm temperatures causing mass-loss rates of more than 0.009 g/day. Over a decade following removal of the entrance-constricting wall, the population increased from 2,000 to 13,000 bats. Previous recommendations, based on common-sense observation, to open blocked cave entrances are confirmed by this study. The similar case of Coach Cave, Kentucky, offers the potential for recovery of 100,000 Idiana bats.

Page Thumbnails

  • Thumbnail: Page 
407
    407
  • Thumbnail: Page 
408
    408
  • Thumbnail: Page 
409
    409
  • Thumbnail: Page 
410
    410
  • Thumbnail: Page 
411
    411
  • Thumbnail: Page 
412
    412
  • Thumbnail: Page 
413
    413
  • Thumbnail: Page 
414
    414
  • Thumbnail: Page 
415
    415