Bat roosts and historic structures on National Park Service lands in the Rocky Mountain Region
Bogan MA and Geluso KK. 1999. Bat roosts and historic structures on National Park Service lands in the Rocky Mountain Region. USGS; Midcontinent Ecology Center, Department of Biology, University of New Mexico. Albuquerque, NM
In 1997 and 1998, we observed over 30 roosts of bats, mostly little brown myotis, M. lucifugus, in structures at Fort Laramie National Historic Site (FOLA), Bents Old Fort National Historic Site (BEOL), Glacier National Park (GLAC), Grand Teton National Park (GRTE), and Yellowstone National Park (YELL). We monitored temperatures in 23 occupied sites and 34 unoccupied sites at BEOL, FOLA, GRTE, and YELL. Almost all bats found roosting in structures at FOLA, GLAC, GRTE, and YELL were adult female or young M. lucifugus. Maternity colonies of little brown myotis varied in size and ranged from 20 to approximately 3,000 individuals. A few big brown bats (Eptesicus fuscus) and Townsend's big-eared bats (Corynorhinus townsendii) were found roosting solitarily at GRTE and FOLA. Small numbers of Yuma Myotis (M. yumanensis) and pallid bats (Antrozous pallidus) roosted at BEOL. In general, maternity colonies of M. lucifugus appear to be selecting roosts on the basis of warm nighttime temperatures and presence of small spaces during both pregnancy and lactation. This seems especially obvious at FOLA, where we have the best comparisons and largest colonies. At the other parks, somewhat more variability exists, although warm nighttime temperatures and small spaces were common to most maternity roosts. Although we cannot predict from our data any absolute minimum, maximum, or range of temperatures that bats might select, our data support the generalization that buildings with small spaces and warm nighttime temperatures are most likely to have bat colonies. Where possible, thought should be given to discreet modifications that might change nighttime temperatures or roosting sites in historic buildings to make them less desirable to bats. Additionally, providing alternative structures with warm nighttime temperatures that bats appear to prefer should be considered.
- Type
- Unpublished Report
- Authors
- Bogan, Michael; Geluso, K
- Date of Issue
- 1999-07-06
- Publisher
- USGS; Midcontinent Ecology Center, Department of Biology, University of New Mexico
- Units
- FOLA , GLAC
- Keywords
- Animal Studies, Bats (Chiroptera), Bents Old Fort National Historic Site, Fort Laramie National Historic Site, Glacier National Park, Mammals, Threatened-Endangered-Sensitive Animals, Yellowstone National Park