Creel, S., J. E. Fox, A. R. Hardy, J. Sands, B. Garrot, and R. O. Peterson. 2002. Snowmobile activity and glucocorticoid stress responses in wolves and elk. Conservation Biology 16(3):809-14.http://www.montana.edu/wwwbi/staff/creel/snomoGC.pdf
RELEVANT TO: ROADS/OFF-ROAD VEHICLES
WILDLIFE
MONITORING/ADAPTIVE MANAGEMENT
DESCRIPTION
This article discusses stress responses from snowmobile and wheeled vehicle activity as measured in fecal glucocorticoid levels in elk in Yellowstone National Park; and from snowmobiles in wolves in Yellowstone, Voyageurs, and Isle Royale National Parks. No hunting occurs in these parks
MAJOR FINDINGS
For wolves, fecal glucocorticoid levels were higher in areas and times of heavy snowmobile use; and for elk glucocorticoid concentrations were higher in response to snowmobiles than to wheeled vehicles.
Immunoassays of fecal glucocorticoid levels provide a sensitive and noninvasive method of measuring the physiological stress responses of wildlife to disturbances.
For wolves glucocorticoid levels were higher in areas and times of heavy snowmobile use.
For elk, day-to-day variation in glucocorticoid levels paralleled variation in the number of snowmobiles after they controlled for the effects of weather and age.
Also for elk, glucocorticoid concentrations were higher in response to snowmobiles than to wheeled vehicles after they controlled for the effects of age, weather, and number of vehicles.
The stress-hormone levels correlate with snowmobile usage on both short (daily) and long (annual) time scales.
Even with these stress responses, there was no evidence that current levels of snowmobile activity are affecting the population dynamics of either species in these national park study locations. The authors note, however, " A large body of research on captive mammals and humans shows that large, prolonged GC elevations typically reduce survival and reproduction (p. 813: Munck et al. 1984; Sapolsky 1992)). Although data on fitness effects of GC elevations in the wild are currently limited, the clear expectation from lab studies is that fitness effects will increase as a stressor becomes more severe or more prolonged " (p. 813).
QUESTIONS RAISED FOR THE THREE FORESTS
- Have any studies been conducted regarding wildlife/motorized recreation on the Forest?
- Has monitoring been done or have observations been made?
- If so, are they being used for the planning process?
- Has any explicit consideration been given to cumulative effects of drought, competition with livestock, hunting, and motorized recreation on mule deer, elk, or any other species on the Forest?
RELEVANCE TO FOREST MANAGEMENT
Snowmobile activity must be considered cumulative with other winter stresses on sensitive or declining species of wildlife in the Forest.