WINTERING MOOSE VS. OIL/GAS ACTIVITY IN WESTERN WYOMING

Abstract

We examined possible impacts to wintering moose (Alces alces) resulting from oil and gas related disturbances in western Wyoming. We selected 45 variables to sample repetitively in 34 timber and willow (Salix spp.) stands of similar habitat quality and expected to contain moose but differing in exposure to oil-and-gas related disturbance. Discriminant analysis showed that two variables, number of shrub species and whether the stand was located next to a plowed road, accounted for 79.4% predictability of moose presence or absence. Moose using plowed roads were often forced off by vehicles (forced exits) or left at their leisure (free exits). At free exit sites moose chose significantly fewer steep and more level slopes as compared to random samples. In 80% of the forced exits, moose left the road in areas of significantly shallower snow than the roadside averages. Relative to people on snowshoes or skis and snowmobiles, trucks caused the greatest escape distance, displaced the greatest percentage of moose, and caused the most disturbance to moose. People on snowshoes or skis caused the least impact. Recommendations are given for conducting oil and gas activity in/near moose winter range.