Impact Mitigation Analysis of Helicopters on Mountain Goats in British Columbia

The winter range of mountain goat (Oreamnos americanus) and helicopter-assisted backcountry recreation activities often occur in the same mountainous regions of British Columbia, Canada. Mountain goats have been identified as a provincially yellow-listed species of concern that are sensitive to helicopter disturbance. Cascade Environmental Resource Group Ltd. was contracted by Coast Range Heliskiing Ltd. to develop methodology for determining helicopter flight paths within its commercial recreation tenure, which eliminate visual and drastically minimize auditory disturbance to potential mountain goat populations. This poster illustrates the various stages of the analysis performed to reach that objective.

Critical winter range for the mountain goats within the commercial recreation tenure area was identified and populated with randomly generated points representing mountain goats throughout the range at a density of one per hectare. Attributes were added to each point to include a stationary rotation point, a radial distance for analysis of two kilometers (in accordance with government recommendations), a vertical offset to account for the standing height of a mountain goat, and a second vertical offset to account for flying height of helicopters above ridge lines. A viewshed analysis was performed incorporating the above parameters and using a base triangulated irregular network generated from 20-meter contours. Helicopter flight lines, and pickup/drop-off locations were subsequently adjusted to avoid regions visible to potential mountain goat populations. Where logistical flight paths are required within the determined goat viewshed, helicopters are required to maintain an elevation of 2,000 meters above the surface.

The study is based on the premise that terrestrial barriers, such as mountain ridges, influence what an individual animal is able to see and hear. This technique could be applied to mitigation strategies for a variety of sensitive species in land management situations in which terrestrial barriers are a factor.