"Heliskiing activity has increased in many areas of mountain goat (Oreamnos americanus) range, particularly in British Columbia (B.C.). Current B.C. guidelines recommend that heliskiing activity remains ≥1500 m from mountain goat winter range when the helicopter is visible to animals, and ≥500 m when the helicopter is masked by topography. Whether these guidelines effectively prevent disturbance of mountain goats, however, is unknown. In 2007 - 2010, we examined locations and movements of 11 female mountain goats relative to heliskiing activity. We determined the proximity and frequency of heliskiing activity that animals were exposed to given current guidelines, and through examination of disturbance responses, determined how guidelines could be revised to better mitigate impacts of heliskiing activity. Although adherence to current guidelines eliminated most heliskiing activity that could result in disturbance, incidental helicopter approaches occurred within 1500 m of collared mountain goats with frequencies of exposure up to 1 h ∙ month⁻¹ ∙ animal⁻¹. Animals reacted to helicopters ≤2 km away, and responded equally to visible and non-visible helicopters. Seasonal effects on movement behaviour, however, were not evident, potentially because of the low frequency of helicopter exposure. We recommend that the B.C. guidelines be revised to: 1) establish no-fly areas within 1500 m of goat habitat regardless of visibility; 2) require pre-planning of heliskiing activities to ensure that no-fly areas are effectively avoided; and 3) extend no-fly areas to 2 km where heliskiing frequencies exceed 1 h ∙ month⁻¹ to minimize the cumulative effect of incidental encounters. These guidelines should apply consistently to all helicopter activity."
