Responses of wild reindeer (Rangifer tarandus tarandus) when provoked by a snow-kiter or skier: A model approach

Abstract

We compared reindeer (Rangifer tarandus tarandus) fright responses towards a directly approaching snow-kiter or skier in Norefjell-Reinsjøfjell, Norway during winter in 2006–2007. Fright response distances sampled in the field were significantly longer when approached by a snow-kiter than by a skier. A simulation model predicts a different outcome of daytime disturbances for reindeer from free ranging snow-kiters versus skiers confined to prepared ski trails. The expected number of encounters with reindeer increases linearly with increasing number of snow-kiters until it reaches a threshold level and then stabilizes, but the number of snow-kiters reaching a threshold will vary depending on the speed of the kite (252 snow-kiters at 8.8kmh−1 or 96 at 20kmh−1). The relative loss of habitat and daytime feeding for reindeer following encounters with snow-kiters moving randomly within their range increases progressively up to a 100% reduction at 241 or 111 snow-kiters at a speed of 8.8 and 20kmh−1, respectively. Above this number of snow-kiters, reindeer will not feed and have nowhere to escape. Reindeer progressively reduce up to 7.5% of their daytime feeding until the number of skiers reaches 105. Above 105 skiers and as the number of skiers continues to increase, reindeer find refuge away from ski trails and their feeding time increases and returns to a zero percent reduction at 133 skiers or more. Long fright responses by reindeer towards snow-kiters and potentially very negative population consequences necessitate additional information on snow-kiting activities and appropriate management measures in reindeer habitats.