Short-term behavioural responses of Svalbard reindeer Rangifer tarandus platyrhynchus to direct provocation by a snowmobile

Abstract

Short-term behavioural responses of 101 groups of Svalbard reindeer Rangifer tarandus platyrhynchus to direct provocation by a snowmobile were recorded in April (late winter) 1987. The median size of groups was 3·3 animals. The first visible responses of reindeer to an approaching snowmobile usually involved independent behaviour by different individuals in a group. Flight, by contrast, was a co-ordinated group response. Group median response distances were: minimum reaction distance, 640 m; disturbance distance, 410 m; distance at initial flight, 80 m; and distance of flight, 160 m. Group median response times were: total running time, 22 s; total location time, 38 s; maximum duration of disturbance, 193 s. Energy and time budget models indicate that one median flight response can cause an increase in a reindeer's daily energy expenditure of approximately 0·4% and a loss of daily grazing time also of 0·4%. The study failed to detect any way in which the current level of snowmobile traffic might substantially reduce the physical wellbeing of Svalbard reindeer.