Movements and Activity Budgets of Caribou Near Oil Drilling Sites in the Sagavanirktok River Floodplain, Alaska

Abstract

Movements and activity patterns were compared for caribou (Rangifer tarandus granti) near two active drilling sites on the periphery of the Prudhoe Bay oilfield and for caribou from a control site. Caribou on the experimental and control sites had similar movement rates and activity budgets, but many localized responses to the roads, pipelines, vehicle traffic, and other structures and activities were observed. Insect harassment had an appreciable effect on caribou movements and activity budgets. Groups harassed by insects moved approximately twice as fast and spent at least 50% less time lying and feeding than did unharassed groups. Of the 99 groups that approached a road, pipeline, and/or drill site, 70.7% crossed directly, 19.2% detoured around the drill site, and 10.1% reversed direction and left the study area. No evidence was found that caribou cows and calves were avoiding the area because of drilling operations.

Key words: caribou, Rangifer tarandus granti, movements, disturbance, insect harassment, Prudhoe Bay, petroleum development