Caribou distribution near an oilfield road on Alaska's North Slope, 1978–2001

Abstract

Abstract Previous research in the Milne Point oilfield in northern Alaska showed that the density of caribou (Rangifer tarandus) in the calving period within 1 km of a road was significantly lower after construction than before construction of the road. This was interpreted as displacement from the road and a functional loss of habitat and has been extensively cited as a documented effect of oilfield development on caribou. We continued this study with additional aerial surveys flown during 1991–2001 and compared caribou numbers and density in 6 1-km intervals from the road over 3 time periods: pre-road construction (1978–1981), early post-road construction (1982–1987), and recent post-road construction (1991–2001). During the recent post-road period, the densities of calves and of all caribou were not significantly lower within 1 km of the road than the densities in the pre-road period. In addition, calf density was higher in the interval within 1 km of the road than in the intervals 1–6 km from the road...