High-voltage power lines near wild reindeer calving areas

Abstract

Within ungulate home ranges, suitable calving areas are of crucial importance for maintaining the reproductive potential of populations. Using GPS telemetry from a unique time series spanning before, during and after the construction of a 420-kV power line, we present results on calving site locations and area use during calving for two wild reindeer Rangifer tarandus tarandus populations (Setesdal West and Setesdal East) in Norway. For both populations, reindeer consistently preferred a core calving area at 4–8 km distance from the new power line in all three periods, indicating little preference of areas near the new power line. A reduction of the use of areas up to 6 km from the new power line during construction in Setesdal West may possibly indicate a disturbance effect. Contrary to our expectation, reindeer area use close to the new power line increased after construction in Setesdal East. Reindeer intensely used areas close to another existing 132 kV power line crossing the core calving area of Setesdal East during all years. However, reindeer area use was reduced up to 2 km from existing parallel 420 and 300 kV power lines located at the periphery of the calving area in Setesdal West, likely because of poor habitat. Our findings indicate that power lines may not be a disturbance causing avoidance effects for wild ungulates, while construction activities can induce a temporary reduction in area use.