Wild reindeer: impacts of progressive infrastructure development on distribution and range use.

We investigated the distribution of wild reindeer (Rangifer tarandus tarandus) from aerial surveys in 1986–1998 in 622 contiguous 4-km² grid squares in relation to density of power lines, roads and ski trails in the Nordfjella region, south-central Norway. Density of reindeer was significantly lower in developed quadrats compared to undeveloped quadrats and decreased with increasing density of development. No reindeer were observed in areas exceeding 1.3 km/km² of linear structures and only 1.1% of the reindeer were observed in areas exceeding 0.8 km/km² of linear structures, an area constituting 17% of the study area. The results imply that development, and also the degree of development, affect the availability of range for wild reindeer. Furthermore, the results suggest that reindeer may abandon areas once disturbance exceeds a critical level. We conclude that there is a need for cumulative impact assessments of the overall development in Norwegian mountain regions, to preserve the last remaining wild reindeer populations in Europe. [ABSTRACT FROM AUTHOR]