Terrain structure and selection of denning areas by arctic foxes on Svalbard

We examined the relationship between the distribution of arctic fox dens and the occurrence of rugged terrain on Svalbard, Norway, using indices of terrain ruggedness (TRI) based on contour characteristics from topographic maps in 240gridcells, each 4km super(2). The distribution of rugged terrain co-varied with occurrence of arctic fox dens. Moderately rugged terrain (TRI=1.5-3.0) constituted only 21% of the total study area, but contained 77% of all natal dens recorded in the study area. Large clusters (8-36km super(2)) of moderately rugged terrain were generally preferred for location of den sites compared to smaller scattered clusters of rugged terrain. The importance of rugged terrain is discussed in relation to snow cover, exposure, soil conditions and distribution of prey species. This simple and non-invasive analysis of terrain ruggedness may be used to predict the distribution of potential arctic fox denning areas across landscapes.