Habitat assessment of a relict brown bear Ursus arctos population in northern Spain Original Research Article

We assess the habitat quality of a small remnant population of Eurasian brown bears Ursus arctos in northern Spain based on a habitat evaluation procedure and analysis of bear distribution and road density. Habitat evaluation was based on our knowledge of bear habitat requirements using a combination of radiolocation and sign data and analysis of four variables (forest cover, elevation, distance to nearest village, distance to nearest roadway). Herein, we use those results to calculate habitat suitability indices for 1 km2 UTM cells over 3500 km2 of bear range, by summing scores (from 0 to 1) for each variable. Roughly 15% of the study area was classified as high-quality bear habitat. In secondary bear range (sporadic presence) the average unpaved road density was more than twice as high compared to that in primary, year-round, range, and was highest in areas outside of the bear range. The applicability of our habitat evaluation procedure to other small remnant Eurasian bear populations is proposed.