• Version
• Download 10
• File Size 206.92 KB
• Create Date 1 January 2001
• Download

The number of brown bears (Ursus arctos) in the southeastern Italian Alps increased during the past decade due to the expansion of the Slovenian brown bear population, which is recolonizing the Julian and Carnic Alps. Overall, the habitat in these areas is still very good quality and suitable as permanent range for bears. However, the traffic system and human settlements form a massive artificial barrier and hinder recolonization of the Alps by brown bears. To quantify and categorize existing wildlife passages, we examined the freeway, main road and railway line for 76 km from Gemona to the Austrian border and recorded all walls higher than 3 m, fences along freeways, all measures against rockfalls and avalanches, cliffs with slopes >75°, human settlements, and open landscapes >300 m without any forest or scrub cover along the roads and railway line on a 1:5,000 map. We classified 21 corridors averaging 200 m (SE = 193 m) as high quality passages (total length = 4.2 km). Poor quality corridors, where bears are forced to cross roads or the railway line, and potential corridors had lengths of 9.2 and 14.6 km, respectively. We recommend that high priority be given to conserving and ameliorating the few existing corridors. The southeastern Alps act as a bottleneck between the Dinarids-Balkan and the Alps. The few remaining high quality wildlife corridors in this study area are a bottleneck within the bottleneck. The permeability of the southeastern Italian Alps is of crucial importance for the recolonization of the Alps by brown bears and other large mammals.