The effects of traffic on large carnivore populations in Croatia

Abstract

Abstract Roads and railways are causing habitat fragmentation, disturbance and direct mortality to all three species of large carnivores in Croatia. As traffic is becoming faster, quieter and denser, and the number of traffic routes is increasing, so traffic kills are on the increase. Traffic related mortality in Croatia involved brown bear Ursus arctos, Eurasian lynx Lynx lynx, and grey wolf Canis lupus. During the period 1986-94, 19% (42 of 217) of the total brown bear mortality was caused by traffic (as compared with 11% until 1985); 6.6% (10 of 151) of total Eurasian lynx mortality during the period 1978-95 was due to traffic, and 3.6% (20 of 560) of total grey wolf mortality since 1945 resulted from traffic accidents. Large carnivores in the first year of their life were found to be significantly more vulnerable to such accidents than older individuals, relative to their share in the population (wolves p<0.05, X 2 = 9.64; bears p<0.05, X 2 = 5.52; and lynxes p<0.1, X 2 = 2.91). The main habitat corridor for all three large carnivore species in Croatia was found to be in the central part of Gorski kotar, which is bisected by major road and rail traffic routes. On the new highway, which is under construction through the area, there will be numerous under- and overpasses, and several green bridges were proposed in order to reduce the impact of traffic on wild animal populations. Key words: Croatia, traffic kills, grey wolf, Canis lupus, European brown bear, Ursus arctos, Eurasian lynx, Lynx lynx