UNGULATE TRAFFIC COLLISIONS IN EUROPE

The expansion of highways and roads can fragment natural habitats and thus decrease the viability or ungulate subpopulations. It can also in crease the number of vehicle collisions with wildlife. Although collis ions apparently contribute to only a minor part of the annual mortalit y for most ungulate populations, they have become a serious road-safet y problem in Europe, the United States, and Japan. To better understan d this threat to biodiversity and road safety, we reviewed European an d, secondarily, North-American and Japanese literature on ungulate tra ffic collisions. In contrast to the results of some long-term studies, we argue that the relationship suggested between the number of road k ills and traffic volume is confounded by population dynamics, changes in traffic volume, and sampling intensity. Although sexes may run dist inct seasonal risks of collision, the age and sex composition of road kills reflect population structure in the field. We also argue that ob served seasonal and daily patterns in the number of road kills, relate d to life-history features of the species involved, should form the te mplate for solutions to the problem. We found no strong evidence of th e effects of permanent warning signs, 90 degrees light mirrors, scent, or acoustic fencing on the number of kills per crossing. To reduce th e risk of ungulate traffic collisions, we recommend a combination of f encing and wildlife passages for roads and railroads that combine high traffic volume with high speed. For secondary roads we recommend seas onal application of intermittently lighted warning signs, triggered if possible by the ungulates. We emphasize the need for educational prog rams.