Renar och klövvilt på järnvägar : en studie i järnvägars effekter på ren, älg och rådjur i norra och mellersta Sverige under 2005

Abstract: Roads and railroads have significant impact on the surrounding landscape and the wildlife living in it. This study aims to provide an overview of the effects caused by railways to reindeer, roe deer and moose in Sweden in order to make more detailed assessments within this topic in the future. The method used is a study of literature on the subject and a synthesis of databases with information about wildlife mortalities, traffic intensity and fences in the study area; northern and central Sweden. The databases were used to compile digital maps using ArcGIS. Infrastructure brings change to the surrounding landscape and its function as habitat for wildlife. Railroads cause barrier effects such as fragmentation, wildlife mortality, loss of habitat and loss of connectivity. Wildlife mortality affects the strength of a population of animals, in the worst case causing the extinction of an entire species within an area. Railroads have different effects on wildlife mortality, depending on traffic intensity. Medium intense traffic causes the largest amounts of railroad killed animals. The Swedish Railroad Administration has tried different methods for minimizing wildlife mortality on railroads, with different results, fencing being the most effective way of keeping animals out of railway area. Wildlife fencing, in order to avoid accidents with reindeers has decreased the numbers of reindeers killed by railway traffic, although inadequate fences have opposite effects and pose as a trap for animals. During the study period reindeer were the animals with the highest mortality. Railroads in the part of the study area where reindeer live are the only ones that are to some extent surrounded by wildlife fences. The railroads in those areas were amongst the most lethal railroads in the study area. Train traffic on these railroads was medium high. Railroads with low intensity of traffic had little wildlife mortalities. High intensity traffic railroads did also have little wildlife mortalities. The study shows that railroads are far more dangerous for moose, than roads are, measured by the number of killed animals per kilometre. The effects caused by railroads on wildlife have to be thoroughly assessed and the results from this study could be used as a springboard for further studies.