Analysis of spatial patterns and factors influencing wildlife roadkills in Korea

Background/Question/Methods Recently, wildlife movement has been interrupted and mortality has increased in Korea because habitat fragmentation increased and conservation areas were isolated by road constructions. The purposes of this study are to investigate how many roadkills happened, which factors influenced it, what kind of spatial patterns showed and to find optimal locations needed some measures for mitigating it. Our study area was 107Km of 3 roads near Jirisan national park which is the largest national park in Korea and Sumjin river which flows along the southern part of Jirisan national park. We had surveyed roadkills between 2004.7.1 to 2007.1.8 everyday using a car and implemented 16 environmental variables such as weather, road type, landuse, vegetation etc. Logistic Regression model was used to know significant factors and to predict the probability of roadkill. K-function and Getis-Ord Gi statistic were used to analyze spatial patterns. We also did spatial analyses by taxon, for some endangered species and for seasonal patterns. Results/Conclusions The number of total mortality by roadkill is 5,695 including 1,792 mammals, 1,329 birds, 970 reptiles, 1,604 amphibians. The number of total species is 97 including 21 mammals, 65 birds, 4 reptiles, 7 amphibians. 16 endangered species of Korea were founded. We built models and analyzed spatial patterns using whole roadkills, by taxon and for a specific endangered species each taxon. These individual species are Leopard cat (Prionalurus bengalensis) for mammal, chinese scops owl (Otus scops) for bird, toad (Bufo bufo) for amphibian, water snake (Natrix tigrina lateralis) for reptile. Landcover, vegetation, road type, existing fences and culverts were significant factors which influenced roadkills. Although roadkills were distributed whole place on roads, the mortality of some taxa such as amphibian happened on road which was located along a river or a stream. We found roadkill hotspots at some areas which were used as eco-corridors by wildlife and where there were few facilities such as fences and underpasses to help wildlife to move cross a road. As the public concerns about roadkill have been increasing in Korea, the government wanted to reduce it and to make some measures for mitigating it. This study showed that we need to investigate the type of roadkill, significant factors and spatial patterns for finding an optimal location needed some measures.