Individual study: Scent-marking, forest clearing and supplemental feeding reduce moose Alces alces–train collisions along the Rørosbanen railway line, southern Norway
Andreassen H.P., Gundersen H. & Storaas T. (2005) The effect of scent-marking, forest clearing, and supplemental feeding on moose-train collisions. Journal of Wildlife Management, 69, 1125-1132
In Norway, there has been a steady increase in moose-train collisions from approximately 50/year in the 1950s up to 1,000/year in early 1990s. One of the worst affected areas is a section of the Rørosbanen railway in the south of the country, where collisions occur mainly during winter. Since 1990, attempts have been made to reduce the number of collisions. In this present study, the effectiveness of forest clearance along the railway line, scent-marking, and feeding stations in reducing the number collisions in winter along a 100 km stretch of the line was assessed.
Study area and data: The study railway line section runs along a valley bottom (surrounded by forested hills) into which moose descend in winter. Winter data (86% of total collisions recorded) were analysed for 18 years (1 July 1985 to 1 April 2003; 1,045 winter collisions analysed).
Treatments: Ten, 500 m sections were treated with scent in 1994-1995 and a further 10 in 1995-1996. Two feeding stations (6 and 8 km long) were established in 1994, and one (4 km long) in 1995. Eight forest clearings (0.9 to 14 km long) were established from 1990 to 2002. In total 31 ‘sites’ were subjected to treatment. Sections where treatments were not applied were used as controls.
Fencing: Fences are effective but application limited because of expense. In 1995 along the line, a 1 km, wire-mesh fence was erected. This eliminated moose collisions (up to April 2003) except for one at a fence end. As this was the only fenced length, and as almost 100% effective, this stretch was excluded from further analyses.
Scent-marking: A commonly used repellant scent 'Duftzaun' (which contains components from brown bear Ursus arctos, wolf Canis lupus, lynx Lynx lynx and humans), was applied along 10, 500 m long sections during the winters of 1994-1995 and 1995-1996 (spraying on trees and bamboo canes at 5 m intervals) during the first days when snow exceeded 20 cm depth. One treatment lasted for 3-4 months.
Forest clearing: Sections were cleared of vegetation higher than 30 cm, thus were devoid of food and cover during winter; they were maintained by cutting each year.
Feeding: Landowners initiated winter feeding in 4 side-valleys used by moose during migration towards the winter lowlands, in an attempt to reduce traffic accidents in the area. The supplemental food comprised baled and silaged graminoids and/or herbs, provided from when the snow accumulated in the hills (usually November) until April-May.
The average number of collisions each winter was 0.58 moose/km. Except for one scent-treated site, the other 30 treatment sestions showed a decrease in the number of accidents (average 46%) compared to controls. Within the treatment sections there were 2.5 times more moose killed/km/year compared to control sections before initiation of treatments. The number of moose killed per km in treatment sections was fairly constant but tended to increase in control sections over the study period.
In cleared areas there was a 49% reduction in collisions, in food supplemented areas a 40% reduction, and in scent-marked areas a 85% reduction. Whilst scent-marking had the highest average effect, it was only applied for short distances in a few years and there was a large variation in effectiveness, thus the beneficial effects observed are questionable. Along some sections combined treatments were applied; sections cleared of forest or supplemented with food were compared with sections with both clearing and supplemental food; this did not reduce the number of collisions significantly compared to areas with only one treatment.
Conclusions: Within the treatment sections there was a reduction in moose collisons (30 out of 31 sites) compared to control sections. Forest clearing and supplemental feeding appeared effective. More trials are needed to assess the effectiveness of scent-marking.
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