Temporal patterns of moose-train collisions in British Columbia - implications for mitigation

Where train tracks bisect moose habitat, trains may collide with moose, impacting the local population and creating a safety concern for rail traffic. Understanding the patterns underlying these collisions, is critical for helping managers choose the right mitigation methods to reduce mortality on railways. Our objective was to analyze the long-term temporal patterns of moose-train collisions. We used data on moose-train collisions from British Columbia (Canada) obtained from Canadian National Railways and British Columbia Rail Corporation. We analysed data from collision events that occurred between 1990 and 2010, excluding 1995-1996 for which there were no data. A total number of days, when moose-train collisions occurred (LD), and a total number of moose killed from collisions (LK) were calculated in annual, seasonal and monthly resolutions. We also investigated distribution of these data for day of the week. We used chi(2) and Mann-Kendall tests to investigate whether LD or LK changed over time and Pearson correlation coefficient to relate these trends to the annual moose harvest in the analysed period. The number of days in which moose-train collisions occurred varied by year and by time of year. LD occurred most often in winter and least often in summer, with the highest number being recorded in February and the lowest in July. There were no significant differences in the number of moose-train collisions on various days of the week. We found no significant trends in LD for seasons, months (except for November) and weekdays for the period under investigation. In general, LK revealed a temporal pattern as LD, however number of killed moose was significantly lower on Fridays and Saturdays comparing to other week days. Because moose-train collision patterns did not change significantly between years, we assume that the temporal patterns exhibited in our study likely hold true from year to year and can be used to inform managers considering mitigation measures aimed at reducing moose-train collisions.