Summer 2021

Newsletter Archive


New Paper Alert!

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Developing a correction factor to apply to animal-vehicle collision data for improved road mitigation measures.

Ever wonder how big an issue injury bias is in animal-vehicle collision data? Pretty big it turns out - for every animal carcass reported in traditional road surveys we found an additional 2.8 died away from the road.

Road mitigation to reduce animal-vehicle collisions (AVCs) is usually based on analysis of road survey animal carcass data. This is used to identify road sections with high AVC clusters. Large mammals that are struck and die away from a road are not recorded nor considered in these analyses, reducing our understanding of the number of AVCs and the cost–benefit of road mitigation measures.

We designed an approach in Canadian Rocky Mountains whereby a group of very dedicated citizen scientists reported animal carcasses on walking surveys over a 5-year period. These data were compared with traditional road survey data. We found a correction factor of 2.8 for our region can be applied to road survey data to account for injury bias error in road survey carcass data. A correction factor improves AVC estimate accuracy, improving the identification of sites appropriate for mitigation and cost-benefit analyses of when to invest in road mitigation.