Identification of bird collision hotspots along transmission power lines in Alberta: an expert-based geographic information system (GIS) approach

Bird collisions with electrical transmission lines are a cause of avian mortality. The exact magnitude of the problem is not known because most avian mortality goes undetected; however, existing mortality estimates make this phenomenon a significant ecological, social and economic concern. Electric utility companies operate thousands of kilometres of transmission line, making it difficult and costly to identify problem sites and prioritize areas for mitigation. Existing research suggests that mortality is not evenly distributed, but spatially clustered in areas with particular combinations of environmental and physical attributes. We used a combination of a geographic information system (GIS) and multiple criteria evaluation (MCE) to predict collision risk hotspots at a landscape scale. Model predictions were validated through preliminary field sampling, which yielded strong evidence that this approach can successfully predict high-risk collision zones. Our spatial approach was a novel application of risk theory within GIS, was transparent, can be easily replicated, and is transferable to other areas with similar problems.