Cross-posted from FLAP Canada, originally written by Dr. Krista De Groot — a Landbird Biologist and the BC Breeding Bird Survey Coordinator with Canadian Wildlife Service, Environment and Climate Change Canada.
High collision mortality was documented during winter and migration spurs conservation action at the University of British Columbia.
We recorded 152 collision deaths at our 8 study buildings across 225 days of standardized surveys. However, after applying correction factors for carcasses missed due to carcass removal by scavengers (and people), and for searcher error, we estimated that 281-486 collision fatalities occurred at these buildings during the same period. Given that there are 224 similarly-sized buildings on campus, annual mortality may be as high as 10,000 birds/year at UBC. We also found that even after accounting for their abundance on campus, Varied Thrushes were 77 times and Spotted Towhee were 58 times more likely to collide with buildings, compared to average species. These western North American species are new to the list of species most vulnerable to collision mortality.
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