New study reveals Varied Thrush as a species that is disproportionately vulnerable to window strikes on the west coast of Canada

A new study about bird window collisions out of UBC by Environment Canada biologists Krista DeGroot et al. reveals that Varied Thrushes are the species most often affected by window strikes in the west coast of Canada. This study showed for the first time, that during winter, Varied Thrushes are 77 times more likely to be involved in fatal window strikes.

Collision mortality is extremely high at UBC. More than 10,000 collision deaths occur per year at UBC. It was 4 times higher in the fall than a study done by Hager et al. in 2017 at college campuses across North America. This shows that window collision rates will also be high at homes and at other campuses and buildings in the Vancouver area and along the Pacific Coast.


In contrast to studies conducted elsewhere in North America, collision mortality in winter was as high as mortality during the spring migratory period at UBC.


This has detrimental implications for the large resident and overwintering populations of terrestrial birds in southwestern BC, including the Varied Thrush.

To read this interesting study that was just published by Oxford “Year-round monitoring at a Pacific coastal campus reveals similar winter and spring collision mortality and high vulnerability of the Varied Thrush,” please click HERE

Varied Thrushes are the species most likely to be involved in window strikes - Photo: Melissa Hafting


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