Estimated number of birds killed by cats in Canada

Blancher estimated the annual mortality of birds caused by cats in Canada, applying methods similar to large-scale predation assessments elsewhere. By combining figures on the numbers of pet and feral cats, the proportion that hunt, and per-cat predation rates drawn from available studies, the analysis estimated that cats kill on the order of one to several hundred million birds in Canada each year, with feral and stray cats accounting for a large fraction. The work identified cats as among the largest human-related sources of bird mortality in the country and discussed the considerable uncertainty in the estimates, particularly around feral cat numbers and predation rates. It contributed to a growing body of national-scale assessments quantifying the conservation impact of free-ranging cats on bird populations.