Killer Cats.

What does my cat do when she is outside? Where does she go? My cat would never hurt anyone...

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        Over the world at large (Pimm et al. 2006) and in North America in particular (NABCI 2016), populations of many wild bird species are declining. Humans are responsible for the destruction of an estimated 269 million birds and 2 million nests in Canada annually (Calvert et al. 2013). Among the sources of avian mortality are cats (Felis catus), buildings, electrical power, transportation, harvest, agriculture, forestry, communication, oil and gas, fisheries, and mining (Calvert et al. 2013). Predation by feral and domestic cats and collisions with transmission lines, houses, and vehicles are the leading causes of human-related avian mortality in Canada. Together, these five sources account for greater than 95% of all human-related bird fatalities in the country (Calvert et al. 2013). Cat predation is the most significant human-related source of avian mortality in Canada (Calvert et al. 2013).

        Canadian house cats kill an estimated 100 to 350 million birds annually (Blancher 2013). In effect, approximately 2-7% of birds in southern Canada fall prey to cats each year (Blancher 2013). The potential for cats to significantly reduce bird populations is thus justified and has been evidenced by the implication of house cats in general and feral cats in particular in the extinctions of no less than 33 known bird species (Lever 1994). Vulnerable bird species include those with nesting or foraging life histories on or near the ground (Mead 1982; Dunn and Tessaglia 1994; Coleman and Temple 1996; Lepczyk et al. 2004); those that occur in or near residential areas, or that frequent bird feeders (Dunn and Tessaglia 1994; Coleman and Temple 1996; Lepczyk et al. 2004; Maclean et al. 2008); those that are small relative to a pet cat (Dunn and Tessaglia 1994) or of similar size to a feral cat (Hubbs 1951; Fitzgerald 1988; Paltridge et al. 1997); and those with at-risk populations in Canada (COSEWIC 2012). Feral and other free-ranging cats occur in large numbers in southeastern Ontario as a result of particularly high human population densities (Rosatte et al. 1997; Rosatte et al. 2001). For the local bird populations, the consequences of a flourishing feline population could be devastating.