Feral and Free-Ranging Pet Cats Kill Far More Birds in the Continental United States than Previously Believed, Smithsonian Study Finds

February 4, 2013 by Pete Marra

Anthropogenic threats, such as collisions with man-made structures, vehicles, poisoning and predation by domestic pets, combine to kill billions of wildlife annually. Free-ranging domestic cats have been introduced globally and have contributed to multiple wildlife extinctions on islands. The magnitude of mortality they cause in mainland areas remains speculative, with large-scale estimates based on non-systematic analyses and little consideration of scientific data. Here we conduct a systematic review and quantitatively estimate mortality caused by cats in the United States. We estimate that free-ranging domestic cats kill 1.4–3.7 billion birds and 6.9–20.7 billion mammals annually. Un-owned cats, as opposed to owned pets, cause the majority of this mortality. Our findings suggest that free-ranging cats cause substantially greater wildlife mortality than previously thought and are likely the single greatest source of anthropogenic mortality for US birds and mammals. Scientifically sound conservation and policy intervention is needed to reduce this impact.

This article summarizes the information in this scientific paper:

Scott R. Loss, Tom Will and Peter P. Marra. The impact of free-ranging domestic cats on wildlife of the United States. Nature Communications 4, Article number: 1396 doi:10.1038/ncomms2380

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