Domestic Cats Take Biggest Bite out of Wildlife

In the report, published in Nature Communications, scientists estimate that cats, especially strays and feral cats, kill 1.4–3.7 billion birds and 6.9–20.7 billion mammals in the U.S. every year, numbers that are two to four times previous estimates and higher than for any other human threat, including poisoning or collisions with automobiles, buildings, or wind turbines (the study did not consider the threat to birds and mammals from anthropogenic climate change). Most of the species killed are native, such as shrews and voles, rather than introduced species like the Norway rat.

Most of the killing (71% of birds and 89% of mammals) is attributed to the country’s 80 million stray and feral cats. What to do about feral cat populations can be a source of friction between environmentalists and animal-welfare activists, but all sides agree it highlights the necessity of spaying and neutering pets.