Cats - mass assassins in the animal world

American cats kill billions of birds and mammals every year, scientists report.

Each domestic cat in America kills 4 to 18 birds each year. ( Photo: photosof.org)

Pete Marra, an ecologist at the Smithsonian Conservation Biology Institute in the United States, and colleagues work out the role of domestic cats in the disappearance of billions of birds and mammals each year. According to their survey results, Americans feed about 84 million cats. In addition to the number of cats living on the streets of about 30 to 80 million, Livescience reported.

After analyzing some previous studies, Marra found that each domestic cat kills 4 to 18 birds and 8 to 21 small mammals (such as mice, chipmunks) each year. Meanwhile, an average cat on the street kills 23 to 46 birds per year, from 129 to 338 mammals.

Thus, cats kill from 1.4 to 3.7 billion birds a year, from 6.9 to 20.7 billion small mammals.

"The number of birds in the United States decreases by 15% every year because of cats," Marra said.

In order to reduce the number of birds and mammals that die from cats, the team should limit the release of cats. However, they have not found a solution for wandering cats.