Outdoor cats kill between 1.4 billion and 3.7 billion birds a year, study says – The Washington Post
Outdoor cats are the leading cause of death among both birds and mammals in the United States, according to a new study, killing 1.4 billion to 3.7 billion birds each year.
The mammalian toll is even higher, concluded researchers from the Smithsonian Conservation Biology Institute and the U.S. Fish and Wildlife Service, ranging from 6.9 billion to 20.7 billion annually.
The analysis, published Tuesday in the journal Nature Communications, suggests that feral and owned cats pose a far greater threat than previously thought. One study in 2011 estimated that cats in the United States kill roughly half a billion birds annually.