With razor-sharp claws and a penchant for chew toys, backyard and feral cats are serial killers of small mammals and birds, according to a study published Tuesday in the journal Nature Communications.
The study’s figures were apocalyptic: 2.4 billion birds and 12.3 billion small mammals such as mice, voles, squirrels and rabbits are killed every year by U.S. cats, the researchers reported.
Those are just median figures. The study’s bell curves top out at 5 billion and more than 25 billion, respectively, for birds and mammals.
“This study…demonstrates that the issue of cat predation on birds and mammals is an even bigger environmental and ecological threat that we thought,” said Dr. George Fenwick, president of the American Bird Conservancy in Washington, D.C.
Peter Marra and Scott Loss of the Smithsonian Conservation Biology Institute and Tom Will of the U.S. Fish and Wildlife Service’s Division of Migratory Birds crunched numbers from 90 previous studies on cat predation to come up with their findings.
While backyard cats kill their fair share, an estimated 80 million farm cats, strays and feral felines are responsible for 69 percent of bird mortality and 89 percent of mammal mortality, according to the study.
“Despite these harmful effects, policies for management of free-ranging cat populations and regulation of pet ownership behaviors are dictated by animal welfare issues rather than ecological impacts,” Marra and his co-authors concluded.
Alley Cat Allies, a Bethesda, Md.-based feline advocacy group, called the findings “part of the continuing propaganda to vilify feral cats.” President and co-founder Becky Robinson added that the study was “bad science” and “a veiled promotion by bird advocates to ramp up the mass killing of outdoor cats.”
Robinson’s group favors Trap-Neuter-Return (TNR) over euthanasia as the best way to deal with millions of feral cats that roam the country.
“Because of the success of TNR, which stabilizes and then reduces the population, places where there were once large colonies of feral cats have seen those colonies fade away,” Robinson said.
“There is good reason for cities to change from ‘catch and kill’ to ‘neuter and return,’” she added.
The fact that cats like to kill living things is not new.
John Coleman and Stanley Temple, who conducted a four-year study, reported in a 1996 article in Wisconsin Natural Resources magazine that domestic cats killed from 8 million to 219 million birds every year in their state alone.
Alley Cat Allies called the Coleman-Temple study “bad science,” too.