The war of emotions between cat lovers and bird watchers, always simmering, has new fuel for its flames. According to the Smithsonian Institute, free-ranging cats, both pet and feral, are the single greatest factor in the decline of songbirds in the United States.
Appearing last week in the British web journal Nature Communications, the Smithsonian study estimates a death median for cats of 2.4 billion songbirds in continental America every year. That finding, coupled with an estimated yearly kill of 12.3 billion small mammals, makes domestic cats by far the greatest human-involved threat to wildlife, far ahead of pollution, habitat destruction, poisoning, climate change, wind farms and collision with buildings.
Most Canadian songbirds over-winter in or migrate through the United States, Mexico and Central America but the Smithsonian cautioned the study should not be randomly applied.
The paper's co-authors are Peter Mara and Scott R. Loss of the Smithsonian, and Tom Will of the Fish and Wildlife Service. They said great care was taken to make the report scientific and impartial.
"When we ran the model, we didn't know what to expect. We were absolutely stunned by the results," said Marra
However, cat protectors, animal rights advocates, songbird guardians and environmentalists have been quick to speak out.
George Fenwick, president of the American Bird Conservancy, said the study gives reputable science to back ABC's claim that cats should be kept indoors. This is disputed by organizations such as Alley Cat Allies whose policy is that scientific data is "manipulated to malign cats and used widely to dredge up a false and counterproductive debate."
In Nova Scotia, the Hope for Wildlife rescue and rehabilitation society posted a media story about the study on Facebook as information for its members but almost immediately removed it after cats' rights advocates attacked them as agents of anti-cat propaganda.
Society director Hope Swinimer said such divisive arguing must end. She suggested that while it is no longer deniable that cats have "a significant impact on wildlife populations", no-one should look on the findings as either a victory or a defeat. Both sides must cooperate to "start taking steps in the same direction to help both wildlife and feral cat populations," she stated.
"It took decades to create these problems and we all need to put steps in place together that over the long term will help both cats and wildlife," Swinimer said.
According to co-author Loss, news media around the world reacted with surprise and contacted the Smithsonian for additional information. A common question, he told The Halifax News, was for a recommended cure, something he and his colleagues were hesitant to offer.
"However, we hope that the large amount of wildlife mortality indicated by our research convinces some cat-owners to keep their cats indoors, and also that it alerts policy makers, wildlife managers, and scientists to the large magnitude of wildlife mortality caused by both owned pet cats and un-owned cats," Loss stated.
Ray MacLeod is a freelance outdoors writer. He lives in Waverley.