Domestic cats pose a major threat to birds

Betty Firth’s column on dogs and cats states the obvious: golden retrievers have more cognitive capacity than do cats (full disclosure: I’ve lived with golden retrievers all my life). She then wades into the even more fraught issue of cats killing birds, citing the opinion of “internationally recognized cat and dog researcher” John Bradshaw that “in all likelihood, your house cat is probably a clumsy and inefficient hunter” because they aren’t “born in the wild and taught to hunt by their mothers in their first two months of life.”

Don’t believe it. First off, Mr. Bradshaw is expert only when it comes to cat-human interactions (“Anthrozoology,” as he calls it), not cat-wildlife interactions. If he were, he would know about the damning literature on mortality of birds caused by both feral and domestic cats. The best paper on the subject, “The impact of free-ranging domestic cats on wildlife of the United States” was published in Nature Communications in 2013. The authors did a data-driven, systematic review of studies of predation rates of feral and domestic cats, and estimated the magnitude of bird mortality caused by all cats. Their conservative estimate: Cats kill between 1.3 and 4.0 billion birds each year across the contiguous United States. While the majority of this carnage was caused by feral cats, domestic cats were thought responsible for between 400 million to 1.25 billion of those bird deaths. That means domestic cats rival or surpass all the other direct sources of human-caused mortality, including collisions with windows, buildings, communication towers, vehicles, wind generators and pesticide poisoning. A study in Canada reached a similar conclusion.

I didn’t have to go any further than my living room easy chair to see evidence of this. On occasion I’ve spotted neighbors’ cats stalking birds at my bird feeders, and often see their tracks in the snow there. Once, while watching evening grosbeaks on the feeder out the window, I witnessed a neighbor’s cat suddenly rocket into view from under the feeder, its paw stretched overhead ala LeBron James going in for a dunk, except in this case the cat deftly swiped a grosbeak off the rim of the feeder before dropping back out of sight.

Responsible cat owners who have made the decision to keep their cats indoors shouldn’t be fooled by Mr. Bradshaw’s poorly-informed opinion about the impacts domestic cats have on bird populations (and other animals, including small mammals, reptiles and amphibians, which could fill another letter). Keep on keeping your cat indoors. For those interested in more information, check out the American Bird Conservancy’s website under, appropriately, the “threats” link.

Steve Wilson

Tower