a new study, by some migratory bird experts at the Smithsonian, estimating that cats kill 1.4 to 3.7 billions birds in the US every year, and 6.9 to 20.7 billion mammals. Most of the killing is not done by house pets, but by stray or feral animals.
Scary numbers, if they are anywhere near correct.
But I have to wonder: what impact does this have? My neighborhood is full of birds. Leaffall every year reveals at least three new nests in just my yard. I find it hard to imagine that any more robins or mockingbirds could live on my block, even if all the predators disappeared overnight. Has anybody noticed a major decline in the songbirds of exurbia, or the pigeons of our cities? What is the natural songbird population for a wooded suburb, and does the concept have any meaning?
The real concern, I guess, would be if cats prey preferentially on rare birds that we are trying to preserve -- bluebirds, or red cockaded woodpeckers, or some such -- thereby encouraging starlings, song sparrows, and robins to spread even more. But I haven't seen any such claims. The researchers do say that cats prefer native chipmunks to invasive brown rats, which is hardly surprising given that a brown rat is about 20 percent of a cat's mass, and fierce.
Is there some impact on other predators? Are cats out-competing falcons or foxes or weasels?
Or is it just that bird fanciers hate cats and cat people, and since they can't live out their fantasies of poisoning all the cats in the country, they produce these studies instead?