By Matt Miller, senior science writer
Does the loss of bird populations begin with a meow?
When most conservationists think about the biggest human-caused threats to native birds, they list things like oil spills, habitat destruction, invasive species, climate change, collisions with windows, pesticides and wind turbines.
But those threats, serious as they are, pale in comparison to what may be the number one killer of wild birds: Cats.
That’s right. Your beloved Tabby could be a wildlife destroying machine, a genuine conservation threat.
That’s what researchers suggest in a recent paper published in the journal Nature Communications. They found that free-ranging cats killed between 1.4–3.7 billion birds and 6.9–20.7 billion mammals annually in the United States.
That research has been widely publicized by birders, and widely ignored by everyone else. Especially cat lovers.
Researchers Scott R. Loss and Peter Marra of the Smithsonian’s Migratory Bird Center and Tom Will of the U.S. Fish and Wildlife Service Division of Migratory Birds suggest that feral cats (those not owned by someone) kill the majority of birds.
But still, a simple way to save the local fauna is to keep your Siamese or Manx indoors, or on a leash.
Bird Versus Cat. Bird Lover Versus Cat Lover.
The researchers hope their findings lead to solutions for free-roaming cat management. But maybe they shouldn’t be too optimistic.
Conservationists and outdoor enthusiasts have a special fondness for birds. We put up backyard feeders. We list them, we count them for citizen science projects, we marvel at their migrations.
The problem is, it would appear most people love cats even more. (And the native voles, shrews and chipmunks that cats gobble by the billions? They lack a fan base, even though they’re vital parts of the ecosystem).
According to the study, the United States is home to 84 million owned cats and another 30 – 80 million unowned cats (which includes truly feral felines and those living in fed but free-roaming colonies).
As environmental writer Ted Williams claimed in Audubon, “The political power of wildlife advocates is dwarfed by that of the feral cat lobby. Last year, for example, it squashed federal legislation to remove exotic species from national wildlife refuges because feral cats might be among them.”
People love their pets, of course, and it’s quite possible to own a cat and not decimate the local songbird population.
More problematic is that many people now feel similar affection for feral cats.
There are many clubs and advocacy groups — with clever names like Alley Cat Allies — devoted to feeding colonies of feral cats, which essentially bolsters the population. Like other predators, cats will hunt and kill even if they’re not hungry—it’s their biological imperative.
To be fair, some of these stray cat activists promote programs where feral cats are trapped, neutered and returned. In theory, this would reduce the cat population over time.
In practice, there is no evidence this works. On the contrary, colonies of cats encourage people to release their unwanted pets at the feeding sites, and the overall population continues to climb.
Other cat lovers claim that cats have just replaced other predators that can’t coexist with humans in their suburbs and cities. I understand that point of view. But free-roaming cats are subsidized with food and shelter from humans, so they exist at much higher densities than other predators.
Save the Birds, Control Your Pet
As with most conservation issues, this one is about values as much as science. Some people see cats, including free-roaming ones, as an important part of their local fauna.
Others observe them stalking birds at their bird feeder and have a visceral negative reaction—as I did, when a cat interrupted my recent participation in the Great Backyard Bird Count.
I understand the devotion people feel for their pets, and for cats in general. But I come down on the side of the birds (and the voles and shrews). It’s time to start having hard discussions about managing feral cats.
In the meantime, you can make an immediate difference for bird conservation. It does not involve politically difficult and expensive solutions, like addressing energy development or sprawl.
You simply have to control your cat. It’s a scientifically valid conservation action that you can take today—and know that you’re saving countless songbirds and small mammals.
Opinions expressed on Cool Green Science and in any corresponding comments are the personal opinions of the original authors and do not necessarily reflect the views of The Nature Conservancy.