House Cats: the Most Damaging "Alien Animal Species"

I hesitate to report on this subject with any frequency due to the extreme polarization of modern society. It’s worse than Democrats vs. Republicans. It’s worse than Bears fans against Packer fans. It’s almost as bad as Mars and Venus a.k.a. men vs. women. Some say it’s the difference between cat people and dog people but I don’t think that’s accurate. Dog people aren’t vindictive enough to be anti-cat and some dog people are also pro cats. It’s more as though there are cat people and anti-cat people.

The point is, cat people and anti-cat people never see eye to eye about cats and don’t much get along with one another in general about other issues. They don’t trust one another and when one side or the other comes up with an argument for or against cats, the other side is skeptical, at best, often defensive and is likely to become offensive before long.

Personally, I’m a dog person but I try to get along with both groups. Luckily, there are enough subjects in the outdoor world about which to editorialize each week, it’s easy to ignore the issues wrought by domestic cats.

Sometimes, however, I feel duty bound to bring up the touchy subject. Just as it’s my duty to once in a while cover ice fishing safety or the importance of winterizing boat engines; now, at risk of incurring the everlasting wrath of my cat-person readers, I must report.

A recent paper released by the National Academy of Sciences revealed invasive mammalian predators are killing endangered species around the world at much higher rates than previously known and are arguably the most damaging group of alien animal species for global biodiversity.

In case the term “invasive mammalian predators” has you wondering, remember this. Few segments of society are more careful of sensitive wording than researchers. Sensitive wording is a euphemism for “politically correct wording.” In their reports, cats are usually referred to as “non-native predators.” I suppose non-native predators could include feral European hedgehogs, Asian mongooses and a few other species; realistically, the research was about cats. Feral and free-roaming cats are not often specifically mentioned for fear of losing funding from cat people donors.

Here’s what the recent NAS findings concluded.

Non-native mammalian predators (cats) have caused the extinction of 87 bird, 45 mammal, and 10 reptile species and have helped put another 596 species at risk of extinction, according to the study by Dr. Tim S. Doherty and colleagues. The researchers estimated this to be double the number of extinctions previously attributed to non-native predators (cats).

On behalf of the cats, it’s not as though they seek out rare species to mow down like a linebacker seeks out ball carriers. Cats are equal opportunity predators and might just be in the right place at the right time to further impact populations already suffering from habitat loss or other negative factors.

Most extinctions are not linked to cat predation, writes Doherty. Cats-gone-wild are only linked to 44 percent of modern bird, mammal, and reptile extinctions. The other 56 percent manage to die out without the encumbrance of being killed off by cats. Still, in my mind, 44 percent is significant number. If it was only one or two percent, non-native mammalian predation would be much more a non-issue.

This study confirms, yet again, just how dramatic the impact a feral and free roaming cat will have on bird and other wildlife populations. Not only does it confirm, it’s striking evidence the problem is even greater than previously recognized.

The only realistic long-term solution is to contain cats, which simultaneously protects the cats and wildlife. After all, they are often called house cats.

Cat lovers, no one wants to take away your cats. Most of the non-cat lovers recognize your desire, your need, even your addiction to having the little purr-pets underfoot. Just recognize they aren’t a natural part of the outdoor world. Spay and neuter the ones selected to live with you and keep them indoors where they belong.


Invasive predators and global biodiversity loss