Outdoor pet cats kill more animals than wild cats do in the same size area

Originally published at: https://boingboing.net/2020/04/30/outdoor-pet-cats-kill-more-ani.html


This is why my cat is an indoor cat, has a catio, and a stroller in which she takes rides around the neighborhood. She would annihilate the local squirrel and bird population (or at least attempt to) if she went outside. Instead she just stays inside and jump scares my dog.


Apparently, every year North American pet cats with outside access kill between ten and thirty billion birds and mammals.

This makes me wonder about the impact of other mammals, and the rate at which those creatures targeted by cats breed. There were only two pet cats seen outside in my old neighborhood. We had increasing numbers of birds and squirrels every year. There were also foxes, snakes, rabbits, chipmunks, and mice. Cats, foxes, and snakes tended to go after the last two - probably because they were already on the ground and easier to catch.

I’m not saying cats should roam around outside. It’s unsafe. However, the figures make me wonder if cats are sometimes blamed for depopulation due to other reasons. The last dead squirrel incident on my block (that wasn’t caused by a car) was caused by a dog. :thinking:


This is why my kitteh is strictly indoors.

Much like @CarlMud, I should probably build a catio… been thinking about getting her a leash, too.


Seems like we’re already dealing with a profoundly impacted ecosystem? There’s no connection between what we have now and what used to be here, so what’s the correct population density for house sparrows, house finches, or rock pigeons in an American suburb?


Other than much needed farm cats, how many people let their cat out doors?

We do have a lot of “trash kitties” around my apt. (So called, as they hang out at the trash areas, mainly.

1 Like

Shouldn’t the areas compared be relative to the size of the cats? I.e. how many creatures does a cougar kill within a radius 50 times the average length of a cougar vs. how many creatures does a domestic short hair kill within a radius 50 times the average length of a domestic short hair?

1 Like

We had a house a few doors down that had five or six outdoor cats. Our neighborhood is basically a lush mini jungle but we did not realise to what extent until they moved out and the cats with them. All of the sudden we started seing big changes. Within a year, we were seeing a plethora of species we had never seen before. Tons of lizard species, garder snakes, robins, bluejays, wood peckers, opossums, squirrels, and many finches.


It’s not just currently owned pet cats that are let outdoors (I have neighbours who let their two cats out, although they are excellent ratters, they also kill birds), it’s also the abandoned and stray cats, particularly the unspayed un-neutered cats that go on to proliferate. The trash kitties around your place are most likely mostly abandoned, strays or ferals.


Yes. I know people feed them. I think the apt. complex at least traps and spays/neuters them. I assume it is to help keep the mice population down.


every year North American pet cats with outside access kill between ten and thirty billion birds and mammals

For what it’s worth, I’m sure the arthropod death toll is up there too. The other day I noticed that my two tabbies (who are indoor-only cats) were in full-alert, tag-team hunting mode, intent on something under the coffee table. “They’ve cornered a house centipede”, I immediately thought. I switched on the flashlight and checked. Sure enough.

(I scooped it into a plastic cup and put it in the back yard. I’ve told them that house centipedes are our friends and fellow predators, but they pretend not to understand.)


Yeah, TNR is probably the best humane solution for ferals that can’t be adopted. And around trash, as you say, they are likely doing something to keep the vermin down. It sounds like it’s a managed feral colony if they are being spayed/neutered and someone is feeding them. The ultimate hope is that the colony will reduce in size if they are not breeding.


I think it’s more an issue of territories. Even a bobcat has a much, much larger territory than a typical domestic cat.


(baby talk voice)

"Who’s a cute little murderer? You are, yes you are, yes, yes, awwwwww . . . . "

(scratching behind ears, rubbing belly.)


Obligatory xkcd^H^H^H^H theoatmeal cartoon: https://theoatmeal.com/comics/cats_actually_kill


Bobcats and cougars are distant relatives though. Comparisons should ideally be made with the African Wildcat (Felis Lybica) and the European Wildcat (Felis Sylvestris), the domestic cat’s two closest relatives.


Delightful creatures?

1 Like

Not that distant (even if African wildcats are the primary ancestors of domestics) – bobcats can even interbreed with domestics. Like the case of wolves and coyotes interbreeding with each other and domestic dogs, it’s a reminder that the species concept isn’t defined as ability to interbreed (as in a common misconception), but whether they commonly do.


kill all the rats!


I wasn’t thinking about breeding and focusing on behavior.

Cats diverged from Felis Lybica just 10,000 years ago, they are basically the same species (Although some conservationists object to that kind of thinking), but the bobcats diverged from the ancestor of Felis Lybica at least 2.5 Million years ago. That is like comparing modern humans to the first city dwellers and Australopithecus respectively.