"Should Cats be Culled to Stop Extinctions?"


A BBC article today with this (prob intentionally inflamatory/provocative) title raises interesting questions. Of course, those of you in NZ have been wrestling with this issue for a while.

One side of me looks at the sweet wittle kittycat and thinks “how could they even think of that?” My puttens aren’t an invasive species (or IS as my mother likes to call them)

The other side of me thinks about all the seabirds and many other species that cats and rats and goats etc have threatened or eliminated and I think “go for it!” Just be humane.

This is another article along the same vein - a bit stomach-turning, so be warned.



Where I live dogs are only let outside under supervision, and usually on a leash. It’s probably partly because I live in the city but I think even in the country dogs are usually kept supervised or on their owners’ properties. Dogs are still a big issue around the world, but here the culture has changed for the better.

I think cats should be treated the same way. They shouldn’t be going off their owners’ property, and ideally never outside without supervision. I don’t think the problem will really be “solved” until people do this, because otherwise new cats will keep being added to the populations. And I do think feral cats should be taken out of the wild. Of course, ideally they should be taken and adopted out, but realistically there are a lot more cats out there than households willing to adopt them.
I don’t like that they would have to be killed to deal with the situation, but the problem is so big I can’t imagine any way for us to care for the environment and also have cats in it. They just cause so many problems:

Many people have suggested trapping, neutering, and returning cats to the wild (TNR), but my understanding is that in general research on the method has found that it’s not effective at reducing the population unless it’s done super diligently, because new cats from elsewhere keep joining the population.

Australia is actually trying to do a pretty intense cat cull, although I guess there are questions about how effective it will be: https://phys.org/news/2019-02-feral-cat-cull-million-scientifically.html

Edit: In terms of laws the city of Calgary has the best system I’ve heard of so far. Cats must stay on their owner’s property, and off of their property they can be trapped. Then the owner can retrieve them for a certain period of time before they are put up for adoption.


Agreed - it only takes one pair to create 16 or more kittens in a season, if conditions are good and the kittens from the first batch will be of mating age before the season is over. And while lifespan is shorter in the wild, with the mating urge removed there will be much less fighting, so they may live many years and neutering doesn’t change the instinct and need to hunt.


TNR should actually be more effective than culling from an ecological standpoint. If you just cull the cats, you’re creating a vacuum. A location can only support a limited number of cats, depending on the resources available, and if there’s a gap it’ll be filled with kittens and migrants.

If you turn neuter cats and return them, you can at least avoid creating this vacuum and you buy yourself more time to neuter and spay most of the population, and get a better result in the end.


people get pissed about the issue of being ask to keep their cat indoors, but it’s really annoying to spend so much time restoring our property to native habitat and then have some cat someone else lets roam come on our land and kill our birds! No i am not going to kill the cat as it belongs to one of our neighbors, but i think it’s really crappy behavior by that human. Then again i heard coyotes the other night… for better or for worse the problem may go away.


@sarahduhon I think that is definitely part of the solution, and you make a good point about population pressures. My neighbor kept trapping and relocating squirrels to save his peach tree and couldn’t understand why more squirrels kept showing up lol. I think there is probably a range of solutions that need to be considered, and those for cities are probably different from those for, say, small islands with many endemic species, like New Zealand’s Ulva and Stewart Islands. Island communities may not be able to withstand the hunting pressure for the remaining years of the cats’ lives.

Then there is the example of the goats on Isabela Island, in the Galapagos. They ate everything, including all the endemic wildflowers and all the vegetation that was in reach of the tortoises. One variety has a shell in the front that comes down fairly low, which prevents them from raising their heads very far to feed. The goats were basically starving them out. Now, goats aren’t as cute as cats (others may disagree lol), but a lot cuter than rats (hey, personal opinion!), and the Ecuadorean government (administers Galapagos) looked at all the many IS control programs, and came to the conclusion that the only approach that had a hope of saving the tortoises and restoring the flora was to kill the goats. There were some 250K of them, depending on whose numbers you believe. It was ugly, but it worked.


Oh @charlie! How could you?!! Lol. Just kidding. Well, mostly! I am one of those awful people who lets their cats out. Mine are altered, but they are very good hunters. If they would confine it to the mice and voles and other rodentia that come in from the wooded park and have set up in the garage, I wouldn’t mind, but I do hate it when they go after the birds. But… they are 12 years old, and trying to keep them inside at this point… Well, all I can say is I don’t know who would go mad first. When these 2 pass on, I intend to train my next cats to the harness and leash, and keep them inside.

On a related note, I did have an electric fence installed at my old house to keep the cats in. The sales guy thought I was nuts. It worked, but only until one of the cats worked out that if she held her head in a certain way the sensor wouldn’t pick up the signal from the fence, and she’d just sashay over the perimeter.

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well, i just don’t see why my hard work to restore habitat should be destructive recreation for someone’s cat rather than what it is intended to be. They don’t act like ecosystem members since they are trained to kill as much as possible. If you can somehow keep the cat on your land that’s fine, and i don’t have a problem with farm cats controlling mice in a barn (better than rat poison) but they need to stay off mine. Again i don’t hurt the cats i see but i absolutely yell and haze and chase them off. The neighbors probably also think i’m nuts.


I do know people who shoot cats that come onto their land, so, well, be careful.


The following links may be disturbing because of the graphic nature of the photographs so please consider this before clicking.

I’ll share this regarding TNR:

I would also recommend this about disease, especially Toxoplasmosis:

And specific to birds:

This is a U.S. based conservancy group for those unfamiliar. For anyone not familiar with the subject there are many citations and links to resources on their site. Apologies for the U.S.centricity.

I am completely opposed to TNR for many reasons. I would support culling but I think widespread implementation of strict and enforced laws and the trapping, without releasing, of feral populations would be an ideal first step that might be better publicly received. I’ll leave it at that for now.


yeah from most of what i know, TNR doesn’t really work. I’m sure there are exceptions, but there are a lot of varied issues with it too.


and fishers, and GH owls oh my!


I’m NZ, and have always maintained we should have live trapping and put collars on them with loud noisy bells… If there is an owner feeding them, they will live, but if they are reliant on catching birds for food, then they will likely starve. If this could be done through local council etc, and they charge a fee/fine to owners that haven’t bell-collared their cats, that would be even better!

While I love cats, and have 5 of my own that do not leave the house, the problem with ferals is that they are destroying far more than bird populations. Hawaiian Monk seals are being effected by Toxoplasmosis from cat dropping that get into the ocean due to rainwater runoff. I love cats but there are way too many wild cats and if this is the only way to protect other species I am not opposed.


My understanding is that cats can generally figure out a way to walk that doesn’t set the bells off. Although I guess some effort could be put into designing a better bell…
Some people use bright flashy collars which apparently do reduce kills, but that’s only for prey with good colour vision that are able to see the cat beforehand.

None of the proposed collars, bells etc. deal with the larger issues of environmental destruction as they are geared to “prevent kills.” Birds’ behavior changes when predators are in the area. They may be less successful nesting because instead of finding food they’re guarding nests or watching out endlessly for cats (and dogs have the same effect!) and may not even nest in areas that have been successful in the past. Even without death they are impacted and their behaviors change. These items are to me just a way for humans to feel better about the destruction they could personally prevent. I’m horrified when the people doing this are scientists but maybe I need to stop assuming they would somehow have higher standards for their own personal behaviors.

If you need your cat to go outside to feel better somehow, build an outdoor exclosure with chicken wire and netting that prevents bird entry. The cats can play without wanton unnecessary destruction and disease spreading.

Other thoughts: Having cats outdoors is often terrible for the cat’s health as far as diseases that couldn’t otherwise be contracted if they had been kept indoors. Also, they may be attacked and suffer greatly at the paws/claws of other cats, dogs, and all manner of wildlife. Picture a society where pet and feral dogs are free to roam around without rabies vaccinations, defecating in your garden, near your well source, terrifying animals and humans and causing traumatic road hit situations with cars, while killing and heavily impacting the behavior of native (and sometimes seriously threatened) wildlife. Would you be okay with this taking place in your yard?

This is me treading lightly and trying to keep my emotions in check. I have very strong feelings about this issue. As someone with plenty of health issues the thought that a neighbor’s choices could sicken me or destroy my property makes me just as irate as if they were intentionally dumping toxins in my water and I believe it should be dealt with similarly.


Everyone states TNR does not work but at least it has worked in some areas and been shown to be beneficial elsewhere whereas culling has been shown to have no effect or have the opposite and create a short term spike in cats before returning to levels previous. Studies on both sides are scewed (and abc birds certainly has their own agenda) but the one study I did find to be actually scientific methods showed the short term spike followed by a return to previous levels. More true studies are needed but it is a fact euthanasia does not work.

It’s a human issue. Humans need to be educated and change their ways.

Fear mongering about disease is inappropriate. Studies show that disease, including Toxoplasmosis is just as prevalent in indoor cats vs ferals.

I do not think a discussion on this topic is at all useful or even appropriate for the forums. It only leads to strong opinions and disagreements.


euthanasia works if you get all the animals you are trying to euthanize though. It doesn’t make sense that TNR would work better because you just leave the cats there longer, and actually do neuter most of them, the same thing happens,just 5-10 years later - the population crashes of those cats but other ones come in anyway. Right? TNR is a feel-good ‘solution’ but the bottom line is, dead cats don’t eat wildlife. You may choose not to kill the cats because you value them more than the wildlife. That’s a fine opinion to have, but i don’t think painting it otherwise makes sense.

And… some of us with immune issues or whatever, choose NOT to have cats? And we don’t have that choice if other people’s cats are pooping in our garden?

I don’t think this discussion is inherently inappropriate unless people get personal about it… that being said, it’s fine to ignore the posts. Maybe there is a way to mute them?


I am very fond of cats, and fond of all animals, but on small isolated islands which are home to numerous rare species that are directly or indirectly being wiped out by the cats, I say absolutely the cats should be eliminated, even by culling. We can’t afford to lose more species to extinction because of irresponsible releases of pets that have become feral. And an island overburdened with the maximum possible population of feral cats is also not pretty sight, and is ultimately is no good for the cats either.


If think the reason why there is so much debate on this particular topic is because the subjects that would be killed are cats. Most humans really like cats, and there are a lot of interesting studies focused on why. But this is an explicit bias. If the article was on goats, rats, or yellow crazy ants, I don’t think people would be as upset about it.