Unlike wild predators or feral cats, domesticated, human-owned cats don't live or die by how much they kill. There's no feedback loop that would prevent them from hunting their prey into extinction. If they over-hunt birds one season and can't catch enough the next, their owners will simply supplement the difference.

It's not even clear to me that birds are a primary food source for domesticated outdoor cats. They might be hunting them just for sport.

Why are you applying human morals to cats?

He's not; cats are notorious for hunting for pleasure. I love cats; I've owned many. They are little killing machines.

How are they?

We might consider it a bad thing to kill for sport, but why is it bad for animals like cats to enjoy hunting and killing other animals? Cats have no such moral restrictions.

No morals were implied or intended. Hunting for sport is unconstrained by population feedback loops.

It’s not about morals. It’s about environmental/ecosystem balance. Parent comment talked about feedback loops and over-hunting.

>It's not even clear to me that birds are a primary food source for domesticated outdoor cats. They might be hunting them just for sport.

This seems like a condemnation of hunting for sport to me.

We must be coming from different places.

I still don't see a condemnation at all. Other than the implication that sport is not constrained by hunger and therefor can have unbounded externalities, which again is not moral, it's a practical observation and concern for bird populations.

Maybe you could pinpoint further which part of the sentence you quoted brings in morality.

Keep your f%@#g cat indoors - or at least in your yard. Cat's don't "deserve" to be outside wandering free and I sure as hell don't need them on my property terrorizing wildlife, tearing up my garden and shitting all over the place.

And no, you're kitty is not a "natural predator" rebalancing anything. It's a pet and as such should be kept under you're control.

Entitled "free roamer" cat owners are the worst - and breaking leash laws in just about every jurisdiction out there. I have zero problems trapping trespassing cats and turning them over to animal control. Not sure why people feel entitled to get a pass on this - it's BS.

Why don’t they deserve to be outside? I disagree with that - I think they do deserve it because it keeps them happier. I find your description of cats (“terrorizing wildlife”, “tearing up my garden”) to be hyperbolic. Domestic cats don’t typically do things like eat through a vegetable garden. As for leash laws - that’s more necessary for dogs because of their potential for aggression and harm to humans. Cats are VERY rarely aggressive, non threatening to almost all humans, and are more likely to run away from humans than say a pit bull.

Your house cat(s) probably don't do much damage.

Something like 2/3rds of domesticated cats are feral.

All told, cats kill > 1 billions birds in North America.

Like this article says, with so many factors and poor data collection, it's hard to quantify everything.

But please do your part. If your cat does go outside, please consider putting a bell on their collar.

Frankly this "they do deserve it because it keeps them happier" reeks of sheer entitlement and disdain for personal property and boundaries. I have had terrible experiences in the past with neighbour cats. And if you don't think cats are aggressive you clearly haven't seen a caterwauling fight mess up the neighbourhood or scratch kids up badly.

Also, many people are allergic to cats. Some of them develop even serious health problems like anaphylaxis. Please restrict your cat strictly to your property.

Wow, you're like the opposition to Peta.

Cats are a smaller problem in New Zealand than is often claimed. The possums and rats are far worse, to the point where NZ is engaging in bio-chemical warfare against them. However the worst thing for birds are not those small mammalian predators humans brought there, but the massive destruction of their livelihood: https://en.wikipedia.org/wiki/Deforestation_in_New_Zealand

Yes, stack rank risks & threats.

Yes, prioritize benefits & ROI.

Yes, cats kill their share of birds.

Yes, keeping cats indoors feels like recycling plastic (pointless).

But I still do it. Because I don't want to be part of the problem.

We make what improvements we can.

It's blame shifting, easier then changing their own consumption behavior, less expensive then spending money on bird feed.