Millions of birds are being killed by outdoor cats by Nicole Mortillaro, CBC News · Posted: Mar 26, 2026
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I’m Nicole Mortillaro, and I am a proud “crazy cat lady.” I have three of the little furry psychos and I love them to death. But I do not let them outside, because I know they can impact the environment — but also because I want to keep them safe. So what exactly is the impact of letting them outside unsupervised? And why do people do it?
Cats are prolific hunters and they are killing a lot of birds
Cats are incredible hunters. They are ambush predators with incredibly flexible spines, sharp claws and insanely sensitive hearing, as well as night vision. They are stealthy and agile. They were made to hunt.
Which is why letting them outside to roam freely poses a danger to the local environment.
I used to live on a street where an outdoor cat was a prolific hunter. Numerous times I saw her trotting away with a bird in her mouth. It was mostly house sparrows from a nearby bush they frequented. I started calling it the “murder bush.”
So I wondered: How many birds do cats kill each year?
First of all, it’s hard to get solid numbers on cats alone, but it’s estimated there are roughly nine million cats in Canada, making them the most popular pet in the country by some accounts.
It’s also difficult to get a good figure of how many birds they kill a year. Some estimate that upwards of 100 million birds in Canada are killed each year by cats. An estimate conducted in 2013 brought that to between 100 million and 350 million.
But a recent study out of the University of Guelph did a new estimate with more recent data than the 2013 one, and it put the number of birds killed by outdoor cats between 19 and 197 million.
Yes, that’s a big margin, but co-author Ryan Norris said that’s because each factor taken into account has its own margin of error, which is just exacerbated as you put them together.
“Coming up with an estimate like that is … let’s say a 20-, 30-step process,” he said. “There’s all a bunch of numbers that go into it.”
But no matter the figure, that’s a lot of birds. And that’s just in Canada.
Norris noted the type of birds killed varies depending on location. In the city, it’s more likely that the cats are catching native species rather than migrating birds, which Norris said is almost preferable.
JFC!!! This is bullshit. Native species are vital and beautiful, and sing too. You are murder and torture enabling douches, Mr. Norris, and CBC. House cats belong in the fucking house!! It’s wrong for them to be allowed outdoors to torture and kill in the most cruel ways possible, even if they only killed native species. Of course they kill more native than not, migratory birds are not here year round. This is gross propaganda that many cat owners will use to justify letting their cats out. Fuckers.
“Cats are keying in on things like breeding birds,” he said. “And, you know, nests are easy to find for cats.”Ya sure, to find, but that’s also bullshit. In my decades of observing cats torture and kill, cats don’t bother going for birds in nests. Young fledglings are extremely susceptible to cat torture, as are adults tending them. Nesting adults are powerful protectors of their nests. Why would cats risk getting their eyes or nose pecked, when they have endless others much easier to access for their torturing?
In places outside of cities, the impact on wildlife can be greater, with cats also hunting smaller mammals, he said. These cats could even be ARE going after endangered or threatened species.Cats are a vicious species, vicious agents of suffering just like humans that own them are. I’ve watched cats torture their victims for hours, often not even killing them at the end (I go put an end to the suffering, if I can). They just walk away to torture another victim to satisfy their greed for causing suffering in others.
He said the people he’s talked to in his various studies who let their cats outdoors have good intentions about the environment, but they don’t realize the impact their cat has on it.There is no way you have good intentions of any kind, if you let your cat(s) out. You have cruelty and selfishness, that’s about it.
The impact on unsupervised cats can be great. Feral cats are even believed to be behind the extinction of animals on several islands. Believed to be? It’s been fucking proven. What is this CBC? Propaganda to feel good about murder by selfish cat owners?
One study estimated that each year, cats kill 1.3 billion to four billion birds and 6.3 billion to 22.3 billion mammals.
Keep house cats in the house! They shouldn’t even be allowed to roam free on farms. Because cats take pleasure in torturing, they don’t stop. I live surrounded by farms, and am myself tortured watching my neighbours’ cats come to my place to torture birds and other creatures. It’s horrific to observe. I love insects, birds, toads, frogs, weasels, etc., nearly daily, I must run out to chase cats away, sometimes 4 or 5 cats a day. There are campgrounds near my place, which are operations of torture and abuse by 1) at the end of the season, many in their massive RVs abandon their cats which is cruelty to those cats, and 2) those cats come to my place, to torture other species.
Human over population and greed is destroying life on earth, and humans have too many cats.
A 2017 study by Humane Canada, the national federation of Society for the Prevention of Cruelty to Animals and humane societies, found that 28 per cent of households with cats allow their feline friends to spend at least some time unsupervised outdoors. I bet it’s one hell of a lot more than that. Where I’ve lived, everyone that had cats, let them out and had cat doors precisely for that reason.
But why? Lee Niel, a behavioural biologist at the University of Guelph, is interested in answering that question.
“I think that there are the two sides. I think there are people who feel really strongly that cats need to go outdoors in order to have their needs met.Ya, typical hideous humanity, not give a shit about any other life, just them and theirs And I think that there are also people who are less concerned about cat welfare,” Niel said. “I wouldn’t say that it’s just one size fits all in terms of the reasoning.”
For all the concern for the welfare of birds, there are also numerous dangers for cats outdoors. But in Niel’s research, that doesn’t seem to be a consideration for some owners.
“When we sort of ask questions, you know, are you concerned about car accidents? Are you concerned about parasites, disease, these types of things? They were less concerned about the risks, and they felt more strongly about the benefits,”I believe it’s more ecause they are lazy and selfish people (the majority of humans, in my experience) who don’t want to spend the time supervising their cat(s), or walking it/them on leash, or spend money to build cat enclosures in the yard or on their balcony she said. “So they felt that outdoor access was really necessary for their cat to have good welfare.”Such humans are douche fuckers who do not give a shit about other life, just their killer cats. Every fucking year, birds and their song becomes less and less.
Niel also noted there’s a perception that cats are more likely to have behavioural issues if they’re kept indoors, though she noted there’s no clear evidence of that.If that were the case, then it’s high time to criminalize humans having cats. FFS
There are some ways you can still allow your cat to experience the outdoors or to use their hunting instinct.
One is a “catio,” an enclosure for cats that allows them to enjoy the outdoors without posing a threat to wildlife. The downside is that these can be expensive.
Another solution is to “catify” your home. Cats like to jump and sit on high perches, which can keep them a little more active.
As well, cat owners should provide their furry friends with toys and engage with them in play, using things like cat wand toys to allow them to hunt.
The solution to ending cat predation of birds and other wildlife is simple, Norris said.
“We know what to do with cats: keep your cat indoors. But it’s getting people to do it,” he said. “So how do you get people to do it? I don’t know. It’s a difficult one.”Oh FFS! It’s fucking easy. Implement laws to keep cats indoors, and limit how many cats each household can have. In my experience, few people are happy with one cat, they often have two, three, four, five or even more. That’s a lot of wildlife killing if the cats are allowed out.
— Nicole Mortillaro
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