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Comment by trhway | Hacker News Reader

>You’re probably aware that in North America alone for all cats kill between 10 and 30 billion native birds and small mammals a year

and how many of those birds and mammals were old and ill and would be killed by other predators in similar situation in non-developed areas? Why didn't you specify that comparative number? May be because that would have shown that the cats are just doing the job of other predators pushed out by humans?

Btw, the cats kill up to 4 billion birds annually. At the same time 3.5 billion birds die hitting glass of the buildings. Cats kill old/ill. The birds hitting building aren't majority old/ill. Thus killings by cats are mostly beneficial to the bird species while glass buildings make tremendous damage to the bird species.

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What evidence do you have that the birds killed by cats are mainly old or ill?

Cats being an invasive species in most places on earth means that most bird species have not evolved with them as a natural predator, and so are at an innate disadvantage.

And yes, birds hitting man made structures is a major problem. There can be two bad things at once. Just because there are two bad things doesn't mean we give up tackling one or the other.

>What evidence do you have that the birds killed by cats are mainly old or ill?

it is well established pattern of predation in the Nature. Again, you specified the total number without providing the old/ill number. The relation of those numbers can completely change the conclusion, and i can only wonder why you didn't provide the old/ill number.

>Cats being an invasive species in most places on earth

What planet "earth" you're talking about? On the 3rd planet from Sun the wild cats are practically everywhere. And in the places where there are no cats, there are still similar predators - ferrets, foxes, etc.

>And yes, birds hitting man made structures is a major problem. There can be two bad things at once.

No 2 bad things here. Predation by cats is natural, and thus mostly good, in the Nature-way, for the species being predated upon. The man made structures are really bad as i described in my previous comment. Yet somehow you want to tackle the first and not the second.

The word natural is doing a lot of lifting here. I think we are talking past each other because we don’t have the same framework for understanding how ecosystems work. Predation by an invasive species is not natural in the sense that the species did not coevolve. It seems we don’t agree that cats are an invasive species or even on the definition of an invasive species

There is very little natural in the unnatural environment of the human developed areas. That train has long left the station. That includes the natural predators. With those natural predators gone, cats are doing the job of those predators. Whether you call the cats invasive or not - the label doesn't matter in that situation, somebody has got to do the job.

And the main invasive species is humans. The humans invade and change the environment, and the cats are actually natural in that new environment.

The burden of proof is on the one making the claim.

I claimed billions of birds are killed each year by cats and provided a source (and there exist many more).

> Again, you specified the total number without providing the old/ill number. The relation of those numbers can completely change the conclusion, and i can only wonder why you didn't provide the old/ill number.

You claimed they kill mainly the sick and old birds but provide no sources for this claim, then attack my source for not containing the proof you failed to provide.

> On the 3rd planet from Sun the wild cats are practically everywhere.

So are rats. Would you call them a native species in places like Hawaii? No, neither are cats.

> somehow you want to tackle the first and not the second

Because this thread is about cats, not buildings. This is just changing the subject when your argument won’t stand up to scrutiny.

>The burden of proof is on the one making the claim.

>I claimed billions of birds are killed each year by cats

you claimed it is a bad thing. Where is the proof for your claim?

>provided a source

Smithsonian with that felon convicted for animal cruelty toward cats.

>So are rats. Would you call them a native species in places like Hawaii? No, neither are cats

Hawaii take how much percent of Earth?

> At the same time 3.5 billion birds die hitting glass of the buildings.

Do you have a citation for this? Are you comparing North American cat deaths to worldwide building collisions? Estimates I'm seeing of North American center around 600 million, a far cry from deaths due to cats.

It is in US:

https://www.nationalgeographic.com/premium/article/birds-win...

>a far cry from deaths due to cats.

No, they are about the same. The 3.5 billion is the top estimate similar to how 4 billion is top estimate for killed by cats. The lower estimates in both cases around 1 billion something.

That's an interesting update. I remain a bit skeptical based on the fact that the obvious sources I'd look to for this sort of thing haven't updated on that study (it seems to be https://www.tandfonline.com/doi/full/10.1676/23-00045), and I'm not really able to evaluate it on my own. USFWS (https://www.fws.gov/story/threats-birds-collisions-buildings...) is citing the previous numbers, as is Wikipedia (https://en.wikipedia.org/wiki/Bird%E2%80%93window_collisions).

FWIW 3.5 billion is not the top estimate, although I'm not sure how to interpret the way the estimate is stated ("annual mortality may be minimally 1.28 billion–3.46 billion or as high as 1.92 billion–5.19 billion"). What does it mean to have a range for each end of the range? The author only quotes the absolute lowest number from the study in press about it (see https://www.lehighvalleynews.com/environment-science/3-5-mil...), but maybe is just preferring to be conservative.

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