Sunday, January 19, 2020

Wildfires or Cats - What's the Bigger Threat?

In the past couple of weeks I've seen figures saying that 1 billion animals have been killed by fires in Australia ... and figures that say that every year, "free-ranging domestic cats kill 1.3–4.0 billion birds and 6.3–22.3 billion mammals annually" (Nature Communications, 2013) in the USA alone.

So every year, cats in the USA might be responsible for more than ten times as many animal deaths than this year's devastating fires in Australia.

Personally I quite like cats. I wish they wouldn't take birds, but at least in our neighborhood, we have a much bigger problem with rabbits - so for the sake of tulips, crocuses, grape hyacinths, and many other plants, I think the cats might be helpful. (Sorry, bunny lovers, I don't mean to horrify you.) But who knows, maybe even keeping the rabbit population under control is a job best left to native predators. However we see it on a neighborhood level, introducing a predatory species that kills billions and has few if any predators of its own doesn't turn out well for ecosystems.

If we really want to save wildlife, many of us are right behind initiatives to curb greenhouse gases, plant trees, restore habitats, and if it's done carefully and well we are willing to pay for this with taxation.

But if we wanted to save ten times as many wild animals, do any of us have the heart to tackle the cat problem? If not, the easily-repeated finger-pointing "Science tells us how to solve the problem but you just refuse to, that's irrational and immoral!" comes right back at us.

Frequently Asked Questions and Discussion Points 

There have been a few responses to this post, which I'll try to gather here. (Feel free to post comments and corrections, especially if you think any of the points below are not presented fairly.)

Are you saying that wildfires aren't a problem?
Of course not. For Australia particularly, I recommend donating to https://www.rspca.org.au/

Feral cats are the biggest problem, not pet cats
In terms of numbers, the Nature Comm. article agrees: "The predation estimate for un-owned cats was higher primarily due to predation rates by this group averaging three times greater than rates for owned cats." This argues that controlling the feral cat population is more important than convincing cat owners to keep pets indoors.

Cats have always been part of the natural ecosystem
That's true on most continents, though not Australia and many islands. But the scale of the problem is unnatural. If one-third of human households kept foxes as pets, and every year some proportion or these foxes returned to the wild and bred, then the sheer numbers would cause a similar problem for other species. Similarly, fires have always been part of the natural ecosystem, but the ways human activity interacts with the environment can make them more devastating. Fires are natural, but still devastating, and if anything it makes it even more crucial that humans follow responsible policies that take this into account.

Deforestation and pesticide use on a mass scale are far greater killers of native wildlife than free roaming cats
Again, from the Nature Comm. article"Our estimate of bird mortality far exceeds any previously estimated US figure for cats 13,14,16, as well as estimates for any other direct source of anthropogenic mortality, including collisions with windows, buildings, communication towers, vehicles and pesticide poisoning 13,15,16,17,18,19,20,21." 

So there's a big list of citations to the contrary. It includes a range of studies going from 1979 to 2012, and it's not easy to compare "apples to apples", so I dare say that it's possible and valuable to do further studies. But with the information I have at present, I don't have a good alternative to accepting that cats kill more than pesticides.

Are there other articles that corroborate this research?
http://www.ace-eco.org/vol8/iss2/art3/
https://doi.org/10.1093/jel/eqz035

Omnivores have to kill to survive ... I find the Australian fires more disturbing because lives were lost en masse for nothing.
Yes, absolutely the recent fire events are disturbing beyond belief. And it's notoriously hard to feel an empathic connection with long ongoing events, compared with immediate catastrophes. There is a core emotional difference here - it's easy to want to reduce fires, or diseases, we have little or no emotional sympathy with bacteria, let alone fires. It's hard to frame a policy for controlling cats without feeling that it's grossly inhumane to blame them for being themselves, whereas we don't feel that we're "blaming" fires or bacteria for anything - we don't feel that they're advanced enough evolutionarily speaking to be "blamed" at all. 

Cats should not be demonized, this leads to cruelty
Absolutely. There should be no place at all for feeling revulsion towards cats themselves. It is really bad that anger against cats can lead to inhumane or cruel treatment.

What's a "humane" way to control feral cat populations?
Surely introducing poison to the food-chain is a terrible idea?
It usually is. See https://www.environment.gov.au/biodiversity/invasive-species/feral-animals-australia/feral-cats? for ways poisons in Australia at least have been carefully designed not to harm native wildlife (based on genetic resistance or even different chewing behaviour).

Cats have a right to live just as much as other animals
Cat's don't have a right to be introduced in unnaturally large numbers into new ecosystems and wipe out entire species.

It's wrong to kill cats
Yes, and it's a choice between the lesser of various evils. So it's a kind of trolley problem. But it's a particular case where we humans made the trolley, we are guiding the trolley, and we can see that if we do nothing we're preferring the uncontrolled spread of cats (of which there are already many) over entire species (which are irreplaceable). It's wrong to kill cats, but it's even worse to introduce them, let them kill entire species, and then say that doing anything more about it than neutering some of the cats would be immoral.

Why do we treat dogs differently?
We've been culling / euthanizing / removing stray dogs all over the world for years, because packs of stray dogs are much more of a menace to humans, and because they're a menace to humans, we regard population control as a necessary evil. Of course, it's not that simple, there is a huge variety in ways dogs have been treated, sometimes tolerated, removed, there are similar no-kill policies in some places that people advocate for cats. For a survey of dog population management and its relationship with rabies, see this article. It finds that indiscriminate culling is counterproductive (as well as undesirable), but acknowledges that for unowned dogs, euthanasia is the only way currently available to reduce overcrowding in shelters. Just neutering and releasing stray dogs back into wild or urban environments is hardly ever advocated by anyone - to the extent that this suggestion would be considered ludicrous. It is however very much what we sometimes advocate for cats. The difference between our policies for dogs and cats is based on their size relative to humans - a poor way to make decisions for the host of other species.