I was trying to research the claim that TNR (trap-neuter-return) as a management tactic for stray and feral cats is ineffective, and I found this article very informative, I encourage reading it (if you’re not too triggered by reading about awful things happening to cats.)
My main takeaway is that the health and welfare of feral cats is awful. The link reviews various studies on the health of feral cats and basically they’re full of worms (an average of 53 tapeworms in one study!) and other parasites and carrying and spreading Feline Immunodeficiency Virus (the cat version of HIV, the virus which causes AIDS), Feline Leukemia Virus, Feline Parvovirus, cat flu, and rabies.
(Ectoparasites aren’t covered in the same depth, but I can confirm from casual observation that ticks and fleas do enjoy cats as a food source.)
The article also discusses how common it is for cats to ingest poisons such as Roundup and to eat plastic and other inedible matter when feeding on trash. Multiple studies of feral cat colonies are cited that have found even regularly fed cats eat garbage and ingest great amounts of plastic, aluminum foil and other non-food material.
Death from trauma due to being run over or shot is also very common (the cat from the Croatian study that was brought into the vet with a homemade arrow stuck in its body is going to stay with me).
So if the cats are in horrible health and there’s constant efforts to sterilize them, why doesn’t their population decrease?
What the paper seems to show, is that feral cat colonies are often maintained by a constant influx of new cats. I have anecdotal evidence to corroborate this. Near where I live there is a place with a large feral colony, popularly called the “cat farm,” where people dump unwanted cats. One of the problems I read about (not sure if it was this article or another one) was that areas where a cat colony is established become hotspots for people dumping cats.
(This happens, unfortunately, because other options straight-up don’t exist. My family cared for a feral colony for about ten years. Our low-cost TNR program had a nine-month waitlist, no shelters anywhere in the area accepted cats, and spaying one fertile female at the vet’s cost $200+. It’s legitimately an awful situation to be in, and to this day, my mom’s stress dreams always involve kittens popping up all over the place.)
As much as people talk about cats being “independent” animals that don’t “need” humans, feral cat colonies really don’t seem to establish and maintain themselves without constant human influence. In the studies, feral cat colonies are all in urban areas. In the USA we have actually feral populations of “wild” horses and pigs and some other animals, but we don’t have “wild” cats. (Look at iNaturalist and observations of domestic cats are almost entirely confined to cities and towns.)
(Don’t look at iNaturalist unless you want to see a bajillion dead cats.)
The linked article discusses how common it is for people to feed and sort-of look after colonies of feral cats (talking about Australia, not USA as my experience references, but similar situation). It can’t really be known if some “feral” cats are considered to be “someone’s cat” or not. With all the people that have “outdoor” cats, which can be counted as part of “feral” populations, I think calling cats “feral” obscures the problem a little bit: it’s not so much a subset of cats that have escaped domestication, as a broad spectrum of cats that are neglected to varying extents.
So you have fully unsocialized cats, and you have friendly strays, and you have “outdoor” cats that may be fed or claimed by various people, but they’re all invasive species and they’re all reproducing and fighting with each other and they’re all getting poisoned, shot, run over, infested with parasites, infected with diseases, and killed by predators. And it’s really awful.
Of course I care about the impacts on wildlife, but holy shit, I also care about the cats.
This is a huge part of why I, 1) keep all my cats indoors, and 2) advocate for humane breakup of cat colonies, by adopting out socially able and relatively healthy cats (with curable or at least treatable problems) and humane culling of the others. TNR, from what I’ve seen in my own communities, just leaves more cats to die terribly.
It’s horribly upsetting on a personal level to know that that means thousands of cats will be euthanized; it’s more upsetting to know that those same cats will die in horrendous, awful ways if we don’t, along with a great many others.
