My greatest struggle as an animal lover and environmentalist is that the science is in, and TNR doesn't work. It doesn't work to restrict cat population, it doesn't work to contain disease or improve welfare, and it does absolutely nothing to reduce the number of native species decimated by feral cats annually. Cats are an ecological disaster, especially in North America where the prodigious PR which the internet grants those cats means they're beloved on a mass scale. Popular sentiments like "Cats are still wild animals and you have to let them hunt" and "They won't attack native wildlife if you feed the outdoor cats" are parroted ad-nauseum by facebook aunties and animal rescue groups, despite being patently false and highly variable by individual.
Unfortunately, humans are highly discriminatory against various animal species based primarily on "cuteness" and not on, say, their value to the environment, so the humble vole is hated by suburbanites with a virulency once reserved for man eating beasts of the wild, and the birds that are least adaptable to non-native monocultures are killed by mere human expansion without qualm. This cognitive dissonance results in any genuine calls to cull excessive feral cat (and dog but that's a whole second rant) populations being treated as tantamount to promoting genocide. Somehow the fact that humans created this problem means that the feral cats deserve more grace than the snakes, lizards, frogs and birds they kill in droves every year.
Culling is obviously never a particularly desirable solution but cat populations have been studied and have extremely resistant populations. Between cats that are abandoned, escaped, and natural-born to intact members of the colony, even neutering 75% of the population isn't enough to prevent steady growth of the colonies. Literally the only way to end the problem is to capture EVERY. Single. Cat. As in stop letting cats outside, especially if they're sexually intact. Obviously, this is easier said than done since capturing, providing medical care for, finding homes for, and/or euthanizing cats just from medical necessity, is an expensive proposition. Cats are notorious for escaping homes and vehicles, especially if they're sexually intact, and getting wise to various trapping techniques. They're smart and they'll fight and tear you up, which is why they pose such a threat to native wildlife species.
Because I am a native species environmentalist, I genuinely believe that all cats should be kept indoors, microchipped and neutered. Despite this belief, I have like 6 cats. Three that belong to me and three that belong to my roommates. They all stay indoors, they're all vaccinated and I couldn't imagine my life without my little colony of highly social and opinionated cats. I love cats!
That's why I both hand-rear bottle kittens from rescue groups most years, AND spay and neuter my animals. It's painful to personally raise a kitten and watch them develop personalities, especially since it can be hard to find them homes before they reach adulthood. So many people will say "Just keep the kitten" but I can't! I can't keep every kitten or I wouldn't be able to feed the adult cats I already have. It's just as hard to see a cat that has a good personality lose their spark as they sit in the shelter for years, as it is to have to euthanize a kitten because it's parents were from the same litter and its malformed, or lose a kitten to fading kitten syndrome.
I don't resent the colony cats themselves but I dislike that the cat colonies created by well-meaning cat ladies produce an infinite number of kittens that have to be rescued, raised and rehomed if we want to reduce the damage those cats will someday do to the environment. The resources spent TNRing don't help the creatures that the cats drive toward extinction as their populations grow, and they don't provide resources to stop the inevitable kittens from dying horrible deaths from preventable causes. We domesticated cats, we brought them here, and they deserve better from humans. Unfortunately, they're also a problem that we will never get under control as long as cats are being returned to the very environments they've already decimated.
I recognize that my opinion that all cats should be indoors, microchipped and neutered, and culled if they cannot be socialized, is an over simplified cold analysis of a complex situation. There's certainly arguments to be made about keeping cats for pest control that would have to be addressed even if we miraculously got our entire country to embrace a single consistent policy. Perhaps appropriately microchipped cats could be registered and kept confined to where they're wanted through underground fences. At this point in time, that's a pricey solution but if the microchipping were actually enforced it would lead to innovation and decreased cost, so I'm setting that point aside.
Even though my solution would be unimaginably expensive, it would still be cheaper to do that than to resurrect all the native species that cats have destroyed. When you're talking about low population species that only exist in small patches of wilderness, there's a glaring awareness amongst conservationists that their subject could be wiped out in no time by a cat colony. It's hard to bear once you're aware of it and seeing the impact first hand on a regular basis.
I love cats, but It feels ridiculous on a large scale that all these resources are being dumped into the task of catching these cats only to immediately squander those resources by releasing them. If every cat was captured, kept indoors and desexed, cats could be cherished companions without being a blight on the environment. If they were microchipped, desexed and contained to specific areas, they could continue serving their evolutionary role as pest control for humans.
So many native species have already gone extinct, many without notice or fanfare. The impacts of these extinctions will likely be unknown until the repercussions are already underway. An unimaginable number of species more will suffer the same fate before our society begins to see this issue as the problem it is.