I absolutely understand why someone who loves or respects bird life would be considered about outdoor cats.
What I don't understand is how biologists, who otherwise conduct research on animal population management, dismiss trap/neuter/return out-of-hand...without having conducted any research on it themselves. Most actual research involving spay/neuter of feral cats has been conducted by small animal veterinarians with a clinic background. You would think population management biologists would jump all over this fairly low-cost, "easy-to-conduct locally" research option.
With the increased press due to National Feral Cat Day, it noted otherwise highly intelligent people--usually who have a research background -- release venom about shooting cats with high-powered rifles, etc. These same people would admonish citizens who blasted away at other animals in violation of the law. In most areas, it is illegal to kill a cat that could be someone's property, or any cat at all.
(Note: I do not consider these "shoot, shovel, and shut up" comments to be typical of professional biologists, but the fact that the posters consider themselves professionals is somewhat alarming).
Some wildlife professionals will also suggest, as a solution to cat overpopulation, taking the cat to a shelter. There seems to be little understanding that in many areas, there are no open-admission shelters, and that in many municipalities, no public funding is provided at all for cat control. In my area, shelters that accept cats are doing so out of their own pockets and with donor dollars---donors who expect those dollars to go primarily toward saving the lives of pets.
I am as of yet unfamiliar with any research conducted by a government or university biologist (versus a layperson or veterinarian) involving the sterilization of a particular population of cats actually conducted by that biologist.
In all of the colonies I have been involved with, populations have steadily dropped to near zero, as long as there is a committed caretaker. Situations where kittens have shown up again have been due to a lapse in caretaker commitment. In other words, as long as all or a majority of cats are altered, and a caretaker reports quickly on the appearance of new cats, TNR works on a site-by-site basis.
There also seems to be confusion between an actual colony TNR program, and just offering spay/neuter to the public, including feral cats. If a shelter has spay/neuter options and makes them available to people who have feral cats, this is not a "TNR project." This is a public spay/neuter project.
TNR involves addressing a specific population of cats. If you look at a specific population, fix all or as many cats as you can at that site, remove kittens and friendly cats, and feed and provide shelter for the cats, you can track the success or failure at that site.
But if you provide spay/neuter for a large geographic area and some of those cats "happen to be feral" and your reports of, or intake of, feral cats does not drop, this is not due to the failure of TNR.
Let me offer an example. If a person has a problem with raccoons, and they call a nuisance wildlife control company, and that company excludes or removes six raccoons from the property and repairs the damage and removes attractants, that landowners problem has absolutely been solved---but there has been no real impact on the overall population of raccoons in that county. That wildlife control company could run around doing a bang-up job resolving raccoon problems, reducing disease risk, and making landowners very happy, and never risk wiping out the overall raccoon population.
To have an impact on an overall geographic population, there would need to be a concerted large-scale effort to remove or sterilize animals. Deer hunting seasons would be an example of this. Hunting actually has an impact on populations because thousands of hunters take to the woods during breeding season.
TNR is successful at resolving site-by-site problems. It also is successful at lowering individual shelter intake, if that shelter replaces acceptance of feral cats for euthanasia with spay/neuter of feral cats to be returned to the landowner.
However it will take a number of very large-scale spay/neuter programs in an area, over time, to impact the entire overall population of cats.
So it is understandable that TNR is a "success" --- it permanently resolves a local feral cat problem at a trailer park, college campus, or person's back porch --- at the same time the county, overall, is still seeing a lot of cats.
Wildlife biologists point to this as the "failure" of TNR and a reason to ban or discourage it. These same biologists would never suggest banning private nuisance wildlife control just because the activities of wildlife control trappers does not impact overall nuisance species populations. That idea would be idiotic.
(By the way, raccoons are also a main predator of songbird nests).
A wildlife biologist might respond to this criticism by saying that they encourage nuisance wildlife control operators to kill nuisance raccoons rather than relocate them (Relocation can spread disease, disrupt the new population, and stress or kill the relocated raccoon). They would say they are suggesting the same things for cats: Put them down.
However nuisance wildlife control operators usually have legal options to kill raccoons themselves. Citizens usually cannot kill cats of unknown origin themselves because they could be someone's property. And municipalities may not fund shelters adequately or at all.
In addition, nuisance wildlife control businesses are paid to resolve wildlife conflicts. Because the public perceives cat control as a municipal responsibility (even when the municipality won't fund cat control) they are reluctant to pay for it. And it is illegal, in most cases, for a private citizen or business to offer killing of cats as a service. Some cats could be lost or free-roaming pets.
Locally, I've received calls from people with stray cats who have been turned away by shelters in both Tompkins and Tioga counties because those shelters are simply out of room. The Tioga shelter receives no funding at all for cats from their county and towns.
A local shelter may also be a private, no-kill humane society. If it is against the humane societies mission to accept cats to be killed just because society doesn't want to deal with them, there is no reason for that private humane society (or private rescue for that matter) to deplete their resources attempting to resolve a massive problem that the municipality does not feel is important enough to fund.
There are additional inconsistencies in the attitudes of biologists or birding professionals' attitudes to toward cats that I'll address in future posts.