Sigh… more overhyped cat nonsense.

I realize Jim Anderson and H. Bruce Miller feel strongly about this issue but that’s hardly an excuse for ignoring the legitimate and rational arguments raised by critics of the Audubon/ABC campaign against outdoor cats. It requires a pretty strong personal filter or sheer dishonesty to blanket characterize the TNR advocates and other critics as “cat fanatics”.

I’ve already addressed many of the weaknesses of the Audubon/ABC allegations in detail in previous responses to Jim Anderson’s article from Volume 11 Issue 29 entitled “Cats, Cats and More Cats” (Oct 2007). Unfortunately, the article and its commentary appear to have disappeared from the TSWeekly web site. That’s a shame. I suppose it’s probably too much to hope that TSWeekly staff has the technical chops to recover this lost thread so maybe one of these days I’ll reconstruct it from my notes. For now, I’ll just address one of the allegations…

The risk to humans from toxoplasmosis, roundworms, hookworms, ringworm, and rabies is a bit overhyped. Toxoplasmosis is a real concern and therefore worth spending a little time on. I’ll cover the others in the following posts.

About toxoplasmosis…

There is roughly a 10% chance that you are already infected with toxoplasmosis but this varies greatly with geography, with upwards of 90% incidence in some areas. Most otherwise healthy people don’t realize they are infected since, like many of the infections we live with, our immune system forces it into dormancy. Once infected, your immune systems pretty effectively protects you from reinfection. Occasionally, some experience flu-like symptoms for a couple of weeks. In very rare cases, eye infection, vision loss, and some other severe symptoms can occur. However the risks for severe symptoms are greater for the immunocompromised and the pregnant so prevention is still important.

It’s true that cats can host the parasite, shedding oocysts for a couple of weeks after ingesting an infected rodent. The oocysts can be viable for several months so they’re hardy little buggers. But cats usually develop immunity after the initial infection and so shed oocysts only once in their lifetime. It’s also true that outdoor cats are more likely than indoor cats to host the parasite but, again, only once in their lifetime. Oddly, it’s kittens, both indoor and outdoor, that are the most common hosts.

The accidental ingestion of cat feces from litter boxes or garden beds are a potential vector for transmission to humans but about half the cases are actually caught from uncooked or undercooked meat. Probably the most effective preventative measure is just to not eat undercooked meat and to be diligent about cleaning all surfaces, utensils, and hands that come in contact with raw and undercooked meat. For the pregnant and the immunocompromised, extra measures like avoiding direct contact with likely sources of cat feces may be prudent. Pregnant women whose immune responses are already primed from a prior infection have little to fear.

I don’t believe anyone seriously proposes the complete elimination of the toxoplasmosis protozoa in the wild but it’s worth noting that the human infection rates appear to be declining sharply (despite the increasing rate of cat ownership). In 2000, the best estimate of babies born with congenital toxoplasmosis was about 1 per 10,000 births. Considering the downward trend in the overall infection rates since then, it’s reasonable to project that the rate is now at least half that figure. To get some idea of the scale, in Bend this works out to roughly 1 case per 20 years.

To summarize, if you’re pregnant (and haven’t already been exposed) or immunocompromised (such as suffering from AIDS or taking immunosuppressive drugs), and you have a cat, a reasonable case may be made that you should keep your cat indoors. For the rest of us… not so much.

Now, about hookworms…

Cat and dog hookworms can potentially cause “cutaneous larva migrans” in humans. This is very mild but itchy skin infection (usually on the feet). The human version of this parasite is a bit more aggressive, migrating all the way to the gut and sucking up huge amounts of blood, but the cat/dog versions can’t really penetrate that far into human skin (but still a good reason to maintain segregated dog beaches). All versions of this parasite need warmth and moisture and so can be found mostly in tropical and subtropical climates. High desert residents probably have little to fear from this critter.

In any case, in climates where this is a concern, the primary vector for human transmission (of the non-human version) again is dogs, not cats. Hot humid weather and bare feet are the main risk factors. For the cat, the treatment again is cheap and common. It’s usually not serious but regular deworming takes care of it.

And finally, about rabies…

In the US, rabies infections in humans are rare and getting rarer every year. Three reported cases in 2006 and one case in 2007. In Oregon, there were only 12 reported cases of rabies in 2007; all cases were in bats. Two of these bat cases were in Deschutes County but there hasn’t been a single reported case since 2007. In the entire state, there have been only 4 reported cases in cats in the last 20 years; the last one was 10 years ago in Douglas County. There hasn’t a single reported case of cat rabies in Deschutes County for at least 50 years, perhaps ever (the state data only goes back to 1960).

Obviously, the risk of rabies to our cats, feral and otherwise, in Bend is pretty damn low. I pointed this out already in a correction to one of Anderson’s previous articles but apparently HBM didn’t get the memo 🙂

Really? Is this all you’ve got? A bald-faced ad hominem argument?

HBM, if you search your memory, you might recall my fact-correcting posts on a few other unrelated topics. No, I am not a professional lobbyist, affiliated with ACA, or any other similar group. In fact, before Anderson’s post back in 2007, I wasn’t even terribly interested in this issue. But moving here from a town with a fairly good progressive alternative weekly, I was saddened and appalled at the sloppy fact checking and gratuitous snarkiness coming from the only progressive paper in town. Sometimes I’m just annoyed enough to do the fact checking for you.

No, I don’t have a great deal of time to write posts. Isn’t that a bit of a condescending way to deal with competent writers who actually know how to do research? I’ll let you in on a little secret. It turns out that fact-checking and writing well doesn’t really take that long.

Hmm… sounds like we hit a nerve.

> It’s not an ad hominem argument

Oh please. You were caught with your fact-checking pants down with the exaggerated threats to human health. A principled person would just cop to the error and move on. Coyly phrasing an ad hominem attack as a question isn’t fooling anyone.

> Basically, I think you’re just a
> guy who likes to argue and show
> off his erudition and vocabulary.

And I suppose this too is not an ad hominem argument? The lobbyist insuation doesn’t work so let’s try anti-intellectualism instead? Hey everyone, don’t look at the man with his pants down, let’s sneer at the other man with the big words instead. Sigh.

> I remember how you quibbled, nitpicked
> and hairsplitted every argument that
> was produced on the other side during
> that last discussion and wrote interminable
> posts — so interminable that they had
> to be split into several parts — and
> then expected detailed rebuttals to all
> your points.

This is a pretty unfair characterization but I suppose you’re free to mischaracterize it at will since we can no longer actually point to the thread online anymore. Pretty convenient that.

For the peanut gallery, what really happened is that HBM tried to do that typical tactic of unloading a laundry list of citations copied from the anti-TNR clique’s talking points and basically dared me to refute them. So what’s got HBM’s shorts in a bunch is the fact that I actually met his challenge and politely explained the weaknesses of every single one of them. Yes, the response was long and split into multiple posts but that’s pretty much what HBM’s laundry list (and the old finicky comment software) required. Apparently in HBM’s book, actually responding with the real facts is just quibbling, nitpicking, and hairsplitting.

>
> 1. Reducing wild bird predation.
>

Unless you’re going to take the emotional position that *any* bird predation by cats is an evil act that must be prevented, the important question is whether the predation is harmful to the long term health of the population. Except possibly for a few sensitive areas, the evidence is not convincing that cat predation has a significant impact on most wild bird populations.

The biggest impacts are actually those thousands of individual human activities lumped together under “habitat destruction”. According to one estimate, there are close to 8,000 species threatened with extinction, 99% directly due to human activities causing habitat destruction. More than a 1,000 of those are bird species, of which at least half are predicted to be extinct in 50 years. Human activities have already led to the extinction of 10% of the world’s bird species.

It’s humans, not cats, that are responsible for the major threats to bird life today. More to the point, as far as I know, there is no evidence that *any* species in Deschutes County is threatened significantly by cat predation.

> 3. Making it easier to identify stray cats
> and return them to their owners (and thus
> making it less likely they’ll end up being
> euthanized at the Humane Society shelter).

This argument is fair. Of course, this doesn’t require adopting an indoor-only cat regulation. Implanting microchips is also a one time procedure and national database registration is free. It’s hard to justify an annual registration requirement for something with so little overhead.

> 5. Keeping pet cats healthier (because of less
> exposure to disease and injury by cars, other
> cats, wild animals, dogs, humans).

Interestingly, this notion actually seems to be shared by many on both sides of the TNR debate. It’s very common to hear claims that outdoor cats have 2-3 year lifespans. But based on anecdotal observations, I suspect this claim is as unfounded as the popular belief that humans use less than 10% of their brain or that Saddam Hussein was involved with 9/11. If you recall, this was the claim that first drew me into this discussion a couple years ago. I’ve yet to find much reliable data comparing the mortality of indoor versus outdoor cats.

Perhaps a case can be made that in high density, high auto traffic areas, fewer cats will get injured by cars if kept indoors. But Bend is not really a high density, high auto traffic area. Is injury by cars truly a significant risk in our area?

Perhaps a case can be made that indoor cats are protected from attacks by other animals. But again, is this a significant risk? I could make the same argument to keep my child permanently indoors. But this risk, to my child at least, does not appear significant enough to justify being so overprotective. I suppose the risk to my cats might be higher but again is there any evidence that the risk is significant enough?

And finally, a case can be made that indoor cats are better protected from disease. But unfortunately again, the data seems a bit mixed. It may make sense to make sure our outdoor cats are regularly dewormed and vaccinated but we should be doing this in any case. As long as this is done, it seems that this should take care of most of the risk.

However, feline leukemia virus (FeLV) may be a concern. I’ve read claims that outdoor cats are more likely to contract FeLV but the data I’ve seen seems to show that the prevalence level is the same in stray/feral colonies as it is in pet cat households (roughly 1-2%). Perhaps the risk is considered greater for outdoor cats because they are presumed to be in contact with more cats? In any case, the incidence of infection seems to be largely related to the population density of cats, with higher rates in catteries and multi-cat households.

Transmission of FeLV apparently requires fairly sustained contact, with saliva being the primary carrier. A bite from an infected cat could do it but it’s thought that mutual grooming and shared litter trays and food dishes are the main vectors. Young kittens are much more susceptible than adults. Because FeLV is a fragile virus and because of age resistance, transmission between adults usually requires prolonged intimate contact. I wonder how much prolonged intimate contact do neutered pet cats really engage in with foreign cats. There is a FeLV vaccine but apparently it’s not foolproof. I need to do more research on this one, especially on the local incidence rate. Any local vets care to chime in?

> Nice strawman you’ve erected there, Ric.
> Who said it was “evil”?

Huh? That’s just the qualifier, not the argument. But in any case, it’s not a strawman if that is really your position. Alright, if you like, let’s switch out “evil” with “bad” or “undesirable”. The argument still holds.

Perhaps an analogy might help. These days we are rightly concerned about CO2 emissions. But no one is insisting that CO2 emissions are *always* undesirable. No, that would be silly. Rational people are concerned about *excessive* CO2 emissions.

Look, I understand that empathic people would want to defend the life of the creatures they love. If I see a cat trying to snag some bird or lizard, my instinctual response is to save the victim. But deep down I know that, most of the time, this is an irrational response. Birds and lizards die by the millions every day. Death is a part of nature. Yes, as an individual act, I’ll still save that bird but I’m rational enough to avoid advocating governmental policies based on an irrational empathic response. Let’s save our environmental activism for the things that really matter.

> So why decrease the birds’ chances of survival even
> further by setting cats free to kill them?

Again, the issue is one of significance. Do you know how much wildlife is killed by motor vehicles? Some US estimates claim over a hundred million casualties per year! (note, cats are a very tiny portion of the road kill) In 1991, over half a million deer got hit by cars. Do we ban cars? No. Is this because we’re so dependent on cars? I doubt it. I suspect the primary reason is that the death toll is just not significant enough. The death toll may be something worth monitoring but until it causes a significant impact on the wildlife population, we have other much more significant problems on which to focus our conservation efforts.

> Another strawman. Did I say anything about neutering?
> Neutered cats kill birds just the same as unneutered ones do

[slaps palm to head] Please read more carefully. It should have been clear that the neutering and population data was just the supporting evidence for the following statement about whether keeping cats indoors would have any significant effect on the stray/feral cat population.

> Do you have any idea how rapidly cats reproduce?

Do you? There is another myth floating around about cat reproduction but I’m not really sure what you’re asserting here so I’ll let this one slide. Again, the point is that the data tells us that household cats probably have very little impact, if any, on the maintenance of the stray/feral population.

> Okay, next time I find cat turds in my yard I’ll
> invite you to come over and clean them up. My dog
> isn’t allowed to crap in your yard — why should
> your cat be allowed to crap in mine?

Why do you persist on equating cats and dogs? They are different animals with different issues. We don’t let dogs roam because wild dogs can truly be a threat to humans. We don’t let dogs poop indiscriminately because dog shit is often huge, wet, smelly and visible. Dog shit gets deposited anywhere, gets on your shoes, and attracts flies. You won’t find cat shit on your lawn. Cat shit is small, often dry, less smelly and rarely visible. Cats prefer to bury their shit, usually in sand or dirt, and tend to choose the same spot for any repeat business. The two problems are not really comparable.

If you truly are having a persistent problem with cat droppings, there are several practical strategies you can adopt that are proven to work. One that I’ve heard of that works very well and costs almost nothing is just to set up a small box of sand somewhere near your yard. Cats often prefer dry sand over dirt and mulch and the problem will be contained. If the source is a neighbor’s cat, try working out a plan with your neighbor to slowly move your box until your neighbor can start taking responsibility for maintaining it. Heck, I may even volunteer to help you work on this if you promise to be nice 🙂

> But cats are not part of nature, in the sense
> that they are not part of the birds’ natural
> environment. They are an introduced predator.

So are we. The list of introduced species is a long one. Conservationists make a distinction between merely “introduced” species and “invasive” species. The invasive label is reserved for those species that have a real adverse impact on the natural habitat. As I acknowledged many many times in the past, there may be places where cats can legitimately be promoted to “invasive” status but, as far as I’ve been able to determine, Deschutes County is not one of those places.

> First, I believe the destruction of wild bird
> populations DOES really matter. Second, why does
> it have to be an either-or deal? Why does paying
> attention to, say, global warming mean we can’t
> also be concerned about the loss of wild bird species?

Cart before the horse. You first need to establish that local cats are causing the “destruction of wild bird populations”. Reasonable people can be concerned about the global problems of wild bird populations, including areas where cat predation may actually be a problem, and STILL not be concerned about areas where cats predation is insignificant.

> Pardon me, but this is bullshit (or catshit). Why should
> I have to go to the trouble of maintaining and cleaning up
> a litterbox on my property because my neighbor is too lazy
> and/or indifferent to control his cat? It’s his responsibility
> to take care of his cat’s messes, not mine.

Well, this isn’t very neighborly. Have you even tried to work out a plan with your neighbor to cooperatively address this issue? Or are you just content to grumble impotently about people who don’t share your notions about cats? I don’t know your neighbor but I can tell you that if one of my neighbors came to me, politely asking for my help to address a real problem with one of my cats, I would try to work out a solution that works for both of us. Cat owners, by and large, are not any more irresponsible than anyone else, they just have a different mindset about cats than you. If this is a real problem, and not one just invented for rhetorical flourish, why don’t you try? Like I said, if you promise to be nice, I might even be willing to help.

At this point, I suspect you’re just making this up. I hardly ever see the byproducts of household cats outdoors and I’ve done a fair amount of gardening. I had issues with skunks and opossums but not with cats. Unwanted cat elimination is very easy to control.

> BTW, I invited people to post responses pointing out the
> disadvantages of what I proposed. You posted some rather
> lame attempts to rebut what I claimed were the advantages,
> but said nothing about disadvantages. Does that mean you
> couldn’t think of any?

Sorry if I don’t play by your rules but I thought my counter argument was obvious. You came up with five so-called advantages. I replied with my arguments why each one was either incorrect or weak.

You are the one proposing a new legal burden for cat owners and the expenditure of public funds on maintaining a annual registration scheme, enforcement of indoor-only laws, and the killing of stray/feral cats. The burden is on you to make the convincing argument. You haven’t yet.

> In conclusion, this will be my last response on this topic.
> The discussion has grown repetitive and tedious. Also, I
> find your smug, condescending way of expressing yourself
> extremely irritating. To put it more crudely, you are a
> pain in the ass, and I don’t need another pain in the ass
> in my life. So goodbye.

Suit yourself. When I started this dialog way back when, I believe I was fairly polite and gentle. You were the one that started with the insults and the condescending attitude. If my tone these days annoys you, well all I can say is that you reap what you sow.

Sorry, I keep forgetting that I need to be super explicit in our debates as you seem intent on misinterpreting everything.

“Way back when” did not refer to two days ago, but rather two years ago. Every time I’ve pointed out one of your errors, you seem constitutionally unable to accept it gracefully so I’ve given up on gentle.

And yes, you did use the term “cat fanatics” and although in this article you didn’t explicitly say *all* critics were cat fanatics, that was the impression you deliberately left with additional gems like “idiocy”, “many cat owners will pitch a fit”, “heretical”, and “completely irrational”. And this isn’t even considering the diatribes from previous threads.

For the record, I did not say you made a blanket claim about “all” critics. But I would still have been justified if I did, as without qualification or any fair treatment of the other side, it seems clear you were leading your readers to make that extrapolation themselves.

But, in any case, looking back at the beginning of *this* thread, I agree that I came in too aggressively. Not because I think you deserve it but rather because most of your readers are probably unaware of the prior history.

And finally, the comment about the technical chops of the tsweekly staff was not directed at you. In previous discussions with tsweekly staff it seemed clear that no one there really had the technical expertise to fix problems with the website. Has something changed there since the recent redesign? If so, I apologize for that remark, it was just an expression of frustration on losing the old thread combined with previous frustrations with trying to fix anything on your site. Do you guys have a real technical person on staff now?

>
> Did I call it or did I call it? LMAO!!!
>

Seriously, are you twelve?

Did you really think I was going to be deterred by amateur reverse psychology?

> “This sort of looks like where HBM got his last list of citations”
> Actually, it isn’t.

I don’t believe you. I dare you to find that lost thread and prove it 😉

> I’ve noticed that the anti-cat control people don’t produce any scientific
> studies of their own; they simply try to nitpick the many studies that show
> cats are significant bird predators. It’s a lot like the global warming
> argument. On second thought, no; the global warming deniers DO have some
> scientific evidence that goes their way and a few scientists who agree
> with them.

This isn’t true. I’ve seen several positive studies on the efficacy of TNR programs.

But in any case, it’s pretty telling that you see this as opposing camps producing “their own” studies. If any of that is happening, on either side, then of course we need to carefully look at the results of such studies with a critical eye toward confirmation bias.

By the way, who are these “anti-cat control people” you are referring to? It seems to me that most of the main TNR advocates actually agree with you that the outdoor/stray/feral cat population should be controlled. You guys mostly just disagree on the mechanism of control. They want to reduce feral colonies via a sustained spay/neuter effort. You want to kill the cats.

Most TNR advocates appear to be also in favor of keeping pet cats indoors. As far as I can tell, I’m in a rather small minority that is still skeptical of the arguments for this bit.

Frankly, I’m also not that squeamish about killing nuisance animals but I would rather avoid it if I can and the TNR strategy does seems to work better. In truly sensitive areas where cats are a true menace and whose geography actually makes this a possible solution, I can accept the need for a kill policy. But neither of these conditions exist in Deschutes County so a kill policy here would just be simply ineffective and inhumane.

>
> Why inhumane?
>

It’s inhumane because the conditions haven’t been met. If they are not a significant threat to local wildlife, then a kill policy is gratuitous slaughter. If the kill policy has no hope of working, while an alternative no-kill policy has been demonstrated to work, then again, it’s just gratuitous slaughter.

> if we were talking about rat colonies instead of cat colonies there
> wouldn’t be a second’s hesitation about killing them

Granted, there is a bit of a sliding scale with which most of us apply our notions of humane treatment. The notion of humane treatment follows from our empathic response. Yes, I feel more empathy for a cat than I do a rat. Just as I feel more empathy for a person than I do a rat (or a cat). But that doesn’t mean killing a rat (or a cockroach, or an ant, or a flea) is equivalent to killing a cat (or a person). That’s known as a false equivalency fallacy.

>
> public health risks…
>

There you go again. Perhaps you forgot but let’s summarize those public health risks you listed earlier, shall we?

1) toxoplasmosis… Yes, this is a potential problem, if you’re pregnant (and not already immune) or immunocompromised but at least half of all cases are due to improper handling of raw meat. Although the rate of infection is very low and getting lower every year, vulnerable people probably should avoid handling kitty litter and digging into gardens. The rest of us have very little to fear.

2) roundworms… Cats are not a major vector to humans. Studies point to dogs instead, particularly puppies, in a household as the principal risk factor. Properly cared for household cats should not pose a health risk to humans.

3) hookworms… Causes minor, easily treated skin infection in humans. Cats are not a major vector to humans. Dogs again are the main culprit. Properly cared for household cats should not pose a health risk to humans. A potential problem only in tropical and subtropical climates; highly unlikely to be caught in Deschutes County.

4) ringworm… Not a worm, but a minor fungal infection most common in tropical and subtropical climates and during warm weather in temperate climates; much less common in our dry climate. Humans are much more likely to get infected from other humans. Probably impossible to prevent exposure. Although not common, humans can potentially get it from cats. More of a concern with high density cat situations. Young cats less than one year old, immunocompromised cats, and certain long-haired breeds (Persians and Himalayans) are the primary victims. Healthy adult cats are generally immune.

5) rabies… There hasn’t been a single reported case of cat rabies in Deschutes County for at least 50 years, perhaps ever.

Unless you’ve got something else to add to this list, it’s pretty obvious that in Deschutes County, the public health risk from cats, feral or otherwise, is not terribly high.

>
> TNR does NOT work, as evidenced by the ever-increasing number of feral cats
>

Fascinating. By far, the most popular feral cat management policy in the U.S. is a kill policy. TNR is in it’s infancy and, although increasing, has only been adopted by a small number of communities. And yet somehow the “ever-increasing number of feral cats” is evidence that TNR does not work? That’s an odd conclusion.

> ‘it seems fair to assume’ ‘If we assume’ ‘I’m going to assume’
> ‘I’m guessing’ No kidding?

Pulling qualifiers out of context is cheesy to say the least. What is your point? That I don’t overstate my case like you do?

Here’s a hint. Anyone advocating for (or against) a policy based on scientific grounds who doesn’t use qualifiers is probably lying to you, or that very least exaggerating. Science is rarely definitive and absolute. Honest scientists always qualify.

> ‘Claims from studies published in respected peer-reviewed journals
> are theoretically more reliable but it’s definitely no guarantee of
> infallibility.’ But, if it walks like a duck and sounds like a duck
> and looks like a duck, chances are…

??? Again, what is your point?

> ‘Properly cared for household cats should not pose a health risk
> to humans.’ So you were discussing feral cats…

No, I was not discussing feral cats. I see I used this sentence with both roundworms and hookworms. I’ve already pointed out that, in both cases, cats are not significant vectors for human infection, dogs are. In the case of hookworm, the parasite is also unlikely to even survive outside in our dry high desert climate.

> ‘Taxoplasmosis…’
> Because my garden belongs to your cat or some feral cat, I must avoid it?
> Keep your cat indoors and eliminate the feral population and I will have
> NOTHING to fear from those sources.

Actually, I’m guessing you already have NOTHING to fear from “those sources”. I assume you aren’t pregnant or immunocompromised.

In any case, I’ve already acknowledged that this is a human health risk. My point is that you keep seriously overstating your case. Serious cases of toxoplasmosis are rare. Those suffering from AIDs should be taking the appropriate precautions against infections for a lot more reasons than just the possibility of taxoplasmosis. For the pregnant who are not already exposed (and thereby immune), a rough calculation gives us a congenital infection rate in Bend of about 1 case per 20 years, of which half would be due to improper handling of raw meat. And this rate is dropping fast.

So again, the health risk from toxoplasmosis is very low (and in your case, probably infinitesimally low). Now, I suspect the next response is going to be something like: “It doesn’t matter if the risk is low; Any risk is unacceptable.” If you actually believe this, then may I suggest you look up the risk of driving to work or any one of a million other things that we do every day that present much greater health risks.

Again, the point is not that there is ZERO risk but that you’re exaggerating the risks and overstating your case. The health risks argument is weak. You would do better to stick with the predation argument (which at least has the benefit of some scary numbers and who doesn’t root for Tweety over Sylvester) and the nuisance argument (after all, animals pooping outside does have the ick factor working for you).

> Can you point to ANY scientific evidence that a TNR program has succeeded
> in eliminating or reducing a feral cat population ANYWHERE?

Will any of these do?

Mendes-de-Almeida F, et al. The impact of hysterectomy in an urban colony of domestic cats. International Journal of Applied Research in Veterinary Medicine 2006, 4:134-141.
[Female feral cats in a colony at Rio de Janeiro were sterilized, resulting in a stable cat population and a decreasing trend after four years]

Natoli E, et al. Management of Feral Domestic Cats in the Urban Environment of Rome (Italy). Preventative Veterinary Medicine 2006, 77:180-185.
[A study of a very large number of TNR maintained colonies in Rome demonstrating a decrease in population in those colonies, although a high rate of abandoned intact cats in that area is apparently a local problem]

Stoskopf M, Nutter F. Analyzing approaches to feral cat management – one size does not fit all. Journal of American Veterinary Medical Association 2004, 225:1361-1364.
[After two years, six sterilized feral cat colonies decreased in size an average of 36% while three unsterilized control colonies increased in size an average of 47%.]

Levy JK, Gale DW, Gale LA. Evaluation of the effect of a long-term trap-neuter-return and adoption program on a free-roaming cat population. Journal of American Veterinary Medical Association 2003, 222:42-46.
[A study of a TNR program on a Florida college state campus over 11 years. At end of study, the population had decreased by 66%. This one was odd as the first census wasn’t completed until 5 years into the program so the actual drop since the start of the program was quite a bit more than 66% — one reviewer described it as an 86% decline based on a total 155 cats being handled but it isn’t clear to me whether all 155 were present at the beginning of the program]

Hughes KL, Slater MR. Implementation of a Feral Cat Management Program on a University Campus. Journal of Applied Animal Welfare Science 2002, 5(1):15-28.
[A two year report on a TNR program at Texas A&M University. After two years, 158 cats were trapped, 32 adopted, and the population was stabilized with no more litters or nursing mothers observed after the second year. No more litters will of course mean the colony will likely decrease through attrition]

Hughes KL, Slater MR, Haller L. The effects of implementing a feral cat spay/neuter program in a Florida county animal control service. Journal of Applied Animal Welfare Science 2002, 5:285-298.
[A study of a six year TNR program in Orange County, Florida. This one was not directly a study of the efficacy of TNR in reducing population, although you could maybe extrapolate a stabilized population based on the impound rate, despite the human population increase during the 6 year study. The more interesting finding in this study was the significant savings of TNR when compared to the previous cost of trap and euthanize. Just thought I would throw this in as getting more bang for your public dollar is all part of the practical animal control equation]

>>
>> “I think bird control is the major concern now a days.”
>
> Yeah, those vast swarms of chickadees, nuthatches and
> goldfinches sure are a problem.
>

Again, what’s with the knee jerk snarkiness?

Bird control is indeed a major concern in some areas. You can find serious bird control efforts near some flight paths and in many urban and coastal areas where some birds can cause unsightly and/or unhealthy results. Feral bird control is also a concern for some agricultural and poultry businesses. Some birds can also cause serious property damage.

Again, even a tiny amount of research into this before indulging in snark would have revealed an entire industry devoted to bird control services and merchandise.

A more measured response would have to be ask what relevance does bird control have to this particular discussion. I can’t think of any relevance. And I’m not aware any major bird control issues in our neck of the woods. Sounds like a non sequitur to me.

>> “Yes, cats can reproduce rapidly… an argument why TNR has a better
>> chance than cat-kills.”
>
> Sorry, I don’t follow your logic. Neither dead cats nor neutered
> cats can breed.

You’ve missed the relevance of the discussion following this statement about colony population growth. If the observations from that study are accurate, unmanaged colonies with any breeding members tend to reestablish themselves fairly quickly. So a kill policy really only has a chance if ALL the breeders are killed before nature takes it course. This is probably both hard to do and very expensive. But a TNR policy can remove the breeders WITHOUT also reducing the capacity stresses that would normally result in another colony growth spurt so the entire colony doesn’t need to be trapped within the short window that a kill policy has. This makes TNR both easier and cheaper than a kill policy.

In addition, another advantage that I haven’t addressed yet is the cooperation of civilians. Despite the cartoons, I suspect animal control rarely involves patrolling officers randomly picking up strays as they happen to spot them. That would likely be a hugely inefficient process. Most animal control is probably done in response to citizen requests/complaints. But many citizens do not want the cats killed. A kill policy often gets little cooperation from cat lovers, which again makes it very difficult to kill all the breeders in an area before new kittens refill the gap. On the other hand, it’s much easier to get cat lover cooperation with a TNR policy (even volunteer support!).

A kill shelter also contributes to the number of abandoned cats as many cat owners who can no longer care for their pets and cannot find someone to adopt them are reluctant to have them killed in the shelter. A no-kill shelter option could help mitigate this.