There’s another good letter on KeysNet.com about the feral and/or free-roaming cat issue.

Trap-Neuter-Release Works by John Donnelly.  There is evidence to believe that it can.  I found this site, which takes an in-depth look at TNR.  It is critical of TNR, but not reflexively so.  The take-away here is that TNR on its own is problematic, but TNR combined with other methods can be effective.  Another method cited is providing sanctuary – sterilization plus cat enclosures for non-adoptable cats.  Notice that this site, as critical as it is of TNR, does not recommend euthanasia as the first or only option.

We advocate first and foremost socialization and adoption of feral cats. We also advocate enclosed sanctuaries run by non-profit organizations or enclosures on private properties. When those options are not possible we will always advocate euthanasia over release to the wild. For those folks out there who think life and death on the streets is preferred and more humane than euthanasia – think again.

I also found a study that compares three population control methods based on a simulation model.

1. TNR.
2. Lethal control (euthanasia).
3. Trap-Vasectomy-Hystorectomy-Release.

TVHR outperformed both TNR and lethal control at all annual capture probabilities between 10% and 90%. Unless > 57% of cats were captured and neutered annually by TNR or removed by lethal control, there was minimal effect on population size. In contrast, with an annual capture rate of ≥ 35%, TVHR caused population size to decrease. An annual capture rate of 57% eliminated the modeled population in 4,000 days by use of TVHR, whereas > 82% was required for both TNR and lethal control.

The debate in the comments following Donnelly’s letter, as always, devolve into an argument between those who support TNR and those who support euthanasia.  Those who “side” with the cats and those who “side” with wildlife.  Those who believe humane treatment of cats means euthanizing them to spare them from a short and miserable life in the wild and those who believe the cats can exist comfortably in a “managed” colony.

What makes this issue really tough is that everyone makes good points.  The Upper Keys shelter is focusing primarily on euthanasia.  But it’s not working.  There is still a large population of feral/free-roaming cats.  Nobody’s actually keeping track, but there are still numerous reports of large numbers of cats.  Even staunch opponents of TNR acknowledge that.

The abstract mentioned above estimates that a trap rate of greater than 82% is needed to reduce feral cat populations using lethal control or TNR.  That is to say, neither method on its own is terribly effective.  Here’s a little more information on the TVHR study and why scientists think TVHR is more effective at reducing feral/free-roaming cat populations.

Here’s a link to another study that suggests that TNR and euthanasia have comparable success rates at low immigration rates (ie. introduction of new cats).  At high immigration rates, euthanasia is more effective.  But one variable this study doesn’t take into account is the trapping rate.  It simply assumes that a given percentage of the cat population is treated or euthanized.

I have to wonder if people avoid taking animals to the Upper Keys shelter because it has such a high kill rate.  The shelter has noted that there has been a steady decline in the numbers of animals brought in.  At the same time, people continue to report high numbers of feral cats.  Here’s an FAQ about outdoor cats from the Humane Society.  There’s a discussion of why trap-kill on its own doesn’t work – mainly because people are reluctant to participate and because they will continue to feed outdoor cats whether its legal or not.

We can argue over whether feeding outdoor cats is “right” or “wrong” but let’s just be practical for a minute.  If both trap-kill and TNR rely on high trapping rates, wouldn’t it make sense to assume that the method which encourages greater public participation would be more effective?  If people aren’t bringing animals to the shelter how can they be sterilized or euthanized?  The simulation study suggests that TVHR could succeed at much lower trapping rates.  Perhaps TVHR is an idea worth pursuing.

Monroe County government has demonstrated that it is indifferent to the issue.  County staff has gone so far as to distort reported numbers, presumably in an effort to hide differing funding levels.  It’s an indication that they are not at all serious about addressing the issue.  I believe that a change in leadership will be needed before the county is capable of handling this issue responsibly.  Until then, it’s up to the citizens to figure this out on their own.