The debate about TNR between TNR advocates and some wildlife (especially bird) advocates gets
really venomous.
The one thing on which everyone agrees is that the goal is zero homeless cats. The question is
the most effective method to get there. (Actually, the anti-TNR groups like to portray TNR advocates as psychologically deranged self-serving cat hoarders who have no interest in reducing the feral/free roaming cat population. But the fact is the goal of TNR and TNR advocacy groups is zero feral/free roaming/community cats).
The most vocal opposition to TNR includes The Wildlife Society, The American Bird Conservancy (ABC Birds), and some members and field offices of the U.S. Fish & Wildlife Service (though the U.S. Department of the Interior has no official position).
I have studied the problem of cat predation extensively, as it is the primary argument against TNR programs. My research has been used to help shoot down bills in Wisconsin and Florida that would allow the hunting of cats. I responded with an extensively researched letter to the State of New Jersey when one of the Department of Environmental Protection's councils proposed reclassifying domestic cats to "exotic animals" (which would have allowed them to be legally hunted). I also publish research taking apart poor scientific studies used to support anti-TNR positions. I publish here:
http://www.straypetadvocacy.org/cat_predation.html
TNR is not a perfect solution, and it is just one piece of what needs to be an overall strategy. A multi-prong approach is required, one that includes low-cost spay/neuter programs, adoption programs for strays and kittens, leash laws that do not impede the practice of TNR, and educational programs at a minimum.
The facts are that we've achieved an approximate 82% spay/neuter rate among our pet cats in the U.S., and currently only about 50% of people allow their pets to roam at all. So when it comes to our pet cats, we're dealing on the margin here. And while I don't have a problem with the ABC Birds' Cats Indoors! educational campaign in theory, I have a problem with it because it comes with so much rhetoric and a funded, concerted campaign against TNR programs and all feral/community cats.
One of the many debates hinges on the question, how many feral cats are there? TWS, ABC Birds, and the USFWS like to greatly inflate the number of feral and free roaming cats. But the bottom line is that no one knows how many feral cats there are in the U.S. Numbers range from 13 million (winter)/24 million (summer) all the way to a multiple of the number of pet cats (currently approximately 86 million). That first estimate (13/24 million) is based in some kind of science (surveys cross-referenced with road kill data, typical wildlife estimation technique). The number most frequently tossed about is 100 million feral cats, though that number has no basis in science or statistics.
Whether or not feral and roaming pet cats are reducing the bird/rodent populations is a real hot potato.
Yes, cats hunt. Yes, fed cats hunt. Yes, in cats the "prey/hunt" instinct is not dependent on the "hunger drive." Yes, it is true that domestic cats are not native to the Americas, but they've been here for (at least) three centuries, and our birds evolved in the presence of predators.
So
are domestic cats impacting the bird population?
Clearly, in island or isolated habitats, the answer is yes. On the North American continent? It's not clear at all that they are. Don't forget, two of the most populous birds in the U.S. are the House Sparrow and the Starling. Both are non-native species. In bird-hunting cats (and not all cats hunt, and not all hunting cats hunt birds), these species represent the largest portion of bird kills. So maybe the cats are helping to provide an ecological serivce (OK, that's a stretch, but I hope you get the point).
The fact of the matter is that cats are rodent specialists. Some cats do hunt birds, and some very successfully. But cats are first and foremost opportunistic, and one thing that studies of cat predation on birds does not take into account is the possibility of cats scavenging dead or injured birds.
The real problem is that the habitat is being destroyed. Our cities and suburbs are eating up their habitat, our farms are killing their insects and poisoning the environment with herbicides and pesticides. The leading expert on bird glass collisions estimates that 1 billion birds die each year (in the U.S.) from flying into windows.
So while it is possible that someone's feral cat colony is responsible for the lack of birds in somebody else's backyard, it may be due to many reasons, and what we're seeing is a coincidence. Or the birds are now visiting a back yard that doesn't have cats prowling around. One thing is for sure, the majority of birds that are at risk from cats are ground feeders. Cats don't fly.
I think the "solution" of feral cat sanctuaries, in an ideal world, is wonderful. But when so many towns and cities don't even have the funding for TNR programs or low-cost spay/neuter programs, where's the money going to come from? And in places that have explored the option, where to locate such sanctuaries have been subject to incredible and often heated debate.
Ultimately, TNR has proven to be a more effective method of feral cat management than trap-and-kill because
people volunteer their own time, and often spend their own money, to do it. When towns have a trap-and-kill policy, or anti-cat animal control officer, most people do not call to report stray or feral cats. Witness the many posts on TCS who come here to ask what to do - they don't want to call animal control because they don't want the cat killed. So when those towns switch to TNR as an official policy of animal control, people start reporting the animals. Which is going to be more effective?
TNR is more affordable. And it stops the breeding. Let's face it - trap and kill is what brought us to where we are.
To implement trap-and-kill with any efficacy to reduce the feral/free roaming/community cat population, you need animal control officers, people willing to trap the cats and take them to county shelters, where they have to be held for minimum holding periods (taking up valuable space and time for cats that could be adopted out!), and then a licensed vet has to be paid to euthanize them, and then disposal has to be paid for.
Cat eradication programs have been implemented on a number of islands. These are instructive.
http://www.messybeast.com/eradicat.htm One example is Marion Island. The island is 12 miles long and 8 miles wide. It took 16 years to eliminate between 2,500 and 3,400 cats from the island.
Statistical models indicate that for trap and kill to be effective at reducing the cat population (not eliminating it), you need a successful trapping rate of 50%; for TNR to be effective, you need a successful sterilization rate of 70%. (Happy to provide the references if you're interested).
The anti-TNR advocates like to ask, "how many volunteers will it take to trap 70% of 100 million cats?" The same question can be asked of them - how can towns and cities across the country afford to trap 50% of 100 million cats? In fact, the anti-TNR groups generally have no "plan" other than opposing local legislation that supports TNR efforts: e.g. feeding bans should be implemented, and the cats left to die, getting hit by cars, eaten by coyotes, or starving to death. ALL of their "plans" (other than feeding bans) are targeted at domestic pets, and completely ignore the feral and community cat populations. The problem? Those feral and community cats keep breeding while they're still alive. And I've yet to see any one of these plans address this issue beyond leash laws, mandatory spay/neuter laws, (both policies that target pet cats, not ferals) and feeding bans.
The comments (3 pages of them) in reply to this blog is an excellent portrayal of the debate between TNR proponents and the wildlife conservation contingent in an incredibly civil discourse:
http://magblog.audubon.org/feral-cat...s-dollars-year (BTW, here's my published response to the article Audubon addresses in the blog:
http://www.straypetadvocacy.org/PDF/17reasons.pdf)
If you take the time to read through the blog comments, please note that Peter Wolf analyzes the published research related to cat predation (
http://www.voxfelina.com). It was a publication by Travis Longcore that got Peter interested in digging into the research used by the anti-TNR people in the first place. Travis Longcore is a Professor at UCLA, and Science Director at the Urban Wildlands Group, the group that brought suit against Los Angeles to stop a city-wide low-cost spay/neuter program from being implemented because vouchers could be used for feral cats. And I'm Laurie.
Now, all of that said. There are places where TNR is not appropriate. And in those instances, Alley Cat Allies, Best Friends, and other TNR groups/advocacy orgs or the local groups and people, participate in relocating the cats. There are areas where there are threatened species, and removal of the cats is appropriate.
But you should know, it's not always that simple. There are also areas where there are threatened species, and removal of the cats has been disastrous. It depends entirely on the flora and fauna of the area. There are several island habitats where cat removal programs were implemented but the programs failed to take into account the non-native rabbits and/or non-native rodents. Without the cats there to depredate the rabbits or mice (or whatever), the explosion in rabbits devastated the birds' nesting grounds, or the explosion in mice meant that eggs were being eaten, not hatched.
It's a controversial subject. But for me, while a part of the issue is what is humane, part of the issue is what is going to work.
I have a somewhat unique perspective on this, I think, because I wasn't a cat lover. I liked cats, as I like all animals. But I was a bird watcher. When cats turned up in our yard, we called animal shelters. When no one would help, we started researching what to do. So I entered TNR with no preconceived notions, and no particular love of cats. That happened later.
If you're interested in references, studies, links, whatever, just let me know.
