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7/24/2014 6:10 PM
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  Countering the predation issue

Question from Cathy:

I know you have addressed the wildlife predation issue before, but I was wondering if you could give your top arguments of what you would say when people bring up this discussion. The reason I ask is that our group is working on developing a TNR program but we have one guy with a wildlife degree who always quotes these studies about the decimation on the wildlife population by these non-indigenous cats and how they must be removed. Some people give him credibility because of his degree and I'd like to have some short, well-thought out responses.

Nathan Winograd's response:

One of the golden rules of advocacy is to tailor your response to your audience. You do not want to sound like an encyclopedia, nor do you have to get overly detailed, nor do you have to know the intimates about every study. Don't lose sight of the forest for the trees. You are, in the end, an advocate. Respond succinctly, in a straightforward and thoughtful manner.

My favorite strategy is to write a detailed, scientific position paper, which is sent out to people in the community--the media, commissions, city council, friends, allies, other groups, VIPS, caretakers, whoever your target audience is. But when I make speeches, when you actually go before the commission, or council, or are interviewed by a reporter, I make a different argument--one of compassion, and lifesaving. That two pronged approach (scientific analysis on paper to rebut the claims of Mr. Wildlife Degree in your community, and a broad message of showing kindness to cats in person) is effective.

I always start with the efficacy of TNR for all the reasons I won't repeat here. How it works, how it reduces impounds and deaths in shelters, how it protects public health. I always end with the humane argument. How the cats are out there through not fault of their own. And how we can choose kindness over killing. In the middle is the nuts and bolts:

A. The starting point of any analysis in assessing wildlife predation is a two fold inquiry: 1. does the species exhibit predatory behavior? and, 2. how much? In other words, does the predatory behavior adversely affect the prey populations? "In biological systems it is insufficient merely to have found one animal will eat another, that is what predators do--[the more important question is whether that] is predation within normal limits." (Tabor, The Wild Life of the Domestic Cat, Arrow Books, 1983.) In short, is there evidence that cats actually negatively impact the prey populations?

Paul Errington identifies the problem: "Preying upon a species is not necessary synonymous with controlling it or even influencing its numbers to any perceptable degree. Predation which merely removed an exposed prey surplus that is naturally doomed is entirely different from predation the weight of which is instrumental in forcing down prey populations or in holding them at given approximate levels." (See Ellen Berkeley, Maverick Cats: Encounters with Feral Cats, New England Press, 1992.)

B. The studies cited by Mr. Wildlife Degree not only utterly fail to address the impact of cat predation, but they are severely flawed in their methodology. (I SAY THIS WITH A FAIR DEGREE OF CONFIDENCE, BECAUSE EVERYONE ON THE ANTI-CAT CITE USES CHURCHER'S STUDY IN ENGLAND AND THEN COLEMAN'S STUDY IN WISCONSIN FOR THE PROPOSITION THAT CATS ARE DECIMATING BIRDS).

Chucher looks at what kind of prey cats were bringing home in an English Village. He then extrapolated from that to come up with how many cats were killing birds across Great Britain. So, for example, if 10 cats bring in 100 birds, then 1,000 cats kill 10,000 birds, and so on. By guessing as to how many cats were in Great Britain, Churcher concluded with an astronomical number of killed birds. But is science really that simple? For one, how did the birds die? did the cats kill them? were they roadkill? were they fledglings who would have died anyway? was there any indication of disease in the prey? was the catch freshly killed or were the cats dead for days? Being scavengers more than predators, few cats would pass up injured or dead birds? In fact, Churcher has no qualitative information whatsoever. All of this missing information could have been supplied with little additional effort.

For example, two French researchers Moller & Eritzoe examined birds killed by cats vs. those that met accidental deaths by crashing into windows. They examined the birds for various factors, the most significant of which was the health of the bird. They found that while windows were non-discriminating and killed healthy and sickly birds equally, the birds cats killed were significantly sicklier than those who crashed into windows, with 70% of them slow movers and fledglings!

But more importantly, Churcher ignores that several hundred birds in his village must die each year to maintain a stable population, that the highest number of birds brought home were at the time of the first broods (lots of already doomed fledglings!), and that the village's bird density was 9 x higher than the rest of Britain?

So taken together, what does Churcher actually prove? "Taken together, these elements suggest another interpretation: cats are simply weeding out birds from an overcrowded population. Nor are they apparently catching healthy birds at their peak of winged life; wintertime is most stressful on birds that are old or sick, and fledglings tumbling down from nests could account for the high count in early summer. And with only 130 dead sparrows recorded by Churcher, the cats kill--or find--less than half the numbers that must be annually culled to sustain their populations." (J. Elliott, "Of Cats and Birds and Science: A Critique of the Churcher Study," 1994.)

Two years after that original "study," all pretensions of scientific objectivity disappear. In his second paper, he describes cats as "ruthless killers," predation as "the slaughter," while prey is a "luckless mouse," or a "very frightened baby rabbit." Is this science?

Coleman in Wisconsin is even worse. In his paper, "Cats and Wildlife: A Conservation Dilemma," Coleman states that "Recent research suggests that rural free-ranging domestic cats in Wisconsin may be killing between 8 and 217 million birds each year," citing footnote 10. And what is footnote 10? An article in Wisconsin Natural Resources written by HIMSELF. Coleman cites himself. So let's look at the article. What does it say? "Here are our best GUESSES at low, intermediate and high ESTIMATES of the number of birds killed by rural cats in Wisconsin" BASED ON THE SAME OVERSIMPLIFIED, HGH SCHOOL LEVEL FORMULA THOROUGHLY DISCREDITED IN THE CHURCHER STUDY. For one, it is not RESEARCH. It is a GUESS. Second, there is no basis for the number of cats he GUESSES live in Wisconsin. Third, is a range from 8 to 217 million a statistically valid range? Absolutely not. It shows a shockingly low level of scientific rigor and confidence. Finally to get at his low and high estimates, he ASSUMES cats kill rate is 20% on the LOW end and 30% on the HIGH end. Is this fair? Studies in nine states had the range as "Few" on the Low end to 3% and 20% on the high end. If you eliminated the Few and the 20% which are off the curve, it would be a 3% range to 14% on the high end for percentage of total prey being birds. A New Zealand study had it pegged at 5% by scat analysis, in Australia it was 5.2%, and another study in New Zealand had it at 4.5% in only 12% of the cats! Coleman's numbers are off the charts and over inflate his "findings." But even then, he is making assumptions that aren't valid: he assumes millions of cats, he assumes they are all allowed outdoors, he assumes they are all young and agile and able to hunt equally, and he assumes each one is regularly killing birds despite the fact that as many as 50% of people do not let their cats outdoors, that American cats are getting fatter and less agile, that American cats are living longer and cannot hunt as well as they get older, and that some cats are just lazy or lousy hunters.

Coleman is a guess, not a study. It is, worse, a bad overly inflated guess. In an interview with a reporter in 1994, even Coleman admitted as much: "The media has had a field day with this since we started. Those figures were from our proposal. THEY AREN'T ACTUAL DATA; that was just our projection to show had bad it might be." But that hasn't stopped anti-cat groups from using the stuff as if it was handed down from Mt. Sinai.

C. There is a large body of scientific literature that is ignored by Mr. Wildlife Degree, precisely because it contradicts his conclusions.

Roger Tabor found that cats have low success as bird hunters and that the bulk of their diet is garbage, plants, insects, and other scavenger material. In short, cats are not impacting bird populations on continents. Fitzgerald & Karl found that "cats suppress populations of more dangerous predators such as rats and thus allow denser populations of birds than would exist without them." Robert Berg found that cats were not impacting quail population in San Francisco even though quail nest on the ground. Mead found no evidence that cats are impacting overall bird populations. Colemand & Brunner concluded that "The common belief that feral cats are serious predators of birds is apparently without basis." A Worldwatch Institute 1994 Study found that birds are in decline due to drought, habitat loss, overtrapping, and water pollution. Cats are noticeably absent as factors. A 1988 study by the University of Georgia blamed forest fragmentation across Southern U.S. for decimating songbirds. A Colorado Wildlife Dept. study in 1994 blamed drought. National Geographic lined declines to poisons in environment, particularly lawn care products.

C. TNR actually helps meet the goals of Mr. Wildlife Degree because... (Here I would note all the reasons I mentioned in past posts, which I won't repeat here, about the alternative being do nothing, meaning cats are breeding, roaming and foraging for food, I would note that neutering significantly reduces roaming which means less contact with wildlife, and I would note that even if the cats were killed, other cats would move in to fill their territorial void left by cats). Less cats, controlled feeding, means less hunting. Here, you might also note that many studies have found that upwards of 75% of birds killed by cats are non-native starlings which compete with native birds for habitat, so that the net effect of cat predation may actually be complementing the goals of native species advocates.

D. Where does it end? If we must kill cats because they kill birds, where do we draw the line? (some think this argument is silly, but I have found it very useful as the media tend to like it a lot.) A lot has been written about the supposed controversy surrounding feral cats, much of it of dubious value. Common sense, not statistics or hard-line arguments, could have pointed the way, as it did as early as 1949 when then-Governor Adlai Stevenson of Illinois, vetoed a bill to restrain cats: "We are all interested in protecting certain varieties of birds. That cats destroy some birds, I well know, but I believe this legislation would further but little the worthy cause to which its proponents give such unselfish effort. The problem of cat versus bird is as old as time. If we attempt to resolve it by legislation who knows but what we may be called upon to take sides as well in the age old problems of dog versus cat, bird versus bird, or even bird versus worm. In my opinion, the State of Illinois and its local governing bodies already have enough to do without trying to control feline delinquency." So why, 50 years later, is Mr. Wildlife Degree still belaboring the point?

E. Indigenous vs. non-native wildlife. Mr. Wildlife Degree's proposal to round up and kill cats because they are "non-native" is based on a troubling belief: value comes from lineage, and worth as a species stems from being here first. The belief that some species of animals are worth more than others because they were here first is backward-thinking and shortsighted. But it is hardly surprising. The call for extermination of animals in the name of protecting others deemed more worthy by some arbitrary standard is not new. "Cats kill birds, so we must kill cats." This is the banner under which Mr. Wildlife Degree and other native species advocates have long rallied to label cats as "pests" of our cities and "invasive non-native" intruders in our parks and countryside.

But cats aren't the only ones to be targeted for slaughter in the name of protecting other species or preserving "native" habitats. They have been joined at different times and in different places by red foxes, gulls, cowbirds, elk, sea lions, coyote, mountain lions, ravens, skunks, raccoons, wild horses... the list goes on. Referred to as "garbage animals," "alien" species, "weeds," and "vermin," these creatures have become scapegoats for the massive habitat destruction, environmental degradation, and species extinction causes by one species and one species alone: humans.

For nativists, the point is clear: the lives of these animals don't count, and therefore they can and should be eliminated to protect more important species and to preserve "natural" environments. Had we honored and preserved life, had we treated all animals--cats, birds, and every other creature who shares our planet--with the respect they each deserve, we might have spared many of the species now lost forever.

To us, there are no "garbage" animals and slaughter and death aren't the tools we need to preserve life. To do that--to preserve the life of all animals--we believe we must honor and preserve the life of each.

I hope that is a helpful starting point.