In a joint media release, the American Bird Conservancy and The Wildlife Society team up to misrepresent the results of a recent predation study, decrying the “ongoing slaughter of wildlife by outdoor cats.” Meanwhile the University of Georgia researcher contradicts her previous position that “cats aren’t as bad as biologists thought.”

“To be persuasive we must be believable; to be believable we must be credible; credible we must be truthful.” —Edward R. Murrow

“‘KittyCam’ Reveals High Levels of Wildlife Being Killed by Outdoor Cats,” declares a media release issued today—a joint effort of the American Bird Conservancy and The Wildlife Society, and, to my knowledge, the first of its kind.

It’s difficult not to see this as an act of desperation—the PR-equivalent of an all-caps e-mail. I’m surprised it hasn’t happened sooner, though, given all that ABC and TWS have in common. Their shared disdain for TNR, obviously, but also their utter disregard for science, scientific literacy, and the truth about the impacts of free-roaming cats. Two peas in a pod, as it were. (Irony: peas are, alas, not native to North America.)

And so, their joint media release is exactly what one would expect: heavy on errors, misrepresentations, and glaring omissions, and light on defensible claims.

The Study

The KittyCams project was conducted by Kerrie Anne Loyd, a doctoral candidate in the Warnell School of Forestry and Natural Resources at the University of Georgia. As her advisor, Dr. Sonia Hernandez, explains on her website, Loyd “analyzed hunting and risk behaviors (crossing roads, encountering predators, contact with other cats, etc.) to address questions related to predation of cats on native wildlife as well as about the type and frequency of cat risks.” Hernandez and Loyd are, we’re told, “interested in improving the welfare of both cats and wildlife and continue to work on educational materials using images and statistics from the “KittyCams” project.”

Interested in the welfare of cats? I have my doubts—in part because Loyd was among those former Smithsonian researcher and fellow Warnell alum Nico Dauphiné thanked “for helpful information, advice, ideas, and discussion in researching this subject” in her 2009 paper “Impacts of Free-ranging Domestic Cats (Felis catus) on Birds in the United States.” [1] And we all know how interested Dauphiné was in the welfare of cats.

In any case, although Loyd’s work has not yet been published either as a dissertation or in a peer-reviewed journal (hardly the seal of approval its typically made out to be, though, as I’ve pointed out previously), we know a bit about it from information she’s made available online as well as through interviews.

Some of which Loyd might want to forget about.

In today’s media release, Loyd is quoted as saying: “The results were certainly surprising, if not startling.” In an interview with CBS Atlanta in April, though, she expressed surprise of a very different kind: “Cats aren’t as bad as biologists thought,” she conceded.

Not the sort of thing that goes over well with the Anti-TNR Establishment. Perhaps Loyd’s “revised” comments are her way of making amends.

Percentages

“Of particular interest,” notes the media release, “bird kills constituted about 13 percent of the total wildlife kills.” Thirteen percent of how many? As the Athens Banner-Herald reported in April, “just five of the cats’ 39 successful hunts involved birds.” [2] That’s right: five. Fifty-five cats, 2,000 hours of video—and just five birds.

Such games are typical of ABC and TWS, of course. Whatever it takes to keep the witch-hunt alive!

Bird Species

Which species of birds are we talking about? Are these common? Rare? Native? Non-native? Etc. It’s curious that ABC and TWS, which claim to be concerned with the “ongoing slaughter of wildlife,” aren’t troubled by such “details.” Interestingly, the only avian casualty documented on The National Geographic and University of Georgia Kitty Cams Project website is an “injured phoebe.” And, as the Cornell Lab of Ornithology website explains, “Eastern Phoebes are common and their numbers are stable or increasing in most areas.”

(Actually, it’s not even clear whether or not the cat behind the camera was responsible for the phoebe’s injury; none of the 13 video clips posted documents a cat coming into contact with a bird.)

Population Impacts

“Cat predation is one of the reasons why one in three American bird species are in decline,” claims ABC president George Fenwick. Where’s the evidence? Certainly not in Loyd’s study!

Indeed, in their contribution to The Domestic Cat: The Biology of Its Behaviour, researchers Mike Fitzgerald and Dennis Turner thoroughly reviewed 61 predation studies, concluding rather unambiguously that “there are few, if any studies apart from island ones that actually demonstrate that cats have reduced bird populations.” [3]

Something else to keep in mind: predators—cats included—tend to prey on the young, the old, the weak and unhealthy. At least two studies have investigated this in great detail, revealing that birds killed by cats are, on average, significantly less healthy that birds killed through non-predatory events (e.g., collisions with windows or cars). [4–5]

As the UK’s Royal Society for the Protection of Birds notes, in refreshingly straightforward language: “Despite the large numbers of birds killed, there is no scientific evidence that predation by cats in gardens is having any impact on bird populations UK-wide… It is likely that most of the birds killed by cats would have died anyway from other causes before the next breeding season, so cats are unlikely to have a major impact on populations.” [6]

If Michael Hutchins, TWS’s executive director/CEO, wants to discuss an “inconvenient truth,” let’s start here.

By the way, outdoor cats are the norm in the UK, unlike in this country where something like two-thirds of cats are indoor-only. [7–9] And, of those that are allowed outside, approximately half spend less than three hours outdoors each day. [7–8]

Previous Estimates “Estimates”

“Based on these results,” notes the release, “American Bird Conservancy and The Wildlife Society estimate that house cats kill far more than the previous estimate of a billion birds and other animals each year.” These folks really ought to read their own propaganda. In their 2010 book, The American Bird Conservancy Guide to Bird Conservation, ABC claims there are “532 million birds killed annually by outdoor cats, with the actual number likely being much higher.” [10]

Among the book’s three authors is… (wait for it)… George Fenwick. (George: I’m happy to send you my copy—frankly, I don’t find it terribly useful.)

Extrapolation

“If we extrapolate the results of this study across the country and include feral cats,” argues Fenwick, “we find that cats are likely killing more than 4 billion animals per year, including at least 500 million birds.”

But nobody claiming to have even the slightest regard for science would extrapolate from five birds killed in Athens, GA, for the purposes of developing a nationwide “estimate.” (No doubt Fenwick is, as is common practice at ABC, also inflating the number of outdoor cats for his calculations.)

The UNL Study Paper

The University of Nebraska-Lincoln “study” referred to in today’s media release was, in fact, nothing of the sort. To anybody familiar with the topic, it’s clear that the paper’s authors have little understanding of the key issues surrounding feral cat management in general or TNR in particular—never mind the relevant science. Hildreth, Vantassel, and Hygnstrom misread, misinterpret, and/or misrepresent nearly every bit of research they reference. And, some of what they include isn’t valid research to begin with.

None of which was enough to discourage ABC, which, in December 2010, referred to the paper as a “peer-reviewed study report.” Now here they are again—along with TWS—once again endorsing a paper that wouldn’t pass muster in a 100-level science course.

Contrary to the claim made by ABC/TWS, the UNL paper didn’t find “that feral cats were responsible for the extinction of 33 species of birds worldwide.” Its authors merely copied and pasted what they’d read elsewhere.

When I untangled this one last year, I discovered that of the 33 extinctions tabulated by Vinzenz Ziswiler in 1967, only eight were attributed to cats exclusively. And, of those just two have stood the test of time: the Stephens Island Wren and the Macquarie Island kakariki (red-crowned parakeet).

(I can understand if Fenwick & Co. don’t want to read their own publications, but they ought to at least be reading Vox Felina!)

“Feral cats prey more on native wildlife than on other invasive creatures”? Again, nonsense.

As I pointed out nearly two years ago, Hildreth, Vantassel, and Hygnstrom misread the very work they cited. What Olof Liberg wrote in his 1984 paper was this: “Most cats (80-85 percent) were house-based and obtained from 15 to 90 percent of their food from natural prey, depending on abundance and availability of the latter.” [11] He was merely drawing the distinction between food provided by humans and any prey that cats might eat as food.

Again referring to the UNL paper, ABC and TWS resort to one their usual tactics: scaremongering. “Most feral cats (between 62 and 80 percent) tested positive for toxoplasmosis (a disease with serious implications for pregnant women and people with weakened immune systems).”

In fact, “testing positive” is not a useful measure of a cat’s ability to infect other animals or people; it’s merely an indication that antibodies are present in the cat’s blood—to be expected after they shed oocysts. [12] And what about those “serious implications”? Actually, researchers suggest that “seropositive cats are likely to be less of a public health risk than seronegative cats.” [13]

• • •

As I say, the ABC/TWS joint media release is exactly what one would expect: an attempt at persuasion not through truth and credibility, as Murrow advocated, but through blunt force—through nothing more than amplification and repetition. Then again, when your position is supported by neither the science nor public opinion what choice have you got?

Literature Cited

1. Dauphine, N. and Cooper, R.J., Impacts of Free-ranging Domestic Cats (Felis catus) on birds in the United States: A review of recent research with conservation and management recommendations, in Fourth International Partners in Flight Conference: Tundra to Tropics. 2009. p. 205–219. http://www.pwrc.usgs.gov/pif/pubs/McAllenProc/articles/PIF09_Anthropogenic%20Impacts/Dauphine_1_PIF09.pdf

2. Shearer, L. (2012, April 24). Kitty cams show what Athens’ roaming cats are up to. Athens Banner-Herald, from http://onlineathens.com/local-news/2012-04-24/kitty-cams-show-what-athens-roaming-cats-are

3. Fitzgerald, B.M. and Turner, D.C., Hunting Behaviour of domestic cats and their impact on prey populations, in The Domestic Cat: The biology of its behaviour, D.C. Turner and P.P.G. Bateson, Editors. 2000, Cambridge University Press: Cambridge, U.K.; New York. p. 151–175.

4. Møller, A.P. and Erritzøe, J., “Predation against birds with low immunocompetence.” Oecologia. 2000. 122(4): p. 500–504. http://www.springerlink.com/content/ghnny9mcv016ljd8/

5. Baker, P.J., et al., “Cats about town: Is predation by free-ranging pet cats Felis catus likely to affect urban bird populations?“ Ibis. 2008. 150: p. 86–99. http://www.ingentaconnect.com/content/bsc/ibi/2008/00000150/A00101s1/art00008

6. RSPB (2011) Are cats causing bird declines? http://www.rspb.org.uk/advice/gardening/unwantedvisitors/cats/birddeclines.aspx Accessed October 26, 2011.

7. Clancy, E.A., Moore, A.S., and Bertone, E.R., “Evaluation of cat and owner characteristics and their relationships to outdoor access of owned cats.” Journal of the American Veterinary Medical Association. 2003. 222(11): p. 1541-1545. http://avmajournals.avma.org/doi/abs/10.2460/javma.2003.222.1541

8. Lord, L.K., “Attitudes toward and perceptions of free-roaming cats among individuals living in Ohio.” Journal of the American Veterinary Medical Association. 2008. 232(8): p. 1159–1167. http://www.avma.org/avmacollections/feral_cats/javma_232_8_1159.pdf

9. APPA, 2009–2010 APPA National Pet Owners Survey. 2009, American Pet Products Association: Greenwich, CT. http://www.americanpetproducts.org/pubs_survey.asp

10. Lebbin, D.J., Parr, M.J., and Fenwick, G.H., The American Bird Conservancy Guide to Bird Conservation. 2010, London: University of Chicago Press.

11. Liberg, O., “Food Habits and Prey Impact by Feral and House-Based Domestic Cats in a Rural Area in Southern Sweden.” Journal of Mammalogy. 1984. 65(3): p. 424-432. http://www.jstor.org/stable/1381089

12. Dubey, J.P. and Jones, J.L., “Toxoplasma gondii infection in humans and animals in the United States.” International Journal for Parasitology. 2008. 38(11): p. 1257–1278. http://www.sciencedirect.com/science/article/B6T7F-4S85DPK-1/2/2a1f9e590e7c7ec35d1072e06b2fa99d

13. Vollaire, M.R., Radecki, S.V., and Lappin, M.R., “Seroprevalence of Toxoplasma gondii antibodies in clinically ill cats in the United States.” American Journal of Veterinary Research. 2005. 66(5): p. 874–877. http://dx.doi.org/10.2460/ajvr.2005.66.874