SPRING 2003/VOLUME 17, NUMBER 2



In Defense of Bird Feeding

On December 27, 2002, a front-page article in The Wall Street Journal proclaimed, “Crying Fowl: Feeding Wild Birds May Harm Them and Environment. It Lures Pests, Causes Illness; Changing the Relationship Between Man and Nature. A Booming Business in Seed.” A litany against bird feeding, the article provoked responses nationwide from bird enthusiasts and scientists who refuted the article's points and complained about the unbalanced coverage. Several Birdscope readers requested the Lab's point of view. Portions of the response below were printed in The Wall Street Journal on January 22, 2003.

The meandering article by Mr. Sterba on purportedly negative effects of backyard bird feeding was at best patchy in its coverage of scientific questions involving bird feeding and failed to present any of the distinctly positive aspects of this growing hobby.

Although he quoted figures from the Cornell studies of backyard bird mortality, Mr. Sterba missed two crucial points repeatedly emphasized by the principal author of those studies, Dr. Erica Dunn, now at the Canadian Wildlife Service: “bird feeding is not having a broad-scale negative impact on bird populations,” and “bird feeding does not cause mortality to rise above natural levels through exposing birds to unusual danger from window collisions, disease, or predation.” (E. R. Dunn and D. L. Tessaglia-Hymes, 1999, Birds at Your Feeder).

Most egregious of Mr. Sterba's scientific miscues is his reference to our demonstration that a disease caused 60 percent declines in some House Finch populations in eastern North America. He failed to mention that the House Finch itself was introduced to the East Coast several decades ago. Explosive population growth of this highly gregarious bird throughout the eastern United States made the species unusually vulnerable to a common bacterium, to which native bird species had long since become resistant. Bird feeders may have accelerated the spread of House Finches, but our work suggests that the Mycoplasma epidemic would have spread even in the absence of bird feeders. Disease prevalence increases most rapidly in late summer and fall, when Houses Finches visit feeders only sporadically, and is lowest during midwinter, when finches visit feeders regularly. Most important, the epidemic was not present among any native bird species common at bird feeders in the same region during the same period, and has failed to spread in western North America, where the House Finch itself was native. All animal populations are controlled to some extent by disease, and it was only a matter of time before the eastern House Finches encountered this one.

Mr. Sterba missed an even more important point about the House Finch disease story: tens of thousands of interested citizens across the country who enjoy nature by feeding birds are also contributing information that allows us to study the natural dynamics of this infectious outbreak, plus dozens of other key questions about North American bird populations. Indeed, the well-demonstrated scientific and educational potential of these citizen scientists—often using bird feeders as tools for monitoring and teaching—has prompted the National Science Foundation and the National Institutes of Health to support several major research projects engaging the general public in the process of studying daily, seasonal, and year-to-year fluctuations in bird numbers. From their purely aesthetic value in millions of backyards, to their usefulness in building inquiry skills among classroom students, to their applications in peer-reviewed, quantitative, environmental monitoring, bird feeders present extraordinary connections between our human culture and the natural world. To suggest that they are damaging because they are also used by squirrels and chipmunks, or that they spread diseases that reduce bird numbers, is to ignore a large and growing body of scientifically demonstrated information.

John W. Fitzpatrick, Director, Cornell Lab of Ornithology, and André A. Dhondt, Director, Bird Population Studies

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Suggested citation: Fitzpatrick, John W. In Defense of Bird Feeding. Birdscope, newsletter of the Cornell Lab of Ornithology, Spring 2003. www.birds.cornell.edu

For permission to reprint all or part of this article, please contact Miyoko Chu, Editor, Cornell Lab of Ornithology, 159 Sapsucker Woods Rd., Ithaca, New York. Phone (607) 254-2451. Email mcc37@cornell.edu