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sibley’s science paper on ivory-billed woodpeckers

The long-anticipated response [1] to the Cornell Ivory-billed Woodpecker paper [2] has been published in Science, the journal that published the original paper, along with a response from some of the original authors [3]. The authors are well-known field guide author and artist David Sibley; birder and tour leader Louis Bevier; Michael Patten, Director of Research, Sutton Avian Research Center; and Chris Elphick, of the University of Nevada-Reno.

Sibley et al. argue that the video image and sound recordings, evidence presented in the original paper, “cannot be taken to confirm the species’ presence because they do not provide independently verifiable evidence.” Like woodpecker expert Jerry Jackson, the authors believe the bird in the video is a Pileated Woodpecker. Jackson wrote a thorough, thoughtful essay in the last issue of the Auk [4] outlining, among other things, why he did not believe the original Science paper provided enough proof. Although the Auk is a peer-reviewed journal, the Jackson piece was not peer reviewed, as it appeared in a non-scientific section of the journal entitled “Perspectives in Ornithology.” Just about everybody and his brother has weighed in on this topic, but the Sibley et al. paper is the first peer reviewed refutation to be published.

In the response, the subset of original authors argue that Sibley et al. are mistaken in their analysis. I needn’t go on, because, really, here’s the bottom line. The video is obviously not conclusive, or there wouldn’t be much debate. A plausible alternative for what appears on the video (that it is a Pileated Woodpecker) cannot be conclusively disproven.

In the Sibley paper, similar analytical tools were used to reach a different conclusion than in the original paper, akin to two researchers performing the same experiment and getting different results. Nor have the “results” presented in the first paper been replicated in two years of herculean effort. An in the world of science, a situation of this nature would generally be considered to be at the “back to the drawing board” stage. And I think that’s where the IBWO is at. Still awaiting rediscovery.

[1] Sibley, D.A., L. R. Bevier, M. A. Patten, and C. S. Elphick. 2006. Comment on “Ivory-billed Woodpecker (Campephilus principalis) Persists in Continental North America.” Science 311:1555a.

[2] Fitzpatrick, J. W., M. Lammertink, M. D. Luneau, Jr., T. W. Gallagher, B. R. Harrison, G. M. Sparling, K. V. Rosenberg, R. W. Rohrbaugh, E. C. H. Swarthout, P. H. Wrege, S. Barker Swarthout, M. S. Dantzker, R. A. Charif, T. R. Barksdale, J. V. Remsen, Jr., S. D. Simon, and D. Zollner. 2005. Ivory-billed Woodpecker (Campephilus principalis) persists in continental North America. Science 308:1460 – 1462.

[3] Fitzpatrick, J. W., M. Lammertink, M. D. Luneau, Jr., T. W. Gallagher, and K. V. Rosenberg. 2006. Response to Comment on “Ivory-billed Woodpecker (Campephilus principalis) Persists in Continental North America.” Science 311:1555b.

[4] Jackson, J. A. 2006. Ivory-billed Woodpecker (Campephilus principalis): hope, and the interfaces of science, conservation, and politics. Auk 123:1-15.

Filed in Birds, Science

Comments on this entry are closed.

  • Tom Andersen March 17, 2006, 3:28 pm

    So you're saying you don't think the ivory-bill still exists or you don't think the discovers have demonstrated that it exists? Or in your mind is there no distinction between the two?

  • Nuthatch March 17, 2006, 5:47 pm

    Well, I'm pretty agnostic on this one. I do not think the Cornell folks offered proof the bird exists, and I am disappointed that Science published the evidence as conclusive, and that the media picked it up as conclusive (although most MSM are not experts on this topic and distribute what they are given). Although I'm sure it was done with good intentions and went to good causes, the hard sell fundraising by both Cornell and TNC, based on such debatable facts, makes me uncomfortable.

    Before this happened, I thought there was very little probability that there were Ivory-billed Woodpeckers in the U.S. What has been offered so far perhaps raises the slim possibility a bit, but if I had to say one way or another whether the bird is extinct, I would say that yes, I think it is.

  • P.M.Bryant March 18, 2006, 12:02 am

    I just read both the Sibley paper and the Fitzpatrick response.

    I haven't reviewed them in detail yet, but I found the Sibley paper to be less than impressive. The analysis done by Fitzpatrick et al appears to be far more thorough than that done by Sibley et al.

  • B and B March 18, 2006, 3:17 am

    Ivory-billed questions

    There is a new paper out in Science magazine that purports to cast doubt on the last year’s celebrated rediscovery of the Ivory-billed Woodpecker in the forests of Arkansas. The first author is David Sibley, renowned birding author and artist.

  • Cindy March 19, 2006, 12:00 pm

    appreciate the links- and I think along the same line as you..
    I think alot of different agendas came into play at once over the IBW.. and not all of them were for the welfare of a bird species.

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