Thursday, March 15, 2007

-- M. Collinson Paper --

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First let me say, that Dr. Collinson has presented an excellently-written/argued paper for BMC Biology, which 1+ years ago would've brought much to the discussion (I think overall it is better than either the Sibley or Jackson pieces). And I don't want anything said here to take away from the quality or eminent fairness of his presentation, nor the effort that clearly went into it.

I s'pose rules are made to be broken, because long ago I wrote that I would not discuss the Luneau video any further since there was NOTHING left to say --- it is unresolvable and further inconclusive debate is largely futile... yet I'm now forced to revisit it again, as Collinson presents but another analysis of that Luneau film via use of a fleeing Pileated video for comparison. Others will debate many of the technical points Martin lays forth (and which are debatable), I'll only lend a few broad thoughts here.

In the end Collinson says (in that wonderful British way of understatement), that concluding the Luneau bird is an Ivory-bill, is "probably unsafe" --- I totally agree; in fact I'll go farther than that --- long ago I wrote (and my view hasn't changed) that it is NOT 100% certain that the Luneau bird is even a woodpecker --- the ASSUMPTION that this bird is clinging to the side of a tree trunk at the onset of the video remains for me unproven --- it is behind a tree, and the precise orientation of its body, not to mention the placement of its feet, are UNKNOWN. (I think the evidence is 'good' that it is a woodpecker, but by no means a certainty, and IF a woodpecker than the IBWO vs. PIWO debate can go on endlessly). Further, it is vitally important, given the headline summaries of this article flying around the internet, to realize that Martin does NOT say the Luneau bird IS a Pileated Woodpecker (though he clearly favors that), he essentially says that it is not at all INCONSISTENT with being a PIWO. Moreover, in his abundantly fair conclusion Martin writes:
"This does not of course necessarily imply that the Ivory-billed Woodpecker is extinct, nor indeed entirely rule out the possibility that the bird in the Luneau video was one. There appears to be no reason to question the anecdotal sight records of Ivory-billed Woodpecker presented in Fitzpatrick et al [1] (or in many online sources), because some of them appear credible, albeit brief... The Ivory-billed Woodpecker may persist in continental North America, and there is enough anecdotal evidence to make this a possibility, but the Luneau video does not support the case. The balance of evidence would suggest that the bird in the Luneau video is more likely to have been a Pileated Woodpecker, but the search for Ivory-billed Woodpecker should continue."
Cornell might, but I have no problem with this conclusion at all.
But here IS the problem --- the Luneau video is but one tiny bit of evidence, yes, ONE tiny bit, out of 50+ years worth of sightings/claims; this continual emphasis on it makes it appear to an unwary public (including many birders) that if IT is debunked than the Ivory-bill does not exist afterall. In actuality, the ENTIRE Cornell case can be thrown out and there would still be enough evidence to justify the current widespread searches throughout Southeastern N. America. Even though he didn't intend it, I fear the Collinson paper once again draws attention away from the breadth of evidence out there and back onto this one pinpoint of interest. And in doing that it creates a lot of sound and fury, but signifies little that hasn't already been said many times over, just without the particular piece of evidence (David Nolin film) Collinson employs.

A final note: On his webpage at one point Dr. Collinson describes himself as not so much an Ivory-bill skeptic as a "universal data skeptic"
--- I like that. That's very much how I see MYself --- having worked in biology or medicine most of my adulthood and probably never seeing a set of data I was comfortable with. And with the paucity and age of data available on Ivory-bills (their sounds, behavior, habits, cavities, etc.), and even Pileateds for that matter, I think it is difficult to draw firm conclusions about so much of the evidence placed before us --- which is why we ought proceed with utmost caution, and with serious consideration of the one thing that has always been central to birding, sightings, and thusly await patiently the completion of rigorous, systematic, thorough searches of appropriate habitats however long that takes --- I'm not sure, but I have a feeling Martin just might agree with that...
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3 comments:

Anonymous said...

As expected, Bill Pulliam has an interesting take on this paper and his blog is worth a visit.

Anonymous said...

"There appears to be no reason to question the anecdotal sight records of Ivory-billed Woodpecker presented in Fitzpatrick et al [1] (or in many online sources)"

Apparently Collison has never visited the Ivory-bill Skeptic Blog. Perhaps he should have done more homework before publishing this statement.

Anonymous said...

I apologize for misspelling his name; it is Collinson with an "n"

Dan Collison is a radio producer who visited Brinkley when it embraced 'The Lord God Bird'

I stand by my critique, as it seems strange to uncritically endorse sight records as credible and not in need of questioning in a peer-reviewed paper and then to state in a blog posting that the sight records are so poor as to not merit serious review by a bird record committee.