Tuesday, February 15, 2011

-- What's David Up To? --

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I thought David Sibley was rather tired of addressing the Luneau video, and the topic of Ivory-bills in general (barring new evidence coming along), so am a bit surprised he has put forth a couple of "recently-revised" posts/discussions at the very time the topic is essentially dead for so many birders...

one is here (which includes several recent comments):


and the other is his fairly methodical analysis of the Luneau video here (forcefully arguing the bird captured on film must be a Pileated):


Is this some sort of pre-emptive strike against Cornell's anticipated defense of their analysis to come later this year in an eventual summary report? ...Or a slap at the brief, undetailed dissing USFWS (in their final report), gave the skeptics/Sibley analysis? ...Or just attempting once-and-for-all to pound some final nails in the coffin of this disputed video? I don't know. Just that the timing seems odd, to be returning yet again to this particular debate.
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9 comments:

fangsheath said...

Perhaps some day someone independent, with as much, if not more, knowledge of videography than birds, will re-examine the Luneau video. I hope so. I for one find Sibley's rehash tiresome and painfully sloppy, and like his original analysis, it says much more about him than the Luneau video. For example, Fitzpatrick et al. did not say that white lines on the back of the Luneau bird were obvious and indisputable. They said, "We regard the presence of white on the back of the Luneau woodpecker as obvious and indisputable." This kind of willful sloppiness is all too apparent in Sibley’s original analysis. The fact that his own drawings of specific Luneau frames show an all-black body where there is obvious pale color speaks volumes about someone who is a renowned artist.

David Sibley said...

Hi Fangsheath, I've just updated my website to correct the quote about white on the back. It doesn't change the fundamental point I was making at all, so I hope you can get past any personal issues and consider the content of my post now.
I agree that it was a mistake to add color to the interpretive sketches that I did for the Science paper. Those should have been simple outlines showing my interpretation of the position of the bird. I disagree that there are any frames showing "obvious pale color" on the body, but it's also not clear that the body is definitely black, and drawing it that way provides an easy target and a distraction from the more important point which is simply the position of the wings and body in each frame.

concolor1 said...

David, the question by CT and Fang was in regard to your timing on re-releasing this material.

Got anything to say on that one?

The scientists here know that it's impossible by definition to "prove a negative," i.e. there are no more Ivory-bills...

It's reasonable to conclude there may be no more IBWO's, but it's also reasonable to conclude they may indeed persist... What I've seen on the former is a lot of "Because I say so" justification, which is wholly unscientific.

Given the material that's reached my inbox, I also think the issue of credible eyewitness reports has to be addressed. And that's coming from an essentially uninvolved "lurker" who's a thousand miles away from "ground zero" but did grow up in the "Bigfoot Propaganda Capital" of the United States. I didn't solicit any of the IBWO reports although I welcome them and have enjoyed the "conversation." We've also got quite a few UFO believers here, and trust me on that one, I can tell the difference...

UFO and Sassie believers are mostly hostile sorts (Jeffrey Meldrum is an exception, but he's also pretty much just a gonzo drama llama who's been thoroughly discredited by his peers); IBWO "supporters" haven't been noticeably hostile except when confronted with strawmen and shell games...

Buck said...

The scientists here know that it's impossible by definition to "prove a negative."

So you can't prove the Luneau video is not a Pileated, right? And you can't prove the stuffed Ivory-bills are not actually ducks?

"any claim can be expressed as a negative" Stephen Hales.

concolor1 said...

Keep tryin' there, Buck. You'll learn this stuff yet if you try hard enough. We "Sputnik kids" learned it way back when after the Ruskies scared the bejesus out of us. That was a very brief Golden Age in U.S. public eduation (I learned about it in teachers' school), and if you want to look at a negative that should have people hollering for positive changes, take a look at Texas schools' test scores that were recently released. It's a travesty. They even make Planet Utah here look good.

To address your strawman-flavored analogy, one "proves the positive" which therefore "eliminates a negative" from consideration. Or at least from reasonable consideration.

The stuffed ivory-bills are not ducks because they are something else. It therefore becomes unreasonable to suggest they are something ducks.

That's strictly dichotomous/black-and-white stuff you're trying to engage with that Luneau video claim, and if you were genuinely looking at matters objectively--noting that some are certain it's an IBWO, and some believe equally strongly it's not--you'd recognize the only black-and-white is found in the bird's feathers, regardless of whether it's an IBWO or a PWO.

And that's a shell game tactic with that "claims can be expressed as a negative" that you tossed in there. Of course they can, but in order to then disprove that negative, you have to "prove a corresponding positive" which eliminates it from hypothetical consideration.

Buck said...

The strawman is "you can't prove Ivory-bills are extinct." Of course not. Not to a mathematical certainty. But the burden of proof is on the claimants, not the skeptics.

I used those examples for a reason, you "eliminated my negative" by "proving" a positive, the stuffed birds cannot be Pileateds because they are demonstrably Ivory-bills. That's exactly what the "Believers" need to do with living Ivory-bills, isn't it?

"The Ivory-bills WERE here. But they flew somewhere else before the cameras arrived." That's a shell game.

I can't prove that the Tyrannosaurs are extinct in a philosophical sense, but I can still know it in a real world sense, can't I?

David Sibley is an honorable man and from the beginning has demonstrated a lot of good sense on this issue.

concolor1 said...

Lessee...

But the burden of proof is on the claimants, not the skeptics.

Because you said so?

Q.E.D.

The bar hasn't been raised by the skeptics? And there are no ad hominems aimed at the claimnants?

That's a pretty perjorative set of quotes you put around "Believers," incidentally...

I posted a few months ago about a Peregrine Falcon that three witnesses saw in my parents' suburban back yard. Nobody seems to doubt that one...

I also find it interesting you picked a T. Rex as an example, rather than, say, a coelacanth...

And in a strict philosophical sense, T. rex persists as well...

http://www.washingtonpost.com/wp-dyn/content/article/2007/04/12/AR2007041202043.html

>The first results, described in today's issue of the journal Science, show that the collagen protein in T. rex bone is extraordinarily similar to that of the modern chicken, confirming current thinking that dinosaurs' nearest cousins are birds.

Sorry, I just can resist slipping back into my teacher slippers...

BTW, you're engaging in further strawman stuff with the unspoken implication we don't believe Sibley in an honorable man...

Some of us would like a few questions answered, that's all (even if the answer is an honest, "I don't know").

Now perhaps he could address them himself...

FAV said...

It’s refreshing to see Mr. Sibley respond positively to a pertinent, critical and corrective comment by Fangsheath. There seems to be a small chance that Mr. Sibley really wants to settle the AR video question via a conciliatory, constructive and amicable way.

The dispute weakens the overall community in many ways whatever side you’re on, and impacts the conservation of the Ivory-billed.

Many of us feel, and certainly CT has mentioned it several times, that the subject species in the AR video should be determinable by independent study. These species are quite different.

Here is a preliminary proposal that is appropriately novel for the situation. I have always contemplated smoking guns that might be simple to measure yet diagnostic. This led to immediate wing beat Hz consideration which has been used for decades to accurately group conspecifics or distinguish between congenerics flying, sometimes at great distances from the observer. For example Snowy Egrets vs American, Sharp-shinned vs Copper's Hawks, A. Crow vs Fish, etc.

Another simple but unexplored data set of the AR bird is the distance traveled in the ~ 4 s and derivatives such as speed. Although I have never mentioned such a nuanced "concept" until now, the AR bird always seemed to subjectively cover relatively more ground than a PIWO is physically capable of in 4 sec.

If a PIWO, it can travel a certain maximum distance and reach a maximum speed in the 4 s. I hypothesize if its an IBWO, the distance that bird traveled would exceed the maximum distance a PIWO can travel in 4 s and top observable PIWO speeds would be exceeded.

There would be an adjustment for acceleration acceptable to each camp. The PIWOs distance and speed
will be determined by all parties searching and finding the fastest PIWO in existing videos. New videos might also be accepted. The skeptics/study can use the fastest PIWO that can be found in the thousands of tapes.

The distance traveled by the AR bird must be measured in the exact DeView position by a neutral, capable, independent and willing surveyor(s) or equivalent. A conservation group has some funds towards the project assuming that an individual(s) like Mr. Sibley, from the skeptical camp will also contribute, discuss and agree to the project parameters, map the flight path in relation to trees, assist in compiling the PIWO control data set, distribution of final results, etc.

Thanks, Fred Virrazzi

fangsheath said...

In my opinion both Fitzpatrick et al. and Sibley et al. suffer from far too much subjectivity and this rehash is more of the same. Quantification of pixel values, among other things, is called for, and above all, much more data on pileateds. Interested persons might want to examine pixel brightness values on the putative body of the Luneau bird with different wing positions and compare to the Nolin videos (deinterlaced, of course, for proper comparison). I have done so and find the results quite interesting.

Incidentally, I agree with Sibley et al. that the Luneau bird is likely seen with wings largely open in the "perched" frames in which pale color is clearly visible. Both sides in the debate have badly misinterpreted some data in my opinion. Independent assessment is needed.