Cornell's Luneau video analysis is now available here.
2/9/06 update:
In no particular order, here are some of my first impressions of this analysis:
1. Amazingly, they are still defending the "six-pixel bird", with no mention of it probably being a branch stub.
2. To me, their Pileated Clip 11 looks quite similar to the Luneau bird. As an experiment, if you told a number of "believers" that this was a clip from the Luneau video, I'd be willing to bet that a large percentage would express confidence that Clip 11 shows an Ivory-bill, based on both fieldmarks and "jizz".
3. They show us a video of a Franklin's Gull, leisurely flying away. This is supposed to "prove" that a fleeing Pileated's dorsal wing surface should be prominently visible when viewed from behind.
This comparison makes no sense to me. Instead of admitting that their stiff-winged Pileated re-enactment model was seriously flawed, they went far afield to find a species where a stiff-winged model might have been more reasonable.
4. In my view, this is unrelated to the video analysis, but is notable: "... a few molting pileateds showing some extra white on the wing have been spotted in the Big Woods region of Arkansas".
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10 comments:
The one thing I don't like about the analysis, is that the camera
in the boat for the Luneau video was presumably no more than
a foot or so off the ground...
or you couldn't see so much of the person in the canoe.
I don't know how this influences the video, though presumably the
flight of the water bird shown (species already escapes me) would look different if the videographer's camera were
closer to the ground.
On the whole I find the evidence intriguing but not very satisfying.
It's better than I hoped for but
there's an unprovable assumption
behind every important assertion.
The perched bird assumption is their weakest, and they did save that one for last. The spreading of the wings slightly as the bird pushes away from the tree to take off.. that is a hard one for me too. And that is supposed to be
showing the white upperwing of an
IBWO. I can't see how the wings
could spread so much in a hidden
bird to show the upperwing.
Why isn't this the underwing I wonder?
And this part is the tightest part
of their analysis IMHO.
Finally, of course, we don't know enough about IBWO's flight to be able to say... this couldn't be a weird Pileated. Did anybody
hear the wooden wingbeats that day?
Paul Sutera - New Paltz, NY
"In Figure S4 in Fitzpatrick et al. (2005) (above) we demonstrated that the wrist-tail distance of the bird in the Luneau video is in the range of 34-39 cm. This is entirely consistent with Ivory-billed Woodpecker and too large for Pileated Woodpecker, which measures 26-31 cm from wrist to tail tip."
That would be true if that was how you interpret the orientation of the bird at that point.I see an almost frontal view of the bird. That which you state is the wrist is IMHO the birds' head. That small extension (tip) is its crest.
The bird is positioned almost vertically and propped away slightly in relation to the tree trunk. The white is the inner part of the wing which it probably flared as it became startled by the approaching boat. Fig.50.
This is a fascinating continuation of events, there must be some comments on this?
Its going to take a few days to go through it, but is anyone who isn't convinced now convinced?
Apart from Tom's comments:
1) The REENACTEMENT doesn't make sense to me - I think this is a joke. The model can't me made to fly like the bird in the video, and feathers could appear differently on a video than paper(i.e. reflect light differently -'white bleeding').
2) WING SHAPE. I disagree with them, because of the problems of accurately measuring this. When I first saw the video, I was convinced that the bird in the video had too rounded wings for an Ivory-bill, as pictures of this showed a narrower wing. Its interesting that measurements of museum specimens show a higher aspect ratio. Notice they show a blurred picture of a real Ivory-bill, that doesn't look like the video, and you can still see the black underwing line.
3) WINGBEAT FREQUENCY. This really is unconvincing. They record a wing-beat hz at 8.6 and compare this to their records of 2-4 beats level flight "and 4-7.5 beats for short periods during hasty departures (n = 5)". "Moreover, experts who have studied Pileated Woodpecker flight using video analysis timed the fastest departures at 7 beats per sec (Tobalske 1996, personal communication). Thus, wingbeat frequency of the woodpecker in the Luneau video is faster than any recorded Pileated Woodpecker".
A sample size of 5 is nowhere near big enough to rule out a Pileated being able to do 8.6, whilst the Tobalske reference (paper published in Auk) is one study where "nonmaneuvering flights with approximately no change in mean altitude were included in the sample". The paper specifically did not look at flapping flight of fleeing woodpeckers. Thus the sample size of fleeing Pileated flights is tiny.
To then try and suggest that this ties up well with the sound recording of an Ivory-bills wingbeats (sample size = 1) is equally flimsy.
4) BIRD LAUNCHING INTO FLIGHT. The whole of this part is wrong, because what they think is the upperwing, is the near vertically held underwing of the bird. Why can't they see this.
5)PERCHED BIRD. This part is a joke.
4) BIRD LAUNCHING INTO FLIGHT. The whole of this part is wrong, because what they think is the upperwing, is the near vertically held underwing of the bird. Why can't they see this.
The website states their reasons for rejecting the "vertical underwing theory" (i.e., lack of a black trailing edge combined with the width of the white that's visible, which they say shows that a vertical underwing would have to be at an angle where that black trailing edge should be visible). That's why they "can't see it".
What do you have to counter their position? At least Cornell presented some reasons behind their assertion.
Notice they show a blurred picture of a real Ivory-bill, that doesn't look like the video, and you can still see the black underwing line.
You can see the black underwing line in that picture, but what affect would the differences in shutter speed and media (film versus a video camera's electronic sensor)?
Regarding Pileated Clip 11, yep this is in many ways similar to the Luneau video of the mystery woodpecker (Cornell says so, so no one here has come to any original revelation)and exactly for that reason this seems to be key. When going frame by frame through this clip occasionally you see extensive white, but in most frames you see extensive black and almost always see black trailing edges.
In essence this clip 11 is really most similar to the re-enactment of the Pileated model and bears little resemblance to either the original Luneau video or the Ivory-bill re-enactment in the consistent amount of extensive white shown on the wings in almost all frames and no hint of anything other than white trailing edges.
Still waiting for someone to produce that Pileated Woodpecker clip that doesn't show black trailing edges in most frames and does show symetrical patterns of extensive white on both the upper and under wing pattern. Waiting, waiting, waiting...hey, this should be easy to do folks. There's a lot of normal pileateds out there and many of us have video cams, so what's the hold-up?
When going frame by frame through this clip occasionally you see extensive white, but in most frames you see extensive black and almost always see black trailing edges.
I need to watch this video some more, but I found the similarities to "the Luneau video" disturbing (and I tend to be on the "believer" side of the fence). It appears to be more in focus than the Luneau video, or perhaps the optical magnification is greater so that the bird takes up more of the frame. Either of those things could account for the black trailing edge being present in Clip 11 and not the Luneau video. I think those issues need to be addressed.
Overall, I have to say I'm surprised by the lack of reaction to the latest analysis. Is everyone still going over it or are your minds already made up so that it's being largely ignored?
"I found the similarities to "the Luneau video" disturbing...It appears to be more in focus than the Luneau video, or perhaps the optical magnification is greater...Either of those things could account for the black trailing edge being present in Clip 11 and not the Luneau video. I think those issues need to be addressed."
They are addressed on the Cornell website, at least indirectly. Whether you're a believer or a doubter, it is important to be objective when confronted with new evidence, such as with all the Pileated clips, especially clip 11. It is clear that any "believer" being diusturbed represents someone being objective (a good thing).
However, this clip 11 is actually very important evidence that supports Cornell's position. This is why it is important to compare Clip 11 of Pileated with the re-enactment of Pileated (and not so much with the original Luneau video)where the purposeful lack of focus still doesn't obscure the blackness of the upper wing, nor the black trailing edge of the underwing (when compared with either the original Luneau video or reactment of model ivory-bill). It is the re-enactment of the Pileated that shows very similar amounts of black on the upperwing and black trailing edge on the underwing to clip 11. This demonstrates the utility of the re-enactments to show how to distinguish a Pileated from a potential ivory-bill even when the videos are blurry.
With the evidence available, we have yet to see any anything to support the notion that a normal pileated can appear the same as what is in the orginal Luneau video with respect to the amount and position of white on the wings. It may be possible that such footage exists, but nothing has emerged yet to discount Cornell's conclusion on this important point that I am aware of.
Clip 11 actually bolsters Cornell's views because of the superficial similarity of clip 11 to the original Luneau Video, but with obvious black trailing edges despite some blurring (as with the re-enacted Pileated model where blurring was even greater). As long as those black trailing edges are seen in almost every frame of videos depicting known normal Pileated Woodpeckers, Cornell's position is supported, at least on this point that normal Pileated can be eliminated from further consideration to explain the identity of the woodpecker in the video.
This doesn't prove the bird is an Ivory-bill, but the alternative explanations become increasing convuluted and remote. I'm sure there will be better arguments against Cornell's interpretation emerging in the future, just have't seen them yet.
Wow, what nice comments I see here. While Cornell is doing their best to argument their findings, the skeptic (read mostly cynical) community just states it is the underwing without any good arguments.
I was in the Dutch Rarity Committee for eight years and I studied dozens of fleeting descriptions, pictures, videos and drawings, so at least I know what I am talking about regarding bird anatomy. Most commenters on this nice blog here obviously should go back in the field or study the first chapters of their field guides and learn what secondaries, primaries, lesser, median and greater underwing coverts really are and where they are!
IMHO I see a bird on the video with white secondaries both on the upperwing as on the underwing. The bird on the tree is really a bird and it is definitely not an underwing (the other perched thing I think is just a thing).
And I seen some white on the back too and you do not have to be an expert to see that.
So imho several observations confirm there is at least a black-and-white woodpecker around with white secondaries.
Here in Europe we think all is just very funny. The extinction / survival of IBW is surrounded by dogma. They can be found only in the oldest and oldest of forest where they need trees that have seen T-rex come and go. Be also skeptic about that. Is that really the case, or is that a dogma, because Tanner and Allen studied the species in such a forest? To be skeptical is a virtue, but be skeptical about everything about IBW, and do not state dogmatically that the Arkansas White River Area is only good Pileated country. You can't be sure about that!
And be fair, how many birders did really looked for them between 1944 and 2000? And moreover, although I regard American birders as the most friendly, helpful, kind, hospitable, genereous etc. birders on the planet, I was never impressed about their birding skills in the field. Even the highest segment of the USA birding community I've met in Europe - Kaufmann, Wilds, Lehman, Dunn, Roberson, I regard them as having just above-mediocre field skills (on the other hand, the best birder in the field ever was an American, Ted Parker!), so the absence of records in that period could be causes by observer-activity as well. And what is wrong with the 1971 record by Fielding Lewis - a colour photo - compared to the last record in 1944 by Dan Eckleberry - a charcoal drawing?
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