The Sibley rebuttal paper is currently available for free here.
The Fitzpatrick response is also available there.
Here are the listed authors of "Sibley's" paper:
David Sibley
Louis Bevier
Michael Patten
Chris Elphick
These are the listed authors of Fitzpatrick's response:
John W. Fitzpatrick, Martjan Lammertink, M. David Luneau, Jr., Tim W. Gallagher, and Kenneth V. Rosenberg
If you want to discuss Sibley's paper and/or Fitzpatrick's response, the comment section of this post may be one good place to do so...
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It's the birders against the ornithologists and various "dudes and stringers".
Its is interesting how the birders have a better "feel" for what's actually true and the Ornithologists have 4 pixel birds.
Nice to see a respectful rebuttal presented finally.
I think it's great that Sibley, et. al. provided a complete frame-by-frame for the beginning of the flight in the supporting materials. It would be nice to see Cornell do the same if they disagree.
One of the things I found most compelling for PIWO was the description of how the translucent primaries of the PIWO would show up as a brighter streak toward the tips. That is definitely evident in
a number of the frames and I don't know how that could be produced by an IBWO wing.
I think Cornell's PIWO wing that they show next to the tree doesn't show the boundary case, PIWO's can show much less black. Would have been nice to see the wing done as a blurry video frame also.
That said, I have to agree with Cornell that I would think a PIWO wing as Sibley depicts in the frames near 33.3 would show more black. Maybe orientation or motion blur account for that. But I've spent the most time looking at the Luneau's takeoff frames and I'm not convinced that Sibley, et. al. have nailed that entirely. But I'll save that for a later post after I've given it some more thought. Basically I'm not seeing some pixels to match what they are describing. One simple example with no consequence is a suggestion that black on the right of the tree in 83.3 could be a wing tip. I see a long line of black artifact appear along the right of the tree at that frame but nothing to suggest a wing tip. Not sure if this is due to different video sources, I'm using Luneau's tif's.
But what I'm left with is... "I wish it weren't so."
the veeb
I wouldn't say they(birders) have a 'feel' for what's actually true. I would instead say they are uptight, mousy types who memorize such things as tertiary feather counts on yellow bellied sapsuckers and comb the fringe on their oriental rugs before company comes over. And as such, they can't stand to have anything in the field of science rely on simple faith until more conclusive evidence poses ever so politely for the camera. That being said, some of my best friends are birders, as am I...
At first glance, what strike me most about the two papers, is their differing views on wing flexibilty. The bird in the video has very flexible, warping, wing surfaces... like a timouse, or dare I say, a Pileated. Fitz, et al seem to be talking about a bird with very stiff wings, their constructed models and open wing photos demonstrate this stiff wing mindset. Sibley, et al talk about twisting wings.
If you want a stiff wing bird think Ivory-bill/Fitz. If you want a flexing wing think Pileated/Sibley.
As for the video...Flexible.
p.d., Ann Arbor, MI
If Cornell could show me a fleeing Pileated, back view, equal distance and amount of blur, yet still showing significant black trailing edges, then I'd say Sibley's analysis doesn't wash.
But instead they chose much "closer" birds that appear to be moving more slowly, and not fleeing directly away from the camera. I'm ready to move on from
the Luneau video. Each side makes
good points. To me, neither is very compelling/convincing.
Paul Sutera, New Paltz, NY
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