That sketch looks pretty similar to the one provided by a reader of this blog in the second picture below. Does it not?
Tuesday
3 hours ago
Thursday, March 16, 2006
Great minds think alike?
An article on LiveScience.com shows the sketch in the first picture below--this appears to be the Sibley group's illustration of the Luneau bird's position in Frame 33.3.
That sketch looks pretty similar to the one provided by a reader of this blog in the second picture below. Does it not?
That sketch looks pretty similar to the one provided by a reader of this blog in the second picture below. Does it not?
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6 comments:
Where is that bird launching from? It's definitely out of scale of the measurements of the tree that Cornell gave. Is it even in scale with the bird that appears on the other side? Is there something else the bird could have flown from? These are the same arguments posted to the sketch posted here earlier.
Have to read the paper...
I haven't seen the actual Science articles yet, but based on this article, it sounds like Fitz has a better case than Sibley*. I particularly don't understand this part of the article:
"There's a black patch on the wingtip as it's flying away, but it should be all white on an ivory-billed woodpecker," Sibley said. "The pattern of black and white just doesn't match what ivory-billed woodpeckers should show and does match what a pileated shows."
Can someone explain why an Ivory-billed should show all white on the wing tips? Aren't their primaries almost (or entirely) black?
*Though I'm not saying that Fitz has necessarily disproved but the null hypothesis as mentioned in the article, but if we'd start with the assumption that both sides have to prove their case, the Cornell side sounds more reasonable to me. Yes, I know that science doesn't work that way. Blah, blah, blah.
One comment in this article from Sibley rings true to me which is that the tips of an Ivory-billed should be whiter. If you look at the photo on Cornell's site of the bird overhead in flight the white makes a straight line across the full length of the wing. I have a copy of a painting by Eckelberry (of last accepted sighting fame) that shows the same thing. Same thing if you look at Sibley.
But if you look at Gallagher and Harrison's sketches of what they saw it looks more like just the secondaries are white. And if you look at the IBWO model that Harrison built to use in the reenactments he recreates that same degree of black in the underside of the primaries. I'm not convinced that an ivorybill couldn't have different flight styles but I always had an uneasy feeling about this specific issue.
The wing tips of what's in the video are very black.
the veeb
The wing tips of what's in the video are very black.
But I'm still not getting the significance of that. Most of the primaries of an Ivory-billed are black, too.
I will concede that the shape of the black in one of the frames is better for Pileated, but again, it comes down to having only a small proportion of the frames available showing this, which brings into question its reliability.
Sibley says...."On an ivory-billed woodpecker, only the outer six primary feathers are black to their tips, creating a relatively small black patch on the wingtip that ends abruptly where it meets the outermost extent of the white trailing edge and does not curve back along the wing;"
Now I do see many frames that have too big of a black tip and what it really is is the missing black fringe along the trailing edge of the wing.
Very subtle but this whole thing is subtle.
I asked a video "expert" friend of mine about where the missing, semi-missing, black fringe could possibly be. He took one look at the video and said "motion blur".
He explained that White will obliterate Black on film or video but not vice versa. He explained it this way. Black is the absence of photons so the film records nothing. But if during the same frame, white due to motion blur overlays the black then the video will record white.
But the reverse is not true! Black will not erase White in the same video frame. He said that since we are looking at compressed video that it's even worse. We are actually looking at several frames compressed into each frame.
So on the down stroke, for instance, the black is there but as the wing moves it is replaced by white in each frame due to motion blur. In fact, that's why the white looks so large. It's smudged over a greater area than it really should be.
Sounds plausible
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