Monday, February 20, 2006

Analyzing the Luneau bird's underwing

From an anonymous source:
To supplement what has been posted earlier by yourself and others, this is my take on just four frames from the Luneau video:

Because I think the pattern of the underwing is the most diagnostic feature in the video, I chose the four frames which show the underwing the best. Please note that I didn't choose or reject frames to illustrate my point, I simply chose the four "clearest frames" of the upraised wings.

Along the left side of the composite are the four frames showing the Luneau bird with upraised wings, flying to the right, with the white being the underside of the right wing. On the right side of the composite, at the top, is a frame from a Tanner/Allen film of the 1930s showing a known Ivory-Bill. On the bottom is one of Cornell's blurred Pileated frames. The two black and white drawings are images from the original Cornell Paper from last spring. The upper is a Pileated and the lower is an Ivory-Bill.

As the Cornell drawings show, the underwing of both birds is largely white with a black wingtip, with the major difference being that the Pileated has a black trailing edge, while the Ivory-Bill has a black stripe through the center of the wing.

To my eye, the Pileated frame is virtually indistinguishable from the Luneau frames, and would be an even better match if it were angled exactly the same. I can see the black wing tip, the white underwing, and what may or may not be a black trailing wing edge. I see these same features in the Luneau video AND the Pileated video.

Furthermore, in none of the Luneau frames do I see any indication of the black stripe that runs through the center of every Ivory-Billed wing. It is not the AMOUNT of white that is diagnostic, it's the PATTERN of the black and white.

I also think Cornell's point about the narrow wing shape of the Ivory-Bill (as shown in the top, right frame) actually works against them. To my eye, each of these four frames shows what appears to be a shorter, more rounded wing, much more like a Pileated than an Ivory-Billed.

In short, I agree with Kaufmann, Jackson, Sibley, Prum and others; the Luneau video probably shows a normal Pileated Woodpecker.


Anonymous said...

There's quite a bit of "a frame here, a frame there" rebuttal happening, but there has been no systematic rebuttal of the entire tape presented yet. I hear rumors, but nothing is published. It makes one wonder if the rebuttals are having a difficult time convincing disinterested reviewers that they are robust enough for publication.

Anonymous said...

Given that the video doesn't seem to have anything going for it, I don't think that is the case. Be patient.

Anonymous said...

If the Cornell paper got published, I seriously doubt there will be much resistance to getting a well-written rebuttal paper accepted.

I'm confident we'll see such a paper well before we see a good photo!