Thursday, January 19, 2006

My take on the Luneau video

Jackson's critical article is out now and it does not contain any detailed analysis of the Luneau video, just an opinion. So I looked at the video again... since no rigorous analysis seems forthcoming. Several things I noted this time:

Very important: The apparent black edges around the white on the wings (leading and trailing edge, and wingtip) are identical in width and intensity to the black halo artifacts around the oar and hand in the forground. Thus it would seem that nothing can be inferred about the color of the trailing wing edge or wing tips. The only definite black is the body of the bird; any real black that may surround the white on the wings cannot be resolved from the halo artifacts.

Now, looking at how the white comes and goes on the wingbeats. The bird appears from behind the tree early in a downstroke. Only the right wing is fully visible. Abundant white is clearly visible throughout this stroke. The bird is dropping relative to the background. All of this white could easily be on the underwing. The second downstroke shows the same pattern, this time more clearly.

Beginning on the third downstroke, the bird is no longer dropping relative to the background. On this stroke, there is a point in mid-downstroke where the visible white diminishes. It then increases again at the bottom of the downstroke. This same pattern repeats more prominently on the forth downstroke: Abundant white initially, then a fading of the white in mid-stroke, then a reappearance of white. The same is seen on the fifth, sixth, and seventh downstrokes.

By the eighth downstroke, the bird is clearly rising relative to the background. Beginning at this stroke, the white no longer fades in mid stroke. Rather, it is evident to a similar amount throughout the stroke. This continues with subsequent wingbeats, as the bird gets more distant and disappears intermittently behind trees.

Ok now that damned interpretation thing...

What seems rather clear to me is that for the first two downstrokes, we are seeing entirely (at least on the clearly visible right wing) underwing. Then, on strokes 3-7 (especially clear on 4-6), we see initially underwing, then a fairly edge-on view of the wing, then upperwing. Finally, on strokes 8-10, the bird is traveling away and upwards, and we see upperwing the whole stroke. This is a bird with extensive white on both the underwing and the upperwing. It is not a normal pileated woodpecker.

But we really need an expert in image analysis to examine this video and account for every feature of every frame.


At 10:22 PM, Blogger Mike's Soap Box said...

Hello Bill:

I just finished reading Jackson's 15 page Auk article. It was not surprising to see T. Nelson as one of his contributers to his Auk paper.

Its funny after the guy (Smitty)who spent countless hours monitoring the Spotted Owl in SE Arizona dies he gave all his data to Suart Healy. I know Stuart and birded with Stuart and Stuart has a lot of issues and a lot of birders not liking him. After reading Jackson's article I wonder "man if Jackson dies will he appoint Tom to be his replacement?" A lot of the article came from a lot of Tom's blog postings. I think or believe Tom contributed to the points of where Jackson was telling the readers that this sighting is a Pileated and not a Ivory-billed Woodpecker.

Here is my prediction: After a few years or even after this year this whole Ivory-billed chatter will dies down and the "official" searches will end, the tours will die, the souveniers will be sold in flea markets, no media and life settles back down to where it was before the announcement. Tom Nelson's blog will go back to gadgets and stocks chatter and most importantly Tom Nelson's birding skills will still not improve, and he will continue to send absurb listing records to out state journal.

All this will die some day and I am waiting for that day. In fact I cannot wait for that day to happen! Tom is going to be like one of them ex-child TV stars. He most likely will go thru some sort of depression after all the this hoopala dies out and his blog dwindles to comments from porn ads and single ads!! Oh time cannot move fast enough!

I like your comments and your blog! Keep up the good work!

Mike Hendrickson
Duluth, MN

At 1:22 PM, Anonymous Anonymous said...

May I suggest that anyone and everyone who has a video camera should go out and try to flush Pileateds off of trees and see if they can duplicate the Luneau video? We just need more video of woodpeckers flushing off a tree from near ground level and then gaining altitude.

At 5:33 PM, Anonymous Anonymous said...

J. Jackson's paper says that Fitzpatrick admits the six=pixel perched bird is probably a tree branch. Will you address this issue in a future post?

Another Hopeful Skeptic

At 5:51 PM, Blogger Bill Pulliam said...

I never did believe in that perched bird thing, actually...


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