Thursday, March 06, 2008

Some old news

On the woodpecker front, cleaning up something from last year I missed...

In all the fun of 2007, I somehow managed not to catch that Mike Collins had posted a video he took in Florida early in that year. I quit checking his site quite a while ago after he made a habit of launching into surreal explosive diatribes against anyone who disagreed with any aspect of his reports (a list which rapidly came to include virtually everyone but himself). Anyway, Mike says this video shows one of the two birds he saw and identified as Ivory-billed Woodpeckers. Unfortunately, this video shows a Pileated Woodpecker. He sees a white underwing with suggestions of a dark stripe up the middle of the underwing. I see blur caused by motion, focus, and pixilation, which inevitably will make an elongated object against a bright background appear light around its perimeter and dark on a stripe up the middle. I base my ID of the bird on its flight. The bird shows full upward extension of the wing at the beginning of the downstroke, which is maintained all the way through to the bottom of the stroke. This is typical flight for a Pileated Woodpecker, and is unlike the flight of the bird in the Luneau video which never extended its wings fully upward or laterally in any of the visible wingbeats.

ADDENDUM: Mike dismisses my Ivorybill writings as "uninformed opinions from the sidelines." Funny, he used to actively seek out my "uninformed opinions" and even quote them in support of his own views, until the first time I disagreed with him on anything. He doesn't yet grasp that it is this behavior, more than anything else, that has completely undermined his credibility with most people involved in this discussion. But back to the evidence. Love it or hate it, the Luneau video is the only video or movie footage that substantial numbers of birders and ornithologists think might even possibly show an Ivory-billed Woodpecker in flight with any minimal clarity at all. It is also the only video of a North American large woodpecker that actually shows a flight style that is not obviously the same as typical Pileated flight. Mike's Pearl videos don't hardly resolve anything but vague flapping. The Choc videos don't clearly resolve flight style either, and aren't in fact undeniably even of woodpeckers. Hence, Luneau is the only empirical comparison material available. Mike's theoretical calculations about what flight styles should be, along with Louis Bevier's theoretical calculation about what wingbeat rates should be, are not real comparison standards. In Mike's Florida video, the flight style is clearly resolved. It matches actual Pileated videos closely; it does not match Luneau. Mike mentions wingbeat rate again, also. The significance of wingbeat rate per se in the first few flaps after takeoff has been show to be nil.


At 4:24 PM, Blogger Tucano said...

Hi Bill,

I have a question for you. How do you know that the bird in Luneau's video is a woodpecker?

I think the first time I encountered this question was in Cyberthrushe's site and it intrigued me. If one accepts Cornell's interpretation of the video then it is easy to conclude that the bird is indeed a woodpecker but if one accepts the Sibley et al interpretation of frame 33 then it is not clear.
In Sibley's interpretation the bird is in flight with its wings pushed all the way up. In this case it would seem that the only thing we can say is that it is a largish black and white bird. The rest of the discussion about the particulars of the distribution of black and white is where all the disagreements rest.


At 9:01 PM, Blogger Bill Pulliam said...

Because according to Cornell there is nothing behind the tree for a non-woodpecker to perch on.

At 8:51 AM, Blogger Tucano said...

Yes, I also subscribe to the interpretation that
the bird was perched on the trunk woodpecker-like.

But in the alternative interpretation of Sibley et al the bird is in flight not perched, or at least has just taken off. In that case I don't think one has grounds to affirm that the bird is a woodpecker. In that case even the taxonomic family has to be established by the analysis of the patterns of black and white. I was under the impression that you didn't agree with Cornell's interpretation of the part of the video where the bird is behind the tree trunk.


At 10:34 AM, Blogger Doug said...

To my friends and me, all experienced birders, neither the Luneau nor the Collins video is definitive. So for now, it all comes down to the credibility of those claiming to have seen the IBWO and the quality of their reported sightings. We all hope for that no-doubt-about it video and/or photo. I am grateful to Mike Collins, Bobby Harrison and others who are working to find, document and protect the IBWO.

At 12:39 PM, Blogger Tim Allwood said...

The Luneau video is a PIWO.

The Collins video is not worth discussing.

The new sighting on Hill's site is poor indeed and at odds with an IBWO. It makes Hill look an even bigger chump. I fully expect the artist / observer to do a painting and sell it.

At 7:58 PM, Blogger Bill Pulliam said...

Tim, have you even bothered to read in detail and actually seriously attempt to understand any of the counteranalyses that disagree with Sibley et al.? I've not seen any evidence you have; you simply dismiss them with a snark or two and no actual re-rebuttal of your own. You seem to believe you have The Truth direct from god and needn't even listen to anyone who disagrees because you already know they are wrong by papal decree. This in fact puts you in the same category as Collins.

At 3:16 AM, Blogger Tim Allwood said...

Hey Bill

Of course, I've read lots and lots of subsequent analyses of the video (from both sides). See Bevier, Sibley, Collinson, Howell et al, ad nauseum. There is nothing to serioulsy suggest IBWO with any level of confidence at all.

But to be nice for once, yours is the only opinion from the believer side that i would invest any faith in as you know your birds and seem like a level-headed chap. Unfortunately this is what sets you apart from other TB folks.

Over and out. Quality blog by the way Bill.

At 7:55 PM, Blogger Bill Pulliam said...

Fair enough, Tim, and thanks for the compliment. I didn't really intend to dredge up all the old arguments again anyway, I just thought (for some reason) I should address this one item that I and many other people had somehow overlooked. As I said last September, until and unless something really new becomes public knowledge there's little more to say on all the old stuff and almost no opinions left to change.


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