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41 comments:
I would think that the odds of the Ivory Bill still living would be astronomically higher than the odds of you Skeptics arguing about "Morphometrics" more than a year after the CLO announcement.
That's why I still have hope for our side.
Signed,
The True Believer
....sniff......
Actually we are arguing about the CLO's "More for Me" tricks.
Thank you, thank you very much. You've been a great audience. I'll be here all week.
I would think that the odds of the Ivory Bill still living would be astronomically higher than the odds of you Skeptics arguing about "Morphometrics" more than a year after the CLO announcement.
Who's arguing? It's more the slow head shake of pity. Anybody who has ever done photo ID understands how error prone it is to make highly definitive statements on shape (or even plumage) from low quality images. That can be true even of decent quality images. The fact that the "science" supporting the IBWO's existence is lagging these well known pitfalls by decades is pathetic.
BTW, if they do find an IBWO, the quality of evidence provided thus far will still suck. That's why everybody wants a real picture, even us skeptics.
Fascinating that this is all still being argued back-and-forth. No one giving any quarter for over a year now.
I was struck with a commentary on another thread by the Herpetologist "Fangsheath" making the argument that the hypothesis explaining away the bird in the Luneau video ws essentially a normal pileated was rejected. Not sure if there are connections, but about the same time there was a rekindling of talk about supposedly huge populations of aberrantly white Pileateds out there on this thread to explain away the video.
Now it is true from a birding perspective the proof based on a grainy short video is not something that would past muster with most State Checklist and Record Committees (Arkansas may be an exception), but if the only published challenge to the Luneau video that the pictured bird could be a normal pileated is rejected, and there is no published rebuttal regarding it being an aberrant pileated (Blog chatter doesn't count), then from a scientific standpoint, the hypothesis promoted by the CLO still stands as the most parsimonious explanation, though in my opinion is still short of proof.
Even with the chatter here and elsewhere regarding the potential for an aberrant pileated, such descriptions from the White-Cache rivers of a purported IBWO don't match any of the described birds by Jim Bednarz nor the leucistic version that was well photographed. So can't be both a normal or an aberrant pileated involved, perhaps it's neither as they would seem to cancel out the arguments for a pileated all together.
Now why did "Fangsheath" pronounce the Sibley et al. hypothesis rejected? Don't know for sure, but perhaps their explanation requires a type of flight mechanics for sustained flight no where else documented (that I'm aware of anyway) AND no video of a known normal pileated (regardles of angle, distance, blurriness)when viewed in its entirety remotely comes close to showing the amount of white frame-by frame that is shown in the Luneau video (plus flashes of white on the back of the bird in multiple frames). Perhaps that is why Sibley et al. were reduced to showing hand-drawn illustrations and a couple of individual frames only of launching birds to support their theory of twisted wing motion.
The Nolin videos discussed elsewhere and here of pileateds definitely illustrate a number of relevant points in these discussions. Some frames do seem to show nothing but white on the underwings when blurred, (point for the skeptics), but in their entirety most frames on all the scenes show obvious black trailing edge (where it ought to be, and not wierdly positioned through twisting as suggested in Sibley's drawings) and wings nearly all black dorsally (set and match for the proponents?).
The key here it seems is with not just a launch sequence or a frame here and there to support the skeptics argument. It is with sustained flight in the entirety of the Luneau video. If the bird in the Luneau video is most likely a Pileated, then why can no one duplicate it, and if the sustained flight style is "twisted" then why is there no model of flight that documents that such a style actually exists?
See http://www.biology.leeds.ac.uk/staff/jmvr/Flight/modelling.htm
for an interesting page purportedly demonstrating how birds actually fly. Perhaps someone has a similar reference to back up the twisted style for sustained flight that I'm not aware of.
Anyway, where does this all lead me? Mostly frustrated. IS there proof from a bird checklist and records committee perspective that at least one ivory-billed woodpecker occurred/occurs in eastern Arkansas? That is clearly debatable (on, and on, and on...). and by definition is not considered to be proof that everyone agrees on (but even state records and checklist committees accept records that not everyone agrees with; yeah I know this is a special case).
Is there a valid published alternative based on either a normal or an aberrant pileated to explain the images? Nope, appears not to be, unless Sibley et al. or someone else can produce a pileated video that duplicates Luneau's and publish in a peer review journal a new interpretation of how birds conduct sustained flight.
No matter how much proponents and skeptics beat their chests over this, the evidence is what it is, no more, no less. We can say at minimum it remains unresolved, but to ignore the existing evidence would be irresponsible.
Cheers
"Anyway, where does this all lead me?"
Your treatise, may I call it that?, leaves you twisted like a pretzel. Buddy, what are you talking about? Somehow you conclude that the proponderance of evidence supports CLO's interpretation? Based on what? Fangsheath? Are you smoking the silly weed?
The only thing you said that was right was "...to ignore the existing evidence would be irresponsible." Yes, and all the evidence points to IBWO being extinct and the Luneau video being a PIWO.
In fact, there is not one shred of evidence to the contrary.
In response to the preceeding, largely incomprehensible comment I'd like to point out that 1) the burden of proof is on the proponents, not the skeptics, 2) it is not parsimonious to assume that a very large, conspicuous North American bird not confirmed for 60 years has reappeared and is glimpsed and heard repeatedly by novices, zealots, and stringers but can't be photographed or seen by unbiased expert birders and 3) Fangsheaths credibility is limited at best (see previous comments on this blog).
The Blom article is nothing short of classic.
Methinks thanks you for the post.
Anon wrote: but if the only published challenge to the Luneau video that the pictured bird could be a normal pileated is rejected,
_________________________________
Dude, the Sibley et al. TC was not rejected, it was peer-reviewed, accepted and published in Science. It has never been rejected or even with it's miserly word count, been refuted. Fang may reject it, but Dude, I do not know a single ornithologist or birder who doesn't accept that Sibley et al were correct - with the exception of thoise on the Fitzcrow et al paper. I don't know how you get that that the most parsimonious explaination is that the bird in the Luneau video is a bird unrecorded for 60 plus years, when there is a published description of how it can be one of the most common birds in the area.
The rest of your note flows fromn the "rejection of the TC" standpoint, and that, methinks, is an error. You are grabbing one line from Fang - which is unsupported - and running. We don't need aberrent plumaged PIWO to make the PIWO ID stick, and we don't need leucistic plumaged PIWO - the bird is a regular ole PIWO.
Few questions - are all of the models on the web page stiff winged -- can the "feathers" flex at all? It doesn't seem so. It seems more like the bogus stiff-winged model in Fitzcrow Rebuttal than a "real" bird.
Is there a rear view of a flexing bird (easy there you "Got Pecker" Boxer fans)?
How did the authors of the TC respond when/if you sent this to them (I am assuming that they don't post to this site)?
Didn't Fitzcrow et al say wings don't twist in their rebuttal. They do twist though. Isn't it fair to show that first wings do twist (hence the Sibley et al. images of wing twisting on take-off, ignored bu CLO), which obviously the reviewers did not know? Twisting is most extreme on take off, but the PIWO in the Luneau video is only a few flaps from the launch position.
And now, to my favourite,
What is the black-white-black object that Fitzcrow claims 1. helps him sleep at night and 2. is the IBWO a few seconds before the PIWO is in view?
if the only published challenge to the Luneau video that the pictured bird could be a normal pileated is rejected, and there is no published rebuttal regarding it being an aberrant pileated (Blog chatter doesn't count), then from a scientific standpoint, the hypothesis promoted by the CLO still stands as the most parsimonious explanation, though in my opinion is still short of proof.
Uh, no. The most "parsimonious" solution to the problem is that the video is simply uninterpretable garbage, i.e., worthless.
There is simply no credible way to point to the data in that video and say "There is no way this is a pileated woodpecker."
You can wave your arms around and flap your wooden models up and down but it doesn't change one basic fact: the video shows only one thing: a very blurry bird flying away.
no video of a known normal pileated (regardles of angle, distance, blurriness)when viewed in its entirety remotely comes close to showing the amount of white frame-by frame that is shown in the Luneau video (plus flashes of white on the back of the bird in multiple frames)
Ah, the argument by assertion. Has the data to support this very strange negative claim been published? If so, where? I'm interested in looking at it.
Perhaps that is why Sibley et al. were reduced to showing hand-drawn illustrations and a couple of individual frames only of launching birds to support their theory of twisted wing motion.
What do you mean "reduced"? A better guess is that Sibley et al. realize that the burden of proving that the IBWO actually exists doesn't rest on them. All they need to do is show that the video 'analysis' in the Science paper is a combination of hackery and wishful thinking.
So can't be both a normal or an aberrant pileated
Again: you haven't provided sufficient evidence to support this negative claim.
If the bird in the Luneau video is most likely a Pileated, then why can no one duplicate it
Show me the exact spot in the river where the bird was, where the boat was, give me the same camera with the same settings at the same time of day with the same light and a well-trained pileated woodpecker and I'll bet you that I can duplicate the freaking video.
But why should *I* have to do that to justify my extreme skepticism about the IBWO's existence and/or my disappointment about the pathetic Science paper? Give me a break.
We can say at minimum it remains unresolved, but to ignore the existing evidence would be irresponsible.
No, the existing evidence should be ignored. It's been picked to the bones. If anything, ornithologist should be looking for better evidence and apologizing to the public for announcing the rediscovery of an extinct large bird based on a garbage video shot blindly from 100 meters away.
Oh wait -- you say ornithologists have been looking for better evidence for 60 years already?
Perhaps it's time to focus on some other plants and animals that need our attention.
an interesting page purportedly demonstrating how birds actually fly
Purportedly? It's 2006.
You mean ornithologists haven't figured out every anatomically possible way that a particular species of bird can take off and fly in such rigorous detail that the bird can be identified based on a handful of wingflaps shot blind from (who knows how many) meters away in a tree-filled swamp?
I'm shocked. Shocked!
Anonymous wrote:
"(plus flashes of white on the back of the bird in multiple frames)"
Take a look at the glare on the back fishcrow's Fish Crow and tell me that you can reliably tell anything about "a flash of white" on a back of a fleeing black bird at the low resolution of the Luneau video.
http://www.fishcrow.com/fishcrow.jpg
Anonymous also wrote:
"The Nolin videos discussed elsewhere and here of pileateds definitely illustrate a number of relevant points in these discussions. Some frames do seem to show nothing but white on the underwings when blurred, (point for the skeptics), but in their entirety most frames on all the scenes show obvious black trailing edge (where it ought to be, and not wierdly positioned through twisting as suggested in Sibley's drawings) and wings nearly all black dorsally (set and match for the proponents?)."
Set and match? I think not. Nolin video is much higher resolution (no 4x magnification necessary for example) than the Luneau video so all bets are off as far as any claims about trailing black. Show me a frame in Luneau that shows a clear wedge of black down the middle of the wing that would be distinctive of IBWO and then I'll listen to arguments because all I see is a lot of white on the underwing and that's true of PIWO as well as IBWO. As far as the twisting you may have a point in that I think there are some frames where Sibley et al. resorted to twisting where dorsal white or glare could account for the white without the depicted twisting, but those other wing options of PIWO could account for the few motion blurred pixels of any particular frame. The Sibley et al. argument is not perfect, but it is very strong taken in its entirety.
anonanon
Thanks for the feedback, but still waiting for something that backs up Sibley et al. besides line drawings and a few isolated frames of birds launching or lifting.
Simply put then, where is the video evidence to back up the Sibley et al. hypothesis? Ain't none. Maybe there will be in the future, but not today.
Simply put again, where is the evidence to support a model of flight where birds wings are perpetually twisted when seen flying directly away from a camera undergoing sustained flight (i.e., more than a frame or two after lifting or launching). Not aware of any, but again the good folks here and elsewhere may be aware of such a model (and I would love to hear about it).
Finally, and simply put again, yes, the burden of proof does rest on the proponents with a bird records and checklist perspective in mind. However, if there is no valid alternative explanation then Fitzpatrick et al. remains the most parsimonious explanation (but a lot of folks don't like it and that's okay) from a scientific standpoint.
Thus far, no alternative explanation can stand up and survive a Scientific analysis. Doesn't mean that someday an alternative explanation could stand up to scrutiny, just hasn't happened yet. Sibley et al. was a valiant try to provide an alternative explanation, dependent mostly upon line drawings to illustrate a potential alternative explanation. However because it fails, there is nothing else standing in the way, scientifically, from an operational position that at least one IBWO did LIKELY exist in Arkansas in 2005.
Same let's say with global warming caused by human emissions of greenhouse gases. The connection though is not proved (yet), but alternatives that can stand up to scrutiny are getting fleetingly sparse.
Sibley et al. hypothesis is rejected (i.e., does not survive from a scientific perspective) due to a flawed model of sustained flight and the lack of any supportive video evidence of a known pileated demonstrating the same charateristics shown in the Luneau video. Since the Sibley et al. hypothesis is based on flawed models of flight, it has to be rejected in my view. Yes, Sibley et al. was accepted after peer-review, but for a piece like this it took a very long time through that peer-review process, apparently due to the problems inherent in it as expressed above. In the final analysis it didn't take long for Fitzpatrick et al to punch fatal holes and dismantle that alternative explanation.
This in turn doesn't prove the bird in the Luneau video is an Ivory-bill, but still waiting for the skeptics or independent (and objective, dispansionate) researchers to produce a valid alternative explanation that survives scrutiny.
Should be easy folks. Lots of Pileateds out there, lots of video cameras, lots of bad videographers. Go get em!
Cheers
"where is the evidence to support a model of flight where birds wings are perpetually twisted when seen flying directly away from a camera undergoing sustained flight?"
Try googling "bird flight mechanics" and you'll get countless explanations, with varying levels of scholarship, of the simple dynamic Sibley described. He mentioned the downstroke... " during which the leading edge of the wings angles down to propel the bird forward and the rear of the wings twist up"
Good elementary school birders can grasp such a basic concept.
I get it. It's a bigfoot until it's proven not one. Elvis lives until he's proven dead (again). And UFOs exist until Mr. Alien tells us they don't.
OOOOO...kkkkkk....I get it. Must.....take....meds....
Why is it that most believers and even many skeptics characterize the Zapruder bird as flying directly away from the camera? In reality the camera was at canoe level whereas the bird was taking off from a tree. The large amount of white on the underwings visible is in large part due to the bird being substantially ABOVE camera level at all times. When looking at a bird from below isn't it expected that the underwing will be frequently visible?
Cheery Anon Wrote: Since the Sibley et al. hypothesis is based on flawed models of flight, it has to be rejected in my view. Yes, Sibley et al. was accepted after peer-review, but for a piece like this it took a very long time through that peer-review process, apparently due to the problems inherent in it as expressed above. In the final analysis it didn't take long for Fitzpatrick et al to punch fatal holes and dismantle that alternative explanation.
______________________________
I am curious why you are hell-bent on discrediting Sibley et al? For the sake of brevity I will address two false accusations made in you two postings:
First, the Sib et al piece did not langush in preer review. The submission to acceptance was typical, maybe even fast if you throw the December holidays in there. I happen to know that CLO missed several delivery deadlines for their rebuttal, and that, at the end the pub. was held up for two weeks because one of the authors was out of the country.
I also know that there are, to my understanding only two groups who read all of the reviewers comments. The editors at Science and the authors and their staff. Now, I happen to know you are not an author or one of the review staff who looked at the pre-pub TC. I am sure you are not the editor at "Science" - so how would you have any idea what the peer reviewers comment were? How?
If you did read them you'd know they were minor, so why misrepresent them?
This, I think speaks to what appears to me to be a KarlRovian attempt to make the false, true (Some of your FALSE statements are...the Sib paper was rejected, CLO blasted fatal holes in the TC (with what? the stiff winged models, photo montage, and wing beat crap?) the TC barely made it through review).
The Sibley piece is supported by the Nolin video - read the ID Frontiers pieces by Don Crockett and others to get up to speed on this. Wings on real birds, not models, twist. The most parsimoneous ID of the bird in the Luneau video is a PIWO - IBWO is not the null hypoth, and is franky, a pretty nutty ID.
Why, I wonder, are you repeatedly making these false claims of editing/reviewing/publishing time lags? Why the repeated assertion that the Sib et al. paper is rejected (by FANG!) Why the chatter that wings don't twist when they do?
Hmmm.
(Please excuse the lack of editing friends, this got eaten twice by the Blog Gremlins so I must hit SEND.)
(PS: This guy/gal makes me feel the need for some poetry. Methinks we need a weekend Poetry Blast Tom.)
Everytime (twice) I post this on BIRDFORUM not one person responds. Perhaps I'll try here. Can someone that believes the Luneau video is a IBWO, explain what the yellow arrows represent.
http://tinyurl.com/er9xj
(you can click the images for a more closeup view)
Using an alias or real name would help us skip over any submission that may be inverse in length to the amount of time that its contributor has been paying attention to pertinent details. In lieu of your names, I'll be on high alert for any submission that defers to parsimony.
Question for Dr. Lester et al.:
If a large sample size of videos of fleeing PIWOs were collected, and the number of wingbeats in the clearly-discernable 1 sec of the Luneau video were found to be significantly outside the PIWO range at p < .001, would this alter your opinion?
And for the TB et al.:
If this same test revealed that the Luneau bird's wingbeat rate was NOT significantly outside the PIWO range at p > 0.05, would this alter your opinion?
The results could alter my opinion. I see no reason why this test cannot be conducted. CLO should have already done it.
Thanks for the feedback, but still waiting for something that backs up Sibley et al. besides line drawings and a few isolated frames of birds launching or lifting.
How about something like: no good evidence for a living IBWO in 60 years, despite the best efforts of thousands of passionate bird watchers.
There, your waiting is over.
Look at the Nolin videos of Pileateds. Use slow speed. They are at:
http://birdviewing.com/
Several sequences show gaping flaws in CLO's arguments. Be sure to concentrate only on those sequences where the bird is flushing down and away, just like the best views of the Luneau video. Level flight doesn't count (which is also shown).
1) The underwing clearly appears mostly white in flight. The Cornell rebuttal said Pileated can't show that. In gliding flight, they are correct, but this bird is actively flapping, and the videos CLEARLY show they are wrong about the pattern exhibited on PIWO. You would think that they would understand the difference, but apparently not.
2) At 14 seconds, you see a wing that is mostly white, shows almost no dark secondaries, and shows black curving around the wingtip ... a dead ringer for pics 3A, 3B, and 3C in the Sibley paper. This black curvature is dismissed as "blur" in the CLO rebuttal, with no evidence (especially since we know that white saturates much more easily than black).
3) At no time can I clearly see the upper surface of the wing until the bird pulls up ... a lot. So there goes the argument that you should see dark upperwings. (By the time the bird gains altitude, the video has gone from crap to total crap.)
So there's your PIWO videos that shows what the Luneau video shows. And it shows real wing movements on real birds, not flat cardboard (an elementary school experiment if there ever was one, and completely without merit since birds don't flap like cardboard). That leaves CLO with their interpretation of the launch, which is totally crappy video.
It is with sustained flight in the entirety of the Luneau video.
Before you make statements like that, you should learn the meaning of "sustained flight", which the Luneau video never shows. Sustained means "maintained at length without interruption or weakening". The video is several seconds long and in that time shows a bird launching, gaining speed, dropping in altitude, turning, then gaining altitude. (I think I have that all correct. It's been a while since I've watched it, and I don't have Quicktime on this computer.) It's not "sustained flight".
"And for the TB et al.:
If this same test revealed that the Luneau bird's wingbeat rate was NOT significantly outside the PIWO range at p > 0.05, would this alter your opinion? "
I think that it is safe to say that nothing will ever change my opinion.
Signed,
TB
"Can someone that believes the Luneau video is a IBWO, explain what the yellow arrows represent.
http://tinyurl.com/er9xj "
You are largely seeing the effects of motion blur of the wing making a complex arc thru the air. The white becomes smeared and actually obliterates any black that was exposed to the ccd area in the camera before the white over traced it. Remember black is the absence of photons so it gets obliterated by any white that passes over the same area of the ccd array due to motion of the wing.
Now the black edging only appears as the black wing tip of the PIWO makes an arc thru which white in the wing never passes.
(Oops, I was only supposed to answer if I believed it was an IBWO. Sorry.)
I hope that's clear. Any questions?
the number of wingbeats in the clearly-discernable 1 sec of the Luneau video
Just read that passage a few times and try to believe that a bird that nobody has documented for 60 years is going to be pronounced "rediscovered" based on such data.
If the wingbeat frequency of the IBWO versus the pileated was not routinely cited as a distinguishing feature in the literature prior to 2005, I am not interested in post-hoc baloney.
If a large sample size of videos of fleeing PIWOs were collected, and the number of wingbeats in the clearly-discernable 1 sec of the Luneau video were found to be significantly outside the PIWO range at p < .001, would this alter your opinion?
I will say this: if there is one pileated in 1000 with a "wingbeat" over a one-second period that matches the wingbeat of the thing in the video, then my opinion is unchanged. What is the minimum size of the pileated population in the Big Woods? What is the minimum size of the IBWO population in the Big Woods?
I see no reason why this test cannot be conducted.
I can see two reasons: time and money.
Painted wooden woodpeckers are dirt cheap.
I still can't believe that those Cornell folks made such clowns of themselves with those wooden birds. It's almost as if they've never seen any documentaries about Bigfoot hunters. Strap on those big feet and walk around the snow -- Look, Mom, I can't even come close to matching the stride distances of the Sasquatch! How much more evidence do you need?!?!
Does anyone really need to go any further than the wooden models? How can people purporting to be ornithologists have done such a thing? We know that PWIOs don't flap their wings like Fulmars because we can see it for ourselves; and I'm guessing that IBWOs don't (didn't) flap their wings like Fulmars either. One thing's for sure is that the bird in the video doesn't flap like a Fulmar.
So - the wooden models represent a humungous, steaming pile of doggy doo-doo, which should discredit the whole paper.
As for http://tinyurl.com/er9xj - aren't there two IBWOs together in one of those pictures ?
Sibley et al. was obviously accepted for publication. However, for a commentary attempting to refute the conclusion on another published paper it did seem to take a good long while from when the rumors started flying about it’s development until it was finally published (which seems unusual for something in Science). Perhaps it took longer than normal to do all those line drawings, since there were no videos available to conduct direct comparisons. And I’ll concede, I don’t know why it was delayed so long after it was submitted, only suggestive that there may have been some issues with it before it was accepted. Anyway, acceptance does not mean their hypothesis cannot be falsified (i.e., rejected). Same with Fitzptrick et al.
If there are no existing models to support Sibley et al.’s claim of twisted wings for birds undergoing sustained flight (despite some vague references here that they really do exist, haven’t seen one yet, so still waiting) and again no single video (montages don't count) that replicates the wing movement they propose for a normally fleeing Pileated, then the hypothesis is then rejected (not the paper itself). Again rejection of the alternative does not “prove” the bird in the Luneau video was an Ivory-bill, we just have to wait for better interpretations, with solid backing from physical evidence (or better modeling) of how a normal (or abnormal pileated) explains what we see.
There are definitely some interesting frames from the Nolin videos that could support multiple interpretations as pointed out here. However, when viewed in their entirety the Nolin videos clearly support the Cornell position. The same is true with the frames previously posted by the Stokes of normal Pileated’s in flight as well as all the woodpecker scenes provided on the Manybirds website (which is a great resource, by the way).
Perhaps Sibley et al. or some other objective (and dispassionate) research group could build better simulation models (computer or otherwise) that provide adequate support for the twisted wing theory for sustained flight and really put this discussion to rest. Then that would be really interesting and a great contribution to science.
Could the poster who says,
"If there are no existing models to support Sibley et al.’s claim of twisted wings for birds undergoing sustained flight..."
please explain very precisely what it is that they think Sibley is saying that needs to be supported. I'd be happy to help find the desired supporting information, but I simply don't understand what it is about Sibley's assertion that is anything other than self evident.
Exactly, very exactly, what is it that Sibley says about wing twist that you do not embrace?
If there are no existing models to support Sibley et al.’s claim of twisted wings for birds undergoing sustained flight
Please re-read my explanation of the meaning of sustained flight. The bird in the Luneau video does not exhibit sustained flight. If you are attempting to compare models of level sustained flight with the Luneau video, you are doomed to fail.
and again no single video (montages don't count)
Why not? Given the nearly infinite combinations of direction, speed, and altitude changes that a bird can exhibit in several seconds, only a person who is ignorant of how bird ID is accomplished would insist on a video that follows the exact movements and timing of the bird in question. This sounds like a worthless demand designed to shut down debate.
BTW, if you skip the fact that it was a montage, how do you explain the fact that the dorsal surface never shows for at least one (actually 2 or 3) given birds? Since CLO said that it must show black (and that broad black secondaries must also show), isn't their flight model proven to be invalid?
Outside of the wing twist that you are smitten with, you might wish to read the following post by one of the Sibley authors. No wing twist is mentioned or necessary. It is a simple assertion that marks appear in the video that are flat out wrong for IBWO and are perfect for PIWO.
http://www.birdingonthe.net/mailinglists/BRCF.html#1149533553
You might also check out these comments:
http://listserv.arizona.edu/cgi-bin/wa?A2=ind0603D&L=BIRDWG01&P=R9561&I=-3.
These all draw upon a wealth of knowledge in bird identification. If you say that the Sibley paper is invalid because you disagree with their flight model (that is, assuming, you now understand the meaning of sustained flight), you must use the same standard and state that the CLO paper is invalid because the Nolin film clearly shows that the marks Fitzpatrick et al say MUST show do not in fact show on a bird flying down and away. Correct?
Perhaps Sibley et al. or some other objective (and dispassionate) research group could build better simulation models (computer or otherwise) that provide adequate support for the twisted wing theory for sustained flight and really put this discussion to rest.
The discussion will not be put to rest such a showing because it is clear that the promoters of the IBWO rediscovery are not interested in skeptical inquiry.
Even if the promoters admitted that Sibley showed their video could be a pileated, they would still claim that Sibley et al had not proven that the bird could not be an IBWO. And what about the double-knocks? THey will ask. And they eyewitness sightings? THey will ask. And most importantly, what about the New York Times article which reported the rediscovery on the front page, a rediscovery which was embraced by millions of proud patriotic Americans and people around the globe? Is Sibley saying that all these people are uninformed and sorta stupid when it comes to these sorts of matters? They will ask.
"Is Sibley saying that all these people are uninformed and sorta stupid when it comes to these sorts of matters? They will ask."
And I will answer, YES!!!
As Yoda would put it, "Descending into farce, this is!"
Among the points made above, the most worthy for a bit further discussion are as follows:
Comment: Didn't Fitzcrow et al say wings don't twist in their rebuttal. They do twist though. Isn't it fair to show that first wings do twist (hence the Sibley et al. images of wing twisting on take-off, ignored bu CLO), which obviously the reviewers did not know? Twisting is most extreme on take off, but the PIWO in the Luneau video is only a few flaps from the launch position.
Response: Yes, a duck launching (or braking before landing, not sure which) and an atypical launch from a narrow snag of a pileated woodpecker viewed from below illustrates that this phenomenon may occur for a very brief moment or two (but note that in the woodpecker footage only about 7 out of 40 frames give the illusion of twisting wings, while about 30 don’t, the latter clearly supporting Cornell’s position). However for the twisting wing theory to have any legs in explaining the Luneau bird this twisting must go on and on after the launch for a bird flying directly away and almost level to the camera showing all that white over and over. If twisting wings for extended, continuous flight (someone didn’t like my use of the term “sustained” flight) was such a “normal” thing, then should be easy to get good additional video evidence to support it. However, apparently none exist, including all of those really cool ones on ManyBirds, which when viewed in their entirety support Fitzpatrick et al. Alas, we only have the imagination reflected in the artistic renditions of a very talented illustrator and field guide author. Twisting wing theory in my opinion is interesting, just not previously documented in the literature (that I’m aware of anyway) nor supported here in this discussion thread (or any other I’m aware of).
Comment: You mean ornithologists haven't figured out every anatomically possible way that a particular species of bird can take off and fly in such rigorous detail that the bird can be identified based on a handful of wingflaps shot blind from (who knows how many) meters away in a tree-filled swamp?
Response: Apparently not, Sibley et al. present a novel theory for birds undergoing extended flight not previously documented in the literature. This ought to be the real news, who cares about the identity of the woodpecker involved!
Comment: As far as the twisting you may have a point in that I think there are some frames where Sibley et al. resorted to twisting where dorsal white or glare could account for the white without the depicted twisting, but those other wing options of PIWO could account for the few motion blurred pixels of any particular frame. The Sibley et al. argument is not perfect, but it is very strong taken in its entirety.
Response: Perhaps other wing options for PIWO could be used instead of twisting wings, but seems doubtful to me. Nevertheless, I appreciate your open mindedness on this critical point. However, for their interpretation to hold water Sibley et al. do depend on wing-twisting to support their argument for explaining all the white shown in most of the frames in the Luneau video. As you say their argument isn’t perfect, but I think it needs to be for this theory to stand. If it doesn’t stand based on any supporting videos or better substantiated models of how birds fly, this alternative falls like a house of cards and must be rejected. Perhaps someone could develop another better alternative that cannot be so easily rejected (I think that would be a great contribution to the science involved here if someone could).
Comment: Try googling "bird flight mechanics" and you'll get countless explanations, with varying levels of scholarship, of the simple dynamic Sibley described. He mentioned the downstroke... " during which the leading edge of the wings angles down to propel the bird forward and the rear of the wings twist up"
Good elementary school birders can grasp such a basic concept.
Response: I have read quite a bit of the historical literature on flight mechanics in recent months, and looked a lot of videos of woodpeckers and other birds, but I took your advice and re-googled and did find some additional references. I did learn about the concepts of loop flapping and pitch stability, leading-edge vortex lifts, blurred bodies and clear heads, and figure 8’s. The figure 8 motion from what I gather seems to be the closest to what is being described as “twisting” by Sibley et al. and seems generally associated with landing, taking off, and hovering (as with the mallard and pileated images), but nothing with respect to anything else that would match with the Luneau video bird.. Even with just landing and take off, though (and like the entire pileated footage ManyBirds, the Nolin videos, etc.) there should be good views of both upper and under wing positions from the rear with such a figure 8 motion, just as Fitzpatrick et al. (and not Sibley et al.) would suggest explains why we see so much white in the Luneau video as both upper and underwing components are involved. Anyway, that’s what I’ve been able to find so far that gets close to the “twisted wing” theory.
Apparently the authors I referenced were all either unaware of, or their work published before, Sibley et al.’s twisted wing theory for extended flight. Or they don’t happen to be papers or Current Ornithology chapters written by elementary school birders. But I note that Sibley et al. provided no citations in support of twisting wing theory for flapping or extended flight. May be this is because there are none, but in case I’ve missed something, I would be most appreciative if you would cite at least one specific example in the literature (and thanks in advance for doing so).
Comment: Why is it that most believers and even many skeptics characterize the Zapruder bird as flying directly away from the camera? In reality the camera was at canoe level whereas the bird was taking off from a tree. The large amount of white on the underwings visible is in large part due to the bird being substantially ABOVE camera level at all times. When looking at a bird from below isn't it expected that the underwing will be frequently visible?
Response: According to Fitzpatrick et al. (in SOM for their response to Sibley et al.) the view angle from camera to bird was essentially level (bird launched 1.3 m above the water, camera was 0.67 m above water 20 m behind the bird at time of launch, 1.8 degrees above horizontal). I would not consider this “substantially above camera.” Sibley et al. (as skeptics) apparently accept this conclusion and further state (in SOM for their TC, for to make other points) that “…in much of the video, the bird is flying almost directly away from the camera,” “moving directly away in continued flight...into the woods.” And later “…the bird is low, over water, and gaining altitude.”
Comment: I am curious why you are hell-bent on discrediting Sibley et al?
Response: Hmmm, not trying to discredit Sibley et al., I’m trying to find justification for their use of a twisted wing theory alternative and not finding any. They clearly believe they have a valid alternative interpretation to present and have worked hard to present it. I admire their “courage” against what most folks even here would agree (at least used to be) an ornithological powerhouse at Cornell. Frankly, it is critical that alternative explanations be developed and tested for science to progress. I am just trying to evaluate their attempt and I find one of their most critical assumptions curious and unsubstantiated that birds (typically or otherwise) conduct extended (or if you wish continued, or as I used previously sustained) flapping flight by twisting their wings. I cannot find any evidence for this other than Sibley et al.’s use of illustrations in this one paper. Surely there are others out there. But with no supportive video, nor an existing model of flight mechanics to back Sibley et al up, true critical thinkers (yes even some of the septics perhaps) have to admit this alternative explanation is not only weak but falsifiable. I found it odd that given the uniqueness of this interpretation Sibley et al. provide no citation, but equally interesting there was a reference to this being suggested by an anonymous reviewer (wonder if they might have a reference).
Comment: so how would you have any idea what the peer reviewers comment were? How?
If you did read them you'd know they were minor, so why misrepresent them?
Response: I don’t know what any peer-reviewer’s comments were. I’m simply a bit surprised that such a critical part of the TC is based on a previously undocumented mode of extended, (continuous, sustained) flapping flight and wonder whether one or more peer-reviewers didn’t wonder about that too. I also wonder whether it crossed any of the peer-reviewers minds to ask why Sibley et al had to depend on illustrations only to present this newly discovered flight style, with no citation or other video evidence to back this up.
It’s really none of my business, but since you brought it up, how do you know that comments were minor? Are you an author, reviewer, or the Editor? If so, please enlighten us on this point, curious minds want to know.
Comment: Look at the Nolin videos of Pileateds. Use slow speed. They are at:
http://birdviewing.com/
Several sequences show gaping flaws in CLO's arguments. Be sure to concentrate only on those sequences where the bird is flushing down and away, just like the best views of the Luneau video. Level flight doesn't count (which is also shown).
Response: Why does level flight not count? The Luneau video is of a bird essentially flying away almost level with the camera. Interesting that one earlier commentator thinks the Luneau bird is substantially above the camera, while you think it is going down and away. And both Fitzpatrick et al. and Sibley et al., essentially say the flight is continuous and more-or-less level, eventually gaining altitude. Anyway, with respect to the Nolin videos in total, for every interesting frame showing support for the illusion of all white underwings there are up to four frames that show clear dark trailing edges and/or dark upper wings, in support of Cornell.
Comment: Sustained means "maintained at length without interruption or weakening".
Response: Okay, how about continuous (as used by Sibley et al.), or extended flapping then?
Comment: please explain very precisely what it is that they think Sibley is saying that needs to be supported. I'd be happy to help find the desired supporting information, but I simply don't understand what it is about Sibley's assertion that is anything other than self evident.
Exactly, very exactly, what is it that Sibley says about wing twist that you do not embrace?
Response: Exactly, very exactly, the scientific support appears to be totally lacking for twisted wing theory to exist as a mode of flapping continuous, extended flight. Doesn’t mean that there is no support for this novel theory though. So, thanking you in advance for anything you find in terms of video or literature to support the illustrations and imagination used in Sibley et al.
Comment: and again no single video (montages don't count)
Why not? Given the nearly infinite combinations of direction, speed, and altitude changes that a bird can exhibit in several seconds, only a person who is ignorant of how bird ID is accomplished would insist on a video that follows the exact movements and timing of the bird in question.
Response: Not looking for a video of a pileated that matches the movements of the Luneau bird exactly, but I am looking for one video of a known pileated that shows almost nothing but white regardless of relative wing position as it undergoes extended, continuous flight away from a camera. Should be easy to get such a video. Plenty of pileateds and plenty of bad videographers. Unless of course it is not possible.
Comment: If you say that the Sibley paper is invalid because you disagree with their flight model (that is, assuming, you now understand the meaning of sustained flight), you must use the same standard and state that the CLO paper is invalid because the Nolin film clearly shows that the marks Fitzpatrick et al say MUST show do not in fact show on a bird flying down and away. Correct?
Response: I’m actually more interested in seeing a good solid alternative interpretation that cannot be so easily rejected as that provided by Sibley et al. As the normal pileated hypothesis gets flushed here, perhaps the aberrant pileated hypothesis begins to be more attractive as the best alternative, just as a number of folks seemed to be pushing for not too long ago (but there are problems with that one too). I disagree with you on the Nolin frames discount the Fitzpatrick et al. interpretion, as stated above regarding position of the fleeing bird, but I am not in the faith-based ornithology camp either that believe this video proves the bird is an ivory-billed.
The issue here is to present a solid single interpretation that the bird could be a normal pileated in a way that is internally consistent and not so easily rejected because the mechanism used to explain the patterns observed don’t exist (or at least there is no supportive evidence that it exists). Sibley et al. are to be commended for a valiant try, and with some imagination got a lot of folks thinking. But imagination, and illustrations, not backed up by physical evidence ain’t enough. I bet someone can do better than this!
Good spirited discussion, thanks for the feedback.
A very wordy commenter above keeps constantly harping about the Luneau bird's allegedly "sustained", "continuous", "extended" flight.
I say those descriptive words are completely bogus, since wing positions on the Luneau bird can only be roughly charted for about 1 second, and since the frames that we've all analyzed are from the bird's initial wingbeats.
Mr Wordy Commenter--can you please answer the question I posed here?
" Exactly, very exactly, what is it that Sibley says about wing twist that you do not embrace?
Response: Exactly, very exactly, the scientific support appears to be totally lacking for twisted wing theory to exist as a mode of flapping continuous, extended flight."
One one more time... what is it that Sibley says about wing twist that you do not embrace?
No, one MORE time... what is it that Sibley says about wing twist that you do not embrace?
It seems that you have inflated "twist" into some vastly more dramatic and mysterious than it is, and much of your argument is centered on this misunderstanding.
During the downstroke, in many birds, the primaries are gently "tipped" with respect to the secondaries, the leading edge is down relative to the trailing edge... aka twist. That's it. it's not a "novel theory".
I can't help myself, again,..."please cite the precise word's in Sibley's text which you find to be in need of support" .
Dar Chatty Wing Twist Skeptic:
You said:If there are no existing models to support Sibley et al.’s claim of twisted wings for birds undergoing sustained flight (despite some vague references here that they really do exist, haven’t seen one yet, so still waiting
and you said
Exactly, very exactly, the scientific support appears to be totally lacking for twisted wing theory to exist as a mode of flapping continuous, extended flight.
_____________________________
Try
http://www2.unil.ch/biomapper/opengl/BirdFlight.html
go about 2/3 of the way through to a section called "Wing Geometry and Flight Stability" by R. Dryden.
There is a section about twisting as a way to maintain angle of attack.
Twisting happens, and can occur during takeoff or flight (sustained continuous or otherwise).
It is not the wacky, novel theory of an underemployed team of field guide illustrators, authors and reserchers.
Can we move on now?
You also said:
but since you brought it up, how do you know that comments were minor? Are you an author, reviewer, or the Editor?
_____________________________
I am none of the above: I was asked to read the TC prior to publication.
Tom,
There are just some people who seem analytical but really are just so far off base that no amount of explanation will satisfy them.
And worse, their reasoning is usually so obfuscated by detail starting from a false starting point (such as morphometrics) that one cannot even understand how their belief system works.
Best, perhaps, to follow Methinks rule that the shorter posts are usually the most irudite and worth response.
Re our Sibley skeptic, someone wrote:
I say those descriptive words are completely bogus, since wing positions on the Luneau bird can only be roughly charted for about 1 second, and since the frames that we've all analyzed are from the bird's initial wingbeats.
No doubt. And one does not need to be an expert on birds to understand that a bird can twist its wing for half a second and not fall out of the sky. As long as it's not made out of wood. Jeebus fricking cripes.
And worse, their reasoning is usually so obfuscated by detail starting from a false starting point (such as morphometrics) that one cannot even understand how their belief system works.
That's why the True Believers are so similar to creationists. The truly devastating facts which point to the IBWO's continued non-existence. Istead, the TB's choose to focus on pixels in an objectively crappy video which allegedly "can't be explained" unless ... you become a True Believer.
The statement from our Sibley skeptic that Sibley's wing twisting explanation is more astounding than the IBWO's rediscovery is utterly disengenuous or stunningly clueless. Take your pick.
Try
http://www2.unil.ch/biomapper/opengl/BirdFlight.html
go about 2/3 of the way through to a section called "Wing Geometry and Flight Stability" by R. Dryden.
There is a section about twisting as a way to maintain angle of attack.
Twisting happens, and can occur during takeoff or flight (sustained continuous or otherwise).
It is not the wacky, novel theory of an underemployed team of field guide illustrators, authors and reserchers.
xxxxxxxxxxxxxxxxxxxx
Thanks for this reference and upon reading the section that was suggested, it occurred to me that there may be some confusion between the previously undocumented phenomenon (apparently) of “full-wing” twisting that was proposed by Sibley et al. versus the well-documented ability of birds to manipulate their primaries to adjust as necessary while propelling themselves through flapping flight. This reference above does indeed refer to this latter activity as “twisting” but only as it relates to the “wing’s end” (or wingtip; i.e. primaries).
This torsion motion is then illustrated with an animated model of a generic flying bird as minor adjustments with the most obvious movement towards the wingtips and the least towards the wing’s base. Just the opposite of what seems to be illustrated by Sibley et al.
This motion described as twisting in the above and other references associated mostly with the wingtips is a far cry from the Sibley et al. “full-wing” twisting theory for birds undergoing direct and continuous flight as the Luneau bird is obviously doing from the last frame in their SOM (Science frame 383.3) to at least frame 700 where both wings are above the plane of the bird’s body. Another point worth mentioning is that this description for twisting at the wing’s end is right in line with Fitzpatrick et al.’s dismissal of Sibley et al.’s interpretation that the curved shape of the black wingtips is a characteristic of pileated and not ivory-bill. Fitzpatrick et al. point out that the impression of large curved black wingtips is actually “movement blur” that is “most pronounced at the wingtips” just as described in the reference above as twisting at the “wing’s end.”
So this and other references actually support the interpretation of Fitzpatrick et al. all the way down the line and call into even more serious question the full-wing twisting theory of Sibley et al. of how birds conduct continuous flapping flight. With no video and no documentation other than artistic renditions of this critical part of the Sibley et al. argument, the present hypothesis of this being a pileated woodpecker must be rejected.
Some here have suggested other means to explain the amount of white seen on the upperside of the wings, while still others have suggested this bird is one of those abundant aberrant woodpeckers in eastern Arkansas. Appears these folks have an opening now to improve upon what Sibley et al. have started as potential alternative explanations to Fitzpatrick et al. Of course, it may not matter if Fitzpatrick et al. and all the rest of the believers continue to completely fail to find this bird again.
Yep, I’m ready to move on now, unless someone comes up with that video clip that should be so easy to get, or actually fully documents the ivory-bill in fact exists to everyone's satisfaction (fat chance either will occur anytime soon).
"Some here have suggested other means to explain the amount of white seen on the upperside of the wings."
...yes, I'm willing to take the time the time to answer anyone who can put in the effort required to produce so may words.
There is no upperside of the wing visible in Luneau's video (except when the wing is folded along the body on the upstroke where we see no white at all). The misunderstanding here is bigger than the misunderstanding of "full wing twist" and "end twist", two very nice new phrases by the way.
Please read what Sibley says without imagining what it is you want him to say. It's not as though he's suggesting that behind the blurry frames the bird is doing sommersaults, or perhaps spinning plates atop long poles. The bird is flying, just ordinary flying, and showing the underside of its wings as one would expect.
Frame 700 does not show upperwing. Look at frame 716. The odd thing would be if the bird could show lots of upperwing white in 700 and lots of underwing white in 716. Now that would be an amazing twist! But both frames show underwing, as one would reasonably expect. Try looking at frames 583 and 600. They show the exact same sequence. Or, try looking at look 583 and 700 together, two nearly indentical wing positions. All underwing.
So let's try a different tack..in your own words... what is it you think Sibley is saying that you do not embrace?
Last week Wing Twist Skeptic asked someone to “present a solid single interpretation that the bird could be a normal pileated”. The following is one individual’s modest review session of the key aspects of the model that numerous observers have arrived at independently.
The video shows at most eleven discernable beats, progressively slowing in frequency. Beats 9-11 are about eight frames in duration. Beats 3-6 are about seven frames in duration. Beat 2 is six frames in duration. And if beat 1 is also six frames in duration, the wings should be fully open in frame 33 as depicted by Sibley.
The downstroke is extremely deep with wings nearly meeting below the body. The upstroke is brief with wings folded close to the body. Both characteristics are typical of PIWO, not at all “duck-like”.
No white is visible during the upstroke. With wings folded close to the body PIWO would be expected to show no white, while for IBWO, with wings folded close to the body and wings moving up at an exceptionally fast rate, we should expect the video to produce one big vertical white blur. This is completely missing in eighteen out of eighteen upstroke frames.
A bird even slightly above the horizon can be expected to show predominantly ventral surfaces, not dorsal… particularly on the downstroke and particularly in the primaries. (Wing twist contributes to this.) It does not seem that both ventral and dorsal wing surfaces show in a single beat. You have to pick one (or identify the transition point and the mechanism that causes it). Ventral is far, far more likely to be correct.
The air-foil shape of a wing (concave from underneath), when seen from behind and slightly below, will emphasize the view of the leading edge (far edge) and de-emphasize the view of the trailing edge (near edge).
Videography tends to over-emphasize white and de-emphasize dark.
That’s it. You can put the rest together yourself… With this basic framework for understanding Luneau’s grainy mess, every frame fits PIWO as well as IBWO. Many frames fit PIWO far better than IBWO (each and every upstroke frame for example)
pd
The following is a Luneau homework exercise…Consider nine wing positions:
Position 1) Top of the stroke, both wings near 12 o’clock
Positions 2 through 7) Downstroke, wings extended, Position 2 = wings at 1:00 & 11:00, 3 = 2:00 & 10:00, 4 = 3:00 & 9:00, 5=4:00 & 8:00, 6=5:00 & 7:00, 7=both wings approaching 6:00.
Positions 8 and 9) Upstroke, wings folded along the body, Position 8 = approx 4:00 & 8:00, 9 = approx 2:00 and 10:00
That leads more or less to this summary of frames 133-1316
Beat number,
followed by frame number,
followed by wing position number:
1 133.3 1
1 150.0 2
1 166.7 3
1 183.3 4
1 200.0 6
1 216.7 8
2 233.3 1
2 250.0 2
2 266.7 3
2 283.3 4
2 300.0 6
2 316.7 7
2 333.3 8
3 350.0 1
3 366.7 2
3 383.3 3
3 400.0 4
3 416.7 6
3 433.3 8
3 450.0 9
4 466.7 1
4 483.3 2
4 500.0 3
4 516.7 5
4 533.3 6
4 550.0 8
4 566.7 9
5 583.3 1
5 600.0 3
5 616.7 5
5 633.3 6
5 650.0 7
5 666.7 8
5 683.3 9
6 700.0 1
6 716.7 3
6 733.3 5
6 750.0 6
6 766.7 7
6 783.3 8
6 800.0 9
7 816.7 1
7 833.3 3
7 850.0 5
7 866.7 6
7 883.3 7
7 900.0 8
7 916.7 9
8 933.3 1
8 950.0 3
8 966.7 4
8 983.3 5
8 1000.0 6
8 1016.7 7
8 1033.3 8
8 1050.0 9
9 1066.7 1
9 1083.3 3
9 1100.0 4
9 1116.7 5
9 1133.3 6
9 1150.0 7
9 1166.7 8
9 1183.3 9
10 1200.0 1
10 1216.7 3
10 1233.3 4
10 1250.0 5
10 1266.7 6
10 1283.3 7
10 1300.0 8
10 1316.7 9
If you look at each position number as a group, say all of the 2’s together, or all of the 4’s together, Luneau loses all of its mystery. It becomes pretty clear what’s going on as your eye assembles a composite average of the frames and starts to filter out blur, fuzz, and artifact. Normal flight. Normal PIWO.
…apologies to methinks for trampling on the brevity versus erudition quotient.
It is clear that the wordy commentator does not grasp the most basic tenets of IBWO skepticism. As explained in comments just above, the reason we cannot explain and have no need to explain the excess white on the upperwing is that the surface with extensive white visible in the video is the UNDER surface. This is extensively white as on any normal Pileated viewed from below. Why the CLO or anyone else thought that the upper surface of the wings would be much more visible than the under surface when the bird was viewed from below (from canoe level, thus from well below normal eye level) remains a mystery to me. If they had spotted the bird from one of the suggested aerial surveys the white would indeed have been hard for us skeptics to explain. That expert birders extraordinarily familiar with the frames in question could not distinguish the upper from the under surfaces of the bird's wings attests to the unnacceptably poor quality of the video.
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