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Ivory-billed Woodpecker (formerly updates) (1 Viewer)

Ilya Maclean

charlatan
Just finished reading the paper myself. Well written and a very compelling case for the Luneau video being just a normal Piliated. In the interest of true objectivity on the matter, a couple of thoughts / questions:

(1) What effect does the fact the video of the known PIWO could not be de-interlaced have? Could it alter the extent of image bleeding and thus the size / shape of black and white patches?

(2) In Figure 1 and 2, in the last two sets of frames compared, the birds do appear to have different postures, judging by the wing shape. It does lend some support to the possibility that, as argued by Cornell all along we are in fact predominantly viewing the upper-wing of the Luneau bird as it gains height as opposed the underwing, which would be viewable if the bird was viewed from slightly below or as it twists its wings. It is actually quite hard to judge this from the video, but if I had to hazard a guess either way irrespective of species involved and plumage details I’d say the latter, just by looking at the bird in motion. That said I’m less sure about what’s going on in the first few milliseconds as it leaves the tree.


Regardless, I think we can now safely say that the Luneau video does not provide conclusive evidence of IBWO persistance, and if anything, fits the bill for being a normal Piliated.

original Luneau video available here:

http://www.sciencemag.org/content/vol0/issue2005/images/data/1114103/DC1/1114103S1.mov

Edit: Agree, it will be very interesting to see if Cornell argue along these lines or do the honourable thing and back down over the video.
 
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Mike Johnston

Well-known member
Ilya Maclean said:
Just finished reading the paper myself. Well written and a very compelling case for the Luneau video being just a normal Piliated. In the interest of true objectivity on the matter, a couple of thoughts / questions:

(1) What effect does the fact the video of the known PIWO could not be de-interlaced have? Could it alter the extent of image bleeding and thus the size / shape of black and white patches?
Yes, Fitzpatrick is citing this as a reason for not accepting Doc's analysis - says it's like comparing apples and oranges. However, the fact that nobody at Cornell is even open to the mere possibility that they might be mistaken is starting to grate on many. Too much at stake I suppose.

But well done for a good paper. A practical application of Sibley's critique. It's certainly making the news in the US. Search for 'Ivory-billed' in Google News and have a look!

(By the way, for anyone who wants to see Doc's example of a conclusive photo, go here and scroll to the bottom. ;) )
 

emupilot

Well-known member
MMinNY said:
I agree (which may be a first for us CE). It's a fine paper (haven't read his blog), well-argued and documented and very even-handed in its tone. It will be interesting to read any rebuttals; it doesn't change my overall view on IBWO survival, but it certainly casts considerable doubt on the Luneau video.

It's also gratifying to note that there was co-operation and collaboration among people on both sides of the debate.

The paper takes a sensible approach, but I have some disagreements:

- It discusses the possibility the Luneau video is of an aberrant Pileated, and states that one has been seen in the study area. The reference is to the albinistic Pileated found by Cornell, but that would not be a candidate for the Luneau video since the aberrant bird found has no black at all. Since the discussion is of what a normal Pileated looks like, I'm not sure why this is brought up at all.
- One of the keys to the Luneau video wingbeat frequency is the duration of the flight sustained at 8.6 Hz. Although the paper might give some new information about the first 4 flaps of a Pileated, wingbeats 5-8 of Nolin's videos are much slower than the Luneau video. As such, they do not support the hypothesis that the Luneau bird is a Pileated. Since the Nolin videos apparently show only flights lasting not more than 1 second, it really says nothing about sustained Pileated flap rate. If any of the Nolin videos are for longer than 1 second, they would tend to contradict the hypothesis that the Luneau bird is a Pileated.
- "In general, larger birds are expected to flap their wings more slowly than smaller birds of comparable wing morphology" True, but that doesn't say anything about Pileated vs. Ivory-billed, especially since their wing morphology is different.
- "The assertion that Ivory-billed Woodpeckers flap their wings more quickly than Pileated Woodpeckers is counterintuitive" Don't historical descriptions describe a fast wingbeat and direct flight? IIRC, it's not just the recording of wingbeats that leads us to believe that Ivory-bills flap more quickly. The conclusion that the wingbeat rate is not outside that for the Pileated is not one that can be drawn from the paper, since it does not claim that Pileateds sustain the high frequency shown in the video for the duration of the video.

I agree with the assertion that we can not say specifically what the bird in the video is, and thus I disagree with the follow-up assertion that it is probably a Pileated Woodpecker. We just don't know, and we can't be comfortable with an identification either way.
 

Ilya Maclean

charlatan
emupilot said:
One of the keys to the Luneau video wingbeat frequency is the duration of the flight sustained at 8.6 Hz. Although the paper might give some new information about the first 4 flaps of a Pileated, wingbeats 5-8 of Nolin's videos are much slower than the Luneau video. As such, they do not support the hypothesis that the Luneau bird is a Pileated. Since the Nolin videos apparently show only flights lasting not more than 1 second, it really says nothing about sustained Pileated flap rate. If any of the Nolin videos are for longer than 1 second, they would tend to contradict the hypothesis that the Luneau bird is a Pileated

This struck me as I read it, but I think there's a crucial difference between the Nolin and the Luneau video that might explain it. In the former, the Piliated woodpeckers only made short escape flights to nearby trees, whereas Luneau's shows a bird that undergoes flight for a sustained period. The period 5-8 flaps, I think it's possible that birds had spotted their landing spots and were already slowing to land. Had they continued I actually suspect they might have sustained their rapid flap rate or even accelerated.
 
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emupilot

Well-known member
Ilya Maclean said:
This struck me as I read it, but I think there's a crucial difference between the Nolin and the Luneau video that might explain it. In the former, the Piliated woodpeckers only made short escape flights to nearby trees, whereas Luneau's shows a bird that undergoes flight for a sustained period. The period 5-8 flaps, I think it's possible that birds had spotted their landing spots and were already slowing to land. Had they continued I actually suspect they might have sustained their rapid flap rate or even accelerated.

Since the sustained Pileated wing beat rate, as I understand it, has been measured previously at well under that in the video, I don't think it is reasonable to assume that the Nolin birds would have continued at that wing beat rate. In any case, the Nolin videos were too short to draw any conclusions relative to the Luneau bird, so I think the author overreaches in his assertion that the Luneau bird is consistent with Pileated. The evidence presented is insufficient to support such a conclusion.
 

Ilya Maclean

charlatan
emupilot said:
Since the sustained Pileated wing beat rate, as I understand it, has been measured previously at well under that in the video, I don't think it is reasonable to assume that the Nolin birds would have continued at that wing beat rate. In any case, the Nolin videos were too short to draw any conclusions relative to the Luneau bird, so I think the author overreaches in his assertion that the Luneau bird is consistent with Pileated. The evidence presented is insufficient to support such a conclusion.

I think what Collinsons and Nolan show amongst other things is the degree of variability in flap rates. Watch this Nolan video (here), there are several piliateds which start off fast and then slow considerably. I don't see any reason why that short period of fast flight wouldn't be sustained for a second or two longer if the bird was really scared and thus fleeing more desperately. I've observed this dozens of times with a whole suite of other bird species here in the UK. Analyses aside, having just watched the Nolin videos side by side with the Luneau one (available here), for the first time, it really does strike me just how similar the birds look.
 
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Xenospiza

Distracted
Supporter
The reasons why Nolin's birds don't sustain fast-flapping flight are explained quite well in the article – they're ready to land immediately.
Should he have chased them out off his garden to get better footage?
 

emupilot

Well-known member
Xenospiza said:
The reasons why Nolin's birds don't sustain fast-flapping flight are explained quite well in the article – they're ready to land immediately.
Should he have chased them out off his garden to get better footage?

Short answer, yes. If he wanted to compare their flap rate to the Luneau video, they would need to be flapping for as long as in the video in sustained escape, since a main point of Cornell's is that Pileated doesn't flap that fast for that long. If video shows a Pileated flapping at 8.6 Hz for 11 wingbeats, that would challenge Cornell's assertion that the Luneau bird can't be Pileated because of the flap rate. Since those videos show the Pileateds' flap rates declining after 4 beats, it doesn't support the hypothesis that Pileateds maintain the initial flap rate through 11 wingbeats. The author assumes the flap rate decreased because the Pileateds were preparing to land; one could just as easily assume that the flap rate decreased because the Pileateds were up to speed. One assumption supports the hypothesis, but the other contradicts it. To test the hypothesis, you need video of 11 Pileated flaps free of excuses.
 
Well, the game's up minus the spurious straw-clutching. The only people clinging to the video as proof are Cornell and a rag-tag bunch of believers. Do any serious birders out there still not get it? I doubt it.

That's not to say Hill won't come up trumps though.

but he won't of course.

Well done Martin.

Tim

PS interesting to note in the Mennill / DocMartin interview Mennill said there may be 'as few as three' IBWOs. What happened to the tens of pairs?
 

cyberthrush

Well-known member
Tim Allwood said:
PS interesting to note in the Mennill / DocMartin interview Mennill said there may be 'as few as three' IBWOs. What happened to the tens of pairs?

I believe the "3" figure refers only to the limited patch of habitat Auburn is exploring (a couple sq. mi.); the '10 pair' figure referred to the entire Choctawhatchee River basin (AL. thru FL. Panhandle).
 

Russ Jones

Well-known member
Tim Allwood said:
Well, the game's up minus the spurious straw-clutching. The only people clinging to the video as proof are Cornell and a rag-tag bunch of believers. Do any serious birders out there still not get it? I doubt it.

That's not to say Hill won't come up trumps though.

but he won't of course.

Well done Martin.

Tim

PS interesting to note in the Mennill / DocMartin interview Mennill said there may be 'as few as three' IBWOs. What happened to the tens of pairs?

Why are you so hung up on this vid Tim? I though it had become pretty much unanimous shortly after it had been picked apart by Sibley et al...inconclusive. Why would someone even bother to write a paper on that? It has already been analysed to death... so what game's up again? Seems to me like nothing has changed...

Seeya,

Russ
 

timeshadowed

Time is a Shadow
Tim Allwood said:
The only people clinging to the video as proof are Cornell and a rag-tag bunch of believers.

Tim et all,

Ok, so the video may not be of an IBWO - what difference does it really make?

I'm tired of beating a dead horse to death. Let's all agree to IGNORE the video and move on. As far as I'm concerned that small video clip is not very important anyway - it's way too blurry to tell anything conclusive.

So let's all agree to treat this video as if it did not exist.

BUT . . .

I still believe that the IBWO exists and is flying free in the southern swamps. Can I prove this? No I can not. But I choose to believe the many sighting reports of IBWO's down through the years. That is the basis of my belief, not some 4 second blurry video clip.
 
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slobyn

Well-known member
I also interpreted Mennill's comments this way.

cyberthrush said:
I believe the "3" figure refers only to the limited patch of habitat Auburn is exploring (a couple sq. mi.); the '10 pair' figure referred to the entire Choctawhatchee River basin (AL. thru FL. Panhandle).
 

Sidewinder

Well-known member
I suspect that we'll be learning a lot more about woodpecker flap rates in the future. I thought the initial concept to use the IBWO audio was a reasonable one, but the conclusion should have been couched in more cautious terms. Given the number of video cameras carried into swamps these days, and especially with much of the resulting footage being "owned" by the Cornell and Auburn/Windsor search teams (they're in the best position to accumulate such footage), someone should soon be able to assemble a sizeable data set on flap rates of the PIWO. I'd be very surprised if we don't see a much more thorough study published in the next year or two. When that happens, we will likely look back at the Luneau and Nolin videos in a different light.
 
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John Mariani

Well-known member
Ilya Maclean said:
I think what Collinsons and Nolan show amongst other things is the degree of variability in flap rates. Watch this Nolan video (here), there are several piliateds which start off fast and then slow considerably. I don't see any reason why that short period of fast flight wouldn't be sustained for a second or two longer if the bird was really scared and thus fleeing more desperately. I've observed this dozens of times with a whole suite of other bird species here in the UK. Analyses aside, having just watched the Nolin videos side by side with the Luneau one (available here), for the first time, it really does strike me just how similar the birds look.

Exactly. Why assume that any bird uses it muscles and feathers the same way every time?

The first Nolin flight sequence shows a Pileated flying left to right with what looks to me like a typical rolling woodpecker-type flight. Pileated can also fly more crow-like without obvious wing-tuck swoops between wingbeats. They just don't always fly the same. These are dynamic living creatures, and it seems to me that we can reasonably expect their behavior and flap rates and flight speed to vary from situation to situation and bird to bird.

It's sort of amusing to me that so much time and energy has gone into analyzing something as trivial as flap rates - trivial except as it relates to a few seconds of one blurry video. On the face of it the argument seems shaky. First use a single old sound recording to determine the flap rate of IBWO, and then make an ID partially based on the slower flap rate expected of a PIWO...based on what? have flap rates of all bird species been carefully analyzed and recorded just in case an issue arose? Outside this debate I don't recall anyone ever using a second-by-second analysis of comparitive flap rates to identify a bird. To justify the claim that the Luneau bird was IBWO it seems like they were really reaching hard for any plausible clue that bolstered their position.
 

griffin

Well-known member
I have just started reading this thread (honestly) and I have to say it brings me some comfort knowing there is something more contentious and vitriolic in the birding world than the existence of Scottish Crossbill :D

Brothers in arms and all that.

Now if you don't mind, I am off to count and compare the wingbeats of different crossbill species.................... screw the calls ! ;)


Linz
 

Rediscovered

lazy lurker
Be careful with reading this thread - it's worse than cigarettes. Much more addictive, and much, much worse for your health. I'm considering returning to smoking.

griffin said:
I have just started reading this thread (honestly) and I have to say it brings me some comfort knowing there is something more contentious and vitriolic in the birding world than the existence of Scottish Crossbill :D

Brothers in arms and all that.

Now if you don't mind, I am off to count and compare the wingbeats of different crossbill species.................... screw the calls ! ;)


Linz
 

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