Ivory-billed Woodpecker (formerly updates) (9 Viewers)

[dave_in_michigan]

I have measured hundreds (even low thousands?) of specimens and live birds in the hand with micrometers. Even under the best of circumstances there is a noticeable margin of error (when I need to be sure, I'll measure something 10 times and average the values).

Every measurement technique can be quantified for accuracy. Sources of variation come from the measurement tool, the technique, the operator, and the sample itself. Measuring live birds in the hand is going to have huge variation due to technique and operator. (FYI, although it's a good idea to make multiple measurements, you should also have multiple operators make measurements if you really want to understand the variances of your measurements.)

Optical measurements by comparison can be extremely accurate, so I don't think your example is a valid comparison. But anyway, the varation among PIWO reference data alone will greatly overshadow the measurement accuracy from this video.

 

[dave_in_michigan]

We do need David Lynch to direct the definitive film on this story.

I'd like to see that.

But if I was funding it, I'd get Oliver Stone. Either way he wants to lean, he'd find a way to sell tickets...

 

[Louis Bevier]

Optical measurements by comparison can be extremely accurate, so I don't think your example is a valid comparison.

The physical measurement is pertinent because one is measuring a blurred image on a monitor, whether in pixels or millimeters. It is possible to get good images of birds from 70' feet away; I've seen lots of them. In fact, I think most people who try get identifiable images at that distance. The ones we see out of searchers bent on finding an IBW, however, are consistently blurred beyond usefulness--except the Luneau bird, which by shear luck shows just enough information that I could replicate the patterns with similarly blurred images of known Pileateds, unless one is willing to deny the existence of those data

 

[dave_in_michigan]

It is possible to get good images of birds from 70' feet away; I've seen lots of them. In fact, I think most people who try get identifiable images at that distance. The ones we see out of searchers bent on finding an IBW, however, are consistently blurred beyond usefulness--except the Luneau bird, which by shear luck shows just enough information that I could replicate the patterns with similarly blurred images of known Pileateds, unless one is willing to deny the existence of those data

Not me. But then I always thought the Luneau video was junk to start with.

But replicating patterns with similarly blurred images? Yikes. No offense intended, but I'm not sure I'd want to hang my hat on that either.

"Not definitive" suites me just fine.

 

[Jane Turner]

My brain is so fuzzy these days (I was once gainfully employed as a post Doc in an Optical Physics lab)... however one thing that has just struck me rather suddenly.... as I grapple with school grade trigonometry, the approach video has the camera focussed on the reflection (the leading image) rather than the object, thus any plumage features being attributed to the object are actually the ventral surface. I'd love to see the whole uncut video, with the full field of view!

 

[Jane Turner]

Using reference objects that appear in the video and measurements made at the site, I estimated that the bird flew 81 meters in 5.5 seconds, which corresponds to about 14.7 m/s (or 33 mph).

Aha - its an estimation. I wonder if he was measuring the reflection of the bird? It is actually really rather important!

 

[dave_in_michigan]

My brain is so fuzzy these days (I was once gainfully employed as a post Doc in an Optical Physics lab)... however one thing that has just struck me rather suddenly.... as I grapple with school grade trigonometry, the approach video has the camera focussed on the reflection (the leading image) rather than the object, thus any plumage features being attributed to the object are actually the ventral surface. I'd love to see the whole uncut video, with the full field of view!

Nice graphic! You drew the bird's flight as level, but it doesn't have to be. Wherever the black dot and green dot end up in space, you just connect between them to find the distance travelled.

I can't make out much of any plumage on either the reflection or the bird in the "approch" clip. BTW, keep in mind there are two video clips. The shorter clip that shows what looks like a white trailing edge is from the other video, not this approach/reflection one.

Yeah, I'd like to see the orignal uncut version too. Depending on the software used, there is potential that pixels over the whole image have been modified just by cropping the image down like he's done...

 

[Jane Turner]

I was trying to keep it simple to start with - re the flight.

And that is why I want to see the whole video - does the camera refocus on the bird? It also seems to be very close to the water for a woodpecker!

 

[humminbird]

And that is why I want to see the whole video - does the camera refocus on the bird? It also seems to be very close to the water for a woodpecker!

Jane:
John James Audubon once made reference to Ivory-billed Woodpeckers as "abundant". The place? Buffalo BAYOU. Even in the dry season it is "very close to water".

 

[Jane Turner]

Hummingbird - it was how low to the water the bird seems, not that it was over it. Now if it is filmed from 70' up a tree, appears that far away as it passes below, and the apparent difference between the bird and its reflection change so quickly. its almost skimming the water - like a Spotted Sandpiper might.

 

[dave_in_michigan]

Hummingbird - it was how low to the water the bird seems, not that it was over it. Now if it is filmed from 70' up a tree, appears that far away as it passes below, and the apparent difference between the bird and its reflection change so quickly. its almost skimming the water - like a Spotted Sandpiper might.

??? Looks like it's quite a large gap between bird and reflection in the video to me... 10 feet up? maybe more?

Are we looking at the same thing?

 

[PandionMlt]

more than 10 feet? i dnt think so

and since when has flap rate become diagnostic of anything anyway????

esp ina case like this??

this is reeking more and more of ppl clutching at straws more than anything else... although that whitetrailing edge on the bird on fishcrow shook me a bit initially...

 

[salar53]

Shaken

more than 10 feet? i dnt think so

and since when has flap rate become diagnostic of anything anyway????

esp ina case like this??

this is reeking more and more of ppl clutching at straws more than anything else... although that whitetrailing edge on the bird on fishcrow shook me a bit initially...

Since when has flap rate become diagnostic of anything? Funny you should ask that. Perhaps you should take it up with Robert L. Nudds, Graham K. Taylor and Adrian L.R. Thomas in a learned article here:

http://journals.royalsociety.org/content/thr5xu6m7v8150qc/fulltext.pdf

Fred Virazzi passed this article to Dr Michael Collins and they also think that flap rate can be diagnostic.
Not to mention woodpecker expert Bret Tobalske.

You were initially shaken when you saw the white trailing edge? What has relaxed you into the calm of scepticism again?

 

[humminbird]

Not to mention woodpecker expert Bret Tobalske.

In whose opinion? I do not see much in his papers that would convince me of his special skills with woodpeckers. And anyone who would PUBLISH a paper with a sample size of 1 needs to go back to highschool science.

 

[salar53]

Wonder

In whose opinion? I do not see much in his papers that would convince me of his special skills with woodpeckers. And anyone who would PUBLISH a paper with a sample size of 1 needs to go back to highschool science.

Hmmmm. Well he is the Professor of Biology at Portland University. In one area of France alone he has studied seven different species of woodpecker. Perhaps it would be more correct to say that he is a bird-flight expert who has done work on many species of birds, including woodpeckers.
When somebody like Professor Tobalske says that Mike Collins's 29th March bird is a large woodpecker, I pay attention.
And when even I can see those white trailing edges, I wonder..............

 

[Apodemus]

I agree. I need to lighten up. We do need David Lynch to direct the definitive film on this story.

I might have some time to look into Dr. Collins's video clips next week. First, I need to look back over the vague images of what appear to a rhomboid flipper taken by submersible in Loch Ness. For those who say it's not a real creature ever described, au contraire! Sir Peter Scott gave it a scientific name based on this structure, Nessiteras rhombopteryx. I think he had fun with that (think anagrams).

A monster hoax by Sir Peter S

 

[Jane Turner]

One thing that I would really like to see is a video of a known species flying through. I'm sure that there must have been other birds passing. Lets say the bird was 10 feet up, that is just 60' from Fishcrow In a quick test I was able to get adequate film (for ID) of gulls 60' away, using my mobile phone, which I can assure you is not "fancy"

 

[Louis Bevier]

In whose opinion? I do not see much in his papers that would convince me of his special skills with woodpeckers. And anyone who would PUBLISH a paper with a sample size of 1 needs to go back to highschool science.

Regarding Bret Tobalske, I want to make it clear that my criticism was directed at the misuse of his data by those grasping for any way to confirm their belief that an ambiguous and inconclusive video image shows an Ivory-billed Woodpecker. I think Bret Tobalske's work is of the highest caliber. He understands the statistics involved. It is wrong to question his expertise.

After I explained why wing beat frequencies reported in both the Luneau and Collins videos could not be used to eliminate Pileated (mainly because I have measured rates of Pileateds in flight that match or surpass the birds in those videos), the goal posts shifted to an assertion that flight speed was "inconsistent" with Pileated, implying that this feature of the Collins video supported the identification as Ivory-bill. My criticism was directed at this misuse of the cited data.

Since when has flap rate become diagnostic of anything? ... Fred Virazzi passed this article to Dr Michael Collins and they also think that flap rate can be diagnostic. Not to mention woodpecker expert Bret Tobalske.

The 1996 Auk paper by Bret Tobalske focused on the physiological and morphological constraints of flight behavior in woodpeckers. It was not aimed at generating data to show how wing beat frequency or flight speed could be used to discriminate species of woodpeckers. These characters may be useful for identification in some circumstances and for some species pairs. Flap rate has not been shown to be diagnostic for separation of Pileated and Ivory-billed woodpeckers, and Bret Tobalske has never said this.

Let's be clear, Michael Collins did not identify the bird in the field as an Ivory-billed. His video shows something apparently with and without trailing edges of white in different segments of significant duration. Because the image is ambiguous, one can make of it what they want. Collins and others want it to be an Ivory-billed. One expert, formerly a searcher and not otherwise involved with this dispute, wrote to me saying they were sure it was a Pileated. It is worth scrutinizing the Collins video, but it will not settle anything. I find it especially unfortunate that the discussion on this thread was started by someone who came blustering in calling people willfully ignorant and demanding a pay up. Let's keep things in perspective.

 

[MMinNY]

Yes, let's be clear.

I didn't "demand" anything. I wrote "might want to start thinking about paying up." It was a bit snarky, but it was in no way a demand.

And the willful ignorance remark, which was qualified with a question mark, was in response to a comment that referred to Tobalske as "someone," which I took to mean that the poster was either unaware of Tobalske's reputation or was trying to minimize it. The poster also referenced a partial clip that he or she had viewed online, not the actual footage. Hence my suggestion that ignorance, willful or otherwise, was involved.

The point is that quite a few people who post here make comments without having seen the actual footage or even having bothered to read the descriptive material on fishcrow.com. One recent poster didn't even know that Mike Collins obtained his video from above.

I've gotten into it with you before, and at that time I said I expected better of you. I still do. Mischaracterizing my statements is beneath someone of your reputation.

That said, I'm glad you're standing up for Tobalske.

Regarding Bret Tobalske, I want to make it clear that my criticism was directed at the misuse of his data by those grasping for any way to confirm their belief that an ambiguous and inconclusive video image shows an Ivory-billed Woodpecker. I think Bret Tobalske's work is of the highest caliber. He understands the statistics involved. It is wrong to question his expertise.

After I explained why wing beat frequencies reported in both the Luneau and Collins videos could not be used to eliminate Pileated (mainly because I have measured rates of Pileateds in flight that match or surpass the birds in those videos), the goal posts shifted to an assertion that flight speed was "inconsistent" with Pileated, implying that this feature of the Collins video supported the identification as Ivory-bill. My criticism was directed at this misuse of the cited data.



The 1996 Auk paper by Bret Tobalske focused on the physiological and morphological constraints of flight behavior in woodpeckers. It was not aimed at generating data to show how wing beat frequency or flight speed could be used to discriminate species of woodpeckers. These characters may be useful for identification in some circumstances and for some species pairs. Flap rate has not been shown to be diagnostic for separation of Pileated and Ivory-billed woodpeckers, and Bret Tobalske has never said this.

Let's be clear, Michael Collins did not identify the bird in the field as an Ivory-billed. His video shows something apparently with and without trailing edges of white in different segments of significant duration. Because the image is ambiguous, one can make of it what they want. Collins and others want it to be an Ivory-billed. One expert, formerly a searcher and not otherwise involved with this dispute, wrote to me saying they were sure it was a Pileated. It is worth scrutinizing the Collins video, but it will not settle anything. I find it especially unfortunate that the discussion on this thread was started by someone who came blustering in calling people willfully ignorant and demanding a pay up. Let's keep things in perspective.

 

[Louis Bevier]

Tanner's photos of two Ivory-bills in flight

I briefly looked at the Fishcrow web page this morning and noticed that he compares his 29 March 2008 images to some photographs of Ivory-bills in flight taken by James Tanner. Collins says that this "evidence" has been overlooked looked for years. That is not correct.

The Tanner photos are part of an extensive collection materials from the Tensas National Wildlife Refuge archived at Louisiana State University. These flight shots are two of one hundred 4” x 5” resin-coated photographic prints that were formerly accessible at high resolution on the LSU library servers. Lower resolution images are now available through links at the U.S. Fish and Wildlife Ivory-billed web site.

Having studied these as part of research into the Luneau video, I sent these images to Ted Floyd, editor of Birding, because I thought they were relevant to the birding quiz presented last year showing three "birds" flying over the Choctawhatchee (taken by remote camera). I explained to Ted why I thought the quiz birds did not look like Ivory-bills, in part based on these images. That aside, the most important take home message of that photo quiz was how ambigous images can be interpreted in differing ways (I still can't decide if birds are coming or going). The answers reflected this even though the summary supplied with the answer did not highlight this important aspect of identification--we see things the way we want to see them (and it’s clear by his own admission that Geoff Hill thought those three birds were Ivory-bills). It would have been useful to publish these distant flight images taken by Tanner, but for whatever reason, Birding didn't or couldn't (they are free of restrictions if properly credited). Aren't we seeing the same biased interpretation of ambiguous images by Michael Collins?

Attached are two images of Ivory-bills in flight. These are 2x zooms of crops from the highest resolution images that were available at the LSU library. Both were taken in April 1939 by James Tanner. They show that even with crude equipment, better images than any searchers have provided so far are possible when one really is seeing Ivory-bills.

(1) Adult ivory-billed woodpecker in flight, James Tanner, April 1939, Tensas National Wildlife Refuge, item #4171079 in Louisiana and Lower Mississippi Valley Collections, Special Collections, Hill Memorial Library, Louisiana State University Libraries, Baton Rouge, Louisiana; (2) Young ivory-billed woodpecker in flight, James Tanner, April 1939, Tensas National Wildlife Refuge, item #4171079.