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Ivory-billed Woodpecker (formerly updates) (2 Viewers)

Fishcrow video

Note: this is degraded because of the conversion to animated gif. It's just to display a quick slow motion view here...

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Better than Luneau's anyway, IMO.
I looked at it several times, both the original AVI and the animated GIF. I see a hint of a very long neck stretching out in front in one or two frames--of course, one cannot be sure of that, or anything. The overall flight pattern and wing shape remind me of a Great Blue Heron. The hint of lighter tone on the trailing edge, to me, looks like a bit of glare, often present on primaries and secondaries because they have broad flat surfaces that reflect sunlight at certain angles. (I've been fooled many times by the glint off of a Brown Pelican's wings into thinking there was some white on them, for instance.) The fact that the lighter tone seems to come and go with the flapping is, I feel, more consistent with glare than with plumage coloration. To me, too, the bird looks grey, not black-and-white, but of course that will depend on the exposure. For tonal reference, I note that the vegetation looks to be exposed fairly well--in the middle range of the sensor, neither over- nor under-exposed.

I, personally, do not see anything in the video clip that screams "woodpecker", but that is just me. I have pretty good experience with almost all the North American Woodpeckers, and a little bit of woodpecker-watching in the Neotropics. I have been birding since 1966, but I am the first to admit that I can make ID mistakes, and have, on numerous occasions. I do not know a birder who does not.
Of course, the video is so brief, and the bird so distant, it is hard say anything conclusive. The Song Remains the Same.
 
Is the full seven seconds of the video available on the web?

I have a hard time sorting out the video clips from his descriptions, but near the top of his page, he writes, "I obtained about six seconds of video during the approach and after the bird passed the base of the tree. "

As far as I can tell, www.fishcrow.com/flyunder_approach.avi is the approach, and www.fishcrow.com/flyunder_trailingedges.avi is after it passed the base of the tree. The first video plays for about 4 seconds and the second about 2 seconds, but he also says that both of these videos "play at half speed", so that would only seem to acount for about 3 seconds of original video (???), unless I'm misunderstanding his text... He also links to http://www.fishcrow.com/cruising_flight.avi , which plays about 1 second (also "half speed"), but he seems to be providing this clip as a pileated reference video...

Perhaps he'll post a clarification, or better yet, the full original video footage. :t:
 
What does look woodpecker-like to me is the way the wings appear to stroke fully down and a bit to the rear, then bend at the elbow and fold in on the upstroke. (I'm talking about the short clip shown in the animated gif.) But I only really see the one full stroke there, and even that is partially obscured, and very far from clear. But that's how it looks to me. Harder to make out much of anything useful on the "approach" clip, but the wings do seem to fold in, which sure doesn't look like a heron to me...

(Oh, and for anyone tuning in late, I'm strictly amateur status. It just doesn't slow me down from stating my opinions, so caution is advised. |:D|)

My own feeling is that the white trailing edge actually seems quite consistent in the short gif clip. I would expect glare to disappear much more quickly with change in angle through that most-visible downstroke. In a few frames there, the pattern looks very good too, with the white extending right out through the primaries. But like you, I can't really tell much of anything for sure.

Regarding exposure, I'd certainly expect to be able to see white patches on the tops of the wings somewhere in that clip if it was PIWO. No hint of those though...

Dave
 
The flight speed of the Collins bird is also inconsistent with PIWO. Here's his comment from May,13:

"A paper by Tobalske (Auk, 1996) lists the range of the flight speed of the pileated to be 7.5 to 11.6 m/s. The large woodpecker in the March 29 video has a flight speed of about 14.7 m/s. These numbers are consistent with my impression that the bird was flying much too fast to be a pileated when it shot past Tree 6."

It's also worth bearing in mind that Tobalske has no axe to grind, as far as I'm aware, and in the current climate, it took some guts for him to allow Mike to make his name public.

The historical literature does not say Ivory-billed flapped faster than Pileated. Tanner and others frequently refer to the species' fast flight, but not to fast wing beats. Many people conflate these two things; yet speed and flapping rate need not be correlated. By contrast, what we do have is a direct comparative statement by James Tanner that flight pattern “cannot be used as a reliable field character” because he had “frequently seen Pileated fly directly, in no way different from the flight of the larger bird.” We just don't know what the wing beat frequency for Ivory-billed was apart from one sound recording (even that is not verifiable). None of the authors/observers Fred mentions measured wing beat frequency.
 
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Thanks for the links to the videos Dave. I'm not sure I can see a Woodpecker in them - in fact I can see two birds in the approach video and wasn't able to be sure which I was supposed to be looking at! The rather intriguing white in the wings shown on some of the grabs seems to be a lot less evident in the original - its rather uniform grey! What did strike me was the appearance of a long neck at one stage. This might have been artefact - but that would call into question any other claimed detail in the images, since it is a least as prominent (see below). You might persuade me that this was a Cormorant if I had filmed it over my house.... so I guess I could have my arm twisted into believing this is an Anhinga... but lets face it, its not exactly unequivocal evidence of anything


MMinNY said:
The large woodpecker in the March 29 video has a flight speed of about 14.7 m/s. These numbers are consistent with my impression that the bird was flying much too fast to be a pileated when it shot past Tree 6."

I'm struggling here. Where is the known, scaled, object perpendicular to the camera, and in the same plane as supposed woodpecker, that allows a calculation of speed? By all means use the video rate to estimate time, but as for distance travelled, its a wild guess!

Don't tell me... the Woodpecker IS the scaled object. Priceless!
 

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I'm struggling here. Where is the known, scaled, object perpendicular to the camera, and in the same plane as supposed woodpecker, that allows a calculation of speed? By all means use the video rate to estimate time, but as for distance travelled, its a wild guess!

Don't tell me... the Woodpecker IS the scaled object. Priceless!

What about a measured distance between fixed objects, then a measure of frames needed for the bird to pass the two objects? I would like to see how the calculation was made.
 
..........and an estimation of height to account for parallax errors, using a fixed observation point. Oh and 2 secs max of film to make a judgement over.... optimistic in the extreme to be confident of a significant difference from 11.6 m/s... mind you, Anhinghas are quick I expect ;)
 
..........and an estimation of height to account for parallax errors, using a fixed observation point. Oh and 2 secs max of film to make a judgement over.... optimistic in the extreme to be confident of a significant difference from 11.6 m/s... mind you, Anhinghas are quick I expect ;)

Well stated. As I have told others in private correspondence - a LOT of holes in this video.
 
Thanks for the links to the videos Dave. I'm not sure I can see a Woodpecker in them - in fact I can see two birds in the approach video and wasn't able to be sure which I was supposed to be looking at! The rather intriguing white in the wings shown on some of the grabs seems to be a lot less evident in the original - its rather uniform grey!

Hi Jane!

Good reminder to not get too serious about that animated gif I put together. Go to the .avi file if you really want to scrutinize it.

What did strike me was the appearance of a long neck at one stage.
Where are you seeing the long neck? Is it the frame you posted? Because with the wings moving to the rear it doesn't look all that long to me...

This might have been artefact - but that would call into question any other claimed detail in the images, since it is a least as prominent (see below). You might persuade me that this was a Cormorant if I had filmed it over my house.... so I guess I could have my arm twisted into believing this is an Anhinga... but lets face it, its not exactly unequivocal evidence of anything

Yeah, it would be tough to go very far with this one. I could see an argument that the flight mechanics / flap rates / speed are consistent with a woodpecker, but it seems like a pretty tall order to rule out all other possibilities based on this footage.

It sure doesn't look like PIWO to me though. Wings look proportionately too narrow for one thing.

I'm struggling here. Where is the known, scaled, object perpendicular to the camera, and in the same plane as supposed woodpecker, that allows a calculation of speed? By all means use the video rate to estimate time, but as for distance travelled, its a wild guess!

Don't tell me... the Woodpecker IS the scaled object. Priceless!

Lol, that would be funny. I sure hope not.

I think Mike states that the "second bird" in the "approach" video is supposed to be a reflection off the water, but it's hard for me to see that conclusively just from the clip. If it is a shadow [edit: reflection I mean, though a shadow could work as well], that would provide an excellent way to quite accurately determine both the height and location of the bird across the clip, and you could get a pretty accurate estimate of speed from that. The math would get a bit tricky, but if you approximated the flight as a straight line it would be pretty straightforward, even if the bird's elevation was changing.

Dave
 
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It can't be a reflection - the flap rates are different - I think :eek:)

and more to the point how do you get a refection off water looking up through trees?
 
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It can't be a reflection - the flap rates are different - I think :eek:)

and more to the point how do you get a refection off water looking up through trees?

Yeah, I don't know. Hard to match the flaps exactly...

Mike shot the video from 70 feet up in a tree, looking down, so that's definately water you're seeing, not sky.
 
In any case - one of these UFO's is clearly flying faster than the other..... unless its close to us ;

One day I'll get my head round the geometry of an approaching reflected bird - the rate of change of apparent distance between the image and its reflection.... mind you height and speed of the bird are going to remain as variables whatever!
 

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dave_in_michigan; said:
Yeah, I don't know. Hard to match the flaps exactly...

Mike shot the video from 70 feet up in a tree, looking down, so that's definately water you're seeing, not sky.

Ah that would support the Anhingha theory nicely - harder to support over a big bit of wood!

I tease!
 
dave_in_michigan; said:
At the top of his page, Mike posts a wider view of the "approach" video vantage point so you can get oriented.

http://www.fishcrow.com/down_bayou.jpg

So it looks like his posted clips are pretty well cropped to start with...

Thanks!

I can see a white trailing edge to the object in the right of centre at the top of that photo. No red on the head either It MUST be an IBWO surely.. I should stop teasing, but its Friday

Strikes me that if he is looking down on the birds from just 70' its a pity the videos don't show more. The bird now seems awfully small - like Kingfisher sized!
 

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"A paper by Tobalske (Auk, 1996) lists the range of the flight speed of the pileated to be 7.5 to 11.6 m/s. The large woodpecker in the March 29 video has a flight speed of about 14.7 m/s. These numbers are consistent with my impression that the bird was flying much too fast to be a pileated when it shot past Tree 6."

The data for flight speed cited are from table 7 in Tobalske's 1996 Auk paper. The sample size: n = 1 (this could be combined data for both male and female at one nest; because Tobalske did not distinguish the sexes, he averaged all flights for a location nest--see footnotes and methods). The total number of flights contributing to the observed range: n = 11 (by one or two birds).

The idea that anyone can exclude any species based on such limited data and come up with a number that adequately addresses the range of variation is laughable. (I also don't think the Collins bird or birds, however many he is referring to in these clips, is of a woodpecker or a duck; anhinga, green heron, immature white ibis, the list goes on.) On top of that, the air speed data presented is for level, non-maneuvering flight. The possible speeds for Pileated are certainly beyond what is reported.

Jane Turner is absolutely right (as per usual) about the lack of any known reference scales to measure speed. But not just that, any estimation of the speed requires some measurement of error. Note that the value cited by MMinNY from Collins's web site gives the single exact value of 14.7 m/s. Given the distance from the object, the blurred nature of the images, camera shake, tree shake (?), branch and body movements, height of bird above water and mud (did height vary? does he know?), we would need some replicates with similar objects recorded at known speeds to provide some estimate of measurement error. To give a speed to a tenth of a meter per second without any error and so close to the possible air speed of the species he WANTS to exclude is deceptive. 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).

As for what is in the Collins video(s), it/they is/are unidentifiable.
 
The data for flight speed cited are from table 7 in Tobalske's 1996 Auk paper. The sample size: n = 1 (this could be combined data for both male and female at one nest; because Tobalske did not distinguish the sexes, he averaged all flights for a location nest--see footnotes and methods). The total number of flights contributing to the observed range: n = 11 (by one or two birds).

.

Oh dear. I understand that the paper was not just on Pileateds, but to make sweeping statements on the evidence of one bird (or a pair) over 11 flights, well.

If you measured me running over 100 metres 11 times you'd get a range of 11 different values, if you were then to say all humans run at x speed from those measurements you'd be in for a huge surprise when you watched the Olympics...
 
In any case - one of these UFO's is clearly flying faster than the other..... unless its close to us ;

One day I'll get my head round the geometry of an approaching reflected bird - the rate of change of apparent distance between the image and its reflection.... mind you height and speed of the bird are going to remain as variables whatever!

Because the reflection is on the ground, you can figure out it's location directly. (If needed, you could send someone out on a boat to match the position in the video, and just measure it, but there are ways to find it opticaly as well).

If you draw a line from the camera position to the reflection, then the line leaving the reflection point and up to the bird is exactly the same angle, and also in the same vertical plane.

Then because you can calculate the exact distance to the reflection, and you also know both the angle up to the bird and the angle from the camera's view between reflection and bird, you can figure out the distance from camera to bird. And then you essentially know exactly where it's located in space.

I'm sure that's about as clear as mud... If you do that just for the first point and the last point, you can approximate a straight line for the bird's path. But you can also do it for each bird/reflection pair and therefore plot the bird's location through space for each frame. Then you can figure out the bird's speed between each and every frame.

Looks like 90-some frames with both the bird and reflection, so they should be able to get pretty accurate info on the bird's speed. Sure there will be some +/- errors measurements, but if done with some care, it's possible to get quite accurate positional information.

With the distances and geometry involved, movement of the excact camera position (hand or tree movement) can be calculated, but they will have almost no effect on speed calculation accuracy.

If someone really wanted to get serious about knowing the margin of error, they should also run a quick check to measure the frame speed variance on the camera used. Any variation here would have a much larger effect on speed calculation errors, but I expect any digital camera to have very precise and repeatable timing.

FWIW. This whole flap speed / flight speed seems shakey to me as a diagnostic tool, unless you're using it to rule out herons and such. Calculation of the speed in the video is can be plenty precise. It's the reference data that's all over the map.
 
Yeah - but its fun trying.... :)

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).
 
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