Ivory-billed Woodpecker (formerly updates) (4 Viewers)

[emupilot]

If the attachment worked, this is the famous backlit overhead flight shot of an Ivory-bill with white wing linings barely discernible at close range.

For reference, here is Tanner's "Young ivory-billed woodpecker in flight, April 1939 "

View attachment 227584

Pic is from Tensas River National Wildlife Refuge, U.S. Fish & Wildlife Service, Ivory-Billed Woodpecker Records (Mss. 4171), Louisiana and Lower Mississippi Valley Collections, Louisiana State University Libraries, Baton Rouge, Louisiana, USA. Reference their item #106, also labeled as Tanners # 417079p link - use the webpage to increase zoom to 100% to achieve the view I'm posting here.

Tanner claims this is a young IBWO, but the tail looks too short and broad to me, I don't see the proper white on the leading edge of the wing, and where's the Ivory Bill ??? ... :-C

 

[dave_in_michigan]

Yes, there are different versions of that shot floating around the net. Here's another, where the contrast is a little better. I'd love to find a hi-res version sometime. This is hands down my favorite IBWO photo. Absolutely spectacular.


"Female Ivory-billed Woodpecker leaves as male arrives"
photo by James T. Tanner - 1937

 

[humminbird]

Am I the only one who notices the drastic difference in wing shapes and primary colors on these shots?

 

[MMinNY]

First post here in a very long time. Glad the discussion has remained civil.

I'm on the fence about this one, although I think it must be either a RHWO or an IBWO. I'm leaning toward IBWO based on the appearance of the wings in the early frames, but I have by no means made up my mind.

I have some observations regarding the apparent white on the tail. First, the pattern isn't quite right for a Red-headed; as far as I can tell, the white is limited to the tail but doesn't appear on the rump (in fact few, if any, of the frames that show a dorsal view of the bird have white on the rump or tail) or body, as would be expected in a Red-headed.

When I first looked at the white in the video, I had the impression that it was a consequence of lighting conditions. This seems to be supported by the fact that the appearance of the white is inconsistent during the sequence and only shows up in some of the later frames. If you look at Dave's frame 105 (great job Dave!) the tail appears to be entirely white, not what one would expect in either species. This leads me to think the white may have been caused by glare (as Mike Collins argues on his site) and/or the refraction of light through the tail feathers.

I don't claim to be certain about this interpretation. Just throwing it out for discussion.

This one looks like a red-headed to me. Look at this screen shot. The light part on the wing (which should be white) matches the light part on the tail (which means it would also be white).

 

[Jane Turner]

What about the structure, is that glare too?

 

[emupilot]

I might suggest a more constructive response would be to discuss what the structure of the bird tells you about its possible identity. Back lighting and resolution also affect our interpretations of structure and coloration - your take on how we should take those effects into account would be a welcome contribution.

What about the structure, is that glare too?

 

[dave_in_michigan]

Structure looks all over the map to me, depending on the frame. Keep in mind I'm just a hack...

Head looks completely missing in frame 72, and then quite longish the very next frame... Quite a few look short, while 84-87 are a bit longer... I don't know if any of those longer ones have a chance to rule out RHWO though.

The wing aspect ratio would seem a key point to me, but I wonder in some frames if it's possible to distinguish one wing from the other, or whether the wing is really at full 90 degrees to the camera (full extension view). I'm not sure how you go about picking and choosing from various frames, or if that's even a good idea.

I don't know if tail flairing is a problem or not, but the length sure seems to be a question. I'd ask wheather the tail length is still ok for RHWO on the longer images, like 83 or 94. For IBWO I seem to recall that immature IBWO has a shorter tail -- maybe there's some data on yearlings, but I sure don't know what it is.

 

[Jane Turner]

I might suggest a more constructive response would be to discuss what the structure of the bird tells you about its possible identity. Back lighting and resolution also affect our interpretations of structure and coloration - your take on how we should take those effects into account would be a welcome contribution.

don't look at individual frames, look at the moving gif - the overwhelming impression is of a rather stocky and short-winged bird

 

[emupilot]

Wing dimensions can be compared against video of known Red-headed woodpeckers and hopefully a size estimate can be obtained as well which would settle matters in short order. I'll leave that to the experts. I agree more generally that the bird does not fly how we expect an Ivory-bill to fly. However, I think alot of caution is warranted regarding our expectations since none of us has first-hand experience nor video for reference.

don't look at individual frames, look at the moving gif - the overwhelming impression is of a rather stocky and short-winged bird

 

[timeshadowed]

Mike Collins has submitted an inquiry to the Frontiers List about his video clips. This should be very interesting.

 

[Sidewinder]

Mike Collins has submitted an inquiry to the Frontiers List about his video clips. This should be very interesting.

I was hoping this would happen. I also hope the discussion is as civil there as it has remained here thus far. Mike can be brusque and confrontational (and has been treated as bad or worse), but even if the ivorybill's probability of existence is slim at best, we should be grateful for his effort to document it.

I'm concerned the white is not extensive enough on the wings. I'm also with Jane on looking at the half-speed video (which seems to be all we have to view from Mike). I spent much of Saturday evening examining images one at a time, but on Sunday I viewed the flight at half-speed over and over, and it just seems consistent to me with a smaller woodpecker. Would love to be wrong.

 

[Birdingcraft]

don't look at individual frames, look at the moving gif - the overwhelming impression is of a rather stocky and short-winged bird

I fully agree. Although pictures (both moving and stills) can be deceiving, my immediate first impression was RHWO.

 

[dave_in_michigan]

I know Mike's is half speed and the animated gif is aroud 1/4 speed, but my first impression is that RHWO has much faster wingbeats with less paused "tucking". But then I've never seen RHWO in slo-mo... It would be nice to be able to look more closely at some RHWO footage for comparison, but all I can find is on youtube, and I'm not able to change speeds or look frame by frame with that. (Suggestions?)

Anybody know where to find RHWO flight footage for comparison?

 

[Ilya Maclean]

White on both upper and underwing appears to be confined to secondaries (+ at most inner primaries). It also appears to have white udertail coverts consistent with Red-headed, though I’m also struggling to make out a white leading edge on the underwing (which would be need for IBWO too). The shape is more consistent with Red-headed.

See attached blown-up from a couple of Dave’s gifs and compare with an IBWO & Red-headed.

Incidentally, Mike's other clips are here:
http://fishcrow.com/flight3nov09.mp4
http://fishcrow.com/glide3nov09.mp4

My guess would be Belted Kingfisher for two & three is almost certainly an Anhinga

 

[pcoin]

Collins ID frontiers/RHWO in flight

Mike Collins has submitted an inquiry to the Frontiers List about his video clips. This should be very interesting.

Collins post is here, one response is here--suggests 5 November video is Red-headed Woodpecker.

I know Mike's is half speed and the animated gif is aroud 1/4 speed, but my first impression is that RHWO has much faster wingbeats with less paused "tucking". But then I've never seen RHWO in slo-mo...

Anybody know where to find RHWO flight footage for comparison?

Red-headed frequently make slow fly-catching flights, or slow half-gliding flights between two perches, in my experience. I think of their flight as being very leisurely compared to other SE US woodpeckers, such as the Red-bellied.

Excellent still images of a RHWO in flight are here. I don't see any good videos on the Internet, but there probably are some.

 

[cyberthrush]

I was hoping this would happen. I also hope the discussion is as civil there [Frontiers of Identification ] as it has remained here thus far....

the Frontiers discussions are almost always civil and very enlightening... I just don't know how seriously most members there will even take these videos; I'm a little surprised they even allowed Mike to post them there; most members may consider it a waste of time.

Some folks keep bringing up the under fore-wing of the bird as not appearing white -- this is not an issue, as both the IBWO & RHWO can routinely appear dark there when backlit. BUT, there are tons of other issues. I'd be amazed if official consensus calls this an IBWO.

 

[Ilya Maclean]

one response is here

Nice to see Dan Lane came to the same conclusions as I did!

Some folks keep bringing up the under fore-wing of the bird as not appearing white -- this is not an issue, as both the IBWO & RHWO can routinely appear dark there when backlit

Agree, that's probably why you can't see the white leading edge on the underwing, which makes it even more consistent with RHWO

 

[Cillana]

That's what I was thinking too. You can't see the white on the belly or the forewing because it is backlit. But you can see it on the trailing edge of the wing and the base of the tail because more light can pass through there.

 

[dave_in_michigan]

Well, I've sorted out the calculations for the bird's speed and distance from Mike's flight5nov vid. Results might be useful for evaluation of candidate species like RHWO. I just want to confirm some details about the camera first, then I'll post up the info.

 

[dave_in_michigan]

It seems Mike may have some delays in getting the shots I need to confirm the lens field of view. Nevertheless, I'm fairly confident that my information is correct based on the specs of the camera, so I'll go ahead and post what I have.

Since there is no scaled reference near the bird, I've set up the calculations to show the bird's speed and distance from the camera as a function of bird size. I have selected frame #85 for this purpose. Select dimension 'x' according to expected size for candidtate bird (RHWO, IBWO, etc), and read the chart to see the corresponding speed and distance according to that inputted dimension. As expected, a larger bird would have to be further away, and traveling faster than if the image is of a smaller bird. [on edit: So for example, if x=6.5" for RHWO, the calculated speed in the video is 12.3 mph. If x=15 for IBWO, then the calculated speed in the video is 28.4 (bigger bird = faster calculated speed). Question then is whether the calculated speed matches what is expected for the candidate bird.]



Intended Purpose: calculated speed can be used for evaluating the viability of candidate birds such as red-headed woodpecker.

I'm also including here a view of the spreadsheet created for these calculations. I've included brief descriptions of each calculation step (and in some places the formula description). It's a bit crude, but there should be plenty enough detail for full transparency.



Flight speed is calculated between frame #66 and #104. The bird's direction of travel appears to be roughly perpendicular to the camera, particulary at the very end of the video clip. Since the distance to the bird is more than 20 times the traversed distance of the bird's flight, the calculation method used should be sufficiently accurate for determining flight speed.

If anyone has a desire or sees a need to have this analysis "published" in a more permanent online location somewhere for reference purposes, please let me know.

Dave