Best laid plans . . . I’m pushing back the posts on historic range and evidence but hope to get to them soon.
In going through some of the remaining unexamined images from past trail cam deployments, Geoffrey McMullan came across an intriguing image. He sent me the file for the entire day without indicating where the image was located or what interested him about it. Reviewing cards is challenging; it’s tedious, while demanding focus and attention to very subtle changes. It can be easy to overlook hits of any kind. Nevertheless, this particular frame leapt out at me immediately, even though the object involved is indistinct and is only present in a single frame (more on that later).
I’ll begin by sharing and discussing the image, before and after stills, a time lapse video, and some additional captures comparing other animals with what’s shown in the frame. I’ll follow that with some of the discussion that has taken place among the active searchers in our group and some of the biologists who are advising us. Matt Courtman suggested that everyone on our email list give three reasons they like the image for ivorybill and three counterarguments. Not everyone followed the suggested format, but I’ll draw on those emails as well. I’m hoping this will give you some insights into our process and also give you some additional ways of looking at the image, which I believe to be a picture an Ivory-billed Woodpecker, even as I recognize that it isn’t nearly good enough to stand as proof.
I’ve done my best to present this material in a clear and careful manner. This is not an image that lends itself to immediate, easy interpretation, as some of the discussion reveals. At the same time, a lot can be gleaned from a close, careful look at the raw image, and the preceding and following frames. The various enhancements and comparison captures provide additional context.
A further caveat: I write this blog to maintain a log of our efforts and to share our results with readers on an ongoing basis, in an honest and transparent manner. As with any scientific endeavor, our search is in a constant state of flux. Everything is subject to change and reappraisal based on the evidence. We offer this image with that as background. Most of us believe subjectively that we have found an area that is used by Ivory-billed Woodpeckers, at least periodically. We all recognize that we do not have enough objective “proof” to “convince” third-parties that this is so. The subject image, so far, is just an intriguing part of the mosaic. It’s up to you to decide whether it moves the needle toward “proof” in your mind.
The image was captured on July 12, 2017. The target tree is a hickory that lost its top in a storm in March of that year. And we’ve had a camera aimed at it ever since. This is in area where we’ve found extensive scaling on hickories over the years and where we’ve had a number of auditory encounters. It is within the same contiguous forested area, several miles from the site of the March 2017 recordings. While squirrels are frequently captured on the target stub, there have been few woodpecker hits, and there was no obvious foraging sign on the trunk when I last visited in June.
Perhaps the most informative way to view the image is to step through the time lapse video frame by frame and compare the before, during, and after images. (You may have to download the clip to do this.) This will help clarify what’s object and what’s background. If you’re having trouble downloading the clip (and associated comparison clip), contact me, and I will share the files via Dropbox. I encourage you to click on the individual still frames to see larger, zoomable versions.
Here are two versions the relevant capture, one in its original, unprocessed form and another with a Luminar vividness filter applied, sandwiched between unprocessed captures from 20 seconds before and 20 seconds after. The arrow is pointed at the object of interest.
Here’s the time lapse video clip.
Here is a version of the still, resized using Topaz A.I. Gigapixel, an automated, artificial intelligence-based, image enhancement program. Following that are two enhancements, and a detail therefrom, made using another processor, Let’s Enhance. Both of these programs are automated, so except for selecting enlargement percentage and general processing parameters, I had no influence on the resulting images. Note that the prominent silhouette, which suggests a woodpecker’s head and neck, is blurred, background foliage, not part of the object. Assuming that the object itself is an ivorybill, I think the capture suggests the bird is angled slightly away from the camera, with head and neck inclined to the right.
Edited to add: A significant number of readers have misinterpreted the image, despite my explanation. To reiterate, the somewhat woodpecker head and neck-ish silhouette is background vegetation. The object’s head and neck are not visible. This detail, scaled up as much as possible, should be helpful, despite the loss of resolution.
Next are a squirrel and a presumed Red-bellied Woodpecker (9-11″ including head and tail) captured on a different day. They are included for scale. Both are a little lower on the trunk and are therefore closer to the camera. The captures are followed by a 50-frame Quicktime clip showing both the smaller woodpecker (suspected RBWO) and some squirrel activity. The comparison suggests that the object, which appears to be perched in typical woodpecker fashion, is too big to be a Red-headed Woodpecker (8.3-9.8″ including head and tail) and is slightly larger and more substantial than the head and body of an Eastern gray squirrel (9.1-12″). No tail, head, or neck is discernible, so the size of the object is in the appropriate range for an ivorybill body. (Total length is given as 19-21″ with tail at 5.5-6.7″ and bill at 2.3-2.9″) More discussion, including my responses (in italics) to some questions and comments (in bold and italics), is below.
An ornithologist wrote:
. . . I have tried every possible way to call that something other than ibwo but I can’t make it into anything else. The general impression of size and shape and even posture / body position relative to the tree is spot on.
And then in response to my explanation about the foliage that had caused some confusion:
I was seeing body only, folded wings white patch.
Early on, I had the following exchange with another biologist and ivorybill researcher:
Interesting. First, as I said before, I am no expert on trail cam photos like these. It looks like a black and white object for sure, with white on the bottom, but to my eye it is not possible to determine what kind of object it is. For sure, a bird would make a lot of sense. And if it is a bird, given the location, and pose on the trunk, a woodpecker would make a lot of sense. I am not sure if I see white at the top of the object as well?
How big is the tree that the object is sitting on, and is that scaling on the other side of the tree or remnants from when a branch that broke off? Have you seen bark scaling in that neighborhood?
I’m pretty sure that it’s a bird and therefore a woodpecker.
I think I see a white saddle and possibly a dorsal stripe. I also think it is too big to be a Red-headed, based on the squirrel and on a smaller woodpecker that’s on the trunk in another frame from another day; I’ll have to find that image.
The tree is a large hickory stub. What looks like scaling is where bark came off when the top fell. It is in an area that has had a good concentration of hickory scaling over the years.
If you have software that enables you to step through it frame by frame, the movie clip can be very informative. Flip Player is an easy one to use.
Thanks. I just looked at the entire series step by step with Quicktime and it is very intriguing. One question: could some of the white (or all of it) actually be sky in the background? The other frames show sky in the same location. I am not saying that it is, just trying to rule out possibilities.
My answer (another person raised a similar question):
I don’t think so. To my eyes, it’s pretty clear that the white is on an intervening object. I think the white on the object actually covers some of the dark area (as well as the lighter patch) behind it in the preceding and following frames.
And the conclusion:
Good. It is a very intriguing picture.
There was also this exchange with a consulting biologist:
If it’s okay with you, I may include a version of the comment in the blog, anonymously of course.
I can’t prove a negative, but I’d bet my bottom dollar that it’s not a squirrel.
Sure, no problem. But let me add the following.
What are the chances of a large woodpecker kind of critter showing up all of sudden in one frame and no sign that it either flew in or left or was in view beyond the one frame 20 seconds or anytime later.
An alternative could be some other sort of critter ( apparently larger than gray squirrel, perhaps fox squirrel, possibly raccoon) that worked up from the ground up the tree and then went back down out of view of the reconciliation.
As you said can’t be sure this is even a woodpecker or any other bird.
Beyond all that, still “interesting” but how many times…
I had one point of disagreement:
I mostly agree – with one quibble. It’s not unusual for birds to show up in a single frame and no others (the probable RBWO in the other clip, for example); it’s much rarer and (more difficult) for mammals to do so.
My correspondent recognized the quibble as a fair point, and it bears repeating that there have been very few woodpecker hits on this tree, probably because it is very recently dead. This exchange also led me to suspect that some of my colleagues were thinking the background foliage was part of the object in question. The discussion ended with this observation:
You are right Mark, I was interpeting the background veg as looking like the neck and head, which really made me wonder why so faded. However, now we have a frame 33 of the Luneau Video situation.
Anyway, thanks for the re-orientation.
Another member of the group also mentioned Luneau, and the similarity is striking, although there’s no accompanying video, and this single capture seems to show more than the Luneau frame.
1) first the obvious, I can’t tell much from the original picture other than it is long and somewhat “thin” relative to more stocky animals. Based on the zoomed in picture, however, it is a live bird; I can see no way it was photo shopped or that it was placed there as a wooden (or otherwise) replicate. I think it is easy to dismiss any attempt at faking it.
Definitely no fakery here 😉
2) The zoomed in image is impressive, it certainly appears to have a white back (which is a slightly different color than the white of the sky next to it) and I see what appears to be two white stripes on the back as well. The comparison of a probable RBWO on the same tree is noteworthy and clearly shows the relative size of the bird in question.
I think the size comparison stands regardless.
Negative concerns –
1) Any of the above positive impressions may be a function of zooming in well beyond the camera’s ability to correctly interpret what’s really there.
Actually, I think that it’s somewhat more compelling unaltered, if you can toggle.
3) The only one frame concern ****** brought up . . . . . . while I don’t think this is a squirrel or mammal of any kind and I’m not at all concerned about this particular series (see below), I am puzzled that the bird in question would not have shown itself on other occasions as well. Are there any pictures of this tree with a PIWO on it? How many pictures (days) do you have images from this camera on this tree? Is the primary foraging area on the other side of the tree? I’m assuming you have several days in not a few weeks worth of pictures on this tree (?)
The camera has been there for over a year, and I’ve gone through countless images. No other suggestive hits. Lots of squirrels. I don’t recall specific PIWO hits on the target tree, although there may have been some, and I’m sure there were at least a few from the deployment. This is one of the targets that has no scaling on it as yet; visits from woodpeckers have been few. As with the RBWO, I suspect birds may be hitting the tree in an exploratory manner at this point and are not staying long.
Just FYI . . . .This is [not far] from where we saw the bird that I ended up thinking was a RHWO and that you weren’t quite so quick to give up on, closer to where I had the long neck and tail silhouette sighting after some ADKs.
An additional note about not concerned about this series and only one frame . . . . .I feel strongly that IBWOs are incredibly wary, much more than we have been assuming them to be. And as any resident bird, it knows its territory very well and that anything “new” or different in that territory could spook it. I hunt as you know, and can vouch that turkeys and waterfowl are often that way . . .one thing out of place from the normal and they leave . . .
With that said, I wouldn’t be surprised, if this is an extremely wary IBW, that it knew something was not quite the same in the area and stayed on the far side of the tree on purpose . . . Even as I type it and re-read it, it sounds a little crazy but since I know about that level of wariness in other species I take it seriously. I know the discussions about wariness and “Tanner’s birds” etc but not sure birds now would act the same way as birds 60 – 80 years ago. If they are that wary, then that also has implications to where the camera is moved. It has to be close enough for a good picture but far hidden well enough to not spook the bird. (If you talk to Tommy or others about new deployment of the camera, my thoughts about how the wariness of this bird is pretty well known and doesn’t have to be anonymous).
I’ve wondered about this myself, and it seems like a pitfall when it comes to putting cameras very close to target trees. With time, however, I suspect birds would become habituated. It’s always a trade-off with these cams, and unfortunately, they have to be placed quite close to the targets.
Thanks for keeping me in the loop Mark – all in all, this has the most “real” field marks and most potential of anything I’ve seen.
I really do think it’s an IBWO . . . it’s at least more cause for optimism and grounds for staying with the trail cam strategy. As I’ve said, I think we’re finally in a position to do it right.
Here’s the response:
Thanks for more clarification Mark – yes I did toggle back and forth, now that I’m not so worried about what I thought was head, neck and bill, the unaltered is more intriguing.
Good to know its been there a year, I agree that birds will get used to it being there over time. The picture has July 17 2017 along the bottom, is that correct or is it July 2018?
I also forgot that this was a tree that you were interested in before any scaling started . . . .that’s pretty exciting and would explain my other concerns about infrequent use and no PIWO use. Pretty exciting in that (if a 2018 picture) the best is yet to come for woodpeckers. Regardless of IBWO, keeping a camera on this tree and having a sequence that shows which woodpeckers use tree, when and how (assuming there are differences based on tightness of bark etc) would be cool from that area.
Frankly, as I was looking at the picture(s), I thought a few times “Damn, I think he got it” . . . . . . Thanks again,
The picture is indeed from 2017. But there’s no scaling on it as yet, so it’s worth staying with.
I hope these exchanges help to illustrate some additional challenges related to trail cams, while revealing something about the review process. I think the object in question is an Ivory-billed Woodpecker; so do some of my associates. It’s not proof beyond a reasonable doubt, but it is an encouraging and suggestive piece of evidence.
Regarding the Blog
To follow up on some comments I made in the previous post, I’m still reflecting on where to take the blog in the future and am interested in hearing from readers about their reasons for visiting, as well as what they find most helpful or enjoyable to read.
When I first started blogging in 2013, I had a few purposes in mind. Foremost among them were replacing the original Project Coyote website, which had not been operational for a couple of years, and inspiring hope in other searchers and the general public. At the time, the organized, well-funded searches had long since wound down, leaving the field to handful of independents, most of whom were searching quietly.
In the intervening five years, readership has grown, approaching 40,000 unique visits and 110,000 page views at the time of writing. My reasons for blogging have also evolved over time. When Frank Wiley was alive, he was happy to have me play the more public role, while he stayed mostly in the background. Between 2013 and Frank’s passing, Project Coyote was mostly Frank, Steve Pagans, and me; we had a number of friends, advisors, and visitors to the search area, but their active involvement in planning, strategizing, and on the ground activities was limited. During this period, the blog became a place for me to share trip reports, including details of possible sightings, and to work through my thinking on various aspects of ivorybill history, behavior, and ecology.
The blog came to play another role for me – reward for an effort that has been expensive, lonely, and sometimes thankless. I enjoy watching the traffic spike when I post something, especially about suggestive material and possible encounters. (At the same time, I sometimes get a little frustrated when it appears that people visit the site and don’t read the material or listen to the audio that’s posted; this seems to happen often according to the analytics.) I think that some of my initial haste in posting about the possible sighting was influenced by this reward (while my haste in posting my subsequent misgivings was driven by an exaggerated sense of responsibility). This is true even though Project Coyote has become a true team effort, and I can get great support and insight from my trusted collaborators.
I don’t think posting in haste is salutary, and in retrospect, it probably would have been better to take a long pause to consider and consult with the rest of the team. Even then, I suspect it might have been better to refrain from posting altogether. (Since the post is already up, some additional discussion follows below.)
The bottom line is I’m not sure if there’s value in posting additional trip reports, possible sightings, and suggestive but inconclusive data or if it would be better to circulate this material privately. I’m open to persuasion in either direction.
The Possible “Wooden Wings” Sighting on April 27, 2018
In retrospect, the main reason I started to question myself about the April 27th sighting was my failure to see any white on the wings, something that started to nag at me the following day, even before I found a Pileated Woodpecker roosting in the immediate vicinity. Of course, had the bird in question been a PIWO, some white should have been visible if lighting conditions and sightlines had allowed for it. One advisor asked if the bird could have been a Wood Duck or a Hooded Merganser. I think this is unlikely for a few reasons.*
I saw neither Wood Ducks nor Hooded Mergansers (the latter are not common in the core search area) during this trip. There were small stubs and a broken limb on the back side of the tree, poor perches, but no cavities, and my impression at the time was that the bird was a woodpecker that had landed briefly and then flown from mid-bole on the larger cypress in the photograph below. The bird flew away and to the left over the clearcut and then apparently returned, within a minute, to one of the two trees in the background farther to the left. I thought it was into the one farther in the background, a hickory, not the closer tree where a Pileated went to roost, approximately 20 minutes earlier, on the 29th.
One final comment on the sound of the wingbeats: I’m not familiar with Ruffed Grouse wingbeat sounds, which Tanner suggested were similar, and have not seen a Ruffed Grouse in the field since I was a kid. They’re rare in my county, and I suspect the numbers have declined based on the lack of recent eBird records. All are from before 2000. I listened to a couple of recordings of Ruffed Grouse wingbeats, and while memory can be tricky, I think there’s a similarity between them and what I heard on April 27 and in November 2009.
I should also point out that Tommy Michot and/or I staked out the area through the morning of May 3rd. Pileateds were heard but not seen in the vicinity of the possible sighting or using the sycamore roost during that period.
While my initial certainty about the sighting has diminished, I am still hard pressed to explain it as anything other than Ivory-billed Woodpecker. But there is room for uncertainty, so the sighting must remain a possible. My life list will have to wait.
One final note, I did not see or hear anything else suggestive of Ivory-billed Woodpecker on this trip, except for a couple of possible double knocks in response to Barred Owl playback on the 27th, earlier in the day and several miles away from the location of the possible sighting.
I’ll have another post soon on our plans for the immediate future and some additional images from the most recent trip.
*Edited to Add: Unfortunately my recording device (probably the microphone) malfunctioned last trip. There’s nothing on any of the tracks. Thus, my dictated observations on the night of the possible sighting went unrecorded as did any ambient sounds. Because I’m confident in the accuracy of my initial write up, as I had given brief oral descriptions of the incident to Matt and Patricia but had not consulted anyone or looked at any descriptive materials.
Update 2, May 2, 2018: I have always made being forthright with my readers a priority. I chose to revert this post to draft in order to pause and reflect. Based on recent events and the prematurity of the post and first update, I think some changes in my approach to blogging are in order, something I will address in a future post.
I have decided to restore the initial post and the first update to public view because I owe it to my readers and think it’s the right thing to do.
As several people have pointed out, I was too hasty in “accepting” that whatever I saw on April 27 was a Pileated Woodpecker. My description of what I heard and saw on April 27th was inconsistent with Pileated, and I stand by the description. My observations of a Pileated Woodpecker going to roost on the 28th differed from what I heard and saw on the 27th. From an email sent early in the morning on the 29th:
A PIWO came in, overhead, either silently or very soft wingbeats when it landed. It drummed a couple of times and went to roost about 20 minutes before sunset but continued tapping from inside the cavity for about five minutes. (The bird on the 27th had come in no more than 2 minutes before sunset.) I hope to have gotten some decent photos. All PIWO sounds in the area stopped ~8 minutes prior to sunset.
It strikes me this morning that this behavior was somewhat different than the other bird’s; last night’s PIWO must have seen me, but my presence didn’t prevent it from coming very close and going directly to the roost. The other bird appeared to have been spooked by my presence.
Here’s what I know: I am confident I heard the wing sounds, as described, and am personally convinced that what I saw was a large woodpecker. I’m also confident I saw a PIWO going to roost near where the other event took place, on the following night, approximately 20 minutes earlier relative to sunset. I have the pictures to prove that. The rest is inference.
It’s easy (for me at least) to get overly enthusiastic about possible encounters; its also easy for me to turn around and look for ways to discount or discredit them in my own mind. To some degree, this is a good thing and probably comes with the territory, unless you’re delusional or prone to self-inflation. Still, there are points at which enthusiasm and skepticism become unhealthy. This applies to personal enthusiasm, self-skepticism, and to the way others respond to ivorybill claims. The Internet environment feeds unhealthy responses.
Regardless of anything else, this was a productive trip. We have six cameras deployed (thanks to Erik, Geoffrey, and Jay for contributing a new cam each) – five on hickories, either recently dead or in decline, and one a big sweet gum stub, three years dead, with some very recent bark scaling and signs of beetle infestation, in an earlier stage of decay than the Singer Tract tree where Pearson observed ivorybills feeding in the early 1930s. While this work could well be something other than ivorybill, and the bark is loose, it seems worth watching for a while.
I have been monitoring this stub since the top came down; in fact, we deployed a camera there in the spring of 2015, only to lose it to flooding. (The new deployment is higher on a nearby tree.) This suggests that our main strategy for camera trap placement – finding potential feeding trees and stubs in advance of any large woodpecker activity requires a multi-year commitment.
Even in this impatient world, patience is a virtue.
Update, April 30, 2018: Based on an observation last night of a Pileated Woodpecker going to roost in the sycamore cavity shown below and an exploration of the clearcut area this afternoon, I strongly suspect the bird I saw on the 27th was also a Pileated Woodpecker. I still have trouble squaring what I heard and saw with Pileated, but the circumstances suggest that’s what it was. I’m opting to leave the content up, with this correction, in the interest of transparency. I will undoubtedly have more to say on this in the near future. Accepting that the bird in question was a Pileated Woodpecker in no way affects my view that the sounds Matt recorded in March and the ones Matt and Phil recorded in March 2017 were made by Ivory-billed Woodpeckers.
Original Post: I initially planned on including this sighting in a complete trip report but have decided to write it up and post it now as a kind of dispatch from the field. I may include some further commentary and imagery when I post the full report sometime within the next couple of weeks.
I expect this post will attract a number of new readers, so I want to preface the account with a few comments. Friends, associates, and many regular readers probably know that I’ve had a handful of possible sightings over the past 11 years, a total of seven, if memory serves. This over many hundreds of hours in the field. With the exception of the November 2009 sighting in the location where a suggestive trail cam photo was obtained a week later, I have not had a high level of confidence in these possibles and have rejected two of them as the product of wishful thinking. Last night’s experience was altogether different, even when compared to the 2009 possible, as was my reaction to it.
Here’s what I wrote to my inner circle approximately one hour after the sighting. I have made a few minor edits for clarity and to protect the location and have added revisions/corrections/additional comments in bold italics:
I’ve already shared this with Matt and Patricia, and I dictated the details into my recording device (which has been a little buggy) immediately after the incident. I haven’t listened yet, and this will include some additional details. (Any substantive differences between the recorded comments and the contents included here will be addressed in the full trip report, though I don’t anticipate there being any.)
I arrived at the spot where Matt made the recordings last month at approximately 6:40 PM (I was in the area before sunrise too). I sat facing WSW; the area directly across the water from me was recently clearcut. There are trees along the bank with an open expanse behind. Sunset was at ***. The events described took place between 2 minutes before and three minutes after sunset, by which time I had pretty much given up hope that anything interesting would happen.
There were two cypress trees across the water from me; one perhaps 1’ DBH and the other over 2’. I did not consciously register a bird flying in to the larger cypress, but I suspect I sensed it. (In retrospect, I wonder if I unconsciously heard it flying in, as my focus for the evening was on listening.) In any event, my first conscious observation was of a large woodpecker taking off from the backside of the tree. My impression was that it had flown in and took off almost immediately on seeing me. I was able to hear the wingbeats, which sounded stiff and wooden, not muffled and whooshing like the PIWOs I’ve heard. (I’ve only heard PIWO wingbeats when birds were directly overhead or when I’ve flushed them at very close range.) I was looking more or less directly into the remaining sunlight (the sun had long since gone below the tree line), and the light was very low, so I could only see a silhouette. The wings were long and narrow, and the overall GISS (General Impression, Size, and Shape) was not PIWO. After several flaps, the bird went into a glide, and I lost sight of it very soon thereafter. I’d estimate I had eyes on it for 2-3 seconds.
I continued to watch the area when what I took to be the same bird flew in to some hardwoods perhaps 20 yards SSW and 10 yards inland from the cypresses. I heard the wingbeats again but could not locate the bird in the trees; darkness was falling rapidly. I made a split second decision to try some Pileated playback to see whether it would provoke a response. PIWOs had been calling and drumming until a few minutes before this incident. I did several rounds of playback using the iBird Pro app and got no response or visible reaction. At this point, I checked the time, and it was three minutes past sunset.
FWIW, I find this sighting more personally compelling for IBWO than any of my previous possibles, including the one in the old search area where we got the trail cam photo a week later. (As implied by the updates, my view on this has shifted – as I not only heard wingbeats but saw white on the wings and the suggestive trail cam image obtained a week later adds support; there’s a closer temporal association than there is with the recordings Matt obtained just over a month before.) Some of this is gut feeling, but the wingbeats (audible at 30-50 yards) wing and body shape, the glide, and the lack of response to PIWO playback (though the hour was late), all contribute to my interpretation. Would I bet my life that this was an ivory bill? No. Will I add IBWO to my life list? I’m not sure, but I’m closer to doing so than I ever have been.
So there it is. I’m going back to the same vicinity tomorrow morning, though I may go to the edge of the clear cut.
The cavity in the attached image may also be of interest. It is likely fairly fresh, as Matt would likely have seen it last month had it been there then. I staked it out this morning and nothing emerged. It is southeast of where I was stationed.
I returned to the area this morning and found an additional interesting cavity in a sycamore about twenty yards south of the oak and hickory where I last saw the bird.
It was either not used overnight or had been vacated by the time I arrived, as I had encountered an almost uncanny delay that caused me to miss the sunrise. I reached the end of a long gravel road, about a quarter mile from my planned stakeout spot and ran into a turkey hunter. As so often happens, a conversation ensued, and to my astonishment, he told me his name was Kuhn. I asked if he was related to the Tallulah Kuhns, and indeed he was; he was far from home himself, and we were nowhere near Tallulah. He had known his cousin (not sure what degree) Edith Whitehead and was aware of her father’s work on pecan agronomy and hybridization, though he knew nothing of the ivorybill and his relative’s central role in the story. What an extraordinary (almost in the Sagan sense) coincidence.
A final note, while I saw no field marks, the wingbeats are an acoustic equivalent. As Fredrik Bryntesson reminded me, Tanner wrote about the sound very explicitly. I knew this in general terms, of course, but the actual language took me a little by surprise:
A description of the wing sounds is found in Tanner’s monograph, p. 58: “The wing-feathers of Ivory-bills are stiff and hard, thus making their flight noisy. In the initial flight, when the wings are beaten particularly hard, they make quite a loud, wooden, fluttering sound, so much so that I often nicknamed the birds ‘wooden-wings’; it is the loudest wing-sound I have ever heard from any bird of that size excepting the grouse. At times when the birds happened to swoop past me, I heard a pronounced swishing whistle.”
I’ll leave it there for now.