I’m looking forward to returning to Louisiana at the end of the month and have high hopes that our trail cams will reveal just what’s removing bark from the trees in our search area.
In the meantime, I thought I’d compile a new group of links to images showing bark scaling (without accompanying excavation) done or suspected to have been done by Pileated Woodpeckers. Obviously long dead snags are excluded. Compare these images with the work we suspect to have been done by ivorybills, all on live or freshly dead wood. As discussed in this and other posts, it’s our hypothesis that the differences are anatomically determined.
And another (scroll down).
Apparently a long dead snag, suspected PIWO, note small chips on the ground and the way they appear to have been flaked rather than pried off.
I suspect the work from Congaree shown on this Cornell Mobile Search Team page is Pileated. As the commentary indicates, it’s somewhat consistent with what would be expected for IBWO, but it’s patchy and not extensive:
This appears to be a softwood. (Our diagnostic criteria include only hardwoods). Even so, note the layered appearance:
Another softwood, also showing the tendency to flake bark off in layers rather than knock off large chunks:
Hard to tell the age of this snag, but note the layered appearance on the right. The apparently stripped limb in the foreground appears to be long dead:
Frank recently found a series of images from our trail cam deployment discussed here. These photographs, taken with a second camera, are of very poor quality, but they show what is clearly a Pileated Woodpecker on the target snag. Frank’s discovery led us to re-examine some of the images discussed in Frank’s post and elsewhere on the site because they gave us a reference object to assess the size of the birds in two other low quality trail cam photos.
Based on this reference object and informed by outside evaluations, we’re confident that the “mystery bird” discussed in this post is in fact a Red-headed Woodpecker. (We still concur with the author’s analysis of the other image discussed in the post.) The bird is clearly behind the tree but not very far from it, and it is simply too small to be anything else. Despite my initial interest in this photo, I had been leaning toward Red-headed based on feedback from a number of people and on the length of the tail.
I have always thought that this was the most intriguing image in the series, although some reviewers have disagreed.
I’ve also always believed that the bird was behind the snag and in front of the somewhat more distant small branches, which would mean it’s large. Frank, who has by now reviewed perhaps 1 million trail cam images, has always agreed with this interpretation.
Frank’s discovery of the Pileated sequence led me to re-examine this photograph and dig a little deeper. One reviewer suggested that motion blur made it impossible to make any judgments about size or distance from the camera. In response, I did a bit of research and found Focus Magic, a forensic program designed to reduce or eliminate motion blur.
The results of running the image (bird only) through Focus Magic are interesting. (No other processing was done.)
I shared this processed image with Louis Shackleton, a professional photographer friend who has a background in ornithology. I also sent Louis one of the Pileated images and these two other trail cam photos that were taken within an hour and ten minutes of the first, on December 7, 2014.
The first of these shows what we believe to be either a Red-headed or an Ivory-billed Woodpecker in flight and behind the snag. The other shows an intriguingly shaped but badly blurred bird in flight, passing between the camera and the snag. (The motion blur in this image is so severe that I was unable to make any meaningful improvements using Focus Magic.) Louis had this to say about the photographs he reviewed:
“ . . .I concur that the first image is the most interesting. Comparing that and the image of the PIWO on the tree, it seems to be larger, [and] as you say, I think it’s beyond the snag. The second image, it’s also beyond the snag, but there’s no way to gauge how far. The third image, it’s definitely in front of the snag, but also no way to tell how far in front.”
Frank and I interpret the photograph as follows. It shows a long-necked, long-tailed, slender-bodied bird that is somewhat larger than a Pileated Woodpecker flying upwards at about a 35 degree angle. There is white on the trailing edge of the wing, although it’s unclear whether this white is on the underside of the left wing, the upper side of the right wing, or both. We do not believe this white to be an artifact, since it appears faintly in the unaltered image; it becomes more fully resolved when the blur is eliminated; it is still present even at a blur distance of 20, the highest Focus Magic setting, when image clarity breaks down significantly.
A couple of considerably more ambiguous features are also intriguing. The bird appears to have a fairly distinct and sizeable bill, and in the Focus Magic iteration in which the white is most clearly defined (blur distance 13), there’s a hint of red on the head, although this could easily be an artifact. While the William Rhein film of an Imperial Woodpecker in flight was shot at a different angle, we think the profile and structure of the IMWO in that footage strongly resemble our mystery bird.
Edited to add: To facilitate comparing our mystery bird with the Imperial Woodpecker in the frame shown above, I’ve created a composite image using the 13-35 de-blurred image, which I’ve also brightened. In addition to flying downward, the Imperial is angled slightly away from the camera, foreshortening the neck and obscuring the bill.
It has been observed that there’s nothing to prove our mystery bird is a woodpecker, and that’s a fair point; however, the size, shape, and apparent white on the back of the wing are all consistent with Ivory-billed Woodpecker. We realize that this is far from conclusive but can think of few alternative interpretations, all of which are problematic.
I thought I’d address a couple of comments from ibwo.net written in response to the recent post on sightings and evidence from 1944-2003. Duck Stamp reminded me that Lewis’s story and identity were revealed in Tim Gallagher’s The Grail Bird, and Houston pointed out John Fitzpatrick’s discussion of the images in a presentation on the rediscovery.
As far as I’m aware Gallagher was the first to name Lewis as the photographer, although Lewis had partially disclosed the story in his book Tales of a Louisiana Duck Hunter (1988). The book was self-published, did not mention the pictures, and seems to have otherwise escaped public notice for 15 years. Lewis wrote:
“I hurriedly put the dog I was working in the trailer with the others and walked toward the point where the birds had entered the trees. I found the male right before me on the trunk of an eighteen-inch cypress.
I kept my eyes glued to the bird and cautiously moved forward . . . I was surprised to be within thirty feet of the bird before it flew to another tree. It suddenly started flying from tree to tree and then disappeared into the depths of the swamp. I didn’t spot the female after I entered the swamp but I had for an extended period obtained a clear unobstructed view of the male bird at very close range.”
He told Gallagher and Bobby Harrison the same story, adding the photographs back into the tale and including this strange and somewhat implausible detail:
“‘…so I put it on top of my head like this and I walked straight toward the bird to see how close I could get.” Fielding stood up and mimed holding a camera on top of his head.’”
While this could be true, it seems far-fetched, at least to me. My guess is that Lewis was teasing or testing Gallagher and Harrison somehow. In some ways it brings to mind Lowery’s initial question about the quality of the images; if this were a hoax, why would Lewis tell such an odd story, one that would be sure to raise doubts?
Edited to add: Frank Wiley and another person I respect don’t see the story as being implausible, and given the wide angle of the camera’s lens, holding the camera over one’s head and keeping an eye on the bird makes sense. In addition, I was reminded that the fact that the photographs show the bird on two different trees makes the idea of a hoax seem even more far-fetched, since it would have involved scaling two different trees, a lot of effort for little reward.
Fitzpatrick’s comments on the Lewis photos come at 24:00 into the Cornell video. Fitzpatrick suggests that there’s too much white on the wings, and that the white includes the secondary coverts. He goes on to say that the posture is the same (I don’t agree), and that the suspicion in the 1970s was that it was either a specimen or a composite of specimens.
There’s an inherent contradiction in that argument, since a specimen or a composite would have actual ivorybill coverts unless Fitzpatrick meant a composite made from other species. Either way, the latter suggestion was unfamiliar. It strikes me as being thoroughly implausible, since it requires an additional layer of elaborateness. I don’t think the images are sufficiently defined to be certain about the coverts. In addition, ivorybill specimens show considerable variation in terms of the extent of white on the wings. Frank Wiley has looked at a significant percentage of the study skins available, and I have looked at a number of others. The average male presents a bit more white than the average female, but these slight differences in the amount, and presentation of white are not enough to conclude that this is a sexually dimorphic character of the species.
Despite the strange story about how he took the pictures, I still find the Lewis photos persuasive because of the bark scaling and cavity, the likelihood that the feet are in fact visible, especially in the second photo, and the fact that George Lowery accepted them; in addition, Tanner did not take as aggressively negative a stance as he did with many other reports, though he could have gone easy out of respect for Lowery.
I’ve been corresponding with Mississippi-based searcher Christopher Carlisle both privately and on Facebook, and our conversations have inspired some additional thoughts on bark scaling and led me to revisit Cornell’s 2006-2007 final report, which includes two interesting photos of Pileated Woodpecker work on sweet gums taken by Martjan Lammertink in Congaree National Park. I was familiar with the document, which is available here but had forgotten about the images. Scroll to page 30 (some additional images of interest from Texas appear on the following page.)
While it’s a tiny sample, there may be some value in comparing the Congaree photos with the work on two heavily scaled sweet gums in the Project Coyote search area.
Correction: the tree in the second image is a hickory.
While it was not possible to examine this scaling up close, the bark appears to be tightly adhering on both trees, and the decay state is likely comparable to the Congaree sweet gum. The work in both cases is on the boles, and the size of the trees involved seems to be roughly comparable. Beyond that, the scaling is dramatically different in a number of ways. Most obviously, the suspected IBWO work from our search area is far more extensive than the PIWO work from Congaree (I suspect the small patches of scaling in the lower photo are the work of a Hairy Woodpecker). As I’ve discussed, PIWOs are not well-suited to scaling bark, anatomically, and it’s not a preferred or efficient feeding strategy – accounting for 23% of observed foraging behavior in Tanner and 7% in Patricia Newell’s more recent and PIWO-focused study.
The most significant difference though is in the appearance of the edges. When Pileated Woodpeckers scale tight-barked hardwoods, they typically remove the bark in layers, as in these images. This layered scaling is also very apparent in the photos from Congaree, and it’s absent from our sweet gums as well as from the extensively scaled oaks and hickories that we found in 2013-2014. Our trees show very extensive scaling with no indication that bark has been removed in stages; the edges are clean and incised and very large areas have been stripped, down to the sapwood. If Pileated Woodpeckers were the cause, it would be reasonable to expect that there would be some sign of layering, especially given the surface area involved, which far exceeds that shown in the Congaree photos or any others I know of (on hardwoods) from the Cornell searches.
The high branch work from Texas is intriguing, but the resolution of the images is insufficient to determine whether this clean scaling or whether there’s some excavation, especially on the lower portions. In addition the work is not nearly as extensive as some of the high branch work we’ve found.
Edited to add: I’m more intrigued by extensive work below the crown, as in these images. One tree (in the third photo is), definitely a sweet gum is from the old search area. The other tree, which I believe is an oak, is within a hundred yards of where I recorded kent-like calls in 2013, although the photos were taken a year before.
There are several other images of sweet gum scaling from Congaree in this report from the mobile search team, but this work does not involve the removal of bark from large contiguous sections of trunk, and the resolution is not sufficient to tell whether the bark has been removed in stages, although it appears to be in at least one of the four photographs. If I were to find it, I would assess this work as being mildly interesting but would not get excited about it in the absence of other indicators.
To return to my exchange with Chris, it gave me the opportunity to revisit this material, to give some more thought to my hypothesis about feeding sign, and to make some adjustments:
- I think scaling on pines, even live ones, is physically possible for a pileated, although the bark will often show signs of having been removed in layers, meaning the edges will not appear as clean. Nonetheless, I do not think there’s a way of reliably determining what species has scaled a pine in the absence of a direct observation and suspect that even HAWOs and RBWOs can scale extensively even on recently dead pines.
- For the work that I think is diagnostic, the species that I think are most reliable are oaks, sweet gums, and hickories. I think that the distinction is an easy one to make once you’ve seen the work firsthand.
- In the old Project Coyote search area, we had persimmons, hackberrries, and honey locusts that had very suggestive scaling and lots of it. But the bark on honey locusts tends to loosen early in the decay process. Hackberry bark fractures, and while persimmon bark is thick and tight, it tends to loosen when the wood is still very hard. These qualities complicate the analysis, though I’m confident some of that work was done by IBWOs. There was a vast difference between the size of bark chips from known PIWO foraging on honey locusts and suspected IBWO foraging on the same species.
- Extensiveness and quantity (concentrations) are important to look for too, especially when there are a lot of pines or an abundance of more easily scaled hardwoods. For this analysis, I include looking at high branch work but otherwise don’t ascribe a great deal of importance to “Tanneresque” sign, unless there’s a lot of it, and it’s associated with what I think is diagnostic.
I am not suggesting that this is the only way that Ivory-billed Woodpeckers forage. There may be seasonal and regional variations, but I suspect that some of this type of work will be present in any area where IBWOs are resident. It’s not necessarily easy to find. I agree with Fangsheath, from ibwo.net, that the failure to do so should not be treated as evidence of absence, but I’m convinced that finding this very specific type of work is compelling evidence that IBWOs are present.