My response to Laura Erickson's IBWO thoughts

Laura Erickson put up some IBWO thoughts on her blog tonight, and I'm posting my responses here. Laura's blog entry is here in its entirety in black type, and my comments are interspersed in red.

----Laura writes:
I'm here in Santa Barbara--what a breathtakingly beautiful campus! I'm in heaven!

While I was flying, I put together my final thoughts before tomorrow's sessions about the Ivory-bill. This seems like a good point to explain why I trust 100% in the Ivory-bill reports of the past couple of years in Arkansas.

One of the big and obvious questions is, could the birds seen and the one videotaped be a leucistic Pileated Woodpecker. I find the likelihood of this to be more remote than the likelihood that the bird or birds seen were Ivory-bills. I know of no records of oddly-plumaged Pileated Woodpeckers with completely pure white flight feathers that show top and bottom on the trailing edge of the wings yet with no white where they’re supposed to have it, on the underwing coverts.

Abnormal Pileateds have indeed been mistaken for IBWOs in Texas. Please see this link.

See this blog post for my thoughts on an abnormal Pileated.

I'm referring to a completely normal one, except that on one or both wings, it has some secondaries (and possibly primaries) that are white. I think that such a bird could be a source of mis-IDs in this case, and I think such a bird may have been a source of IBWO mis-IDs in the past.

I don't see where any of Cornell's sight records mention non-white underwing coverts.

Most of the sightings were very brief, and the people reporting them focused primarily on the white trailing edge of the wing in the few seconds the bird was in view—exactly the field mark Tanner emphasized was THE critical one. As far as I’ve noticed from what has so far been published, no one makes note of the bill color, and only Casey Taylor noted a long beak. But Tanner emphasized that the bill was difficult to see under many observation circumstances. Most people saw little else than the white trailing edge, but Melissa Driscoll’s April 11, 2004 sighting included details of the white line extending from the wings up the long neck, and Melinda LaBranche’s April 10, 2004 sighting noted the narrow area of red on the bird’s crest.

"White line extending from the wings up the long neck" and "narrow area of red on the bird’s crest" could also describe a flying Pileated at those distances.

Casey Taylor’s February 14, 2005 record noted 30 minutes of double-knock display drums and then she watched the bird fly across an open area, noting the white trailing edge of the wings, long neck with white stripe, and black head with long beak—what’s the chance that her bird was a leucistic Pileated that had also adopted the Ivory-bill’s double-knock?

I'm not sure that Casey's bird was the source of the double raps.
8/27/05 update--I'm also not sure that Casey heard distinctive double-raps as described in "The Grail Bird". Please see this link.
In "The Grail Bird", page 246, Gallagher says that Taylor heard all the raps, and then:
---
Casey sat still for about a half-hour without seeing or hearing anything of interest.
---
Only after this half-hour without rapping did she glimpse a woodpecker. Neither "The Grail Bird" or the Science paper specifically say that the Casey's bird came directly from where the raps where last heard.

Finally, why has no field guide author of any field guide ever shown leucism in a Pileated or mentioned that as a possible way to confuse a Pileated Woodpecker for an Ivory-bill if, indeed, there are some Pileateds on record with the entire trailing edge of the wing white?

Abnormal Pileateds have been mistaken for IBWOs in Texas. See this link.

One thing the internet version of the Ivory-bill doesn’t show is the reactions of the people seeing the bird being videotaped and their discussion of what they were seeing—their eyes were obviously more focused than the camcorder, with the autofocus on one person’s knee. John Fitzpatrick said their discussion was also compelling.

To me, the reaction and discussion on the Luneau DVD were not very compelling.
"The Grail Bird" addresses this on page 222 and 223:
---
"What was that?" he [David] asked.
"I don't know," said Robert. "I sure wish I could see it again".
...
David told me later that he never would have mentioned the sighting if not for the videotape. "I just didn't get a good enough look," he said. "....This was particularly frustrating, because I only saw the bird from the rear. When it finally did turn, it was too far away to see the black-white relationship with my naked eye."
---

Even the very brief reports of distant flying birds that where only the white trailing edge of the wings was seen were compelling to me because the observers noted the direct, straight and exceptionally rapid flight, unlike the Pileated’s more swooping and leisurely flight, and most of them noted the long neck and bill and large size.

Actually, out of all seven sight records in Cornell's paper, I only see one sighting that mentions flight style: Jim Fitzpatrick saw the flight of his bird as steady and "loon-like". Tanner writes this on page 1 of "The Ivory-billed Woodpecker":
---
The manner of flight of the bird cannot be used as a reliable field character. Much has been written and said on how the Ivory-bill flies directly and straight while the Pileated's undulates, but I have frequently seen Pileateds fly directly, in no way different from the flight of the larger bird.
---

In the Cornell paper, it looks like three of seven noted a long neck, and four didn't. One of seven noted anything about the bill (Casey Taylor saw it as "long"). Most saw their bird as large, but I'm skeptical that observers could reliably distinguish size differences between a large (19 inch) Pileated and an average (20 inch) IBWO. Tanner said this:
---
...the difference in length is not a reliable character unless the two species are seen together.
---
If I see a single bird, I often have trouble accurately using size to distinguish an American Crow (17.5 inches) from a Common Raven (24 inches). I know that there are other, more expert bird watchers that have this same problem.

Tanner of course does point out that both Ivory-bills and Pileateds vary in their flight patterns, but wouldn’t it be exceptionally odd to find leucistic Pileateds with a white wing pattern exactly like Ivory-bills, and lacking white where they should have it, flying in a manner much more typical of Ivory-bills? In all cases, the observers had seen plenty of Pileateds in the area, and most noted some of all of the important differences in size, long neck, and direct, fast flight pattern.

Gene Sparling’s original sighting that triggered the whole thing, back on February 11, 2004, was rather leisurely—he watched the bird fly and land on a nearby tree.

Of course, Sparling had the initial sighting that sparked this entire thing. On page 146 of "The Grail Bird", there's this interesting exchange:
---
After a long talk with Gene, Bobby told him "It sounds to me like you've seen an ivory-billed woodpecker."
"You think so?" said Gene. "I don't have enough confidence to make that call, but I'm glad to hear you say that".

And I found John Fitzpatrick’s detail by detail analysis of the Luneau videotape compelling, as it took into account not just the white but also the size and the wingbeat rate.

Regarding the size of the bird in the video--anyone interested should take the time to look closely at Figure 1 in Cornell's paper. I think it's likely that Cornell misinterpreted the position of the bird in that frame--rather than perched as shown with folded wing, I think the bird may have already lifted its wing to fly. The extensive white seen may be simply the white lining of a Pileated's wing, and any wrist-to-tailtip measurement would not be meaningful, since the wing is already in motion, and they need a measurement on a perched bird.

This particular size measurement is actually pretty critical to the whole IBWO controversy, and I don't think that it is reliable.

Regarding the perceived white plumage--Cornell said: "With these distances and light conditions, bleeding tends to exaggerate the apparent extent of white in the wings." Also, the extensive white seen as the bird flaps may be the flashing white wing linings of the Pileated.

Why didn’t the team report their sighting to the Arkansas records committee? First and foremost, at the time the first sightings were made, it was essential to keep the whole thing secret until The Nature Conservancy could buy up land—as predicted, land prices have risen dramatically since the word got out. And it was also essential to get into place various protections to keep the site from being overrun with acquisitive birders. Thanks to the careful and deliberate approach the Ivory-bill team used, it was possible to get these protections into place before the word got out to the general public. Also, this kind of sighting is of far wider importance than any one state’s ornithological society, and justifiably needed to be vetted as a North American bird record before it went to a state committee. Of course, Science has a shorter lead time than The Auk, and the importance of this particular sighting really does go beyond ornithology to biology in general, so the approach was both practical and proper, scientifically. And, again as befits a truly scientific approach, the first official revelation of all the details has been held until the official annual meeting of the AOU. The state records committee should be provided all the documentation after it’s deemed acceptable by the AOU, and not until.

I'm not sure if this is true, but I've been told that the AOU won't accept records until the respective state has accepted them. After "The News" became public in late April '05, I don't see any reason why the sight records wouldn't be submitted to the Arkansas records committee. It seems to me that if they were solid enough, they would indeed be submitted and quickly and joyfully accepted.

Birders may find this approach frustrating, but that’s an issue for the sport of birding, not the science of ornithology.

But hello? How could such a huge and once-conspicuous bird have stayed hidden so well for so long? How could David Sibley search the area for 10 days and not see one? Back in 1924, when by anyone’s current estimation the species was more abundant than it is now, the species was already believed to be extinct by many, and it took Arthur Allen a full month to locate any when he made an exhaustive search in Florida—after 30 days he lucked into finding a nesting pair, and then was afforded leisurely looks for quite a while. And what happened to these two birds when the word got out? They were shot, legally, by local taxidermists. There has been so much pressure on this species from the time when indigenous Americans traded in their ivory bills that it’s small wonder that survivors, even as early as 1924, were so secretive.

I'm not convinced that these two survivors were so secretive. I think Allen was looking in the wrong places. Once he found the pair, he was able to continually re-find them, and he was able to observe them closely. And of course, then the local taxidermists were also able to get close enough to shoot both ivory-bills.


Then the species was again estimated to be extinct until it was rediscovered in the Singer Tract in the 30s. Tanner’s study, from 1937 through 1939, was at mainly of nest sites already known, where Arthur Allen had filmed and made sound recordings of the birds in 1935. But even Tanner described the search for birds away from their nesting areas as “looking for an animated needle in a haystack,” and he went to great lengths to describe in his book both how few Ivory-bills existed in the 1930s and how difficult they were to find except in their breeding territories. Tanner noted that the birds he observed were at least as wary as Pileateds, and also that other observers found them to be exceptionally wary.

I have no problem postulating a current IBWO as wary as a Pileated, or even exceptionally wary. I do have a problem considering an IBWO that is so wary that it can consistently avoid remote cameras, quietly sitting camoflauged observers, etc.

Tanner reports that Arthur T. Wayne, searching for them in Florida, wrote that they couldn’t be approached nearer than 300 or 400 yards. Audubon noted that when he appeared under a nest, the two birds abandoned it.

Tanner noted that there is some dispute about how far their sounds carry--some estimates were that it didn't carry very far at all.

Allen did some testing on this subject:
---
However, when we tested the carrying power of one of our recordings of the common alarm note, kent, amplified until it. sounded to our ears normal at about one hundred feet, the call was distinctly recognizable at a distance of 2500 feet directly in front of the amplifier with no trees or buildings intervening. At a 45-degree angle the sound was not recognizable at half this distance.
----

And again, historically birds that called attention to themselves quickly were killed, so it can very reasonably be surmised that any surviving birds would tend to be on the quiet, secretive side.

Again, they were hunted for 200+ years, and yet the last ones we knew were still quite noisy and relocatable at the right time of year and day. The hard part was finding them the first time, which makes sense. If there were no birds present in a few square miles of habitat, you could obviously spend a lot of time looking with no success.

This is one of my biggest concerns about the current situation--we've glimpsed a potential IBWO something like 8-18 times in a small area, but we still have yet to get our first really good look. Is it likely that we could really be that unlucky, or that the bird could really be that wary?

In many ways, the universal acceptance of sight records has become far more focused on personalities than on substance—some birders are accepting as gospel the words of charismatic, popular and trusted field guide authors and people who have written books and species accounts about Ivory-bills even when these people have themselves never seen an Ivory-bill, as if they somehow have more insights than anyone else who has read the primary literature on the subject. And how can anyone quote Roger Tory Peterson about the validity of these current sightings, as if he were still alive?

Of course, you must be referring to my blog post formerly titled "Roger Tory Peterson weighs in". When I wrote that title, I honestly didn't mean to imply that the late Peterson had arisen from the dead to comment on the current controversy. I apologize!

For more clarity, I've re-titled the post "The late Roger Tory Peterson on IBWO behavior".

There also seems to be a bit of mistrust about the American Association for the Advancement of Science and its peer-review process. But the Cornell Lab and The Nature Conservancy have far more to lose if these reports are discredited than they have to gain if they’re accepted—and as far as I can tell from reading and listening to John Fitzpatrick and other members of the team, the entire group is focused on preserving the habitat far more than they are on basking in any glory associated with the sightings, and they honestly seem to have gone to great pains to anticipate alternative possibilities and to have done the hard work of proving or disproving them. I do not believe these fine scientists would be promoting this if they weren’t darned sure.

On the other hand, we've got knowledgeable "third parties" such as David Sibley, Kenn Kaufman, Richard Prum, Mark Robbins, and Jerry Jackson going public with their skepticism of the sightings and the video. I don't think these fine people would be questioning this if they didn't have serious doubts.

I do think that it is important to keep an eye on what knowledgeable third parties are saying about the evidence. The consensus of third-party judgment can be more objective than the judgment of those very close to the action. Of course, that's why we have courts, basketball referees, and Bird Record committees. I consider myself an honest person, but still, it's hard to be completely objective when asked whether I'm a better than average driver, or whether my son is an above-average basketball player.

I’m not a blind believer—I believe in these sightings because the brief view of the wings and wingbeats in even the internet compressed view of the Luneau video show a distinct difference between how this bird flies and how a Pileated flies, and in the proportion of the wings to body, as well as the obvious white trailing edge. I’ve viewed the careful setups Cornell produced to compare both size and pattern of the video with positioning models in the same area, filmed from the same spot, and seen how painstakingly they worked to check and recheck their accuracy.

Beyond that, I think if skeptics discount sightings, especially when they ridicule them as looking for Big Foot, they do a serious disservice to both ornithology as a science and to birding as a sport. There is no fossil or specimen record that Big Foot ever existed.

Of course, you must be referring at least in part to this blog post of mine. I stand by this comparison of the current Bigfoot and IBWO evidence. The late Eirik A.T. Blom made a similar comparison here.

I honestly don't mean to ridicule anyone. I think if you look at the current Bigfoot and IBWO evidence objectively, you really do have to acknowledge that there are many uncomfortable similarities (ie many sightings, fuzzy pictures, inconclusive audio, and tree damage, yet no definitive proof). My key point is this one: If you have lots of weak evidence, the cumulative effect of the evidence doesn't make it strong evidence.

To me the search for Bigfoot is the search for some previously-undiscovered hominid, and I don't think it has the stigma for me that it obviously does for you. I think the probability is low, but nonzero, that such a hominid exists somewhere in the world today. Primatologist Jane Goodall said this in 2002: "As far as I am concerned, the existence of hominids of this sort is a very real probability."

Everyone knows Ivory-bills have lived in the past, and everyone knows that decades have gone by at least twice before when the species was determined to be extinct and then was proven not to be. Dismissing honest, trustworthy individuals and institutions in such a ridiculing manner is not scientific, and goes beyond that to casting doubt whether the birding community and any records committee can be trusted to make any determinations about sight records. I do not want this discipline to go back to the days of identifying birds along the barrel of a shotgun, and I do not want a single Ivory-bill, perhaps the only Ivory-bill remaining, to have to die in order to prove it lived.

I don't think anyone wants to identify birds along the barrel of a shotgun. My standard of proof is David Sibley's: "redundancy. Repeated sightings by independent observers of birds really well seen". The key problem with the current evidence is that the birds were just not seen really well. According to Cornell's paper, in all sightings, four of five key field marks separating IBWO from Pileated were not mentioned. These are the white dorsal stripes, the white neck stripe ending before the bill, the longitudinal black stripe on the white wing underside, and the pale bill itself.

If and when Cornell finds a current IBWO roost hole, I believe Sibley's standard will be met quite easily. At that point, I promise that I will cease my IBWO skepticism. Until Sibley's standard is met, however, I just don't think we can conclusively say that the IBWO lives.

Anyway, that’s my two-cents worth. I’ll be listening to the questions and answers at the Ivory-billed sessions with a critical eye and ear, and will share whatever new details I get.
---