Fleeing Pileated video--compare to the Luneau video

Previously, I wrote this:
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In the Luneau video, I believe we are looking at the bird's white wing linings on both the upstroke and the downstroke.
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Please take a look at this video of a fleeing Pileated Woodpecker. After the bird springs off the tree, I think the next couple of flaps give us views comparable to the key early flaps of the bird in the Luneau video. If you can step through the video frame by frame, you can see how this Pileated shows its white wing linings as it raises its wings high on the upstroke, and you can also see the white wing linings on the downstroke.

In the Luneau video, I don't see anything inconsistent with an ordinary Pileated Woodpecker.

Double-knock skepticism

A reader who is an ornithologist emailed me these thoughts:
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John Fitzpatrick of Cornell has not acknowledged publicly that the Pileated Woodpecker (PIWO) gives a double knock. This behavior has been known for many years; for example, here's a snippet from Short's 1982 monograph (p. 419) regarding "demonstration tapping" in the Pileated. My additional comments are in brackets below:

"This form may occur as a double tap, akin to the drum taps that are characteristic of various species of Campephilus; such a double tap may be associated with copulation or may occur at a prospective nest site (Kilham, 1959d, p. 381). Such demonstration tapping is known in D. javensis and D. martius [a reference to the congeneric White-bellied and Black Woodpeckers]. Drumming takes place all year, but especially marks the prebreeding period, for example, in December and January [when CLO's ARU cuts were obtained] in Maryland (Kilham, 1959d). Bent (1939, p. 175) cites Sutton as indicating that a drumming burst may be followed by three distinct blows, thus resembling drum taps of Campephilus, but Hoyt (1957) did not this these are typical, nor do I."

.... Nothing in the ARU cuts eliminates PIWO or, for that matter, a Red-bellied Woodpecker or Yellow-bellied Sapsucker, both of which "double knock" as well.
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Cache River area combed VERY thoroughly

Cyberthrush asked a key question here:
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...do the skeptics fully appreciate the size/vastness of the territory involved!?
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Actually, I do appreciate the size of the territory. In fact, that's one reason that I'm a skeptic--Cornell's paper says their 8-18 sightings were grouped very tightly in an area only four square kilometers in size. That's equivalent to a square that's only about 1.25 miles on a side.

I believe the area in question is near the center of this Google map. Note that the habitat near the Highway 17 crossing is really just a strip roughly one mile wide.

Once again, the question is "How could you glimpse the bird 8-18 times in such a small area, yet never get a good look, and never hear it call?". The small area where the sightings occurred was combed and recombed--please see this snippet from Cornell's paper for some details:
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Between 12 March and 10 May 2004, 30 individuals spent about 2500 party-hours surveying 15 [square kilometers] of swamp forest in the vicinity of the initial sighting. Observers wore camouflaged clothing and made slow, quiet movements or remained stationary for periods at lake edges and powerline cuts. Between 25 May and 20 December 2004, T. Barksdale spent portions of 165 days (9 to 12 hours per day) observing from a 25 m elevated boom at the forest edge. Between December 2004 and April 2005, we worked in the Cache-White-Arkansas river area with 20 full-time observers and an average of 2 additional rotating volunteers. We devoted 4750 party-hours to searching 145 [square kilometers] of forest for foraging signs and roost or nest cavities by walking global positioning system–guided parallel transects spaced 50 to 55 m apart. Cavities of suitable size were watched from 85 min prior to sunset until 10 min after sunset. Our searching was focused in areas of mature forest that contain concentrations of dead and dying trees. On 2–4 March 2005 we conducted a "saturation search" with 23 observers spaced across the 4 [square kilometer area] of forest in which all the sightings had occurred. We also used eight video-camera traps, which were placed at possible foraging sites over various intervals. Broadcast playback of ivory-billed woodpecker vocalizations was used sparingly.
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The snippet above may give you some perspective on the magnitude of the effort to date. During the "saturation search", depending on how the observers were spaced, it seems to me that it would be difficult for the bird to remain more than about 250 yards from any observer at any time. Doing some math, if 23 observers spent 12 hours/day searching for 3 days, that would be 828 total search hours. If Cornell spent 20,000 total hours searching, that would be equivalent to 24 instances of these all-day, 23-person, 3-day searches.

The search team hasn't yet obtained a single good look at an Ivory-bill, but it seems that they've already made a truly massive effort.

Fleeing Pileated picture--compare to the Luneau video

An alert reader emailed me this:
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I came across a picture of a Pileated in flight that I wonder if you're aware of. It's on this webpage, down at the bottom.

The image shows the underside of the left wing of a woodpecker that is flying away from and to the left of the camera. The leading edge of the wing is down, the trailing edge up. Doesn't it look like the flying bird in the Luneau video?
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I agree. When "believers" see the extensive flashing white in the Luneau video, they think that they are looking at the topside of an Ivory-bill's wings. I think it's likely that they are really looking at the underside of a normal Pileated's wings.

Weak coffee

As I see it, quite a few people examine the Ivory-bill evidence and do recognize that the individual video, sighting and audio pieces are weak. However, they conclude that the combination of all three pieces is compelling. In my view, that type of thinking is not solid.

Benjamin Radford, managing editor of Sceptical Inquirer magazine, said this about weak evidence:

"I liken it to a cup of coffee - if you have many cups of weak coffee, they can't be combined into strong coffee...It's the same with scientific evidence. If you have lots of weak evidence, the cumulative effect of the evidence doesn't make it strong evidence...".

One of my readers emailed to say "There is no control for this experiment". That's an important point. If you're testing a new drug, it's not enough to find that in testing, 55% of patients get better after a month on your drug. If 60% of patients get better after a month on a placebo, then you don't have evidence that your drug is effective.

Similarly, if you get some double-knocks and kent-like calls in 18,000 hours of ARU data, that's not necessarily significant evidence. If ARUs were set up in areas with no Ivory-bills, such as Minnesota, I think just as many (or more) double-knocks and kent-like calls might be recorded. Likewise, if you left some video cameras running in woodpecker territory in Minnesota, focused at 1 or 2 meters, I'd bet that you'd get some fuzzy video of fleeing black-and-white birds. And finally, if you told people that an Ivory-bill had been sighted in Minnesota and they spent 20,000 hours looking, I'd bet that some would get glimpses of large dark birds that appeared to have trailing white wing edges.

It's very unpopular to say this, but I think if you look at the current Bigfoot and Ivory-bill 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). Maybe the Ivory-bill lives. However, it's also possible that the similarities in the Bigfoot and Ivory-bill evidence are not coincidental--this body of weak evidence may actually be the expected result when you search hard for a nonexistent creature.

Gallagher: you have to get a picture

There's an interview with Tim Gallagher here. Here's a snippet (as always, unless otherwise noted, I've added the bold font for emphasis):
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I've had some people in New York and the Adirondacks report a sighting, well outside of the historic range of the birds. I just tell them it's highly unlikely but you have to get a picture. We can't spare people to go chase every report.
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Am I the only one that sees any irony here?

Search team member: several abnormal Pileateds in the Cache area

A reader emailed me this link to a very detailed article (updated 6/9/2005) in the Arkansas Times. The article contains a lot of fascinating tidbits, but this was most interesting to me:
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Arkansas State University professor of wildlife ecology Jim Bednarz has seen several pileated woodpeckers with an abnormal amount of white wing feathers in the Cache River refuge. With Team Elvis, he pursued three birds that showed a flash of white in flight and white on their backs as they were perched. All were pileated.
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Bednarz, though he believes there is an isolated population of pileated woodpeckers in the Cache river bottoms who have an uncharacteristic amount of white on their wing feathers, said the Luneau video has left “no question in my mind that it’s an ivory-billed woodpecker.”
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I've written about this issue previously here.

Washington Post: Bird's Advocates Challenge Corps

Check out this article from today's Washington Post:
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A group of environmentalists is trying to block construction of two federal water projects in Arkansas, arguing they could damage the habitat of the highly endangered ivory-billed woodpecker.
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"We shouldn't risk destroying the last remaining habitat for the ivory-billed woodpecker in the pursuit of extraordinarily marginal projects, at best," Searchinger said.
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In the above article, I see no mention of any doubt whatsoever that the Ivory-bill lives. Doesn't the Post know about the public skeptics?

List of public skeptics continues to grow

For those of you keeping score, here's my list of "third-party" people who have publicly expressed skepticism regarding Cornell's Ivory-bill evidence. I'm only including people that might be considered high-profile and/or highly-credentialed.

1. David Sibley, bird book author
2. Kenn Kaufman, bird book author
3. Jerome Jackson, "world's foremost expert on the ivory-billed woodpecker"
4. Richard Prum, ornithologist, Yale University
5. Mark Robbins, ornithologist, University of Kansas
6. Gary Graves, the Smithsonian Institution's curator of birds
7. Michael Patten, ornithologist, University of Oklahoma
8. A. Nemesio, ornithologist, Brazil
9. M. Rodrigues, ornithologist, Brazil

According to the latest public information that I have, each person above thinks that the entire package falls short of proof. (Prum and Robbins are a special case--in early August, they withdrew their critical paper, and reports suggested that those two were convinced by the audio information. A Nature online article dated September 7 now says "the three sceptics say that they withdrew their PLoS manuscript too hastily.")

Remember, this list only includes people who've publicly expressed skepticism. I'm maintaining another list of highly-credentialed people who've privately expressed skepticism. There's currently an undeniable stigma attached to anyone expressing doubt; I think this stigma will wane, and I think we will then hear from more skeptics.

Here's a list of high-profile and/or highly-credentialed "third-parties" that have publicly stated that they think Cornell's evidence is convincing:

1. Pete Dunne, bird book author

Of course, the obvious observation is "Why are you limiting the list to third-parties? If you included the Cornell search team, the believer's list would be much larger." My answer is this: I think the search team is so committed to their "Ivory-bill" discovery that they can't be expected to do true objective, cold-hearted analysis of the evidence any longer. I think they've invested so much work and time into this project that expecting them to step back, take a fresh look and ask "Could this really all be a mistake?" is asking too much.

List of public skeptics

For those of you keeping score, here's my list of "third-party" people who have publicly expressed skepticism regarding Cornell's Ivory-bill evidence. I'm only including people that might be considered high-profile and/or highly-credentialed.

1. David Sibley, bird book author
2. Kenn Kaufman, bird book author
3. Jerome Jackson, "world's foremost expert on the ivory-billed woodpecker"
4. Richard Prum, ornithologist, Yale University
5. Mark Robbins, ornithologist, University of Kansas
6. Gary Graves, the Smithsonian Institution's curator of birds
7. Michael Patten, ornithologist, University of Oklahoma
8. Louis Bevier, was assistant editor of The Birds of North America, and is currently an associate editor of the journal North American Birds
9. A. Nemesio, ornithologist, Brazil
10. M. Rodrigues, ornithologist, Brazil
11. John Kricher, biology professor, Wheaton College, Norton, Massachusetts
12. John T. Rotenberry, biology professor, University of California Riverside. President of the Cooper Ornithological Society
13. Hans Winkler, ornithologist at the Konrad Lorenz Institute for Ethology of the Austrian Academy of Sciences in Vienna and co-author of Woodpeckers: A Guide to the Woodpeckers of the World.
14. Noel F. R. Snyder, author of the books The Carolina Parakeet: Glimpses of a Vanished Bird (Princeton, 2004) and The California Condor: A Saga of Natural History and Conservation (Princeton, 2000).
15. John Acorn, biologist, writer, broadcaster, and university lecturer
16. Robb Hamilton, who served on the California Bird
Records Committee from 1998 to 2001
17. James Bednarz, Cornell searcher and member of the IBWO Recovery Team
18. Steve N. G. Howell, bird book author and a past member of the California Bird Records Committee

According to the latest public information that I have, each person above thinks that the entire package falls short of proof.

Remember, this list only includes people who've publicly expressed skepticism. I'm maintaining another list of highly-credentialed people who've privately expressed skepticism. There's currently a stigma attached to anyone expressing doubt; I think this stigma will wane, and I think we will then hear from more skeptics.

Here's a list of high-profile and/or highly-credentialed "third-parties" that have publicly stated that they think Cornell's evidence is convincing:

1. Pete Dunne, bird book author
2. William S. Moore, woodpecker expert from Wayne State University (Detroit). Moore is currently researching the evolutionary history of the Campephilus woodpeckers with Martjan Lammertink, a leader of the Ivory-bill search team in Arkansas .

Of course, the obvious observation is "Why are you limiting the list to third-parties? If you included the Cornell search team, the believer's list would be much larger." My answer is this: I think the search team is so committed to their "Ivory-bill" discovery that they can't be expected to do true objective, cold-hearted analysis of the evidence any longer. I think they've invested so much work and time into this project that expecting them to step back, take a fresh look and ask "Could this really all be a mistake?" is asking too much.

References:
This July 2005 New York Times article provides more information on the public views of Sibley, Kaufman, and Dunne.

Jerome Jackson commented on the controversy in a January 2006 Auk article. A link to that article is available here. An excerpt: "Prum, Robbins, Brett Benz, and I remain steadfast in our belief that the bird in the Luneau video is a normal Pileated Woodpecker".

More skeptical quotes from Prum (December 2005), are available here.

More information about the views of Graves and Patten (September 2005) is available here.

More information about the views of Nemesio and Rodrigues (May/June 2005; also Nov/Dec 2005) is available here.

This Birder's World article (published online February 2006) provides more information about the views of Kricher, Rotenberry, Winkler, Snyder, and Moore.

Nature article asks: But is it really alive?

Nature online has published an excellent article on the Ivory-bill controversy. In the article, two additional skeptics criticize the strength of Cornell's evidence--these skeptics are Gary Graves, the Smithsonian Institution's curator of birds, and ornithologist Michael Patten. According to the article, Richard Prum, Mark Robbins and Jerome Jackson now say that they withdrew their critical paper "too hastily".

Here's a key snippet:
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Even so, the three sceptics say that they withdrew their PLoS manuscript too hastily. They are getting support from other ornithologists, including Gary Graves, the Smithsonian Institution's curator of birds, who argues that the bird shown in the crucial video may be a pileated, not an ivory-billed, woodpecker.

And some authorities say that there is unpublished evidence that helps prove that the bird in the video is a pileated woodpecker. They are referring to a 1953 film of a flying imperial woodpecker (Campephilus imperialis), a species extinct in its home range of western Mexico. Some years ago, Lammertink secured a copy of the film, which had been taken by a birding enthusiast. It was among the evidence shown to ornithologist Michael Patten, research director at the University of Oklahoma's Sutton Avian Research Center in Bartlesville, when he visited Cornell in June.

Ornithologists generally agree that the imperial woodpecker is a sister bird to the ivory-billed, with many similar characteristics from coloration to the distinctive double-rap. But Patten was struck by the imperial's flight patterns. "As soon as I watched the film," he says, "I was absolutely certain they didn't have an ivory-billed woodpecker. The bird in the film flies utterly differently to the one in the Cornell video."

Fitzpatrick is not troubled by the film of the imperial woodpecker, arguing that it sheds little light on whether his video shows an ivory-billed. "They are like apples and oranges," he says of the two videos, because of different camera angles and stages of the birds' flights.

To the sceptics, the strongest evidence to support the theory that Elvis lives are the sound recordings. And although Prum and Robbins are impressed by them, Jackson, Graves and Patten are more cautious. The evidence is tantalizing, they say, but not conclusive. "The sound recordings don't validate the flimsy sightings records," says Patten.
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(I've added the bold font above.)

Wing beat rate in the Luneau video

Here is an interesting, fairly new article from Cornell's web site.

A snippet from the above article:
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While skeptical ornithologists recently claimed that the video images, captured in the Big Woods of eastern Arkansas in 2004, likely show the smaller but similarly patterned pileated woodpecker, new studies indicate that the pileated woodpecker beats its wings between 7 to 7.5 times per second in a slow rowing motion.

By comparison, the bird in the video flies at a rate of 8.7 beats per second in a direct duck-like flight consistent with historical accounts of ivory-bills. Fitzpatrick played an April 1935 audio recording, made by the Lab of Ornithology's founder Arthur Allen, of an ivory-billed woodpecker in the Singer Tract in Louisiana flying away from its nest hole. The flapping wings are clearly audible. Using a spectogram showing audio patterns over time on a graph, Fitzpatrick showed that the 1935 ivory-bill had flapped its wings at 8.6 beats per second.

"My personal view is that I am convinced there are ivory-bills out there, one or more," Fitzpatrick said. "Absolutely convinced."
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In my personal opinion, this "wing beat" argument constitutes "grasping at straws". For one thing, the bird in the video does not fly directly away--it is weaving back and forth through the trees (this weaving is easier to see at full speed in the Luneau DVD than it is in slow motion in the online video).

For another thing, the difference between 7.5 flaps per second and 8.7 flaps per second is not large. I see no reason that a Pileated, weaving in initial escape flight through the trees, couldn't fly at 8.7 flaps/second.

Which of these blobs are Ivory-bills?

A few days ago, I wrote that Cornell's distant, perched "Ivory-bill" may actually be just an artifact of an unfocused camera.

If you purchase a copy of the Luneau DVD here, you can see for yourself what I wrote about.

I took the time to capture a few of the many apparent black-and-white blobs on trees in the Luneau DVD, and I've posted them here on Flickr.

I think that all eight of these pictures are probably just artifacts of an unfocused camera. I think that Cornell might suggest that two of them are views of an Ivory-billed Woodpecker. Here's a challenge for you--which two are Ivory-bills, and why?
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1/23/06 update--according to Jerome Jackson's January 2006 Auk paper, John Fitzpatrick of Cornell has admitted that this so-called "six-pixel bird" is likely a branch stub.

It's all about the roost-hole

Yesterday, cyberthrush posted some thoughts about the current Ivory-bill evidence here. Both of us agree that the video is weak, and that the audio evidence is inconclusive.

We do have a major difference of opinion on the sighting evidence. Cyberthrush wrote this:
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I believe the multiple sightings from experienced and credible witnesses at different times, angles, places, of a bird of striking size and features represent excellent evidence, and the likelihood of so many mis-IDs is miniscule. (In the past, multiple-credible observers were a gold standard for a rare sighting; but suddenly in today's video-infatuated world film/photography is the new 'standard.')
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I think the big issue here is NOT the credibility of the observers or the sheer number of sightings; the issue is the quality of the sightings. As you may know, Sibley's standard of proof is my standard: "redundancy. Repeated sightings by independent observers of birds really well seen." The big problem with the current evidence is that we have zero cases where an Ivory-bill was really well seen. For me, a large number of low-quality sightings (ie, glimpses of large birds that appeared to have trailing white wing edges and maybe an unusual flight style) is not impressive.

In the end, I think the whole Ivory-bill controversy really boils down to one thing: finding an active roost hole. Back in the '30s and '40s, these roost holes were found many times, and high-quality evidence was gathered there. If any birds still survive today, someone will find an active roost hole, and indisputable, high-quality photographic evidence and sightings will quickly follow. It's now been 61 years since a confirmed Ivory-bill sighting in America; maybe year 62 will be our lucky one.

By the way, I believe the skeptics are actually very reasonable people. If Sibley's standard (above) is met, I will be satisfied by the proof, and I would bet that Jackson, Prum, Robbins, Kaufman, and of course Sibley would be satisfied as well. (No reasonable person today would ever want or need to see a "bloody Ivory-bill carcass", and frankly, I wish "believers" would stop making that insinuation.)

Ivory-bill skeptic home

As of 1/23/06, if you asked me "What's your confidence level that there was a living Ivory-bill in Arkansas in 2004?", I'd say "less than 1%".

I thought I'd summarize some of this blog's main points in one page, in a question (black font) and answer (red font) format. As always, please click on the links to drill down for more information.
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What do you think, in a nutshell?

I think it's likely that the observers were fooled by fleeting glimpses of abnormal (or normal) Pileateds (both were seen in the area); I think the video almost certainly shows a normal Pileated (and the distant perched "Ivory-bill" is likely a branch stub); as for the audio, I think the double-knocks were quite likely produced by other woodpeckers, and I think the kents are very likely to be Blue Jays.

How do you know that the Ivory-billed Woodpecker is extinct?

I don't know that. I think it is likely to be extinct, but I think it is possible that it still lives.

Who has publicly expressed skepticism of Cornell's evidence?

The list of public skeptics includes bird book authors David Sibley and Kenn Kaufman, Jerome Jackson ("world's foremost expert on the ivory-billed woodpecker"), ornithologists Richard Prum, Mark Robbins, Michael Patten, A. Nemesio, and M. Rodrigues; and Gary Graves, the Smithsonian Institution's curator of birds.

The American Birding Association Checklist committee has not changed the Ivory-bill's status from "extinct"; they are still waiting for "unequivocal proof that the species still exists".

Why are you skeptical of the current video, sighting, and audio evidence?

I think the flying bird in the video is probably a normal Pileated Woodpecker. My detailed video analysis is here. I think the distant, perched "Ivory-bill" is probably just some out-of-focus vegetation, most likely a branch stub.

I think that the seven "robust sightings" were almost certainly mis-IDs--a Pileated with some extra white on one wing could cause confusion. It's troublesome that of five key fieldmarks separating Ivory-bill from Pileated, only one (trailing white wing edges) was reported. These four key fieldmarks weren't reported --the Ivory-bill's white dorsal stripes, the white neck stripe ending before the bill, the longitudinal black stripe on the white wing underside, or the pale bill itself.

I think it's very unlikely that Ivory-bills produced any of the recorded sounds. The double-knocks could easily have been Pileateds, other woodpeckers, or American Crows, and the "kents" were probably produced by Blue Jays.

What other points make you a skeptic?

--the sightings occurred in an area where several abnormal Pileateds were seen. Brief glimpses of such a bird could easily result in mistaken identifications.

--It's very troubling to me that the "Ivory-bill" was glimpsed maybe 8-18 times in a small area, yet never clearly photographed. When last studied 60+ years ago, the bird was conspicuous, at least in certain seasons, and not particularly wary. If it was really there, it should have been seen clearly and well photographed long before now.

--no "kent" vocalizations were reported during encounters.

--no one noted the loud wing noise of an IBWO

--the bird was present in marginal IBWO habitat (it's good Pileated habitat)

--no hard evidence (a feather or an eggshell, for example) has been found


In your view, what is the biggest logical error made by "the believers"?

In my opinion, their most common error is the assumption that lots of weak evidence can be combined to form strong evidence. I've written more on that here.

Is there any form of proof that would satisfy you?

Yes. My standard is David Sibley's: "Redundancy. Repeated sightings by independent observers of birds really well seen." This type of proof was routinely gathered back in the '30s and '40s. You can read more here.

Who are you? Do you have an "axe to grind"?

I'm an avid Minnesota birder with many years of experience. I've birded in Arkansas, and I've successfully searched for the Red-cockaded Woodpecker there.

For over two months after the April rediscovery announcement, I was a "believer" myself. I hadn't looked at the evidence, and I just assumed that Cornell had rock-solid proof. When I read that David Sibley had expressed some skepticism, I was inspired to examine the evidence for myself.

I'm not an ornithologist--like David Luneau, I have an MS degree in electrical engineering. There's no axe--I'm just trying to understand the truth about this situation.

I want to believe that the Ivory-bill lives, but I don't want to believe that if it's not true. If the definitive photographic proof ever comes, I would then be in favor of launching into massive fundraising and Ivory-bill-specific habitat programs. If we ever get definitive proof, I pledge to personally donate a significant-to-me sum of money to the Ivory-bill conservation effort.

I think we have a "level playing field" here. No one involved in the controversy, in their lifetimes, has a single confirmed sighting of the Ivory-bill. We all have access to the same historical books, the same Cornell paper, the same original Luneau DVD of the alleged Ivory-bill, etc etc. In my opinion, not enough people have taken the time to carefully examine this stuff.

Some of my blog entries:
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Jerome Jackson's endorsement
Red flags in the evidence
The smoking gun?
Luneau video analysis
Abnormal Pileated information--why was it suppressed?
Kent calls from Blue Jays
Pileated double-knocks
Why were no Ivory-bill "sound combinations" recorded?
Skepticism from the inside
Was groupthink a problem?
Attacking the questioners

Associated Press refers to "skeptical bloggers"
United Press International mentions this blog
Smoky Mountain News article mentions this blog

Could all those sight records be mis-IDs?
Who has visited this blog?
Just how wary was it?
Was "Elvis" just an abnormally-colored Pileated?
Does Cornell's Aug 24 audio release actually weaken their case?
Jim Tanner said that, in his experience, the IBWO was not very wary
A couple of analogies
The New York Times (8/30/05) backpedals
Nature article asks: But is it really alive?
More details on their noisy flight
Real-world rare bird photos
IBWO tour solicitations panned
Notes from the late Jim Tanner on finding ivory-bills
What does the future hold?
Hundreds of duck hunters in the Cache River area?
Don Eckelberry's Ivory-bill description
Parallels with the 2002 Pearl River search
Bigfoot/Ivory-bill parallels
Ivory-bill hoax in South Carolina, 1971?
Creeping sanity?
Bombshell from the USFWS?
Let's see the Imperial Woodpecker video
Pileateds photographed at bark scaling sites
Huge, clown-like woodpecker videotaped
"We are on a very cold trail right now"

"The awesome PR machine"
Videos of AOU Ivory-bill presentations
The story behind the Luneau video
Some humor

Related links:
Cornell's original paper (and Supporting Online Materials)
The video news release
David Sibley's IBWO page
Answers.com information on IBWO
Google map of Cache River area

Article by the late Eirik Blom on IBWO skepticism
Skeptical article (Jan 2002) by Don Hendershot
Skeptical article (May 2005) by Don Hendershot
Skeptical article (Oct 2005) by Don Hendershot
Web page by Bruce L. "Buck" Nelson, a skeptic

IBWO links from Laura Erickson, a believer
Ivory-bills LiVE!! blog, from Cyberthrush, a believer

A note to cyberthrush

I like Cyberthrush (but I disagree with his conclusions). He's an "Ivory-bill believer" who is willing to question pieces of Cornell's evidence.

He recently wrote this:
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Moreover, on BOTH the up and down wing strokes the bird seems to reveal far TOO MUCH white for a Pileated -- indeed, I'm amazed at those who now argue the bird could actually be a NORMAL Pileated, and need not even be leucistic!!??
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I don't see anything on the video that's inconsistent with a normal Pileated.

In the Luneau video, I believe we are looking at the bird's white wing linings on both the upstroke and the downstroke. Remember, the camera angle is low (from the canoe), and the bird is powering mostly straight away, rising slightly. In that view, I believe we are seeing the mostly-white wing linings as the bird raises its wings, and we are also seeing those wing linings on the downstroke, as the bird powers ahead and slightly up. In some frames, I see what looks like a trailing black edge on the underwing, but the picture is so unfocused that I can't be sure.

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 sketched 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. In addition, I think the picture is so blurry that an accurate measurement just isn't possible.

And about that distant, black-and-white blob that's supposed to be a perched Ivory-bill (about 20 seconds before the "Ivory-bill" flies)? I think it's more likely to be a bit of out-of-focus vegetation.

Regarding the sightings--I don't know anyone who is suggesting that the observers were fooled by an oversized, symmetrical leucistic Pileated. I think the observers may have been fooled by a normal-sized Pileated with an abnormal amount of white on one upperwing. Such a bird was reported in the search area.

If observers glimpsed an oddball Pileated, they might be correct in saying that it "didn't look like a Pileated", and I think their perception of the bird's size and flight style may also be affected. When I look at accounts of the sightings, I don't see that a lot of consideration was given to the possibility of an abnormal Pileated.

Could a Pileated with abnormal coloring on only one wing pass for an Ivory-bill? I think so, given that the glimpses were fleeting. Of the seven robust sightings, I think that some observers only saw the pattern on one wing. Others may have seen only one wing well, and assumed that the white pattern on the other wing matched. Remember that this was not a lazily soaring hawk--those wings are flashing awfully quickly.

Regarding identifying the bird by "gizz", please also note that James Tanner said that size and flight style were not reliable ways to distinguish Ivory-bill from Pileated (please see #1 here). The observers were unlikely to have much experience with abnormal Pileateds, and they had no confirmed experience with Ivory-bills. Given that lack of specific experience, and given a brief glimpse, I think it's asking too much to expect the observers to reliably distinguish an abnormal Pileated from an Ivory-bill.