IBWO tour solicitations panned

I've done some looking and asking around, and I've yet to find anyone who is interested in the high-priced Ivory-bill tours that are being promoted.

In blogs and chats online, there is a distinct lack of enthusiasm, as in this blog entry:

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All this for only $1550 from Little Rock! Sign me up for the medieval torture chamber trip extension, too!
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I've also written about these tours here. Note this snippet:

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...They have a full-page advertisement scheduled to appear in the next issue of Birding Magazine, and they are working with a high-profile birder who says "he can book 1,000 spots with ease."
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Abnormal Pileateds

A few people still claim that "there's no such thing as an abnormal Pileated Woodpecker".

There is a lot of evidence to disprove that claim. Here is some:

1. Arkansas Times article, which says Cornell search team member Jim Bednarz has seen several pileated woodpeckers with an abnormal amount of white wing feathers in the Cache River refuge, and 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.

2. At the 2005 AOU meeting, Ken Rosenberg of the Cornell team publicly admitted that several abnormal Pileateds were seen in the search area, and he mentioned pictures of them.

3. Birding expert Noel Snyder saw an abnormal Pileated in Florida that looked very much like an Ivory-bill.

4. Abnormal Pileateds have also been mistaken for Ivory-bills in Texas.

5. In January 2006, Cornell search team volunteer Sharon Stiteler said in an interview:

I've seen footage of this abnormal Pileated. It's got like two or three feathers on the back that are white that shouldn't be white.

6. Here is Cornell's web page featuring photos of abnormal Pileateds found in the search area.

Ivory-bill segment on "60 Minutes" Sunday

According to this press release, there will be a story on the "rediscovery of the ivory-billed woodpecker" on "60 Minutes" this Sunday Oct 16 (7pm EDT).

False positives?

When thinking about the reported Arkansas Ivory-bill sightings, it's easy to be misled by "false positives".

Let's look at a hypothetical situation:
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Let's say in 20,000 hours of searching (much of it in an area where abnormal Pileateds have been seen), searchers get 200 fleeting glimpses of birds that might be Ivory-bills. That's one tantalizing glimpse per 100 hours of search time. Of those 200 glimpses, observers report eight "robust" sightings where they are about 96% sure that they saw an Ivory-bill. Given those eight "robust" sightings, can we be reasonably certain that someone saw an actual Ivory-bill?
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In my opinion, the answer is "no".

Here's why I say that: if you're 96% sure, that means there is a 4% "false positive" rate. After a massive search effort, if you get 200 glimpses of birds that may be Ivory-bills, that 4% "false positive" rate might lead you to expect eight "robust" sightings, even if there are no Ivory-bills in the area.

Of course, the numbers above are truly hypothetical, and no one can actually calculate that they are "96% sure" that they glimpsed an Ivory-bill. I find it useful to think along these lines, however, because it helps me understand the vast difference between 100% proof (good videos, for example) and a number of so-called "96% sure" sightings. Quality is vastly more important than quantity here.

I think these paragraphs (from this paper) also illustrate how easily we might be misled by "false positives":

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It is useful to begin with a handful of realistic examples that indicate how simple intuition can be misleading. Of particular relevance to college students is a (true) story about a man who received a positive outcome on a first-stage test for the virus that causes AIDS. The test that was used had a 4 percent rate of false positives, and for simplicity, it is assumed that there were virtually no false negatives. The person committed suicide before follow-up examinations, presumably not realizing that the low incidence of the virus in the male population (about 1 in 250 at that time) resulted in a posterior probability of having the virus of only about 10 percent.

To explain this point in class, it can be useful to begin with a hypothetical representative group of 1000 people, and to ask how likely it is that a person with a positive test actually carries the virus, given an infection rate of 1 in 250 for the relevant population. On average, only 4 out of the 1000 actually have the disease, and the test locates all 4 of these true positives. However, among the 996 who do not have the disease, the test will falsely identify 4 percent as having it, which is about 40 men (.04x996 = 39.84). On average, the test identifies 44 of the 1000 men as carriers of the virus, 4 correctly and 40 incorrectly, which means that a positive first-stage test actually produces a less-than-ten percent chance of a true positive. This is a case in which knowing the intuition behind Bayes’ rule can save lives.
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ASU Herald Ivory-bill story

I just found this Arkansas State University Herald article. Below are some snippets in black, followed by my comments in red:
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The ornithology world suffered a loss in 1944 when the Ivory Billed Woodpecker was declared extinct.

Was the Ivory-bill actually ever declared extinct?

That declaration has been proven false, as scientists are now suspecting that the bird might still be alive.

There's not much conviction in the above wording.

ASU Doctorate student Ken Levenstein has recently been appointed team leader by the Cornell Lab of Ornithology at Cornell University for the research of the Ivory Billed Woodpecker.

The Ivory Billed Woodpecker was believed to be extinct since 1944 when loggers working on the Mississippi River destroyed their habitat. Whispers have been said for years about sightings of this magnificent bird, but were ignored by the scientific community.

That's simply not true. Even in the decades prior to 2004, enormous amounts of time and energy were spent fruitlessly following up reported sightings.

“The bird was a really spectacular bird and the fact that it might not be extinct gives us new hope that maybe we can fix something that we did wrong a long time ago.” said Levenstein.

Again, not much conviction.

Dana Ripper, a Master’s graduate from ASU, and undergraduates Kristina Baker and Jamie Conrad were selected to be “searchers.” As many as 40 students applied for Levenstein’s job from various universities from all around the country.“The Cornell University selected some of our students last year for the first part of this project and it’s really exciting that another ASU student was not just selected but appointed team leader,” said Dr. Jim Bednarz, professor of wildlife ecology and Levenstein’s advisor.

Interestingly, this is the same Jim Bednarz who has seen several pileated woodpeckers with an abnormal amount of white wing feathers in the Cache River refuge.

Levenstein, along with Cornell Scientist, Elliott Swarthiest, will be supervising biologists’ efforts. The project is to get underway again in late October.
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TWO Ivory-bills in the Cache River area?

In Tim Gallagher's recent seminar, he says that he believes the "Ivory-bill" that he saw was a female, since he didn't see any red (or any other feature) on the head. Sparling reported seeing red on the head of his bird, which means that if it was an Ivory-bill, it had to be a male.

Putting those observations together, we'd have a pair of Ivory-bills, one of each sex, seen within a quarter of a mile of each other. The area is accessible via a short paddle from a busy road. In 20,000 hours of intense searching, neither bird was ever seen well or photographed; each of the "tantalizing glimpses" was of a single bird, never a pair.

I still think it's possible that an Ivory-bill lived in Arkansas in 2004. However, to "believe" at this point, I think you've got to accept a mountain of implausibilities like the paragraph above.

TNC: odds are 1 in 1.2 million

This article appeared in the Miami Herald recently.

Here are a couple of snippets:

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The Nature Conservancy, long active in wetlands preservation in the Delta and a leader of the woodpecker search, has said 20,000 hours of tracking went into about 60 seconds of ivory-billed sightings during a year. The group figures the odds of seeing the bird are 1 in 1.2 million.
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Evidently, The Nature Conservancy calculated that a 1-second glimpse could be expected, on average, every 1.2 million seconds of search time. If you want a 3-second glimpse, you'll need to search for about 1000 hours (25 weeks at 40 search-hours per week). And remember, your glimpse may be a distant look at a bird that isn't an Ivory-bill.

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Ivory-billed woodpeckers are fast, strong fliers that may cover 20 square miles of territory a day.
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I think the above figure is misleading at best, and it may be part of the 79.48% of all statistics that are made up on the spot.

Of course, no Ivory-bills were ever studied with telemetry (and I think only one was ever banded). I very much doubt that anyone has any data showing that an individual Ivory-bill ever visited 20 different square-mile sections within a single day.

Arkansas Ivory-bill misconceptions

Many people tend to have some false impressions about the Ivory-bill and Arkansas.

Below, in black, I've listed some misconceptions, along with my perspective in red:

1. Cornell reportedly rediscovered the Ivory-bill "way back in the remotest swamp", where humans rarely go.

Well, the key Gallagher/Harrison "Ivory-bill" sighting occurred only about a quarter mile from a busy road, easily accessible via canoe. Hundreds or thousands of duck hunters are in the area every fall.

2. The Ivory-bill habitat in Arkansas is good, and it's improving quickly.

Not true. It appears that many decades will need to pass before the current crop of trees will get old enough and decrepit enough to provide good IBWO habitat.

3. If you choose to believe in the Ivory-bill, you are "siding with the experts".

Which experts? There are many high-profile, third-party experts that have expressed public skepticism. There are very few high-profile, third-party experts that have expressed public belief.

4. The video is conclusive, because it proves the bird is too large to be a Pileated, and the white wing and back feathers are diagnostic of an Ivory-bill.

Nothing in the video is inconsistent with an ordinary Pileated.

5. The video shows a distant, six-pixel perched Ivory-bill.

I think the video likely shows a distant, six-pixel dead branch.

6. The observers were all trained, professional biologists that are incapable of making identification mistakes.

Four key observers were Gene Sparling, Tim Gallagher, Bobby Harrison, and David Luneau. None of them are trained professional biologists. I'm not questioning their honesty; however, I would like to point out that they are human and like all of us, they are fully capable of making mistakes.

The observers may have been victims of groupthink.

7. The observers each noted "all the key fieldmarks of an Ivory-billed Woodpecker".

That's far from the truth. The one key fieldmark was "too much white on the upperwing to be an ordinary Pileated"--this fieldmark may also be seen on an abnormal Pileated.

8. The "abnormal Pileated" theory is implausible.

Cornell has publicly confirmed abnormal Pileateds in the search area.

9. In the reported sightings, some perceptions of size and flight style clinched the identification.

James Tanner said that for a lone bird, difference in length is not a reliable character. He also said he had frequently seen Pileateds fly directly, in no way different from the flight of an Ivory-bill. Some more details are here.

10. The audio is convincing.

I think the audio evidence actually weakens the overall case. Even Cornell doesn't claim that it's convincing.

11. The bark scaling evidence is meaningful.

Remote cameras have captured Pileateds doing this.

12. The ivory-bill is now ultra-wary and quiet.

I think it's far more likely to be extinct than it is to be alive but impossibly elusive. The bird was also vocal when last documented, and we have no evidence that it was getting any quieter.

13. We're likely to get better evidence if we just spend some more time searching.

"Prime-time" Arkansas expeditions in early 2003, 2004, and 2005 have already been completed with no hard evidence of an Ivory-bill. I think it's unlikely that the core problem here is "not enough searching".