This information from Ken Rosenberg of Cornell is extremely interesting to me:
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2. Upper-wing pattern. A questioner asked Rosenberg (who admitted that he was hoping to time his talk so as not to have to take questions) if members of the search team had observed any Pileated Woodpeckers with aberrant plumage. Rosenberg said that there were reports of such birds, and that he had seen a photograph of a Pileated that was missing upper-wing coverts. The missing feathers exposed more white than usual on the bird’s wing. Rosenberg said that the resulting pattern was not symmetrical, and stressed that he had seen nothing to contradict the team’s conclusion that the Luneau bird’s wing pattern was that of an Ivory-bill.
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This is the first time I've seen public confirmation that there was, in fact, at least one abnormally-plumaged Pileated in the Cache River area. I'm sure that this bird's upperwing pattern didn't exactly match that of an Ivory-billed Woodpecker (IBWO), but given the observers' likely mindset, it could be the source of mis-IDs.
Could a Pileated with abnormal coloring on only one wing pass for "Elvis"? 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.
I think it's likely that the observers had plenty of experience viewing normally-plumaged Pileateds, but that they may have had little or no experience with an abnormal bird. If they glimpsed an oddball Pileated, they would 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.
Under the hypothesis "Elvis was actually an abnormal Pileated", lots of nagging questions would fall away:
--why four of five key fieldmarks weren't seen (a Pileated doesn't have the 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)
--why Elvis was never clearly photographed (maybe it was photographed, but since it was obviously a Pileated, no one realized it was Elvis)
--why no "kent" vocalizations were reported during encounters
--why no one noted the loud wing noise of an IBWO
--why the ARUs did not pick up distinctive double-knocks as described in "The Grail Bird"
--why there was no response to an IBWO tape
--why the sightings were concentrated in such a small range (probably coinciding with an area where an abnormal Pileated was photographed)
--why the bird was present in marginal IBWO habitat (it's good Pileated habitat)
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(Note: I think it's likely that the bird in the Luneau video was an ordinary Pileated.)
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2 comments:
"Extraordinary claims require extraordinary proof."
And in my opinion, that proof needs to be even stronger now that we know that there HAVE been leucistic Pileated woodpeckers seen, that at least one was marked much like an Ivory-bill, and that in the search area a Pileated was seen showing an abnormal amount of white.
Also very interesting is how they got a photo of that abnormal Pileated, but not an ivory-bill. Seems plausible that the reason most IB field marks weren't seen, and no IB photo was taken, is that no IB was present. Good views and photos and videos wouldn’t show IBs at all. Only brief or distant sightings and fuzzy video get reported as "robust sightings."
I'm very impressed with your research. It would have been good to know these facts all along.
Hi Cornell75,
I think Cornell's evidence for the existence of the IBWO is weak, and I think the arguments in your comment are also weak.
1. Ken Rosenberg admitted to timing his talk so as not to have to take questions. When directly asked about aberrant Pileateds, he then mentioned the sightings/photo of such a bird. If the aberrant bird(s) were seen far from the "ivory-bill" sightings, surely he would have mentioned that fact. I also have private communications that indicate that that one or more aberrant Pileateds were encountered in the area.
2. What matters here is whether any Pileateds in the area appeared to have abnormal amounts of white on the upperwing. It doesn't matter whether the bird was leucistic, in a state of unusual molt, discolored by something, etc. That's why I've started to use the word "abnormal", rather than the more specific term "leucistic".
3. I'm not convinced that the bird in the video is an abnormal Pileated. I think it could be a perfectly normal Pileated, and that the extensive white seen could be the flashing of the Pileated's white wing linings.
The information that I have is that there was a female Pileated in the area with abnormal white on its right wing. On the "perched blob" view in the Luneau video, the focus is so bad that I don't know whether the bird is showing abnormal amounts of white. However, the view is of the bird's right side, so it's possible that the abnormal bird above is pictured. Also worth noting is that Sparling's sighting could match this abnormal female Pileated--his reported extent of red on the crest matches a female Pileated, and his report of a white patch on the back could also match the abnormal bird. Although he had a close look, he apparently didn't notice anything unusual about the bill color or length, which would also match this abnormal female Pileated.
4. I've used facts and logic to argue that Cornell's evidence falls far short of proof that the IBWO lives. If there was an IBWO in the Cache River area in 2004-2005, I would argue that it's extremely likely that repeated, undisputable photographic evidence would have been gathered. The absence of such evidence is a strong indication (though not conclusive proof) that no IBWO was present.
Specifically what sort of hard evidence do you think the skeptics should provide?
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