==> THEblog devoted, since 2005, to news & commentary on the most iconic bird in American ornithology, the Ivory-billed Woodpecker (IBWO)... and sometimes other schtuff [contact: cyberthrush@gmail.com]
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"There are known knowns; there are things we know we know. We also know there are known unknowns; that is to say we know there are some things we do not know. But there are also unknown unknowns – the ones we don't know we don't know." ....Donald Rumsfeld
Major hoaxes have, luckily, been few-and-far-between in the Ivory-bill saga, though they have occurred, and may again. Steve Sheridan's 2009 hoax was the one well-established (admitted) hoax of recent times, and most presume the Dan Rainsong and Florida "magic guy" (William Smith) story-lines to have also been hoaxes (though never admitted). A few folks may yet believe David Kulivan's 1999 claims to have been bogus, though almost all informed folks lean toward either honest mistake or true sighting for that one.
In earlier years of this blog I occasionally had transparent, bumbling hoaxes sent to me via email. Most were lame attempts, easy to see through, even if it takes extra effort to confirm them as concocted. Most who contrive such stories simply lack the knowledge/skills to pull it off, especially with today's means of scrutiny. Still, I've always believed that a well-executed, difficult-to-unravel hoax is possible by someone ornithologically and technologically knowledgeable enough, and with the patience/desire to do so. It's barely even relevant to the question of whether Ivory-bills persist today, but possibly the most contested hoax/no hoax(?) case is that of Fielding Lewis's tale from 1971. Tim Gallagher detailed the unresolved story in his book "The Grail Bird" (Chapter 7, entitled "The Boxer"); available for free on the Web from Google books:
Over the years a few folks who either had direct knowledge of the story or knew Lewis personally, have emailed me to voice its authenticity or Lewis's veracity… still, I've never felt confident taking either side on this one --- leaning toward authenticity, but only by a slim margin.[ -- For anyone not acquainted with the storyline, Lewis, a prominent Louisiana outdoorsman, presented George Lowery, one of Louisiana's premier ornithologists, with photos of an Ivory-billed Woodpecker on a tree trunk taken near Franklin, La. with a Brownie instant camera. The bird pictured IS clearly an Ivory-bill, the only question never resolved being whether it was living or a stuffed specimen placed on the tree.]One of the Lewis photos was used in a 2001 edition of "Birding" magazine, opening an article by Jim Williams:
It is amazing that even this instance of clearcut photos only takes us down yet another 40-year dead-end of unsettled controversy. Was the bird dead or alive, breathing or stuffed? Only Fielding Lewis knew for sure, and in the realm of the Ivory-bill, one witness is never enough (Lewis died in 2008; Lowery, by the way, died 30 years earlier, his reputation sullied by his trust in Lewis's claim). Often people will ask what possible motive could Lewis have had for such a prank, if that it be, but the motivations of hoaxers can be many, and need not include money, material gain, nor fame. So I don't doubt that he could've had a motive, but to his death Lewis never recanted his claims (and, so far as I know, no further relics/evidence either backing or detracting from his story were unveiled following his demise).
Like the Luneau video, different people can view the Lewis photos and interpret them differently. Did a Brownie camera in 1971 accomplish what 1000's of dollars-worth of photographic equipment since then has failed to accomplish? Ultimately, in regards to the question of Ivory-bill persistence today, it is a somewhat moot point whether or not Lewis photographed an IBWO 40 years ago. Still, one wishes the Lewis story could be laid to rest, one way or the other, once-and-for-all… but like the Kulivan claims, the Sparling-Gallagher-Harrison claims, Tyler Hicks' report, etc. etc., apparently it cannot. It remains in the over-flowing dustbin of the curious, the tantalizing, the frustrating, the aggravating, the likely forever-unknown, that so enshroud this ornithological quagmire. ----------------------------------------------------------------
As one website says, "By all indications, Tuesday is going to be a big day." ...For physics that is, not ornithology. Tomorrow, according to well-circulated rumors, CERN will claim evidence that the elusive Higgs boson has been found.
In honor of that likely pronouncement, I repeat below (only slightly modified) a post I did earlier this year:
The analogy to 'Schrodinger's cat' has been made repeatedly in the case of the Ivory-billed Woodpecker. Another, more-current analogy one might make though is to the Higgs boson. I'm not competent to describe the technicalities of the Higgs, but simply put, years and years of tangential evidence has indicated its likely existence, yet no proof of it has been forthcoming -- one of the major goals of the much-publicized Large Hadron Collider is to establish the presence of this elementary particle (known popularly as "the God particle"... hmmm, echoes of "the Lord God Bird"). Both the LHC and its rival, the Tevatron collider in the US, have recently found rumored evidence (still being analyzed) for the Higgs, after decades of theorizing and failed searches. Hints, glimpses, findings, calculations, debates... but still awaiting proof (sound familiar?).
I'll confess my bias: Schrodinger's cat is mostly an abstract thought exercise... I suppose I prefer an analogy to the Higgs, because so many of those in the know feel sure it is really there, and just a matter of time before that is patiently demonstrated... may it still be so for the Ivory-bill... not Schrodinger's Woodpecker, but Higgs.
Of course, any announcement from CERN will have no real bearing on the Ivory-billed Woodpecker. Still… one may hope.
Apologies to any who are bored with all the Higgs hoopla, but a quick update:
Higgs rumors had been circulating for weeks on popular science sites with the hype feeding on itself in increasing anticipation of today's announcement. And while some do find today's news release quite persuasive, the bottom-line is more cautious, continuing to take a wait-and-see approach (for something more definitive)… in a sense, physicists have heard some double-knocks and kent sounds and had a brief glance of a putative Higgs, but nothing that can be called "proof." They're now predicting 2012 as the year that final confirmation may come --- uhhh, how 'bout we make that a twofer!
And the Don Moser 1972 Life Magazine write-up on the Ivory-bill, which is alluded to in the article, is available on the Web from Google books here (starts pg. 52):
---------------------------------------------------------------- In his somewhat trademark fashion, Mike Collins has once more re-visited some prior video footage (in this instance from the Choctawhatchee in 2007), to again discover the possible presence of Ivory-billed Woodpeckers. Read his report here:
Per usual, the video is not of a nature/quality that would sway any skeptics nor move the debate -- it's not clear to me if Mike seriously thinks this quality of 'evidence' would alter mindsets. And it is almost embarrassing that he keeps pushing such footage on the Frontiers of Identification listserv where most participants are likely to roll their eyes at it (...at the Frontiers site it is not unusual to have a vigorous debate over the identity of a bird even when given perfectly good and clear photographs!... which Mike's frames are not).
There are, as usual, some frames I find mildly interesting, but nothing at all persuasive to my eyes overall. A nice-sounding double-knock is included in one video, though I have certain qualms with it as well, which are probably unresolvable and not worth getting into. Still, I do encourage anyone with the patience left to do so, to slowly, methodically work through the various clips for anything you can glean from them (...though it may not be much). I suspect the clips viewers might find most interesting are those labelled, "climb knock.mp4" and "jasa_movie1mp4".
For sheer perseverance, perhaps no one deserves the glory of eventually documenting the Ivory-bill any more than Mike does; plus, he has the luxury, afforded to few, of a job that allows him more consistent time and opportunity to look for the species in viable habitat. And if he is ever able to obtain video of a quality that confirms the presence of Ivory-bills in the Pearl to everyone's satisfaction, Mike will, in a flash, become one of the most celebrated, renowned birders in the long history of American ornithology (his various techniques, likely to become standard fare in graduate textbooks)… but, unless or until that happens, the verdict on his work seems, alas, far less promising...
For any who may be relatively new to the IBWO saga, and unaware of some of the history for the Pearl River area, preceding Mike's claims, here are a few older background pieces focusing mainly on David Kulivan's story or the Zeiss search that followed it in 2002 (unfortunately, so far as I can tell, the official Zeiss summary pages for their 2002 search are no longer available on the Web -- hmmm, is this because Zeiss now finds it too embarrassing to be associated with IBWO searches, or what gives???):
...and finally, brief, general info about the Pearl River WMA here:
http://www.wlf.louisiana.gov/wma/2789 [Pearl River area pic above via Wikimedia Commons] ----------------------------------------------------------------
In a recent post Ralph Perrine reports he will be searching for the Ivory-bill in the southeast corner of N. Carolina later this winter. An earlier search there by 2 technicians from North Carolina Audubon, primarily of the Waccamaw/Green Swamp area, unfortunately found no evidence for the presence of Ivory-bills. Perrine's post links to a nice, detailed account of 'field notes' on the IBWO from Arthur Allen and Paul Kellogg, pre-Tanner's study. (It mostly duplicates info from Bent and other Allen writings as well as Tanner's later work, but also includes some additional details.):
Over the holiday weekend I also got to be regaled with a few more details of one of the previous sightings from the search in the Congaree of S. Carolina. Sometimes it just seems like we're moving in never-ending circles, though..... (sigh) ---------------------------------------------------------------
The latest issue of Birding Magazine from ABA includes a report from their official Checklist Committee, including the unsurprising decision that the Ivory-billed Woodpecker is not included on the current checklist, remaining instead a Code 6 bird, meaning probably or definitely extinct. The article is available in pdf form here:
Meanwhile, Cornell has uploaded a wonderful piece (~11 mins.) with Chris Saker and Martjan Lammertink on the use of a man-made "double-knocker" box to research the Pale-billed Woodpecker in Costa Rica. Although this was only uploaded recently I assume the design may be the same version(?) of the box that was employed during parts of the IBWO search in the southeast:
...would be good to know to what degree Cornell will make the boxes available to interested independent Ivory-bill searchers, or at least give out the specifications for folks who may wish to construct their own?
FWIW, stills from the Web of Pileateds flying, here:
http://tinyurl.com/7ezs5vpor http://tinyurl.com/74v6ue4 Obviously, you lose a great deal of information in looking at stills versus a video; on-the-other-hand you gain some clarity and sharpness, that blurry, artifactual video may not offer.
And for new folks, here in slo-mo, is one of the oft-referenced Nolin videos of a PIWO in 'escape flight':
For now, just want to make sure everyone is aware that Bill Pulliam has gone ahead and posted more analysis, directed mostly at Louis Bevier's prior work and conclusions (perhaps one of Bill's best posts yet):
And I'd request that if you have comments/questions specific to Bill's analysis you post them on his blog (he shouldn't have to come over here to respond to matters specific to his own work).
ADDENDUM:for quick reference, because of interest in Bill's take on these matters (and new readers to the blog) I've now added direct links in the left-hand column to some of Bill's various IBWO-related posts, right after the list of 'IBWO Links' and before the direct links to skeptics' views. ------------------------------------------------------------------
The first is simply an abstract on the results of the official IBWO search in South Carolina from Matthew Moskwik -- nothing new here, and I don't know that the full report is accessible anywhere on the Web(?) but still worth a glance.
The second is a recent podcast interview with Tim Gallagher from the Wilderness Center site, primarily on the recent Imperial story (starts at about the 24-min. point). Gallagher doesn't give a lot of interviews, and this is probably the best one I've yet heard from him (~35 mins.).
I'm playing with a possible blurb loosely about "null hypotheses" which may or not ever get posted, but for the few who might be interested I'll throw out a couple of other statistically-oriented posts (will bore most, and only of tenuous value here):
The first is an old post from physicist Chad Orzel on "statistical significance" and the second a more recent and more technical post from Razib Khan on research false positives. (I only throw these out because they border on why I'm leery of all statistical discussion in regards to a topic like the IBWO -- discussion of null hypotheses can be tricky at best and disingenuous or misleading at worst -- my first stat professor in grad school blanketly told us to distrust ALL discussion of statistics in journal articles that wasn't carried out by Ph.D.-level statisticians, because most others misapply (or misinterpret) stats! -- though maybe things have improved in the last 35 years since then).
And of course feel free to continue any further discussion of matters in the prior post as well.
ADDENDUM: Tim Gallagher's Imperial story also made NPR today (part of all this sudden attention is no doubt due to Gallagher working on a book on the species… I don't mean that cynically, just that if you have a fascinating story at your fingertips you naturally want to publicize it as much as possible). The segment from "Science Friday" is here (just click on the video to hear the audio):
Given the time it was taking Bill Pulliam to comment on Cornell's recently-released Imperial Woodpecker footage I presumed he was doing his own in-depth analysis of the clips. And indeed he was. I think we all appreciate Bill's consistent attempts to objectively analyze such pieces of data (…and all the moreso given that, amazingly, he does so on a dial-up internet connection!). His analysis here:
To cut to the chase (but I definitely recommend you read Bill's entire post), he concludes that the new Imperial film unhesitatingly RE-AFFIRMS the bird in the original Luneau video as an Ivory-billed Woodpecker. I won't go into the reasoning he marshals toward that conclusion (focusing in part on wing-beat data and 'bowing' motion), nor nitpick over details of his analysis, nor am I personally convinced that this particular film evidence carries as much weight as he (or others) may place on it, but his take is always interesting. Of course, for most readers here, Bill is speaking to the choir anyway.
Until Louis Bevier, or Martin Collinson, or Richard Prum, or Sibley, or some other major skeptic come forth with their own analysis of the amazing film from Mexico the IBWO debate likely won't move any steps forward, and I'm not sure skeptics will even find it worth their time to closely study this new footage of a lone bird -- I don't blame them if they pass -- from their standpoint it's probably a further squandering of their time.
I'll say again what I've said previously… even without the Luneau video (and regardless of what the bird is in that clip) there is more than enough evidence to believe that Ivory-bills persisted into the 21st century, and may still be with us today. Convincing the masses of that though at this point will require more than an analysis of flight patterns or any other tangential evidence; it will require conclusive, indisputable film, or a fresh carcass... the Imperial film can generate a lot of words, most of them falling on the deaf ears of people who have moved on (and it can't explain why no such equivalent film of an IBWO has been attainable in the last 6 years, nor a single active nest-hole found of a bird that has to be actively breeding to still be with us).
On a completely separate note, for anyone who might be interested, once again an original copy of James Tanner's IBWO manuscript is being auctioned on eBay (auction over December 1st), with an asking price of $500+. Merry Christmas!!:
Closing out October, as most know, Cornell has released enthralling film from the 1950s of the (presumed extinct) Imperial Woodpecker in Mexico taken by an American dentist and amateur ornithologist of the day (the only known film of the species in existence). The full story here, from Cornell's "Living Bird" magazine, along with other links:
On the bright side, the historical story is fascinating, and the brief film clips are mesmerizing to a point of eeriness. For anyone who has followed the Imperial and Ivory-bill story in tandem it virtually sends shivers up the spine... and, also shrouds one's countenance with sadness. The report is simultaneously a distraction from, and an incentive for, the more immediately-pressing Ivory-bill story. Perhaps it will inspire some of the remaining IBWO searchers, who's zeal might be lagging, to re-double their efforts, or even inspire others to begin anew.
Having said that though, it is again disconcerting that a single amateur on the back of a mule 55 years ago was able to attain film, at quite some distance and obviously with a 1950's camera, of an Imperial Woodpecker that clearly shows the white 'saddle' back, while 6 years of more recent effort with far better equipment, by far more individuals, with more leads, searching far more locales, for the Ivory-bill, has failed to produce such, either by a person or an automatic camera.
Beyond the sheer historical wonder of the report, Cornell argues that measurements of the Imperial's wing-flaps from the restored film lend credence to their original conclusions on the Luneau tape of a purported Ivory-bill:
"The bird maintains a fast wing-flap rate well into a flight. Data in this film contradict two arguments made about launch and flight behavior of large woodpeckers by Sibley et al. (2006), namely that in normal takeoff a woodpecker holds its tail against the trunk until after its wings are extended and ready for the initial down stroke and, secondly, that woodpeckers larger than the Pileated Woodpecker (Dryocopus pileatus) should flap more slowly than that species. In fact, whereas Pileated Woodpeckers have been documented to slow to flap rates of 3.9 to 6.7 s–1 through wing-flap 8 postlaunch (Collinson 2007), the film shows that the Imperial Woodpecker could maintain a flap rate of about 7.7 to 8.3 s–1 at that phase of flight, despite having a body mass 2.4× larger than that of a Pileated Woodpecker."
Still, the single most important sentence in their 'discussion' section is the first one, which will too often be overlooked:
"The information contained in this 85-s film is scant and must be interpreted with caution."
Indeed it is. We are faced again with a whopping sample size of ONE (without a lot of contextual information), and attempts to draw broad generalizations from it. This would never be done in a study of human behavior, but is (egregiously) done too often with abandon in animal and field studies. Any conclusions reached pertain to a single bird in a specific context during a 2-minute point of time in its life... perhaps they apply more broadly... but it is difficult to know. And I'm all for drawing any conclusions that can be reached ABOUT THIS INDIVIDUAL BIRD, but less confident of how directly such conclusions may apply to Ivory-bills. (Indeed, it's the same complaint I've long voiced for Tanner's observations of a half-dozen birds in a single locale being turned into conclusions that were then applied to all Ivory-bills everywhere.)The main point Cornell seems to wish to make is that it is POSSIBLE for a bird as large as the Imperial (and by implication the IBWO) to maintain a certain high flap-rate never achieved by Pileateds on available film (...ASSUMING you accept Cornell's analysis, and assuming the full range for Pileateds have already been captured and reviewed on tape accurately).And so it goes....
This film, held for an almost unseemly long time by Cornell (since 2006, through the end of the official IBWO search), has been restored, digitized, analyzed by their own people... who now, not too surprisingly, publish conclusions helpful to their cause (would they have even published the results if it were otherwise?) -- and I say that only because cynical sorts will wonder what exactly the lab folks were doing with that film for 5 years before acquiring results to their liking. The entire IBWO debate is polluted enough that skeptics may not take Cornell's conclusions or calculations at face value, unless the raw footage is independently analyzed by impartial third parties (...or else if skeptics themselves analyze it and reach the identical conclusions) -- unfortunately, neither Cornell, nor their critics, nor anyone else with a stake in the debate, are assumed to be objective, unbiased sources of analysis or review anymore, especially given a tendency to cherry-pick data to suit one's purposes. Cornell writes that they have 'allowed for possible inaccuracies in the framespeed of the film'... so, we have their word on that; might have been nice if they had brought in 1 or 2 of their serious critics to collaborate and concur on the analysis.(The internet has spurred a fair amount of such collaboration in math, physics, and even biology these days; in ornithology though, maybe not-so-much.)
Apart from the IBWO debate though, I'm certainly grateful for Cornell's eventual public release of this incredible ornithological relic and the story that goes along with it. For all birders it is a treasure!! Maybe they'll even release a final summary of the IBWO search as promised before year's end, and in time for this winter's searchers to make use of it.... -------------------------------------------------------------------------
Mark Michaels, over at IBWO Researchers' Forum pointed out the below article which briefly mentions that Cuba’s leading ornithologist, Orlando Garrido believes the "Cuban Ivory-billed Woodpecker still lives in remote regions of eastern Cuba":
Meanwhile, in the fun-and-games-with-statistics dept. no less than "The Economist" magazine makes mention of the two recent statistical studies that essentially declare the Ivory-bill extinct (although statistics can't easily or sufficiently be applied to this situation).
And, a nice result for one University of Kentucky professor, whose passion for the Ivory-bill story won him a teaching award from the National Association of Biology Teachers:
The leaves will be off the trees soon, and prime IBWO search conditions prevail again, but no idea how many searchers will spend any significant amount of time in the field this season.... --------------------------------------------------------------------
In a comment on the previous post, "Steve" essentially asks WHAT will it take for some of us to conclude that the Ivory-bill is no more? I was going to respond in the comments (and now Jacob has) but it deserves a separate (more long-winded) post, since it's such a common question:
The basic answer is pretty simple... you send capable folks out to areas that a species might conceivably remain in (or actually have been sighted) and do a reasonably thorough, organized search... AND come up empty-handed... NO credible sightings, nor signs of the bird's presence. THAT would be indicative of possible extinction. You can't prove extinction; you can only keep amassing more and more data toward its support.
If such searches were conducted for the Dodo, or Moa, or even Passenger Pigeon, most likely there would be nothing to show for it. But in the case of the Ivory-bill almost every such large scale search results in (even if skeptics don't acknowledge it) a few sightings claims from credentialed, credible individuals, and additional possible signs of the bird (foraging signs, cavities, auditory encounters) -- if there were sightings with NO such other evidence, it would be more difficult to take the sightings seriously... OR, if there were signs, but without ever any sightings, the signs could be easily written off; but the fact that both types of evidence occur on rare, yet repeated occasions, makes it more difficult to simply ad hoc (because it fits a preconceived hypothesis), label them all 'mistakes' and misidentifications. Indeed, as I've argued previously, if mistakes are this easy and prevalent in birding then doing bird counts and censuses must be a futile waste of time, they would be so heavily flawed in regards to look-alike birds (and the majority of birds have look-alikes). [Indeed, many argue that the actual raw data of bird counts is hugely erroneous (both unreliable and invalid), and the only real worth derives from looking at relative trend figures over extended periods of time.]
Nor does it matter if there are 5000 other individuals with little credibility or experience who erroneously report IBWOs; you can't automatically generalize from such known instances to all cases, but must view each case individually on its own merits (or lack thereof).
Yes, it is hugely troublesome that these unconfirmed claims have been going on for 60+ years without verification or better photographic evidence. And frustrating too that claims still come from widely disparate areas -- almost certainly there can't be that many separate populations of IBWO left. I understand why the likes of Paul Sykes, Jerry Jackson, and others have largely given up hope that such claims make much sense any longer, no matter how credible or certain any given observer. When every followup seems to fail to definitively confirm the birds once-and-for-all, it is easy to conclude that a telling pattern is evident.
I continually have to ask though, if a bird is truly incredibly rare, possibly even hanging on by a thread, residing in remote, difficult habitat (not well-frequented by birders), living principally high up in tree canopies and within cavities, possibly wary of humans, and capable of rapid long-distance flight... then what would the evidence, if any, for its existence look like -- and maybe, perhaps, just possibly, it might look very similar to that which we have before us. The best explanatory fit and best odds for the entire panoply of evidence at hand may still be that a few Ivory-bills swoop and kent and double-knock somewhere in a dense quarter of the American Southeast. ...Or, not. The limits of my own patience do creep closer with each passing year.
And here's the story of another bird species (the Jerdon’s Courser) that relates somewhat to this whole discussion:
My favorite quote from it comes from Chuck Hunter with USFWS:
“If no further observations are made, it could be another 30 years before the species is declared extinct... But within the U.S. Fish and Wildlife community, we are not ready to declare it extinct. I have not seen compelling evidence to suggest it’s extinct.”
That reflects my own outlook (though I think the "30 years" figure an exaggeration)... I'm not just looking for solid documentation that the species exists; I'm looking alternatively for compelling evidence that it does not, and given the number and type of reports across decades, that evidence (for extinction) also remains largely conjectural and less-than-overwhelming.
On a complete side-note, those who recall Dr. Martin Collinson's past role in the IBWO debate, may be interested to know he has authored an article in the current edition of "Birding" concerning the identification of the (likely extinct) Eskimo Curlew:
Apparently yesterday Sept. 1 was the 97th anniversary of the death (in captivity) of "Martha" the last known Passenger Pigeon; probably something worth noting on this blog.
2. The current edition of Bird Watcher's Digest includes an article starting out thusly:
"Paddling along in an Arkansas swamp, you raise your binoculars to catch a glimpse of a huge black and white woodpecker. Your camera, of course, is in its waterproof bag by your side, and by the time you get it out, aim, and focus, the bird is gone. If only your binoculars had a button that could capture what you see. Birders would love such a hybrid device: small, portable, roof-prism binoculars with a built-in digital camera."
Such binoculars have actually been around for sometime now, but the quality was lacking. This particular article more-or-less favorably reviews the new Bushnell SyncFocus 8x30mm binocs (at $200-$300, the quality of the digital photography still might only be good enough for a clear view of a perched IBWO and inadequate for a flying specimen). On-the-other-hand, if you have $1400 or $2000 to expend in this economy you may wish to wait for the recently-touted Sony DEV-3 or Sony DEV-5 video-recording binoculars (due out in November):
3. Finally, on a sidenote, for any of you who own Noel Snyder's 150-pg. 2004 volume, "The Carolina Parakeet," don't give it up cheaply... I just ran across a copy in a used bookstore priced at $50. I've reported here before that some 20 years ago I ran across what I thought was an over-priced copy of James Tanner's original "The Ivory-billed Woodpecker" similarly priced around $50, and today they run for about $500. So who knows.... -----------------------------------------------------------------------
Some time back I mentioned that a bird rehabilitator friend had lost a juvenile Pileated Woodpecker to a black snake that gained access to a pen. And I wondered aloud to what degree snakes may have have been a significant culprit of the historically low reproduction rates reported for Ivory-bills. Interestingly (to me), Brandon Noel concludes in his recent PhD. dissertation that black snakes are indeed the single greatest predator of Pileated Woodpecker nestlings (in the Southeast anyway), and presumes the likelihood that they preyed upon Ivory-bill nests as well, possibly as a significant limiting factor on IBWO populations.
From another site, a story and some photos here of a Pileated protecting its young from an intruding black snake:
And, not a Pileated (instead, a tropical Crimson-crested Woodpecker), but if you missed this video of a Woodpecker protecting its nest from a couple years back, well, it's a MUST-see: