"....The truth is out there."
-- Dr. Jerome Jackson, 2002 (... & Agent Fox Mulder)
“There are more things in heaven and earth, Horatio, than are dreamt of in your philosophy.”
"All truth passes through 3 stages: First it is ridiculed. Second, it is violently opposed. Third, it is accepted as self-evident."
-- Arthur Schopenhauer
Friday, April 17, 2009
-- Four Years Later --
"Oh life is like a maze of doors and they all open from the side you're on
Just keep pushin' hard boy, try as you may
You're gonna wind up where you started from
You're gonna wind up where you started from."
--- Cat Stevens ("Sitting," 1972)
This month marks the fourth anniversary since Cornell Laboratory of Ornithology stunned the birding community announcing that the Ivory-billed Woodpecker had been rediscovered in Arkansas. Yet many remain in doubt as to whether it was real or all an illusion from the get-go.
In the bizarro world of the Ivory-billed Woodpecker not only is a lack of sightings perceived as evidence of IBWO extinction... but even continuous sightings, and appropriate sounds, signs, and cavities, WHEN unaccompanied by indisputable photography, is now viewed as further evidence of extinction.
The only possible definite outcome from these last four years would've been clear confirmation of the species' existence. Lacking that we remain in limbo. There can never be proof that Ivory-bills went extinct in the 1940's as many weakly contend, or in the 60's, 70's, or 90's as some others may believe... or perhaps the "Elvis" bird seen in Arkansas was the very last of his kind. Or... as many STIIIIIIILL believe (and is certainly indicated)... a small scattering of the species may yet haunt corners of the American Southeast... caught thus far only in occasional quick glances, by a lucky few individuals in the uncanny right place at the uncanny right moment, for a species that evades the certainty of the focused camera lens.
The bird continues to be reported, and no actual evidence, beyond sheer conjecture, substantiates a notion that all of those sightings are unreal. Unfortunately, in IBWO circles, the line between conjecture and science barely exists anymore... if it ever did.
Re your "Dude", "Get real" and "That's life" post above.
I will believe in the self-correcting nature of science when a retraction of the IBWO "rediscovery" is published by the author or the editor. There is no "self-correcting nature of science". The peer-review filter has such big holes in it that one could never correct all of the falsehoods that have been published to get tenure, funding, status, etc. The IBWO joke is just the most obvious of them.
- Abderhalden's "defensive enzymes" (biochemistry, immunology)
- Elias Alsabti scandal (cancer immunology)
- David Baltimore and the Thereza
- Imanishi-Kari affair (immunology)
- Jacques Benveniste affair (immunology)
- Bruno Bettelheim (psychology)
- The Bogdanov Affair (physics)
- Cyril Burt affair (psychology)
- Ranjit Chandra controversy (nutrition)
- John Darsee scandal (medicine)
- Charles Dawson's Piltdown man (anthropology)
- Richard Eastell - Actonel Affair (Medicine)
- Shinichi Fujimura (archaeology)
- Robert Gallo (virology)
- Ernst Haeckel allegedly fabricating some of his embryo drawings (comparative anatomy, recapitulation theory)
- Bruce Hall (immunology)
- John William Heslop-Harrison (Botany)
- Woo-Suk Hwang (Hwang Woo-Suk) (cloning)
- Trofim Lysenko's Marxist 'Creative Darwinism' (Agriculture)
- Dănuţ Marcu (mathematics)
- William McBride (medicine)
- Sir Roy Meadow (medicine)
- Raghunath Anant Mashelkar
- Richard Meinertzhagen (ornithology)
- Robert Millikan's data selection in his famous oil-drop experiment (physics)
- Victor Ninov's superheavy element (physics)
- Leo A. Paquette (chemistry)
- Luk Van Parijs (immunology)
- Raj Persaud (medicine)
- Eric Poehlman (medicine)
- Stanley Pons and Martin
- Fleischmann's cold fusion (physics)
- Reiner Protsch (anthropology)
- George Ricaurte (medicine), see also retracted article on neurotoxicity of ecstasy
- Steven Rosenfeld (immunology) transfer factor
- Karen M. Ruggiero (social psychology)
- Gerald Schatten (biotechnology)
- Jan Hendrik Schön scandal (physics)
- S.G. Soal (parapsychology)
- Jon Sudbø, Andrew Jess Dannenberg (cancer research)
- William Summerlin - "painting the mice" fraud (immunology)
- Rusi Taleyarkhan sonofusion or bubble fusion (physics)
- Kazunari Taira (molecular biology)
- Andrew Wakefield (MMR vaccine controversy)
- John B. Watson's Little Albert (child psychology)
- Al Gore (the global warming lie; just Google the dude from Duluth's global warming blog)
Frankly, until we get the published retractions from the perpetrators of the dispicable IBWO farce, all conservation efforts globally will come to no avail, our global economies will continue to spiral downward, global temperatures will continue to rise, and we will increasingly look to Bill Gates, Brad Pitt and Angelina Jolie to solve the world's problems. You believers, including you, loony ol' Cyberthrush, just don't get.
At least most of those were a little bit convincing. The IBWO saga has been a sorry, sorry tale of incompetence and wishful thinking, pseudoscience, poor birding and just plain stupidity and bullshit that is still going on.
Retractions aren't needed. We can see it for what is was clearly.
the above appears to be the rantings from one or perhaps two anonymouses. Sort of reminscent of the feller from Minnesota and his brother from Alaska, minus the imaginary bigfoot head exploding Amy
Harsh and bitter words equates a weak and indefensible cause.
Also, as someone who feels that humans need to be rational while maintaining their faith in certain abstractions, I find this site has a nice mix of postings from both realists and dreamers.
IBWO's are not impossible to detect with adequate time and solid methods in secluded areas with good habitat. Reword for skeptics-----you must get out in the field for a week straight...with no bunks, futbol or pub breaks.
If you haven't been in the field you have no pertinent data, therefore your words are worthless to serious searchers.
Granted you will fool some internet tire kickers and those that consider themselves great birders since they were one of 250 that chased and got that mainland owl, a life tick, as it moved stealthily from widely spaced tree to tree. After all you and your flashlight survived the human bottleneck at the infamous stone gate, it with a width to accommodate only one fat-arse!
The analogies about past human foibles are more a reflection on skeptics' obvious wish to not discuss the constant flow of evidence that the spp. remains in small numbers.
Again skeptics do you have any evidence or even a lazy explanation on what double knocks kents and appears to be IBWOs to many observers and sometimes videos?
Do you have any explanation,(we promise to only chuckle at the foolish rationalizations and not heavily berate) of why no PIWO has ever been filmed with the flight characteristics depicted in the Luneau video, parts which have been confirmed by expert analysis of the Pearl video?
No real need to answer..although we would love to hear about the latest injuries suffered during the most recent rare chase?
While I didn't enjoy that long list of past fraud it does show how common scientists fooling other scientists (and the public)has been - and I think the point was to show believers that they should not feel bad about being fooled since it has happened before.
And just so I can better understand why you (FV) are not a skeptic, could you tell me what constitutes the "constant flow of evidence" that has you believing the species remains in small numbers? Is it mainly (as your comment implies) because there is something that can't be a PIWO in the Luneau video? If so do you really think you are in any position to chuckle at "foolish rationalizations"?
How many pairs were found after the Luneau video?
How are those nine pairs of Geoff Hill's getting on. He must have more by now?
Mike Collins too must have lots of killer pics by now. He was always going on about them.
That guy with the clear photo of the bird in the orange tree - when did he publish that book he was always going on about?
How many more pairs has Cornell's mobile search team found - they were always hard at it every time I checked their blog. Plenty of possible encounters that must have been pinned down now.
And Steve Sheridan, I heard he's seen the bird again too.
It would be good to know the bird is now safely protected and being studied in close detail in numerous locations.
I bet all those skeptics are eating humble pie now. I bet they were fully expecting all those 'encounters' to have petered out into nothing. More fool them eh?
Also do not expect any answers if you can't seriously answer others. I will answer all questions if there is reciprocity and a sense of fair play. Its understand this leaves out cowards, drunks and those that just want to steer the masses towards their points; not a bad tradeoff to lose these types.
Why is there no Pileateds with the wing beat Hz of that videoed by Luneau and in the Pearl?
What possible species are depicted in the last Pearl video?
How is Tobalske and others wrong when he says that is a large woodpecker in that latter video with a wing bound ratio not found in Pileated?
How is it that 9 people in '67 to '69 saw/heard the same bird/pair in FL and a feather was produced that independently tested out as IBWO that it is so impossible to have IBWOs today?
Have you any actual data from the SE US and what is it?
1. a wingbeat in two videos that are not PIWO wingbeats
2. collections of pixels in the Pearl video that are hard to take to species.
3. The belief by some that the wing bound ratio in one of the videos is not a Pileated.
4. Nine people in the late 60s who saw/heard something in FL and a feather that proved that IBWO feathers still do exist (I have actually held IBWO feathers and didn't realize their existence was in question).
So I guess if this is the "constant flow of evidence" then I am starting to see the problem. The reason we can't agree on what "extant" really means is that we also differ on what "evidence" and "constant flow" mean.
And your final question is actually the same one I was asking you, FV. Do you have any actual data from the SE US and what is it?
I take, then, that you're not the "previously devout sceptic" who saw an IBWO in South Carolina!
By the way, is anyone willing to disclose who this former sceptic is?
We've seen too many times in this fiasco how drawing conclusions with too little evidence is extremely undependable.
"It has to be Ivory-bill beak gouges because..." Wrong. It doesn't.
"It has to be IBWO scaling because..." Wrong. It doesn't.
"It has to be IBWO double-knocks..." Wrong. It doesn't.
"It has to be either an IBWO or a PIWO with white saddles." Wrong. It doesn't.
There are boring, simple, alternate explanations for all of this thrilling evidence. Like hoaxes, misinterpretations, non-avian sources, non-woodpecker sources, a PIWO flying a tiny bit faster than normal. On an on.
You've convinced yourself. That's the easy part. Unfortunately the believers must come up with something a whole lot better to convince the people that matter, the people that control money and policy.
Have you any actual data from the SE US and what is it?Here's some It's amazing how much data there is about living creatures.
>>>Okay so now I see that the "constant flow of evidence" that IBWO are extant consists of<<<
JF I have not answered the question on what the "constant flow of evidence" is. No help is needed or probably possible from you on that subject judged by your inability to sincerely converse.
Additionally what nominal skeptic would not know that the Science, Auburn and Pearl papers along with the Choctawhatchee videos constitute evidence? Answer: a provocateur who is a disgrace to the important function of skepticism in science. The Choctaw one shows the researcher saying "Ivory-billed" as a very large and very white pecker flies through.
A total list of evidence would be quite long and if given verbally in private by a small group of researchers to trustworthy individuals would consist of unpublished encounters/field notes of sightings, and suggestive pictures, etc.
Sadly but justly you will not be privy to these worthy discussions. True, skeptics are invited however.
Also a request to the skeptics.....can someone organize your side? I mean its really not fair...for every video, we have a group of skeptics that say its definitely a Pileated, another group---its an aberrant Pileated, another its a Kingfisher, another its too blurry, another its fake, etc.
The most detailed analysis by the most competent video and/or avian flight experts indicate the videos are consistent with IBWOs. Can't your side get together and come out with a unified theory on each of these videos. You look a bit willy------ with all these competing species and theories on each singular video.
The individuals that look far more than "willy" are the people who are keeping this IBWO enviromyth alive at a time when there are real issues government and the public need to address.
Your need to think that there are "sides" in the IBWO rediscovery demonstrates you view this as a sporting event. If that is all it was I would have no issues with it. "Teams" of birders could go into suitable habitat hoping to "score" with real proof that the IBWO exists and defeat the skeptics.
Unfortunately, Cornell, TNC, USFWS, and assorted academics have tried to make this look like "science" - which it clearly is not. By 2050 far more species than the IBWO will be extinct and to not address the real issues facing our ecosystems - and take money and attention from those issues - is my beef with the "rediscovery" and its aftermath.
BTW, the continuing degradation of the earth's natural habitats will not decrease one iota by someone finding an IBWO.
But your posts don't indicate you are interested in much more than the "sport birding" aspects of this story so I urge you to go back out in the woods and do something to make your team proud.
but what kents, double knocks and has too much white on it...all within one minute?
"the people that control money and policy must be convinced."
What is it with you skeptics? One faction says too much money is being spent and this anon says we haven't convinced anyone that has the check book. Which is it?
For you severely out of the loop, influential people at various entities have seen the Ivory-billed and have not broadly disclosed their knowledge. They did relate enough to assist the past money flow.
The species is not easily studied because of wariness, several million acres of suitable habitat not nearly occupied, rarity and a large home range. Several sighting have occurred independent of one another in a tight temporal and spatial span.
This would meet the proof bar for some skeptics (assuming it was all properly collated) but there is no great push to publicly reveal locations unless there is a reason to do so. There are things that can and are being done that do not revolve around the needs of vocal believers or skeptics.
The predation issue is most pressing since it goes to the important question: if there were 30 birds in 1950 +/- 30 years why is the population still so low.
Recently several rattlers were radio tagged; 80% of the transmitters were found in Barred Owl pellets.
In the past I have written that GHOW will restrict IBWOs to larger contiguous, forested wetlands. There BAOW will fill the nocturnal predator niche and it was conjectured that IBWOs are not preyed upon by BAOW.
If the BAOW densities are now higher than they were over the past hundred thousand years and they sometimes predate on IBWOs then this may be causal to the slow population recovery.
BAOW may now have a higher absolute pop density in modern forests due to the elimination of many other predators (wolves, bobcat, cougars, bears, etc.) which probably did not prey on IBWOs. Roost hole availability and competition are co-variables along with larval Coleopteran density.
Rat Snakes and the predator community are also worthy of study. A less diverse mammalian predator community may favor an increase in arboreal Rat Snakes.
Or is that a trick question?
1) Wingbeat - see Collinson's paper showing PIWO can have same as IBWO in 'escape flight'and Bevier here: http://web.mac.com/lrbevier/ivorybilled/Wingbeat.html
2) The last Pearl video is unidientifiable, that's why you're still asking the question.
3) Tobalske is wrong due to 2 above and the fact that bird identification is not made through analysis of wing-bound ratios in crappy videos.
4) Nine people can easily claim to see something that's not there - witness recent events. The feather could be from anywhere of course. Or at a long shot there was even an IBWO extant then - which I seriously doubt.
here's a 5) for free. Take a look at that list and ask yourself why that is the best you can come up with in 60 years.
To the noble "drunk and coward" (from another), thank you for posing debatable points (i.e., points where there can be honest, lively, and contstrucive discussions about) for which I offer the following:
1) Wingbeat- Collinson's paper and Bevier's website are acknowledged as providing additional data to the question, but neither show PIWO can have the same escape flight wingbeat rate for extended flight as what ever it is that is caught in the Luneau video (or for that matter the Hill or Collins's videos). Each (Collinson and Bevier) in their own way admit that they were selective in measuring increments of wing beat cycles to show how high the rate could be. And to my knowledge no one disputes that given a single wingbeat it is possible that both Pileated and Ivory-bill (or for that matter any combination of species) could have similar results, but that is not the point to the wingbeat rate comparison. Picking and chosing fragments of data to support your case and then extrapolating it to compare with an average rate over the same time period with the Luneau video, both Collinson and Bevier end up comparing apples with oranges. In each case (both Collinson's analyses of the Nolan videos and Bevier's own analyses) the Pileateds "pulled up" and slowed way down, while the Luneau video bird kept on trucking. To my knowledge Bevier has never released his videos for independent analyses, but in essence admitted on BirdForum that his videos were not comparable to the Luneau video. Collinson and Bevier, at best opened the door that Pileateds could perhaps have as fast a wingbeat as the Luneau bird, but to date there is no support to suggest that is actually the case after the first 1-3 wingbeat cycles.
Anyone really interested can see Bill Pulliam's graph of this comparison on his blog site between Luneau and Nolan (plus three other) videos. Bevier's videos if ever made public could add an important test to see if they too show up to be typical for Pileated and not matching the Luneau bird for the full 10 or so wingbeat cycles. I suspect that his birds were indeed "stressed" and escaping when compared to the Nolin and other videos. However as I understand the discussion on BirdForum with some chap named "Dave from Michigan," Bevier in essence did admit his wingbeat rate (not just one or two wingbeats) was not distinguishable from other Pileateds.
So while it is not yet conceivably impossible that a Pileated could fly with rapid wingbeats over 10 or more wingbeats, and comparable to the Luneau bird, it is instructive that there is not yet known video of a flying Pileated to back that up.
In addition as Pulliam points out, the discussion over wingbeat rate is perhaps a distraction as it is more interesting to see what may be the cause of a difference between wingbeats of all Pileated's (so far) and the Luneau bird. It is the position of the wings in the downstroke that really intrigues many of us as there is absolutely no doubt with the existing videos of Pileateds that they don't remotely fly the same way as the Luneau bird (and the "bowed" wings and wingbeat rate are likely related phenomena).
This would seem to be an easily falsifiable hypothesis, that is Pileated Woodpeckers can fly like ducks just as ivory-bills were repeatedly described as doing and that the Luneau video bird seems to be doing. One video of a Pileated flying "like a duck" would be all that it would take to reject this characteristic as perhaps consistent with ivory-bill, and to date none exist.
2) I agree the Collin's last Pearl video bird is unidentifiable (actually his other two are as well) using tried and true "birder's" approaches. That is, like seeing definitive characteristics of any kind, but if indeed the last video is of a woodpecker then it is interesting.
3) Who knows what Tobalske actually said to Collins. That aside, the mathematics speak for themselves in showing a woodpecker with wingloading like we think the ivory-bill has/had, and along with other flight dynamics, that the flight of the last Collin's video bird is not consistent with any known Pileated (see point 1 above) and could be consistent with a putative ivory-bill.
But I personally still have a hard time not thinking that bird in Collin's last video could be a duck or a cormorant (birder's persepctive) and I was not present when all the measurements were taken that led to Collins ended up proposing. I like many birders have a hard time "identifying" birds through mathematics and physics from very poor videos, but that is what distinguishes science from birdwatching here in my opinion. Science is looking at data (like wingbeat rates, wing positions, taking measurements to extrapolate size, etc.), forming competing hypotheses and debating them (and often endlessly as in this case). Birdwatching is seeing definitive characterstics that could lead to a "definitive" identification. The frustration of many birders is due to there not being visible any definitive characteristics in Collins' videos, while thoughtful and respected scientists (and few armchair types such as myself) debate the merits of the data in support of one or another hypothesis.
Regardless, it's a shame that Collins' ego got in the way of publishing the theory of what Ivory-bill flight dynamics could be/have been by demanding that his videos be published along side the theory. There is no shortage of ego, however, on all sides in this affair.
4) What recent events does Anon. 5:24 refer, to demonstrate group think in such a case as this (unless it is the endless circular argument involving this case that he is referring to)?
The discussion over the origin and age of the feather from the 1960s central Florida is interesting and from what I understand the feather cannot be considered conclusive as supporting the visual claims made at the time (the feather may be much older than a few years when it was found, others can speculate as to why). To my knowledge no one who knows/knew Agey and Heinzman doubt their integrity (i.e., they were both considered highly credible observers), but that doesn't mean they conclusively saw an ivory-bill.
5) yep that's what it boils down to. Why is this the best that exists after 60-70 years, and especially from the last 5 years of intensive searching? The evidence that exists is very suggestive to some, and not to others, but why this species if it exists is not easily and repeatedly found and verified by others is an unanswered and troubling question.
Now for the long list of excuses...
In his 2 comparative rows of horizontal pictures one can see the time marks of the Luneau video and the PIWO. Notice how the Luneau bird is covering distance at a much more rapid speed than the PIWO. Collinson shows that the two birds have quite different flight speeds.
Collinson and the poor reviewers (its a medical journal, its suspected a prior association with Collinson existed and the fictional article slid by for suspect or incompetent reasons) say not a word about the glaring speed discrepancy.
They either avoided, did not bother to check or knew little about flight dynamics. Bird spp. fly at certain speeds during different types of flight. Its telling that Collinson, despite having a choice of the hundreds if not thousands of PIWO videos, that exist couldn't find a slightly climbing PIWO that matches what we see in wing beat Hz and speed of the Luneau video. The bird in the fourth sec of the Luneau film is almost level.
I have shown Collinson's paper to people well versed in flight dynamics, flight speeds, aspect ratio derivatives, etc., before and after the Pearl video was obtained. Their opinion of the Collinson's paper was uniformly negative in respect to the Luneau video showing the flight characteristics of a PIWO.
That you favor or quote a medical doctors paper who clearly knows little about flight dynamics (or chose to ignore it) is telling in regards to your own acumen on the subject. Perhaps you are Collinson.
Its seems your skepticism is very selective if you can't find glaring errors and obvious cherry picking of frames in both the Science rebuttal and the Collinson paper. In addition neither of these papers were produced by anyone with any note worthy knowledge of video analysis or video artifacts.
For such an important question involving extinction the average skeptic would be very careful with the work of those that are practicing on the job training.
Its clear which papers involved the more skilled in artifact analysis and flight dynamics (Barksdale and Tobalske).
As a skeptic do you rate the comparative experience that the authors and contributors have in complex subjects or is it just one of the many things your skepticism seems to disappear with?
By the way, where are all these PIWO tapes, any PIWO, even one, showing what is seen in AR and LA on the pertinent subjects?
Also what is the rather rare and/or spottily distributed animal that kents and DKs (outside the range of nuthatches) in only the immediate areas where the large leucistic PIWO or mystery bird seems to be.........some with black heads/crests?
By the way a certain high percentage of IBWO kents do not sound anything like a jay or hatch to an experienced listener.
I am very skeptical that you are a highly skilled skeptic.
"...Why is this the best that exists after 60-70 years, and especially from the last 5 years of intensive searching? The evidence that exists is very suggestive to some, and not to others, but why this species if it exists is not easily and repeatedly found and verified by others is an unanswered and troubling question."
Thanks for your thoughtful comments; as to your final question (above) just a couple of things, at the risk of being a broken record:
1. If the population is VERY sparse and spread out over several expansive areas the difficulty of repeatedly finding the birds is NOT that hard to understand, in fact it ought be expected. AGAIN, short of finding nestholes (as they did in the 20's and 30's) the chance of a good photo and repeatability is slim.
As I've said before, the bigger question becomes, can they be that sparse and yet be finding mates and breeding successfully --- I believe that is indeed possible, but the other sad possibility admittedly, is that we are now dealing with a dispersed, non-breeding population of Ivory-bills, that are just living out 20+ year life cycles before their final demise.
"If the BAOW densities are now higher than they were over the past hundred thousand years..."
FV, what is the source of your information? Can you provide references for the rattlesnake predation (that's a pretty high level of predation) and Barred Owl densities over the past 100,000 years (how to get such data?)?
Pardon my curiosity, but where do you get these facts?
So I agree with your pessimistic assessment, but think the whole process happened about 80, or perhaps 100, years previously! The data are consistent with this scenario.
This is Earth Week, folks. I suggest you study up on some real conservation issues (you will find that unlike IBWO, most are not on the other side of the tree). Have any of you “true believers” read about West Coast salmon runs?
You could also determine ways that you and your family and friends can decrease their carbon footprint. BTW, having all birders provide information on the metric tons of carbon expended to obtain the exciting observations they are sharing on the web would be a good start in showing that your birding activities are not simply an indulgence of the leisure class. If a person or organization burns more fossil fuel in a field season than many third world villages do in a year do you really want to praise the person or organization for their “efforts”.
The really important decade will be the one when atmospheric CO2 reaches 450 ppm and ocean acidification starts causing real problems. You should really care about that.
When you list sightings of lone birds and compare the numbers (pair sightings versus lone birds) it looks like a normal age demographic may exist. HAWO have ~ 30% of birds immature.
Other evidence is eyewitness reports of morphological abnormalities which often manifest if inbreeding has occurred. We see only one reliable report of a problem, a color abnormality, yellowish flight feathers by Sparling.
The species also had a strong outbreeding mechanism as shown by Tanner and is a strong flyer.
All mathamatical models of viablity show that inbreeding is not necessarily here yet.
In addition bairdii was shown to be able to breed in overcut areas. The bird is not an obligate gregarious breeder. Coin is practicing a bit of Tanner dogma here; still not learning from obvious pre-conceptions/mistakes.
Coin also seems to be ignoring or ignorant of probable population of several pairs that existed in MS into the '40s.
In addition there only has to be panmixing once every 5-15 years for each offspring to suppress inbreeding. There are some skeptics whose tongue alone could move them interstate in ten years.
I would think it possible diet rather than staining as an alternate choice..lighting artifacts..or maybe a interpative mistake by Sparling.
Why are you so sure its staining?
I also have two other reports of coloration aberration but I dismiss these individuals sightings as at a least partial fabrications.
Wish someone had told Tanner that.
To Anony 3:12,
Actually Tanner visited many places in the 1930s never seeing nor hearing an ivory-bill, but based on his perceptions of habitat (Singer Tractish) deemed reports in the 1930s and into the 1940s were likely valid along the Santee River, Apalachicola River, Suwannee, while others he dismissed because he did not think the habitat was old-growthy enough (for example, Okefenokee and East Texas).
Yet in south Florida, where he also did not see nor hear any and where he admittedly was unfamiliar with the habitats involved (including it turns out mangroves), he deemed them suitable anyway (Highlands Hammock, Everglades)and accepted the 1930s reports and speculated that birds persisted at the time of his 1942 publication.
Today we know that by 1930 many of these South Florida areas were not virgin nor otherwise unharvested areas (the baldcypress anyway). Nor was the Singer Tract "virgin" unharvested old-growth forest (at least not the sweetgum-Nuttall oak most heavily used by ivory-bills) by the 1930s as Tanner and others promoted at the time.
There was seemingly, based on today's standards, no reason really for Tanner to have accepted any of the reports that he did, nor dismiss the many post 1920 reports that he did (particularly Okefenokee or east Texas reports). Certainly based on habitat alone, he shouldn't have accepted the 1930's reports from south Florida. Regardless, he used his best subjective judgement, and at the time no one was better than Tanner in attempting these tough calls when there was no hard evidence anywhere outside the Singer Tract.
And while there is/was no good reason to otherwise doubt John Dennis and others reporting ivory-bills from the Big Thicket in the 1960s and 1970s, or the likes of Henry Stevenson and Herbert Stoddard of their reports of birds during the 1950s along the Chipola/Apalachicola and elsewhere, Tanner did so based on his perceptions of habitat.
I believe it was Collins who pointed out Tanner's rejection of Dennis' recording of a putatative ivory-bill because he could not imagine an ivory-bill in an area where a pine warbler was also singing. He must have forgotten Allen's 1924 picture (the bump on the side of a pine tree) which is perfect Pine Warbler habitat and more interesting he must have forgotten that the ivory-bills collected in east Texas in the early 1900's were from a stand of dying loblolly pines. That doesn't make the reports from Dennis and others from the Big Thicket then and since any more valid, but the reasons for the objections that Tanner gave contradict his own experiences and that of his mentor Arthur Allen.
And while folks can speculate why Tanner was selective in his acceptence of pre-1950 reports and what his motives were for being dismissive of all post 1950 reports, his rationale for dismissing post 1950 reports present many contradictions. That all said, the fact that no one has been able to otherwise confirm to everyone's satisfaction the presence of birds (no matter how good the reputations involved) vindicates Tanner, for now at least and perhaps forever. And until something more definitive emerges, so it shall be.
He was considerably more cavalier about Congaree.
There has been no evidence of inbreeding in regards to outer morphological abnormalities when one summates the reports of field marks observed and reported by reliable witnesses.
A minority of these sightings were robust. Some sighting were robust and lasted several minutes. Many sightings were from a short distance but were of short duration. A large percentage were of flying birds.
There seems to be no direct evidence of inbreeding. Conjecturing, the low present population number could be caused by infertility, higher embryo, hatchling, fledgling or adult mortality, etc., all known manifestations of inbreeding in bird populations.
>>>FV, what is the source of your information? Can you provide references for the rattlesnake predation (that's a pretty high level of predation) and Barred Owl densities over the past 100,000 years (how to get such data?)?
Pardon my curiosity, but where do you get these facts?<<<
The snake predation is high and I too was surprised and a bit disappointed. It is a personal communication to me on an ongoing study that I have connections with. If you have a conservation
related need to know give a way to contact you.
Your Q on Barred Owl populations, you asked where do I get these facts on historical populations.
Perhaps you rushed reading my post. I clearly said "If" BAOW densities are higher now than in the past it could be impacting IBWO numbers.
How do you have this as saying I presented this as fact? Here it is below for a second time. Perhaps it just a misunderstanding.
What is your take on relativity of specific predators populations that make up the complete community if the largest predators are removed as they are in the SE?
Shouldn't the biomass of predators stay ~ the same in an ecosystem, other habitat characteristics being ~ equal, and the remaining predator species see a probable increase in their absolute numbers?
Removing of the large predators has had a tremendous impact on our forested open spaces, deer pop. up, controlled poorly by hunting, other prey species also go up and some of these are fed upon by Barred Owl. Snakes too could go up but they are heavily collected in most areas.
Barred Owls are not collected...and as a synergistic result of removal of large predators snakes/herps go up, BAOW feed on herps. There are several possible modern habitat changes that seem to favor Barred Owls pops.
BAOW are even moving into residential areas in the SE which may be evidence of an increasing population in some areas. In the NW BAOW are displacing Spotted Owls.
>>>>If the BAOW densities are now higher than they were over the past hundred thousand years and they sometimes predate on IBWOs then this may be causal to the slow population recovery.
BAOW may now have a higher absolute pop density in modern forests due to the elimination of many other predators (wolves, bobcat, cougars, bears, etc.) which probably did not prey on IBWOs. Roost hole availability and competition are co-variables along with larval Coleopteran density.<<<<
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