--------------------------------------------------------------------------
"Concolor" sends along this link to a 2006 article (pdf) from Czech professor Jan Swart that attempts to summarize the IBWO situation and also hypothesize about the IBWO's mobility (as an explanation for the scarcity of findings):
http://www.kirtlandbirdclub.org/pdf/ibwobyjanmswart.pdf
ADDENDUM: Dr. Swart has sent along a link to further (updated) comments from him clarifying his current view of the IBWO situation (including pessimism over the species' likely persistence):
http://staff.utia.cas.cz/swart/IBWO.html
(thanks Jan for taking the time to update us)
--------------------------------------------------------------------------
11 comments:
Wow, both items are great! Thanks. I really respect Dr. Swart's analysis, though I don't particularly like his conclusion. The question is still open for me, and I appreciate that the discussion and some searching go on.
He seems to have forgotten his own words. Swart’s original article had an organized perspective on how the IBWO has been able to avoid repeat detections based on ecological constructs. Now: "It is striking how the searches in Arkansas and the Florida Panhandle, as well as much older searches in the Big Thicket and Florida, all seem to follow a similar pattern: initially, a flurry of fleeting observations, wild speculations about the population size, followed by a period in which observations become ever more scarse."
Isn't that what he expected per his original work? Odd. There is no firm reason or actual, new field data, for many to flip flop as they have. Did the evidence change? Didn't they think the IBWO had a low detection rate when they believed in 2005? Or have they forgotten no photo/video of the IBWO existed from Cuba or the US since '48. Are they fickle? The next pix is due in 2060. Was a PIWO filmed with an 8.5 Hz? Did no one get in the field since FL 2006 and see and hear the bird? (Many experienced people have post 'o6 sightings). The flopping will be easier the next time.
The original work had some good points although he seemed to think all individual birds are obligate nomads rather than facultative, the later probably being the case. Not sure what a Carolina Duck was or is and assumed he meant the Parakeet.
On the impatient road to Damascus, where many a desk bound wind up, key points must be addressed and not swept away with declarations of EXTINCT. Detection functions, extreme wariness, the fact that he and others have not seen all the evidence and an analysis of what we do know about PIWO's wing beat frequency and bound flight ratios must be discussed. The proof accepted by official BRC committee, USFWS, The Recovery Committee, et al. and never overturned, stands.
The rebuttal "papers" were terribly flawed and the authors have not accepted that Hz of an IBWO is heavily influenced by wing surface area as has been known since Kitty Hawk or, for the Euro-centric, Santos-Dumont times. Researchers in Baxter State Forest, ME, the Ivory Tower or the Black Forest will not determine the fate of this species. This impatient, casual attitude with some occasional spinning is troublesome for conservation. We all agree that data will turn the tide yet no clear or blurry video of a PIWO exists that shows the characteristics seen in the AR, FL or LA clips. Coincidentally these strange PIWOs/Ibises/Escapes were videoed right where experienced observers had robust, putative sightings of IBWOs.
Its prudent to question musings that casually make sweeping declarations on the important issue of extinction of any species. Many of them formally update us yet never preface their remarks with: Disclaimer--- I have not spent a minute in the field testing my strong opinions. Swart's declares his lack of field data and field experience but doesn't see the obvious results--- an opinion based on a casual and incomplete review of hearsay does not equal extinction. The IBWO can't be partially extinct like some want to have it.
This oft heard cry, for someone other than the cryer, to study PIWO this or PIWO that, is unneccesary since pragmatically its been done by serious researchers. The thousands of data points/videos and field observations of PIWOs are there, its not stored in the Uffizi vaults; anyone can slow mo them. If you are going to claim a triple hedged opinion that any species is extinct please review the existing data. THERE ARE NO VIDEOS of the common species that match the 4 or 5 modern videos of IBWOs in any required data sets.
This may not prove the bird extant but it begs caution when such a terminal status as extinction is about to flow off one's lips as if they are ordering New England Clam Chowder. Some of us prefer Manhattan anyway.
tks
The good news is that the club of people who’ve personally seen an ivory-bill is larger this year than it was last. (Unlike Swart, I don’t see this adding to the evidence that the bird is extinct). There will be people searching this winter, some extensively, with more experience than last year and trying out some new ideas.
On a question Swart asks: “What happens if you hang automatic listening devices in forests that can be assumed to have no IBWO's? Do you hear some double knocks if you listen long enough?”
Probably. I’ve heard very good-sounding “double-knocks” from a downy woodpecker, duck hunters, target shooting, and industrial activity. The automated recorders will only cue you to something that should be investigated in person. Even if no phony double-knocks were detected in such an experiment, it probably wouldn’t change many minds about what has been recorded as putative DKs in ivory-bill habitat. It would be a costly experiment with little potential value.
Back to the believers vs. skeptics, I liked this paragraph from a Defenders of Wildlife document that MMinNY posted the link for in the Ivory-Bill Forum last week:
Although none of the individual bits of evidence are (to me) authoritative or conclusive, in the aggregate the cumulative weight of evidence is (for me) nearly impossible to refute as either chance or mass delusional thinking. Thus, I would characterize my sense for the species’ continued existence conservatively at around 90%, but it is likely higher.
I suppose I like it because I agree with it. I imagine for most people it’s a shade of gray (and it should be unless they've personally seen one). They can decide what likelihood they're comfortable with: 90%, 50%, 20% whatever. As the years go on, it’s inevitable that one’s confidence level will drop unless there’s something added to the mix to maintain it. The author (J.C. Haney) may well have dropped his confidence down somewhat in the three years since he wrote it.
The 0%-ers are strange, however. I've never heard a good argument for a certainty of extinction, and I wouldn’t trust their judgment on anything.
The good news is that the club of people who have personally seen an ivory-bill is larger this year than it was last. (Unlike Swart, I don’t see this adding to the evidence that the bird is extinct). There will be people searching this winter, some extensively, with more experience than last year and trying out some new ideas.
On a question Swart asks: “What happens if you hang automatic listening devices in forests that can be assumed to have no IBWO's? Do you hear some double knocks if you listen long enough?”
Probably. I’ve heard very good-sounding “double-knocks” from a downy woodpecker, duck hunters, target shooting, and industrial activity. The automated recorders will only cue you to an interesting area that should be investigated in person. Even if no phony double-knocks were detected in such an experiment, it probably wouldn’t change many minds about what has already been presented as putative DKs in ivory-bill habitat. It would be a costly experiment with little potential value.
FAV,
can you provide a link to the four or five videos that you consider are of an IBWO please, apart from the Luneau clip?
I have to disagree with you there. Yes it would be costly, but only a fraction of what was spent in Arkansas. The question is not whether DK's in and of themselves occur in southern bottomlands generally, but whether there is a strong correlation between DK's and kent-like sounds. I can tell you that having listened to hundreds of hours of recordings from one southern bottomland site (which has plenty of downies, pileateds, and blue jays, both DK's and kent-like sounds are extremely rare at that site, and there is no apparent relationship between them. Geoff Hill has said that both DK's and putative kents virtually disappeared from his Bruce Creek site after 2006, Visual encounters also dropped off. Yet blue jays, which had been scarce in the winter of 2005-2006, actually became more common.
I think it would be very illuminating to monitor a number of bottomland sites that have plenty of blue jays and pileateds (and other woodpeckers if you like) to see if ANY such site produces correlations between putative DK's and putative kents. Similar monitoring should be done in the Choctawhatchee and the Project Coyote site. But I do not indulge any notion that such a study is likely to be funded until someone produces a reasonably clear image of a living ivory-bill.
I meant red-bellied, not downy.
Fang, an acoustic survey for combined kents and DKs may be worthwhile. I was considering the detection of only DKs in areas known not to be ivory-bill habitat, and what the results would mean to people. I don't think it would change much, regardless of the outcome.
FAV,
can you provide a link to the four or five videos that you consider are of an IBWO please, apart from the Luneau clip?
you might also wish to add your reasoning?
Spat, participate in the thread (flip flopping) instead of constantly trying to assert that you possess self-proclaimed, veto power on what we or BRCs should be looking at or that videos are the only evidence that the AR BRC or any BRC consider when they review submitted records. Also its good to attempt your own internet research and for a real change ----------get out in the field and you will find IBWOs.
A submittal causes all the evidence to be looked at and the AR BRC acceptance that the IBWO existed, stands. Your attempts to parse out videos as the entire submittal will fail miserable as it has done for Sibley and his embattled entourage. Their attempt to overturn AR has failed and even more importantly their interpretation of the video has been repeatedly, summarily and forcefully rejected. In the strangest way they should join Collins to commiserate on what went wrong.
In addition state BRCs look at one submittal at a time in a vacuum, somewhat sealed from what has been reported/voted on in another state. AR accepted the submittal, despite other states dismissing submittals over the decades. Conservation science groups all reports across the range of rare species and doesn't segregate evidence per political boundaries. For example the snow leopard, with only a few individuals ever filmed (and only recently) has an island-like distribution. The population estimate is in the thousands, despite there being video evidence of only a few.
The point of my flip flop post was to examine the logical disconnects of someone zagging from accepting the evidence, to the polar opposite position 5 years later. If individual birds existed in AR and FL circa 2005-06 then a concomitant premise that the species was near impossible to observe from 1945 to 2005 was concurrently strongly embraced.
How do you explain this fella’s and others expectations that a drastically different rate of evidentiary production from 2006 to 2010 should have occured?
And why is the 06 to 07 IBWO observations in FL not considered as making the AR sightings more plausible rather than less as this chap has done?
Also stop expecting to obtain personal field knowledge on a blog or by only dissecting videos/reports on the net, that only a few have the field knowledge to fully disect. For example if you spent time in the field getting your life Wood Hen you would know what is certainly not a Red-bellied, Pileated or duck wings double knocking together.
When you then approach the area and hear a Kent from evidently an abnormaly huge Blue Jay or hatch and then see a very large, mostly white-winged pecker flying away, with non PIWO giss you have either observed and heard a species new to science................... or an IBWO.
Or you've made a mistake? That is also a possibility and perhaps a more likely one than your last suggestion.
You quoted four or five modern videos of IBWO. I was just asking what they were. I would have liked to know why you considered those (other than Luneau) to be IBWO.
Please don't be so abusive either. There's no need.
Spat, I accept you as an expert on mistakes but............someone experienced is not going to misinterpret hearing a Camphephilus double knock then the loudest Kent of their lives and then mkistake seeing a large white-winged woodpecker.
The odds on someone being confronted with a string of things that could even with difficulty be inteprested as a sequence like that are similar to the odds of a monkey randomlingly typing out war and peace.
Try and maintian some level of common sense. If someone competent reports this string of events they have either seen and heard an IBWO or are a Sheridan type.
tks SFTV
Post a Comment