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Ivory-Billed Woodpecker continued (1 Viewer)

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The various points in papers and here is that Pileateds do not compare to Ivory-bills in level flight.

Zebras accelerating is not pertinent at all to the level flight of any bird .
 
But you couldn't get any photos? I'm certainly open to the idea of IBWO still existing, but the fact that so many people claim to have seen the bird and no one has gotten a photo make the whole thing seem reminiscent of cryptids like Bigfoot and the yeti.
No photos yet. Sightings are a matter of seconds. I was on foot each time. I am retiring this year and may search next year with updated methods.
 
I'm somewhat hesitant to add another post to a thread that has long been generating more heat than light. But I genuinely can't help wondering:

- if enough ivory-bills survived the 1940s that the survivors constituted a viable breeding population (and how many individuals would that have to be?);

- given that 70-odd years has now passed, hunting pressure hasn't been an issue for decades, and there appear to be large areas of suitable habitat;

- would the population be expected to increase? Presumably yes; and if so, what would the rate of increase be likely to be?

- would each generation not have become less shy, due to never or hardly having experienced hunting pressure? If the birds are thought to have a 15-year lifespan, the period 1945-2020 that means at least five generations. I can credit that the birds might have become shyer due to hunting pressure, but with the cessation of hunting pressure there's no reason why this should reverse, and there are plenty of examples of other birds and animals becoming less shy/easier to spot after hunting pressure or human interference was let off - I've cited a few in my post #250, including the stork-billed kingfisher, a bird that back in 1920s Singapore was said to be wary enough to flush 100 yards ahead of a boat, but is now easy to approach and photograph.

- Taking into account all the above, plus the birds supposedly being quite mobile, why hasn't the species been rediscovered by now? I mean definitively rediscovered - as in photos or video footage that doesn't need to be National Geographic/BBC quality, but shows adequate field marks? The imperial woodpecker footage from the 1950s certainly isn't great quality, but is more than able to show the distinctive features well enough so that the bird can be clearly identified as such, without having to delve into flap rate. Birds thought to be extinct, like the takahē and the night parrot, and including much smaller species than a crow-sized woodpecker, have been rediscovered without needing every square mile of their range being combed - and by "rediscovered" I mean conclusively so, not just via calls, tracks, or sign. If birds like these can be rediscovered, why not the ivory-bill?


I've read some of the accounts from people who have spotted them, especially David Kulivan. I can fully believe Kulivan was sure of what he was seeing. But over 20 years have passed and much effort has been put in, and no one has succeeded in gathering photos or video even comparable to the 1956 imperial woodpecker footage. Back in 2006 fishcrow (Mike Collins) asserted that "In a few years, people will look back at this time and wonder what the controversy was all about. They will also realize that ivorybills were just waiting to be discovered in several locations." With better and better equipment being available to searchers in the field, how many more years do the "believers" think will pass before a definitive photo or video is recorded? And if no such evidence appears, how long will it take before it's accepted the bird is in fact gone?
 
Sounds like some evidence, even if not proof. Can you expand at all? I can certainly understand why you might not be willing to name the site, but any details would help those of us with an interest and an open mind to make a personal judgement. At the very least, what time of year was this; this might be a key to successful future searches.
All sightings were in January-February-- these are regarded by IBWO researchers as the months with the most chance of a good encounter. Trees have less leaves, birds have more hormonal behavior. First sighting was at Manatee Springs State Park, Florida, across the Suwanee River, of what I initially thought might be a loon. Last three sightings were in Project Coyote search area in Louisiana.
 
It is a bit circular - even by the searchers own admissions, each piece of evidence on its own could fall but united they stand

  • acoustic ‘evidence’ - inconclusive
  • bark peelings/bore holes - inconclusive
  • uncorroborated sightings - inconclusive
  • Therefore blurry videos stills and even more blurry photographs interpreted with an IB bias which supports conclusiveness of acoustic evidence, bark peelings/bore holes and gives credence to sightings otherwise uncorroborated.
I watched those 2005 Pearl River videos that you posted of a putative IB flying down the river towards the observer and thought, as I watched it, someone could quite easily construct a similarly forensic argument as to why it was not an IB.
If probabliltes are used as they should be then you might get a very different conclusion. Fair probabilities are hard to agree upon.

But as a simple example if 100 double knocks are recorded and they fit no other species but Campephilus and then you video a bird like no other but Camp. and then you get roost holes that fit Camp. etc. and you only give each of these occurrences 55 % chance an Camp and 45 % various other unproven explanations but unlikely, you soon get a high 99% chance there is one of more Camp in area.

This would not be evidence of extinction but the opposite.
 
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- would each generation not have become less shy, due to never or hardly having experienced hunting pressure? If the birds are thought to have a 15-year lifespan, the period 1945-2020 that means at least five generations. I can credit that the birds might have become shyer due to hunting pressure, but with the cessation of hunting pressure there's no reason why this should reverse, and there are plenty of examples of other birds and animals becoming less shy/easier to spot after hunting pressure or human interference was let off - I've cited a
I hear what you are saying but you have given no driver for the reversal. The driver for wariness is obvious----lessened lethal interactions with guns. And your assumption that a bird now wary of humans and their associated gunshots can now detmine that the bullets are not coming at them that they hear each year for months, how do they do that?

Also what is your evidence that duck-like birds (rare woodpeckers) said to look and fly like pin tailed ducks by many authors are not being accidently taken. Bad takes are rampant. Do you think the non-duck is taken to the poweres to be or dumped quickly?

Reversal has no easy or rapid driver, unless you can add some.
 
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The Ivory-billed Woodpecker would be a good candidate for the most elusive bird in the world on the basis of the following set of facts (which is unique to this species): (1) it has a long history of rediscoveries; (2) nobody has ever managed to obtain a clear photo without knowing the location of an active nest; (3) many sightings have been reported but nobody has managed to obtain a clear photo during the past several decades; (4) ornithologists were unable to obtain a clear photo during intensive multi-year searches at sites where they were convinced these birds were present; and (5) it is a species of great interest that resides in a region that is easily accessible to a large number of bird watchers. Clear photos were obtained at the nest in the Singer Tract, but photos obtained away from the nest during that study are of poor quality.

1) this makes no sense for a large woodpecker. Full stop.
Makes sense unless circular reasoning is inserted.
 
Is it possible - yes they could evade detection assuming they always kept to areas that no-one ever visits, But is that a valid assumption? The problem is where did that pair come from? Why weren't they unreported there before? Just the one pair? Do they breed? If so where do they offspring disperse to? A pair can't have persisted on their own for 50 years so what about other birds elsewhere? Why does no-one see them well enough to prove their existence?
Never heard of getting every rare, skulky bird that can be anywhere within 50 square miles as easily as you rate. Key West Quail Doves in Florida and other timid birds in Vancouver and Vancouver Island routinenly disappear for weeks even in small parks.
 
I hear what you are saying but you have given no driver for the reversal. The driver for wariness is obvious----lessened lethal interactions with guns. And your assumption that a bird now wary of humans and their associated gunshots can now detmine that the bullets are not coming at them that they hear each year for months, how do they do that?

I can believe any ivory-bills that survived the 1940s might well be shy of man to the end of their lives. But what about their offspring, and the next generation after them, and the next? From say the 1960s onwards they would not have been subjected to the same kind of hunting pressure. Remove hunting pressure/human persecution and there are many examples, across different species, of bolder individuals tolerating the presence of man in order to exploit food sources and habitat shunned by shyer birds/mammals within a few generations. That is the driver for reversal.

I'm not saying the ivory-bill is likely to show up in suburban areas like the pileated woodpecker apparently does, but becoming tolerant enough to allow better photos/video to be taken than what has appeared thus far isn't beyond the bounds of reason - is it?
 
No photos yet. Sightings are a matter of seconds. I was on foot each time. I am retiring this year and may search next year with updated methods.
Some thoughts that came to mind:
There seems to be a likely negative correlation between the duration of the observation and the chance it'll be considered as a IBWO record by a given observer. The longer the observation the higher the chances it'll be dismissed as something else, and the shortest sightings of all seem to have a greater chance to be considered as IBWO. There seem to be no long observations of candidate IBWO (if there are then please, please, describe what you saw, in detail...).
There may be also a correlation between one first very short unidentifiable observation that is considered to be IBWO by a given observer and the next very short unidentifiable observation by the same observer to be considered as a yet another IBWO record, as that observer may have the unconscious biases to consider that 1) IBWO typically will show very briefly only, and the 2) briefer the observation the higher the chances it'll be a IBWO.
Note that I'm one of the people still waiting for some kind of evidence to be eventually presented, not of a viable population, but of the very last examples of the species just prior to extinction, but I see absolutely none.
 
Hi,



In the words of the "Ivory-billed Woodpecker (Campephilus principalis) 5-Year Review:
Summary and Evaluation" by the U.S. Fish and Wildlife Service ...

https://ecos.fws.gov/docs/five_year_review/doc6021.pdf



The recommendation of the evaluation is "Delist based on extinction", but I'm not quite sure if that recommendation was officially accepted.

Regards,

Henning
Odd since there seems have been some recent sightings and areas are large. Others here say there are problesm in past techniques. They seem to agree on only that.
 
I can believe any ivory-bills that survived the 1940s might well be shy of man to the end of their lives. But what about their offspring, and the next generation after them, and the next? From say the 1960s onwards they would not have been subjected to the same kind of hunting pressure. Remove hunting pressure/human persecution and there are many examples, across different species, of bolder individuals tolerating the presence of man in order to exploit food sources and habitat shunned by shyer birds/mammals within a few generations. That is the driver for reversal.

I'm not saying the ivory-bill is likely to show up in suburban areas like the pileated woodpecker apparently does, but becoming tolerant enough to allow better photos/video to be taken than what has appeared thus far isn't beyond the bounds of reason - is it?
you miised my first edit.

I hear what you are saying but you have given no driver for the reversal. The driver for wariness is obvious----lessened lethal interactions with guns. And your assumption that a bird now wary of humans and their associated gunshots can now detmine that the bullets are not coming at them that they hear each year for months, how do they do that?

Also what is your evidence that duck-like birds (rare woodpeckers) said to look and fly like pin tailed ducks by many authors are not being accidently taken. Bad takes are rampant. Do you think the non-duck is taken to the poweres to be or dumped quickly?

Reversal has no easy or rapid driver, unless you can add some.
 
- Taking into account all the above, plus the birds supposedly being quite mobile, why hasn't the species been rediscovered by now? I mean definitively rediscovered - as in photos or video footage that doesn't need to be National Geographic/BBC quality, but shows adequate field marks? The imperial woodpecker footage from the 1950s certainly isn't great quality, but is more than able to show the distinctive features well enough so that the bird can be clearly identified as such, without having to delve into flap rate. Birds thought to be extinct, like the takahē and the night parrot, and including much smaller species than a crow-sized woodpecker, have been rediscovered without needing every square mile of their range being combed - and by "rediscovered" I mean conclusively so, not just via calls, tracks, or sign. If birds like these can be rediscovered, why not the ivory-bill?


I've read some of the accounts from people who have spotted them, especially David Kulivan. I can fully believe Kulivan was sure of what he was seeing. But over 20 years have passed and much effort has been put in, and no one has succeeded in gathering photos or video even comparable to the 1956 imperial woodpecker footage. Back in 2006 fishcrow (Mike Collins) asserted that "In a few years, people will look back at this time and wonder what the controversy was all about. They will also realize that ivorybills were just waiting to be discovered in several locations." With better and better equipment being available to searchers in the field, how many more years do the "believers" think will pass before a definitive photo or video is recorded? And if no such evidence appears, how long will it take before it's accepted the bird is in fact gone?
 
Not following your point . There are peolpe here well above telling you of much evidence and the associated problems in the field. Seems at least some official bodies had recently changed their procrastinations in favorable direction. There is certainly evidence; its not trivial.
 
Some thoughts that came to mind:
There seems to be a likely negative correlation between the duration of the observation and the chance it'll be considered as a IBWO record by a given observer. The longer the observation the higher the chances it'll be dismissed as something else, and the shortest sightings of all seem to have a greater chance to be considered as IBWO. There seem to be no long observations of candidate IBWO (if there are then please, please, describe what you saw, in detail...).
There may be also a correlation between one first very short unidentifiable observation that is considered to be IBWO by a given observer and the next very short unidentifiable observation by the same observer to be considered as a yet another IBWO record, as that observer may have the unconscious biases to consider that 1) IBWO typically will show very briefly only, and the 2) briefer the observation the higher the chances it'll be a IBWO.
Note that I'm one of the people still waiting for some kind of evidence to be eventually presented, not of a viable population, but of the very last examples of the species just prior to extinction, but I see absolutely none.
Several great observations are known. See Kulivan as mentioned see Hicks as mentioned. More.
 
Several great observations are known. See Kulivan as mentioned see Hicks as mentioned. More.
If so where are the details? People can't describe in words what they see? Is this an inability to do so? Unwillingness to do so? What then? No details were seen thus nothing specific to be noted? I may be wrong, but a IBWO would be a most striking bird to see in the field (and yes, I'm thinking of a cluttered habitat with difficult conditions for the observer), with that fantastic broad white rear half of the wing. I just don't understand.
 
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