Ivory-Billed Woodpecker: Extinct Or Not?

rynner2

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Re: Extinct bird found in Arkansas

krobone said:
A woodpecker thought to be extinct for 60 years is re-discovered:

A group of wildlife scientists believe the ivory-billed woodpecker is not extinct. They say they have made seven firm sightings of the bird in central Arkansas. The landmark find caps a search that began more than 60 years ago, after biologists said North America’s largest woodpecker had become extinct in the United States.
..or maybe not:
Woodpecker's existence questioned

Further doubt has been cast on the claim that a bird long-thought extinct is alive in North America.
Fleeting video footage of what many experts believed to be an ivory-billed woodpecker was captured in 2004 in an Arkansas swamp.

But since then, searches have failed to find any hard evidence for the bird.

Now, Aberdeen University's Dr Martin Collinson has told the journal BMC Biology that the video may simply show a pileated woodpecker in flight.

Dr Collinson has re-analysed the footage and says the bird in the pictures appears to have black trailing wing edges rather than the unique white features associated with the ivory-billed woodpecker (Campephilus principalis).

The videoed bird also appears to flap its wings at the rate a pileated woodpecker (Dryocopus pileatus) would - 8.6 times per second.

Format fooling

"A poor quality video of pileated woodpeckers can look like ivory-billed woodpeckers - and in that respect it can catch an observer out; and a mistake can be made. And in this case, I think a mistake has been made," Dr Collinson told BBC News.

The Aberdeen researcher also argues that the missing bird's large size and colourful plumage would surely have been seen by now in the many follow-up surveys.

"The ivory-billed woodpecker isn't some small brown bird that can only be identified by one in a thousand; it's an enormous black and white bird with a red head," argued Dr Collinson.

"OK, these swamps are pretty remote, but there are hundreds of people in there, right now, looking for the ivory-billed woodpecker. Eventually these birds would turn up."

But others still hold to the idea that the video did indeed show an ivory-billed woodpecker.

John Fitzpatrick, a director of Cornell University's Laboratory of Ornithology, said that different formats of the footage resulted in "comparing apples to oranges".

He told the Associated Press that Dr Collinson's evidence about similarities in the birds' colouring, wing patterns and flight patterns were skewed as a result.

When the 2004 video was released, it stunned ornithologists worldwide, with some comparing the discovery to finding the dodo.

It ignited hope that other extinct birds might be clinging on to survival in isolated places.

The last confirmed sighting was in 1944.

Researchers hope robot bird-watchers may yet have the final say. Automated cameras have been set up in the Big Woods refuge of Arkansas to continue to spy for the elusive creature.

"I am happy to be proved wrong; a good photo would end this debate," said Dr Collinson.

"I would be delighted; I would love to see an ivory-billed woodpecker."

http://news.bbc.co.uk/1/hi/sci/tech/6458591.stm
 

PeniG

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The ivory-bill is real, too. The video is not great evidence, frankly, because it's so fuzzy you can find anything you're looking for in it. It's not the evidence that convinces me. We're talking multiple sightings by experienced birdwatchers and ornithologists who were, though hyped up to see it, also continually second-guessing themselves, and recordings of calls, made over an extended period. Also, when you go back over the unconfirmed sightings - including photographs - since 1944, you find a lot of damning of data that would be considered good had the bird not been declared extinct.

One of the most convincing tidbits to be found in The Grail Bird, Tim Gallagher's write-up for the lay audience, is that the birdwatcher who persuaded people to undertake this search didn't see it during that field season. This guy knew, knew, knew that he'd seen it, was desperate to prove it, was out looking every day, and had chances on top of chances to confabulate a sighting - but he didn't. Other people saw it, people who didn't really believe him or their own eyes and kept trying to turn what they saw into a pileated, but couldn't.

I'm a confabulating birdwatcher myself. I know all the dodges. I know the state of mind. These people are not guilty. Either there was an ivorybill in that swamp, or there was a fairy masquerading as an ivorybill. (The second, alas, is a necessary caveat to all cryptozoological stories that don't result in a bird in the hand.) The evidence against them amounts to nitpicking of the "I didn't see it so it doesn't exist" variety.

I don't believe things very often. The ivorybill evidence convinces me.
 

Bigphoot2

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Possible sightings of the Ivory-Billed Woodpecker, the first sightings since 1944

Back from the dead? Elusive ivory-billed woodpecker not extinct, researchers say​

An expedition to the forests of Louisiana say extinction of bird, last definitively seen in 1944, has been exaggerated


Oliver Milman
@olliemilman
Wed 13 Apr 2022 07.00 BST



In terms of elusiveness, it is the Bigfoot or Loch Ness monster of the bird world, so rare and undetectable that the US government declared it extinct last year. But the ivory-billed woodpecker is, in fact, still alive and pecking in the forests of Louisiana, a team of researchers has claimed.
A series of grainy pictures and observations of the bird, which had its last widely accepted sighting in 1944, show that the scrupulously furtive woodpecker is still holding on in the swampy forests of the US south, according to the team’s new research, which is yet to be peer-reviewed.




A three-year quest to find the woodpecker involved scientists trudging through an undisclosed portion of Louisiana woodland to observe the bird and take audio recordings. Unmanned trail cameras, set up to take pictures on a time lapse, and a drone were used to capture photos of the creature.
https://www.theguardian.com/environ...y-bill-woodpecker-not-extinct-researchers-say
 

Sharon Hill

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JaneD

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I bloody hope so but how long has the poor thing got left if there are only a couple still knocking around?
 

Endlessly Amazed

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In the past twenty years, credible sightings of these birds have been documented in Arkansas, Mississippi, Louisiana, and Florida. Note that credible sightings are not accepted by all agencies or specialists. I like to think - but have no information - that the Nature Conservancy has been quietly buying up swampy old growth forests.

For those armchair explorers, who think that if any woodpeckers were still around, they would have been found, I suggest that the difficulty of exploring old growth swamps is easy to underestimate. Large areas, no easy access, few and reclusive birds. I once lived in the Florida panhandle, Pensacola, and the inpenetrability of the swamp forests is hard to describe.
 

Min Bannister

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For those armchair explorers, who think that if any woodpeckers were still around, they would have been found, I suggest that the difficulty of exploring old growth swamps is easy to underestimate. Large areas, no easy access, few and reclusive birds. I once lived in the Florida panhandle, Pensacola, and the inpenetrability of the swamp forests is hard to describe.
I have been on an Ivory Bill bender the last couple of days and one of the problems that I can see is that the old growth isn't that old at all. It seems that all of the IBWs old growth forest was very extensively logged somewhere between the late 19th century when the bird began to get scarce and the mid 20th when the bird disappeared. It may be very difficult to get to now but those areas become pretty accessible once you chop down everything in your path. I am currently reading the report by James Tanner which is very often cited and the decline of the birds is very well charted. There are birds - the loggers move in - there are no more birds. The only example of the birds disappearance from an area that was demonstrated to be not caused by logging is the case of a set of birds that were systematically shot or caused to be shot by a collector.

So it may well be that there is suitable habitat for them now but if they all died decades ago then it doesn't matter a jot.

Here is a link to the paper from the Louisiana sightings mentioned a few posts above which includes photographs.

https://www.biorxiv.org/content/10.1101/2022.04.06.487399v1.full.pdf

I am not hugely convinced by any of them. One of the reasons they give for the difficulty in finding the birds was that Tanner was following a family group during nesting season and they were noisy and active which might not normally be the case. But the current investigators were observing during the nesting season and if they didn't find any family groups during that time, that is not a great sign. They also hardly seem to mention any field signs such as holes which are by far the best way to start spotting woodpeckers. A flipping great woodpecker is going to make flipping great woodpecker holes. Where are the holes and measurements? Where are the samples of flipping great woodpecker poo?

Anyway, my bender continues so I have a lot more evidence to look at.
 

Endlessly Amazed

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Here's some slightly older footage showing the beautiful beast in all its glory

These birds seem to me to be prehistoric - feathered small dinosaurs. Fortunately, they are smaller than we are.

It may be very difficult to get to now but those areas become pretty accessible once you chop down everything in your path.
These are good points. From what I have seen (admittedly very incomplete) and read (ditto), the old growth forests which were easy to harvest were cut down. These were the woodpeckers' main niche. However, in the SE US, there are many very swampy tracts which were not as accessible, did not have the same type of hardwood trees, and so did not have the same extent of harvesting. The sightings of the past 30 years, even if questionable or rejected, were from these swampy areas, if I recall correctly. These are the tracts in which I hope the woodpeckers are surviving in, as relict populations.

But I certainly don't know and am an armchair ornithologist about it. I did once win a bet about the ivory-billed woodpecker, so that is the extent of my expertise :)

@Min Bannister, if in your reading, you run across any discussion of the distinction between swampy and non-swampy forests, please post it here for us.
 

Min Bannister

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These are good points. From what I have seen (admittedly very incomplete) and read (ditto), the old growth forests which were easy to harvest were cut down. These were the woodpeckers' main niche. However, in the SE US, there are many very swampy tracts which were not as accessible, did not have the same type of hardwood trees, and so did not have the same extent of harvesting. The sightings of the past 30 years, even if questionable or rejected, were from these swampy areas, if I recall correctly. These are the tracts in which I hope the woodpeckers are surviving in, as relict populations.
Okay, sounds interesting. It is even harder for me as I am even more of an armchair ornithologist about this, having never been to the US never mind a Florida swamp! So far I have not really managed to get much of a grip on the whole habitat thing as it is so exotic to me but I will put my notes so far down below - hopefully it makes a bit of sense.
But I certainly don't know and am an armchair ornithologist about it. I did once win a bet about the ivory-billed woodpecker, so that is the extent of my expertise :)

@Min Bannister, if in your reading, you run across any discussion of the distinction between swampy and non-swampy forests, please post it here for us.
Tanner reports that in the Mississippi delta, the Ivory-bill occurs in the "higher parts of the first bottoms". These are areas which are only covered with water a few months of the year. This covers the Singer Tract where Tanner found his Ivory-bills.

In Florida they are located in or near swamps or Florida hammocks. but also cypress swamps away from rivers of swampy hammocks.

It seems then that there is no single type of forest that they like so this does not rule out the very swampy areas. Apparently the best predictor for a good Ivory-bill habitat is the density of population of other woodpeckers. Here is where it gets a bit trickier though. To a woodpecker, the best tree is a dead tree. So far so good, you will always get dead trees around. But to an Ivory Billed Woodpecker, the best tree has been specifically dead for 1-2 years only as the mainstay of their food supply is the kind of woodboring grubs that attack the tree under the bark in that time. So as you can imagine, there is only a certain quantity of that kind of wood available. Tanner estimated that 3-4 square miles of suitable forest would be needed for 1 pair of Ivory-bills. The Singer Tract was 125 square miles and thought to contain 8 birds - not all of this area is going to be "suitable". The population had been declining over the years previous to Tanners report. He thought that the population had been particularly high for a short while as a load of trees had been destroyed by fire several years earlier, leading to a good but short-lived food supply.

Some other points to note:-

-The Singer Tract was remarkable for being the only forest in the area that had not been logged over.
-Tanner saw 6 birds out of his estimated 8 in the area. 5 were male.
-A couple of year after Tanner published his report, the Singer Tract was logged over.

So at the moment at least, I remain sceptical as to be able to find enough food, these birds not only needed old forest but they needed a LOT of it in order to have a good enough supply of 1-2 year dead trees. So it would be interesting to see just how large an area these un-logged parts of forest you mentioned covered.

I have ordered a book which covers the modern day search for the Ivory-bill which I hope answers these questions but unfortunately I will have to wait another couple of weeks for it to arrive. :)
 

Min Bannister

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My book arrived - In Search of the Ivory Billed Woodpecker by Jerome A Jackson. I am not very far through it yet but just wanted to list a few points to get my thoughts in order.

Tanner mentions that inbreeding does not necessarily affect birds as much as mammals and so may not be as big a concern as I had assumed though Jackson does mention it as a concern.

The Jackson book goes into more detail on the destruction of the forests and the effects on the birds and it is more nuanced than I thought and actually quite fascinating (if you can try to look at it dispassionately..). Although the forests were very extensively cut before the 1930s, total clearfelling did not occur until the invention of the chainsaw in the late 1940s when everything could be cut down with little effort when previously it was not worth cutting every single tree. However, sweetgum - a favourite of the Ivory-bill - had been selectively cut down prior to clearfelling.

Natural fires were of benefit to the Ivory-bill as they kill trees. Southeastern US has a great deal of lightning, especially Florida which started a lot of fires or even just killed trees by striking them. However logging leaves so much brash and rubbish on the floor of the forest that the fires that occur in logged forests are devastating. Fires are subsequently seen by humans as a Very Bad Thing and then controlled by fire breaks, prescribed burns and the presence of roads that acted as fire breaks. The composition of fire protected forests then changes and becomes too dense for large birds to fly through as there is nothing to stop the undergrowth growing.

A great deal of swamp land was drained and then dammed and leveed. This then made it easier to clear the forest and either put it to agricultural use or build tree monocultures. Drained forest which was not cut changed in composition and also became too dense for large birds to fly through. Swampy forests have high humidity which encourages fungal growth which in turn attacks tree bark which allows the beetles whose larvae provide the food to bore and lay their eggs. Humidity levels can have a dramatic affect of woodpecker numbers - the higher the humidity the better and cutting down swathes of trees and leaving the odd dead tree up "for the woodpeckers" is actually pretty useless as a dead tree standing on its own becomes very dried out and uninviting for beetles.

Tl;dr - The swamp forests and the Ivory-bill had a complicated and exquisite relationship and devastating the forests had an irreversible impact on this exquisite bird.
 

gordonrutter

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Oh, and I accidentally discovered that it is possible to buy a cuddly Ivory-bill and am now extremely tempted to buy one!:oops:
You could start a collection of ivory billed woodpecker toys...
httpswww.bigjigstoys.comimages3p88802_720x@2x.jpg
 
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