Ivory-billed Woodpecker (formerly updates) (1 Viewer)

[cyberthrush]

....

There is a reason IBWOs are EXTREMELY RARE (or extinct). If their numbers didn't crash because of the loss of habitat than what was the reason?

IBWOs lived at a time and in a habitat where every human male old enough to carry and hunt with a rifle, pretty much did carry and hunt with a rifle (and not just on weekends). Hunting/collecting may have had a far more devastating effect on this species than has ever been acknowledged (although even Tanner surmised that hunting was the second greatest cause of the species' decline). In a day when passenger pigeons were being shot by the millions, the shooting of IBWO's may have appeared inconsequential by comparision and yet in fact been just as ruinous to their much smaller population.
The whole history of the IBWO is of a bird that lived and adapted to different forests (mixed hardwood, pine, cypress), and the Singer Tract birds may or may not have been representative of the species as a whole. There's just way too much that isn't known with certainty.

 

[IBWO_Agnostic]

I have a difficult time believing that IBWOs were pretty much exterminated by dudes with (mostly crappy) firearms, and yet now we can't get close enough to photo or video them? I've read the stories of how easy it was to get really close to the birds and kill them. BTW, I'm one of those folks that believe the IBWO did NOT adapt to this by being stealthy and quiet.

 

[fangsheath]

We can and will get close enough to video them, and we will get better video still. Mark my words. But Tanner's ivory-bill, the ivory-bill that scolds intruders and stays at its nest despite the building of blinds nearby, may indeed be extinct. I am forced to wonder, how good a video is good enough, given the assumptions at work in some minds?

 

[cyberthrush]

I have a difficult time believing that IBWOs were pretty much exterminated by dudes with (mostly crappy) firearms, and yet now we can't get close enough to photo or video them? ....

maybe or maybe not crappy firearms, but shooters who lived and breathed in the same habitat as the IBWO and probably had little difficulty finding nest or roostholes at which point the biggest avian target in the forest canopy became a sitting duck -- and don't forget their eggs were widely collected in those days as well.
.................................

on a totally different matter: sorry to impose this and don't know where it should properly go but I was just sent a survey by someone asking me to put it on BirdForum about the IBWO (I don't like such surveys myself, but always willing to try and help out a college student on some project, which I presume this is). So for anyone who cares to take part:

From: Floyd Hayes <[email protected]>
Sent: Thu, 24 Aug 2006 13:10:18 -0700 (PDT)
To: [email protected]
Subject: Ivory-billed Woodpecker: Assessment of the Evidence

Cyberthrush,

I sent the message below to ID Frontiers about an hour
ago. If you could post it on your website and also on
Bird Forum (which I haven't participated in and am
reluctant to sign up for) I would be most grateful.

*****

A simple survey designed to assess opinions on the
currently available evidence for the existence of the
Ivory-billed Woodpecker is posted at:

http://www.surveymonkey.com/s.asp?u=211781934539


If you would be willing to spend a few minutes
answering the fifteen questions, I would be grateful.
All responses are anonymous. At some point in the
future I will make the results of the survey public.
If others can forward this message to pertinent
listserves or blogs I would be most grateful.

Floyd E. Hayes
Department of Biology
Pacific Union College
Angwin, CA 94508, USA

 

[MMinNY]

I'm not discounting loss of habitat as a factor in the decline, but that doesn't mean Tanner's belief in such a high level of specialization is correct. Other factors, including hunting, could have contributed to it as well. I don't know anything about the status of second growth forests in the South in the first half of the 20th-century, but by some accounts at least, the 40s were the bottleneck. There's conjecture but no solid evidence that the bird couldn't survive in second growth forests

If memory serves, habitat destruction impacted PIWO populations for a time as well, but they have recovered. The IBWO undoubtedly sufferred more and was reduced to the point of extinction, so any recovery would have started with much smaller numbers. I wouldn't suggest the IBWO is as adaptable as the PIWO; however, that doesn't mean it couldn't adapt at all.

But they DIDN'T adapt to cutover forests or we wouldn't be here. We'd be watching IBWOs in LA, GA, FL, TX, etc. We'd have great video and photos.

IF IBWO does not/did not need really nice forest, then WHY didn't they persist in numbers sufficient to be documented well (at least once every 20 years or so)?

PIWO is less dependent on beautiful old-growth bottomlands, and they are doing fine.

There is a reason IBWOs are EXTREMELY RARE (or extinct). If their numbers didn't crash because of the loss of habitat than what was the reason?

 

[fishcrow]

...on a totally different matter...

Floyd has put together a good survey, but fortunately science is not a democracy. If it were, it would be totally screwed up like the rest of society. Even though my results are part of the survey, I decided to participate since I would like my views of Cornell's results to be counted. I'm completely convinced of all their claims, with the exception that the kents don't seem to be 100% certain (although it's pretty close).

 

[Bonsaibirder]

I have been told to post this on the 'updates thread' here rather than on the 'insight' thread. In case there is any confusion this post was in response to a post outlining the 'details' of Cinclodes' IBWO sightings to date. This was in the context of a discussion about the merits of taking field notes....

snip

The issue of field notes is a red herring. When you know every field mark of a species, taking field notes is an exercise in phoniness.

Cinclodes has quite clearly demonstrated, not least by this latest post, that he has absolutely no concept of the point of a field description. My faith in his observations is plummeting as we speak.

I wrote down the details of each of my six ivorybill sightings

When ?

but still remember every detail...

So here we have every detail of your sightings, with the proviso that we cannot rely wholy on their accuracy due to the time between the occurence of the sighting and the description being written.

Feb. 2. A large woodpecker flushed from the right bank while I was drifting downstream. It flew away from the water nearly perpendicular to my line of sight. I got my binoculars on it for a few seconds. It clearly had white on the trailing edge of the top of the right wing.

Where? What feathers? All of the secondaries? Secondaries plus coverts? Did the white extend on to the primaries, all of them or just the inner primaries?

I focused on the wings but noticed that the head was all dark and that there was a patch of white where one would expect to see the right dorsal stripe.

Does an "all dark" head mean that the bill and eye were all dark too? Can you honestly say that it didn't have a pale throat or face stripe if you weren't able to see the pale eye or the pale bill? The phrase "where one would expect to see" is very telling in the way you retrospectively construct your descriptions.

Feb. 3. While paddling upstream early on a foggy morning, I noticed a large woodpecker flying over from left to right. I wasn't able to make out any details at first but immediately suspected ivorybill based on the flight, which was unlike a pileated.

Here is some very valuable jizz information. How was its flight different from a Pileated? Pity you didn't write this down asap.

As the bird passed directly overhead, I leaned back, twisted my body in order to stay on the bird, and saw white on the trailing edge of the right wing as the kayak nearly capsized.

Feb. 16. A large woodpecker with very dark and brilliant white plumage flushed from close range on the left bank. The light conditions were ideal, and the bird flew directly away from me. I clearly saw the white trailing edges of both wings, which nearly met in the middle.

Where? What feathers? All of the secondaries? Secondaries plus coverts? Did the white extend on to the primaries, all of them or just the inner primaries? The details you are able to recall (immediately) are an indication of how good the view actually was.

no details = poor views

The wings were beating rapidly as in the Luneau video.

So, a bird in escape flight, flapping quickly, flying directly away - sounds very like the Luneau video. So are you sure you saw the upperwings or the underwings (which we know can look as if they are upperwings due to the twisting of wings in flight from the Luneau and Nolin videos)?

Feb. 17. While paddling upstream in the same area, I had a sighting similar to the one on Feb. 2.

This is a pointless description. All sightings are different. Comparing one to another without any details of what was actually seen is worthless. The lack of details serves to emphasis the quality of the views.

no details = poor views

Feb. 17. While drifting downstream later that morning, an ivorybill flew low across the water from left to right. I clearly saw the white trailing edges of both wings and noticed the sharp demarcation between the black and white parts of the wings.

It was so "clear" that you have no details. Or is that because you didn't write them down at the time?

no details = poor views

Feb. 20. While paddling upstream in the area of the previous three sightings, I saw an ivorybill perched about 15 feet up a tree on the left bank.

I apologise here for previously saying that none of your sightings invloved perched birds. - so lets have a description of what it looked like perched - what you mean you didn't take any notes?

I clearly saw the white trailing edges as the bird flew into the woods.

You must really look up the definition of the word clearly.

no details = poor views

I laughed out loud when I saw the drawings that Gallagher and Harrison made. If you take a drawing of an ivorybill in flight and blank out everything but the wings, you basically have what they drew.

The point of their sketches and ther field notes is that it conveys exactly what they SAW. Not what they think they should have seen, not what they know IBWOs look like, but WHAT THEY SAW.

So why not just say that you saw a large woodpecker with the field marks of an ivorybill on the tops of the wings?

I agree with you that this would be pointless and dishonest. I am not saying that you have not seen IBWOs. I am saying that you have not documented IBWOs to any decent standard yet.

Cheers,

snip

 

[gws]

The '30s and '40s probably would have been the bottleneck, but the good news is that here in the Deep South some of those bottomland hardwoods that the bird may need, such as the Nuttall oak, grows fast, matures early, and goes into decline early.

I'll never forget looking up in a patch of nuttall oaks I saw back in the '80s, in the Mississippi Delta, and wondering what was causing all the scalings. At the time, I didn't know what an IBWO was, but years later I suspect that it was their work.

 

[curunir]

I have a difficult time believing that IBWOs were pretty much exterminated by dudes with (mostly crappy) firearms, and yet now we can't get close enough to photo or video them? I've read the stories of how easy it was to get really close to the birds and kill them. BTW, I'm one of those folks that believe the IBWO did NOT adapt to this by being stealthy and quiet.

Anybody know when market hunting was outlawed?

 

[Curtis Croulet]

Anybody know when market hunting was outlawed?

At the federal level, wouldn't it be the Migatory Bird Treaty Act of 1918?

Edited to add: I thought it was mainly habitat destruction that lead to the near-demise of IBWO, not gun-happy rednecks (though they didn't help). As to the birds' wariness -- if someone finds an active nest, then I suspect they'll find the birds to be as accessible as they were to Tanner.

 

[MacGillivray's Trout]

Floyd has put together a good survey, but fortunately science is not a democracy. If it were, it would be totally screwed up like the rest of society.

Can somebody explain what the heck this means?

 

[fangsheath]

Anybody know when market hunting was outlawed?

Different states enacted protections at different times. Generally the ivory-bill was "protected" by about 1910 (1901 in Florida), but shooting of course continued. At least one taxidermist was apparently arrested for trading in ivory-bill specimens, but Jackson does not say if he was convicted. As the bird became rarer, the price of course increased, and there was also shooting of the birds for curiosity. Tanner explained many people's attitudes at the time: "The idea of conserving the bird because it is scarce never occurs to them at all." He pointed to an incident in which the unwise and extravagant statement had been made in a local paper in North Louisiana that ivory-bill specimens were worth one thousand dollars. A young man killed one hoping to collect. The only thing that kept others from doing so was that the offer seemed preposterous to local people, who no doubt could not conceive of desiring a specimen of a woodpecker simply because it was rare, let alone paying a thousand dollars. The offer was in fact bogus, but the psychology, unfortunately, was all too "real."

 

[cyberthrush]

Different states enacted protections at different times. Generally the ivory-bill was "protected" by about 1910 (1901 in Florida), but shooting of course continued....

I'll take Fang's word on these dates, although my memory was that most of the pertinent laws weren't on the books (and certainly had no real enforcement) 'til the 20's. Even then, the famous pair of IBWOs A.Allen followed in Fla. were collected by the State on the logic of, we better shoot and mount this pair now because there's hardly any left.
Anyway, the real point is that the decimation of IBWOs occurred in the latter 19th century long before any of these laws were in place, and the IBWO could be an item of food, an item of trade, or just fun target practice. Indeed, most believed the bird was already extinct by 1900, until a few were found -- and that circumstance just gets repeated over and over and over again.

 

[Edward woodwood]

Can somebody explain what the heck this means?

mmm....

no

but it's competing with the 'I found IBWOs and it was no big deal really' as top ten post material

Tim

 

[Jesse Gilsdorf]

At the federal level, wouldn't it be the Migatory Bird Treaty Act of 1918?

Edited to add: I thought it was mainly habitat destruction that lead to the near-demise of IBWO, not gun-happy rednecks (though they didn't help). As to the birds' wariness -- if someone finds an active nest, then I suspect they'll find the birds to be as accessible as they were to Tanner.

Probably the interstate transmittal of feathers etc. was before that date. The migratory bird treaty may have been 1918 but as I recall it was about 1940 before it was upheld by the S.C. This would have been after the federal government seized control from the States by the replacing of true federalist judges with Roosevelt appointees. Prior to that time commerce among the states literally meant that. You had to cross a state line to get the fed involved. Thus, if the fed had passed a law it would not have limited in state collections in the slightest. Further, migratory bird treaty probably would have not been construed to cover ivory bills. They are not migratory birds in the literal sense of the word.

Jesse

 

[curunir]

Probably the interstate transmittal of feathers etc. was before that date. The migratory bird treaty may have been 1918 but as I recall it was about 1940 before it was upheld by the S.C. This would have been after the federal government seized control from the States by the replacing of true federalist judges with Roosevelt appointees. Prior to that time commerce among the states literally meant that. You had to cross a state line to get the fed involved. Thus, if the fed had passed a law it would not have limited in state collections in the slightest. Further, migratory bird treaty probably would have not been construed to cover ivory bills. They are not migratory birds in the literal sense of the word.

Jesse

I thought the courts held that any bird crossing state lines was pretty much covered by the act. That may have happened fairly recently though. Migrations come in all shapes and sizes anyway.

 

[fangsheath]

Enforcement was indeed the real issue, and it was nil in most rural parts of the South prior to 1950. As far as that goes, enforcement of laws in general was nil in rural areas. People pretty much took care of their own affairs. Note the rapid destruction of the pair seen by Allen in the 1920's. The Singer Tract was patrolled by people like Kuhn after the birds were found there, but people still managed to shoot ivory-bills there.

 

[theveeb]

I was asked to move this discussion of the merits of comparing fishcrow video head shapes from low res video from the IBWO evidence thread. It [may be] a little jarring if you [weren't] following it before...

In order to debunk the myth that you can't enlarge an image, I took a screen capture of the gull in the upper right corner of the birdforum.net homepage. This image corresponds to simply scaling the pixels (as Don did in his misleading example). This image corresponds to applying high quality interpolation. As this example illustrates, there's a lot more information in an image than the individual pixels suggest. For example, it is well known (the sampling theorem) that only two samples per wavelength are required to completely determine a sinusoid. If you were to draw a picture based on such sampling, it wouldn't look anything like a sinusoid. If you use the information properly, however, you get a perfect image of the sinusoid. You can only go so far when enlarging an image. What you can get away with depends on the nature of the image, but it's clear that the modest enlargement of the image in this movie has not introduced artifacts.

I never said that you can not enlarge an image, I said you need to be careful interpreting the detail that is produced when you enlarge a low-resolution image.

My point in posting:

http://www.virtualbirder.com/fishcrow/perched.gif

was to demonstrate with a zoomed view what was actually physically recorded by your camcorder (i.e. the image on the left) that you de-interlaced (image on right) and magnified for your animation. How is that misleading? It is the source data that was recorded (i.e the actual data). For those unfamiliar with video technology, each of the squares in the left image I posted represents a single sensing element of the camcorder (unless Mike has a 3-chip camcorder in which case it would be 3 optically aligned sensing elements). The dark lines are due to video interlacing where alternating rows are captured each 1/60th of a second.

To take the ~21 source pixels in three rows of the left image that get interpolated to be the head and bill of the bird in the magnified animation and assume you can make accurate shape comparisons is just unrealistic. There a huge difference between a sine wave and a woodpecker's crested head.

Mike's demonstration images really fail to capture the issues of low resolution. Now if you wanted to more accurately show the effects of a low resolution video image on shape one could reduce the size of an image to roughly the size of Mike's perched bird in his source video, de-interlace it, and then magnify it. Hey, that's a great idea, let's try that:

http://www.virtualbirder.com/fishcrow/bird_forum.jpg

Anyone care to comment on the shape of this bird's head or tail? Low-res interlaced images can transform shapes, there's just not enough detail to accurately reproduce the original shape below a certain resolution.

Note I am not saying that the bird in Mike's video wasn't an IBWO. I'm saying I don't think that the bird is identifiable given the extremely low resolution of the image in the animation.

And I do think this is relevant with respect to documenting IBWO's. I don't think Mike's methods given the quality of his image are valid. I would hope people would judge for themselves if this is so, and consider these issues when analyzing and presenting future video.

don c.

 

[timeshadowed]

I was asked to move this discussion of the merits of comparing fishcrow video head shapes from low res video from the IBWO evidence thread. It'll probably be a little jarring if you were following it before...
don c.

I don't think moving the discussion from one thread to another difficult at all. All one needs to do is 'copy and paste' the revelant comments from that thread to this one . . . . and viola we have a complete discussion. But doing so leaves that other thread uncluttered. So that it is possible to quickly read any new information that is posted in that other thread.

I still think having 2 threads is a GOOD IDEA.

TimeShadowed

 

[theveeb]

I don't think moving the discussion from one thread to another difficult at all...

Sorry meant to say it might be jarring if you weren't following it before. I'll edit the post to reflect that.

don c.