• Welcome to BirdForum, the internet's largest birding community with thousands of members from all over the world. The forums are dedicated to wild birds, birding, binoculars and equipment and all that goes with it.

    Please register for an account to take part in the discussions in the forum, post your pictures in the gallery and more.
ZEISS DTI thermal imaging cameras. For more discoveries at night, and during the day.

Ivory-billed Woodpecker (formerly updates) (3 Viewers)

humminbird said:
I can't imagine any birder seriously defending an "encyclopedia" that shows the Ruby-throated Hummingbird (Archilochus colubris) as 7 - 9 cm. This is 1.5 cm smaller than any published data and would put the Ruby-throated as smaller than the Calliope Hummingbird and on a par with the Bumblebee Hummingbird.
Maybe you should blame the Cornell Lab, since the information appears to have been gathered from there, who in turn claim to have used the following as their source of information:

Robinson, T. R., R. R. Sargent, and M. B. Sargent. 1996. Ruby-throated Hummingbird (Archilochus colubris). In The Birds of North America, No. 204 (A. Poole and F. Gill, eds.). The Academy of Natural Sciences, Philadelphia, PA, and The American Ornithologists' Union, Washington, D.C.
 
hummingbird lengths discrepancy

Mike Johnston said:
Maybe you should blame the Cornell Lab, since the information appears to have been gathered from there, who in turn claim to have used the following as their source of information:

Robinson, T. R., R. R. Sargent, and M. B. Sargent. 1996. Ruby-throated Hummingbird (Archilochus colubris). In The Birds of North America, No. 204 (A. Poole and F. Gill, eds.). The Academy of Natural Sciences, Philadelphia, PA, and The American Ornithologists' Union, Washington, D.C.

The original statement was:
I can't imagine any birder seriously defending an "encyclopedia" that shows the Ruby-throated Hummingbird (Archilochus colubris) as 7 - 9 cm. This is 1.5 cm smaller than any published data and would put the Ruby-throated as smaller than the Calliope Hummingbird and on a par with the Bumblebee Hummingbird.

I'll bet that is just a discrepancy between body length and body including bill length--1.5 cm sounds like the length of a bill. I've also seen lengths quoted in some references, such as Robbins' field guide as "length in life", i.e., not a streteched specimen.

Cyberthrush and I had a discussion on his blog about how much larger an IBWO was than a PIWO in life--it is actually very difficult to get good, comparable measurements.

That's me, shooting from the hip at any rate.
 
Mike Johnston said:
Maybe you should blame the Cornell Lab, since the information appears to have been gathered from there, who in turn claim to have used the following as their source of information:

Robinson, T. R., R. R. Sargent, and M. B. Sargent. 1996. Ruby-throated Hummingbird (Archilochus colubris). In The Birds of North America, No. 204 (A. Poole and F. Gill, eds.). The Academy of Natural Sciences, Philadelphia, PA, and The American Ornithologists' Union, Washington, D.C.


Well, just shows that anyone is fallable. The math does not make sense (2.54 cm per inch 7 cm is well less than 3 inches!)

The response by pcoin does not address the math discrepancy.
 
pcoin said:
Furthermore, woodpeckers don't live on the wing--they have to stop to forage, and they are relatively easy to see on tree trunks then. Nobody claims that except for Mary Scott and Gene Sparling in Arkansas, and Kullivan in Louisiana, who claimed to observe perched birds, but they could not write up field notes with sketches, that I have seen, or get a photo or video--2 of the 3 had cameras. All other sightings have been fleeting glimpses of a wraith-like bird. (Oh yes, Tyler Hicks saw one perched for a "millisecond".)

TRE had a look at one for several minutes in Arkansas, briefly joined by another. He had time to talk live with a wildlife official he knew as he was watching the bird. Don't forget the 1971 photos of a perched bird. BTW, I don't know where the "millisecond" thing came from with respect to Hicks' Christmas eve sighting, but the Auburn update page says

It was only about 40 feet away. Tyler could clearly see the “ivory-white” bill on the bird—he said the pale bill “glowed” against the dark trunk of the tree. The crest of the bird was black. He’s sure. No red. The bird presented a profile so he saw one dorsal stripe running from the head to the back. The lower portion of the back of the perched bird was brilliant white. The bird paused on the tree for just a second and then fled. As it launched off the trunk and flew off Tyler could clearly see the broad white trailing edge covering the secondaries and innermost primaries of the dorsal wing surface. In flight, it had a long pointed tail and a long neck which he described as “like a pintail duck”.
(emphasis added)

pcoin said:
During the breeding season, IBWO would have to stay put, call, and drum in order to find a mate. None of this has been seen or heard. Lots of ARU recordings alleged to be calling and drumming, but no sightings of a bird perched doing that. How can that be?

Many of the sightings (including the Christmas eve one) have occurred by pursuing calls heard by searchers. TRE reported the bird he saw making kent calls which sounded very much like old recordings.
 
pcoin said:
I might agree with you on digital point-and-shoots, but a digital SLR such as a Canon or Nikon has fast auto-focus and good manual-focus capabilities--just as good as similar film SLR's. Tyler Hicks, for example, had a digital SLR--see this page. Both the Cornell and Auburn teams have posted pages of photos--they know how to use their cameras.

I've taken thousands of photos with a manual focus film SLR, and over 15,000 with a digital SLR. The digital has a huge advantage in speed--there is no down-time for changing film, and no down-time for processing--errors in exposure can be corrected immediately. On a 1 gigabyte card, now costing about $50, one can take 300 photos on a typical digital SLR--that is about 9 rolls of film, which means no losing valuable time while rewinding and loading 9 rolls. Digital SLR's are now cheap, less than $1,000 new, and older ones can be had on keh.com for $300 used. And if the Cornell and Auburn teams don't have good equipment, I'd have to ask what they are doing with all that grant money.



There's the rub. If a population is spread too thin, bird won't be able to find mates, and the population will die out. This is feared to have happened with Bachman's Warbler, I believe.

Furthermore, woodpeckers don't live on the wing--they have to stop to forage, and they are relatively easy to see on tree trunks then. Nobody claims that except for Mary Scott and Gene Sparling in Arkansas, and Kullivan in Louisiana, who claimed to observe perched birds, but they could not write up field notes with sketches, that I have seen, or get a photo or video--2 of the 3 had cameras. All other sightings have been fleeting glimpses of a wraith-like bird. (Oh yes, Tyler Hicks saw one perched for a "millisecond".)

During the breeding season, IBWO would have to stay put, call, and drum in order to find a mate. None of this has been seen or heard. Lots of ARU recordings alleged to be calling and drumming, but no sightings of a bird perched doing that. How can that be?

The Auburn team was originally saying they must be "detecting" multiple birds. Heck, they claimed to have found birds within an hour of starting searching, or something like that.

Ivory-bills were known to live in family groups. Large woodpeckers are easy to find while tending a nest with noisy nestlings, or leading noisy, begging fledglings about their territory. (And noisy fledglings don't get fed, so they die--that's pretty much the usual case among birds.) Jackson talks about this and is quoted here--you can read his discussion about how noisy and social the bird was.

I just don't believe any actual, living species, can have the characteristic that it never pauses for more than an instant. And the population density would have to be quite high within the vicinity of a nest--and there would have to be successful nesting somewhere for the species to be alive today. That's my problem with this whole fiasco--no nest found in the last 63-plus years--it just boggles the imagination. No breeding population found despite three years of intense searching in Arkansas. None in Florida after two years, despite lots of "detections".

Cheers as well.

All good points. The upland pine thoery is obviously not based solely on a Cuban Ivory-bill comparison, I guess I should have read your link before I replied :)

Although I didn't think about the time saved by not having to change rolls of film, I still feel you are giving far too much credit to DSLR cameras and their abilities. The focusing ability is largely a function of the lens rather than the camera. Canon lenses can be used on both Canon's digital and film cameras and both the autofocus and manual focus speed is the same for both (manual focus speed has nothing to do with the camera and is based only on the photographers speed). I guess what I'm trying to say is that although digital is far more convenient and IMO far more satisfying I don't think there are any advantages over film in terms of speed and/or simplicity. I also don't think a DSLR will make getting a photo of any species easier. FWIW I have used a few cameras, both digital and film and have also shot many birds with them so I am amking this judgement from experience (www.russjonesphoto.com).

I agree with you on the breeding, foraging and otherwise normal woodpecker behaviour that should be expected from Ivory-bills. I also agree that the birds should be detectable given the lifestyle they lead but I though I read that only a tiny percentage of the area had actually been searched. Anyone remember what percentage of the Choc river basin has been covered? The amount of area that has been searched is extremely important in my personal opinion of the IBWO status...

Thanks for all the great links.

Cheers,

Russ
 
Hicks' millesecond

emupilot said:
BTW, I don't know where the "millisecond" thing came from with respect to Hicks' Christmas eve sighting, but the Auburn update page says

Many of the sightings (including the Christmas eve one) have occurred by pursuing calls heard by searchers. TRE reported the bird he saw making kent calls which sounded very much like old recordings.

Hicks' comment about just seeing the bird for a "millesecond" came from an interview. That intereview is a little less confidence-inspiring than the official updates. Who knows?

I don't see that the Auburn team, or Cornell for that matter, ever noted a perched bird making calls or double-knocking--that was to whom I was referring. I meant no disrespect to TRE, but I gathered he was not one of the team.
 
pcoin said:
But of course, everyone will say "there have been all those credible reports of IBWO since the 1940's, but none of the Passenger Pigeon et al."

So I'm going to respond to myself. Cyberthrush and I had this discussion--see this post. My basic argument is that (some at least) people see IBWO because they are still pictured in the field guides while the Passenger Pigeon et al. are not. Being middle-aged, I have some field guides going back to the 50's. Most importantly, the first edition (1966) of Robbins' Birds of North America features the IBWO in a color plate right with the other woodpeckers. The Passenger Pigeon, Carolina Parkeet, etc. are not illustrated. Robbins' work was very popular then, and even now. (I like the art very much, plus the sonagrams.) I remember seeing it for sale in gas stations in the 1960's. Interestingly, Peterson's guide current at that time did not have a color plate of the IBWO. The edition from the 1980's added it, along with thumbnails of the (known-to-be) extinct species, such as Passenger Pigeon, and those were labeled as extinct, but not the IBWO.

Of course, there were reports by people before Robbins' guide was published, But I think some of the IBWO reports over the years have been due to enthusiastic, but inexperienced, beginners. That they have never reported Passenger Pigeons or Carolina Parakeets is due, I think, to the absence of those species from the field guides.

Note that Pough's Audubon Land Bird Guide, and Audubon Water Bird Guide, published 1946-1951, and reprinted to at least the 1980's, did illustrate the Pass. Pigeon, Parakeet, and IBWO. Those, however, were not nearly as popular as Robbins' guide.

I think field guides do play a big part in this. The other major factor is the Pileated. When a person sees (or really notices) a Pileated for the first time they are likely to be impressed by the encounter. A Pileated is a BIG bird and gets attention. When a non-birder has a close encounter of the Pileated kind it could make them curious enough to look it up in a book to see what it is. If the Ivory-billed is illustrated and they see it is rare or considered extinct that may re-shape their memory of the sighting, because a big cool bird like the one they saw just has to be something rare...

People just don't take the same interest in Mourning Doves or escaped parakeets. They don't make the effort to try to identify them in the first place, and the absence of field guide illustrations of the extinct species makes misidentification even less likely.
 
emupilot said:
I'm just pointing out (again) the circular logic of "No recent photos exist! All recent photos are fakes!"

Define "No," "All," and "recent."

About the "all" part, You mentioned 1971 (Lowery) and 2005 (TMGuy?). I think if you polled "skeptics" many would say the 1971 photo(s) look good. The provenance of the photos cast doubt on them when they were first presented, but I don't think there is any unanimity of belief either way.

About the 2005 photo. It's fake. In fact it's a bad fake, which is why I have no qualms about coming right out and say it's a fake. Are you saying it isn't? Otherwise that circular logic bit is a non sequiter.
 
humminbird said:
I can't imagine any birder seriously defending an "encyclopedia" that shows the Ruby-throated Hummingbird (Archilochus colubris) as 7 - 9 cm.

The Nature article was a genuine attempt to compare the information between these two encyclopedias - one an established and supposedly reliable source of general information - the other a very new but apparently (according to the article) comparable resourse.

My sincere apologies Hummingbird for not having read the entire encyclopedia. By the way, are you referring to Wikipedia or the EB?
 
emupilot said:
I'm just pointing out (again) the circular logic of "No recent photos exist! All recent photos are fakes!"

Seems no more circular logic than that of... people keep seeing so many unsubstantiatable (is that a word - well it is now!) views of the species it must still exist!


Are you seriously saying that you think TMguy's photo is of a real bird? The 71 pics seem really quite plausible to me. It not exactly RECENT though is it!
 
Last edited:
emupilot said:
TRE had a look at one for several minutes in Arkansas, briefly joined by another. He had time to talk live with a wildlife official he knew as he was watching the bird.

snip


TRE reported the bird he saw making kent calls which sounded very much like old recordings.


Before you read too much into this, TRE saw a large woodpecker joined by another large woodpecker. The woodpecker he saw well had white on the wings. He was not able to see a dorsal stripe or a white bill, though he did see the bird well. That may be because he did not know to look for it, or it might be that they were not present (i.e. it was a partially leucistic Pilieated).
 
John Mariani said:
About the 2005 photo. It's fake. In fact it's a bad fake, which is why I have no qualms about coming right out and say it's a fake. Are you saying it isn't? Otherwise that circular logic bit is a non sequiter.

Can someone post a link to this photo? Thanks!

Graham
 
cyberthrush said:
one last time: natural selection can operate on relatively short time-scales, and I'm not even talking about mutations here... NOT ALL individuals within a species are identical... wild animals are generally wary by nature; within the IBWO population 200 yrs. ago undoubtedly some birds were more wary than others; it is possible that human pressures in the 19th century caused the warier birds to have a selective advantage such that by the 1930s the relatively few birds left were carrying "wary" genes if you will (not by mutation, but by mere selection), and then of course their offspring ever since may be further selecting for the strength of that gene. In fact if we view it in reverse I think it's pretty obvious to say that IF the bird exists than surely it is very wary and very (relatively) scarce to account for the difficulty of detection. But going in the other direction we simply cannot presume to know how present-day birds behave based on a paucity of data from 60-100 yrs. ago. I wouldn't even try to predict with any certainty the behavior of robins, titmice, chickadees, or any other common-day bird based on 60-100 year old data of a handful of individuals, let alone an extremely rare bird not studied for 60+ yrs. Species are not little cloned automatons; they include tremendous individual variation that natural selection can play upon.

Thanks for the lesson in evolution, but I think you misinterpreted what I meant. Probably my fault for not explaining properly and posting before I thought things through. I wasn’t suggesting that mutations would be the only evolutionary mechanism for changes, but was questioning the relevance of examples of behavioural changes occurring in common generalists. To clarify:

As I understand it, behavioural changes due to evolution can occur in two ways. (1) Gene mutations occur and these mutations become more prevalent due to natural selection. This occurs over long time scales (typically many millennia unless we’re dealing with drosophila), but almost any number of behavioural traits can occur. (2) A particular phenotype (behavioural trait in this context) becomes more prevalent due to selection processes. This can occur quite rapidly, particularly in small isolated populations, but the extent of the behavioural change is limited by the range of phenotypes (behavioural traits) present within any given inter-breeding population.

What little we know about Ivory-billed woodpeckers suggests they occurred at low densities at occupied large territories. The paucity of records since the 1930s (the time-scale we’re talking about them changing from relatively tame to wary) would suggest that any given inter-breeding population of this species would have consisted of a handful of records: extremely liberally up to 50, realistically fewer than a dozen. I question whether such a small population would exhibit the necessary variation in behavioural traits to cause the species to modify its behaviour from relatively tame to wary. Moreover for a shift in behaviour from one extreme to the other to occur, selective hunting of tame birds would have to have been the only factor causing mortality. Otherwise, it would undergo a smaller change. In other words, no mortality due to habitat loss or it occupying sub-optimal habitat, no mortality due to lack of dead wood / nesting sites (for all it’s sins a key component of the recovery plan), no mortality due to chance events and no mortality due to the Allee effect! Again I find this highly improbable. Furthermore, by chance, warier males would have to mate with warier females to produce wary offspring, which slows the rate at which the change in behaviour occurs, unless wariness is inherited predominantly from on sex or females preferentially select wary males. I can think of no reason why these would be the case. Indeed for the latter, one might expect the opposite due to the elaborate trait theory (bright, bold males preferred). That adds to my concerns. Put simply, I just can't see how such a change in behaviour in IBWOs would have occured due to selective pressures .

Sidewinder - I explicitly addressed cultural changes in behaviour in my earlier post. Could you explain why you might expect epigenetic traits to lead to behavioural changes in IBWOs?
 
Last edited:
pcoin said:
Hicks' comment about just seeing the bird for a "millesecond" came from an interview. That intereview is a little less confidence-inspiring than the official updates. Who knows?

I don't see that the Auburn team, or Cornell for that matter, ever noted a perched bird making calls or double-knocking--that was to whom I was referring. I meant no disrespect to TRE, but I gathered he was not one of the team.

Better reread the very event that lead to the Cornell search. The bird was seen perching, hiking up the tree, etc. No calls mentioned or double knocks, but it was a perched bird.
 
bitterntwisted said:
Can someone post a link to this photo? Thanks!

Graham
Tmguy has taken his site down, but the photo is preserved in all its glory on the Birding is Not a Crime blog. Tmguy posted this on the 'believers' forum recently, on the impossibility of mistaking a perched IBWO!
 
Well done Mike. There was a higher resolution pic (though one that still failed to show feather edges etc) posted as an attachment on Birdforum - I just failed to find it though.
 
As regards the 1971 photos, one can be seen here. But even some 'believers' admit they are not conclusive. In the same article Van Remsen says:

They are lousy photos, taken with a Brownie Instamatic camera. The photos remain unconvincing to many people. You can’t rule either way, fake or real, although I’m personally convinced they are the real deal.

The bird's seemingly identical posture on two different trees raised some concern, as did the manner in which they were presented - photos taken by someone, somewhere. What could be done with them?

But they do raise the issue of wariness - these were supposedly taken by someone with a simple camera who was able to get close enough without the bird flushing. If the birds are so wary, how could he do that? And if he could do that, why can't someone now?
 
Warning! This thread is more than 6 years ago old.
It's likely that no further discussion is required, in which case we recommend starting a new thread. If however you feel your response is required you can still do so.

Users who are viewing this thread

Back
Top