Some comments on my 2006 article on the Ivory-bill


In 2006, I wrote an article on the rediscovery of the Ivory-billed Woodpecker, that has recently been referred to in the `Ivory-bills Live' blog that I appreciate a lot. It is probably significant of the present state of affairs that a 4 years old article written by an European with no first-hand information about Ivory-bills should be considered news. Since, however, some people could just now be interested in how an outsider views the present situation, here are a few comments.

When I wrote my article, after studying the evidence as well as I could, I had come to the conclusion that the Ivory-bill was, surprisingly, probably still alive, and I tried to speculate how this was possible and how it was possible that this had gone undetected for so long. I was well aware at the time that the evidence was not water-tight and stated to several people that I believed that conclusive evidence would probably be found in the coming five years, and if it were not to be found, that I might change my mind again. This has indeed happened. I now believe that the Ivory-billed woodpecker is most likely extinct, and probably was so even when I wrote the article. This change of mind, I believe, is nothing to be too shocked about. I do not feel I have been fooled by the evidence (or some people) at that time. Nor do I feel that I may not change my mind on the matter again. As a professional scientist, I know that trying to find truth in the presence of weak evidence is a tricky, but worthwhile endeavor.

Related to this, there is one point I would like to make very strongly. I believe no money has been wasted on the search for the Ivory-bill. First of all, to all people who have raised this issue, I need to say honestly folks, I appreciate how careful you are protecting the American taxpayer, but face it: a few millions are really not that much for a country like the USA, considering what was at stake. Imagine that the American buffalo had gone extinct. It actually came quite close to that. How would that have been? Importing those thin European bisons (yes, Europe actually managed to save its bisons despite having eliminated most of its wildernesses centuries earlier than the Americans) to shoot Hollywood movies about the Wild West? What a humiliation that would have been. How that miss would have been felt. But it seems you missed out on another icon. If then it looks like you get another chance, even if it is a long shot, if you have any guts you give it a try.

Secondly, even as it is, those searches have yielded tangeable result. Not the result hoped for, not a result that is stressed very much, but together, all those believers and God-bird enthusiasts have collected quite a lot of evidence for the claim that the Ivory-bill is no more. They have done a lot more to support this claim than all self-proclaimed skeptics together. That is useful information, because in the period from the mid-70ies up till around the year 2002, there were actually very few people taking a serious look at the old Ivory-bill biotope.

Considering the evidence in favour of the IBWO's persistence, I must say that I was initially most convinced by the observations by experienced ornithologists. I especially appreciated the field notes of the Auburn group. In addition, I thought the sound recordings, especially of double-knocks were good evidence, though only in conjugation with the observations. I also enjoyed the analysis of the Luneau video and Mike Collin's first video, which I considered not less in quality than the former. (My present point of view, perhaps, would be to say that the Luneau video is no better than Collin's.)

The evidence against the IBWO's persistence, I guess, is basically the lack of any conclusive evidence being found in several years of intense searching, plus some knowledge of human psychology. In retrospect, the popularity of the word `Lord God Bird' should perhaps have rung a bell, since God's presence, as we all know, is a universally accepted truth that cannot be proved. 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.

Nevertheless, I find it a pity how these searches now seem to end with a whimper. Given that the old hypothesis, the presence of Ivory-bills, doesn't seem to fit the data very well, it is a pity not more effort is done to find out if the other hypothesis, the absence of IBWO's, can be made to agree with the facts. 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? Can nobody decide about where a Pileated Woodpecker in flight can show white? Why is nobody analysing the serious arguments of Bill Pulliam on the Luneau video? Even if it doesn't change the IBWO debate one could still learn interesting facts about video artefacts and flight dynamics.

One final point I want to make is about the date of extinction of the Ivory-Billed woodpecker. While I presently believe that the species is most likely extinct, and probably has been for some years, this does not mean I automatically accept 1944 as the date of extinction. Although I have doubts about Dennis' Big Thicket claims and am undecided about the claims of Agey and Heinzmann, I see no good reason to doubt the authenticity of the Lowery-Lewis photographs or some of the observations from the 50-ies and 60-ies.

PS added April 2022 I very much appreciate the new evidence presented by Latta et al. It seems to me their photographs are more convincing than any other evidence collected in the 21st century. So do I believe the Ivory bill is still alive? I am not convinced, but definitely less convinced of the opposite hypothesis than I was before. It is a pity this group did not make sound recordings simultaneous with their automatic photo recordings. Kent calls, on their own, have been recorded many times, but are too hard to distinguish from some sounds Blue jays make. However, if this group had recorded kent calls exactly at the moment when their photographs seem to show two or three Ivory bills foraging, the combination of sound and picture would have been very convincing.

In addition, their work has shown that there is a need for automatic cameras that are capable of detecting motion and zooming in on objects of interest. It seems within reach of modern technology. Moreover, developing such systems is of independent interest, regardless of whether they find the holy grail bird. Which stresses the point I made above, that this sort of research makes sense regardless of the outcome and should be applauded instead of ridiculed.

One final note: the supporting movies of the paper show at least twice birds in flight that seem to be the woodpeckers that are claimed to be IBWOs. It is a pity the paper does not seem to analyse these pictures of birds in flight.