I had been planning to do a post with various ivorybill related tidbits in anticipation of the search season, which begins next month. That will be coming in a week or so, but I want to say a little more about Bill Pulliam first (beyond his Luneau video analyses, which I think should be dispositive). This decision was inspired in part by one of our advisors who pointed similarities between what Bill observed in Tennessee and what we’re seeing in Louisiana. While the physical characteristics of our old search area seem to have more in common with Moss Island, Tennessee than where we’re currently focused, Bill’s perspectives are relevant to both.
Edited to add: Moss Island is a small wildlife management area encompassing 3400 acres. I’m not sure what percentage is mature bottomland hardwood forest, but there are a variety of other habitat types. Compared to our search areas it is relatively isolated and distant from other large tracts of forest.
As an aside, Cyberthrush also has a post honoring Bill with a link to an eBird tribute.
With comments included, Bill’s series of posts on Moss Island runs to nearly 54,000 words. There’s no telling how long this series will remain readily accessible online, and indeed some of the images and sound files are no longer available. The entire series is worth reading and saving if you’re seriously interested in the ivorybill. It starts here.
On re-reading the posts for the first time in eight years, I’m struck by how much Bill influenced me without my recognizing it and/or how much the evolution of my understanding between 2009 and today is congruent with the ideas he expressed just as I was getting more deeply involved in searching.
Like Bill, I suspect that the near extirpation and revival of the beaver may be central to the ivorybill’s decline and survival (more about this in my next post). Like Bill, I think that Tanner’s model failed to account for environmental changes that had taken place in the preceding centuries. Like Bill, I think that if the ivorybill survived, it had to have adapted in ways that are inconsistent with Tanner’s a priori assumption that the species is old-growth dependent.
Bill was tough-minded and opinionated. There were times when I thought he considered me a somewhat annoying amateur. While we hadn’t communicated about it in recent years, he took a dim view of my efforts to make sense of feeding sign in the early days. Most of our correspondence took place in the 2000s, while he was still actively blogging about the ivorybill. After that, I sought his input sparingly.
My last exchange of emails with him pertained to the March recordings. Without quoting him directly, I think it’s fair to say he thought the calls were likely or more than likely Ivory-billed Woodpecker. He also thought it unlikely that birds were resident in our search area, based on the pattern of potential encounters, the paucity of strong sightings, and lack of conclusive evidence. I’m not sure I agree; I wish there had been a chance to explore this topic in more depth and that he’d been able to see our search area for himself. Nonetheless, his perspective has led me to consider that other nearby forested areas deserve more attention than we’ve given them to date.
I’ll conclude with three paragraphs from his final post in the Moss Island series. It’s as true today as it was in November 2009 (though I suspect nesting may take place in fragmented second growth, as in our old search area). I hope it inspires you to read the rest. More from me soon.
How does this relate to Moss Island? By Cornell standards, our habitat is unsuitable. Hence, our encounters are largely dismissed out of hand. By doing so, the Cornell approach has painted themselves into a rather nasty corner. The logic is simple. To all appearances, we have Campephilus-like double knocks that are at least as good as what has been heard in the “core habitat” such as Big Woods and Congaree. If one claims that in “core habitat” these represent evidence for the possible presence of Ivorybills, but in “marginal” or “unsuitable” habitat they provide no evidence for the possible presence of Ivorybills, one has committed a logical no-no of the first magnitude. If the same sounds come from places where you have concluded that Ivorybills are not going to be, then you should conclude that these sounds have no relevance to Ivorybills anywhere. Conversely, if you feel these sounds are evidence of the possible presence of Ivorybills in South Carolina or Arkansas, then you must also accept that they would be evidence of the same in Tennessee, Illinois, Mississippi, Florida, Louisiana, and Texas. You can’t have it both ways.
Anyone who seriously considers that Ivorybills might still persist, and that double knocks and other soft evidence have a relevance to indicating their possible presence, should accept that the evidence in total suggests their habitat requirements might be broader than has been assumed by Cornell et al. I’m not suggesting they will nest in fragmented second growth, or even use it as a full-time habitat; but there are ample indications that if these sort of encounters mean anything anywhere then the birds indeed are using fragmented “marginal” habitats for at least parts of their life history. These habitats are hugely more extensive than the “core” habitats, hence this possibility raises all sorts of further hypothetical possibilities for the natural history, survival, and conservation of the species, all of them positive. In the alternative philosophy to Cornell’s, you search where you have learned of rumors, whispers, or credible declarations that something of interest might have been seen or heard there. This of course requires a lot of judgement, and eventually everyone will draw the line somewhere; I’d not put much stock in reports from western Kansas, for example — although good double knocks in Nebraska or Vermont would settle a lot about what they might mean in Arkansas! But until and unless we actually find some reproducible birds and determine what their 21st Century habitat use patterns really are, minds should be kept open.
You will not get anyone involved in the Tennessee project to state that we have established the presence of an Ivory-billed Woodpecker anywhere in Tennessee as a statistical or scientific certainty. None of us has put an Ivorybill on his or her life list. However, if you asked us off the record for our own personal unscientific feelings, I think you would hear several confessions that indeed, some of us do strongly suspect that there has been at least one of these critters tormenting and taunting us in the delta woods for the last several years. Which means we also think that all that follows from this about habitat, behavior, distribution, etc. should be given serious consideration. Interconnected mosaics of fragmented second growth bottomland forest should be included within the spectrum of possible habitats for the species. You will not get anyone involved in the Tennessee project to state that we have established the presence of an Ivory-billed Woodpecker anywhere in Tennessee as a statistical or scientific certainty. None of us has put an Ivorybill on his or her life list. However, if you asked us off the record for our own personal unscientific feelings, I think you would hear several confessions that indeed, some of us do strongly suspect that there has been at least one of these critters tormenting and taunting us in the delta woods for the last several years. Which means we also think that all that follows from this about habitat, behavior, distribution, etc. should be given serious consideration. Interconnected mosaics of fragmented second growth bottomland forest should be included within the spectrum of possible habitats for the species.