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Tuesday, May 28, 2013

IVORY-BILLED GHOST BIRDS

I have tucked away in an old file a letter addressed to me from James Tanner.  He was someone who I had known of since my early teens, although when I initially corresponded with him I didn’t let on that I did.  Back in the days before computer generated form letters, he replied to me with a personal and eminently polite note concerning the graduate program at his institution.

At that early point in my scientific career, I was debating in whose footsteps I might wish to follow.  Would it be those of Tanner- the last individual to study the Ivory-billed Woodpecker- a guide across the Styx into the world of ghosts?  Or, alternatively, would it be with someone who could tutor me in the practical and possible?  My decision turned out to be somewhere between those opposing poles- I would follow an individual who had already left this world, John Sage, a founder of the American Ornithologists Union who was ending his career about the time that Tanner was beginning his.   He was also student of Connecticut birds, so continuing on his distributional studies was something that I could actually do. Back in the early 1970s, when it was still possible to sit in a university collection room alone and unsupervised, I would spend my late evenings in front of Sage’s hand-written catalogs and his tray of preserved Passenger Pigeons, contemplating the individual who had collected them.  To this day, I continue largely in Sage’s shadow (see this work here).

But still, thoughts of Ivory-bills never quite faded.  Over the decades intervening between then and now, I have quietly launched solitary albeit unsystematic searches for them.  In all, my searches have been limited in scope, never reaching the magical thousand-hour threshold that seems the minimum for recording low probability events.  But still, I’ve tried and will likely try more.  There are so many thousands of acres of habitat and so few people out really looking that it has seemed just possible that birds might survive somewhere.  The inaccessible and inhospitable nature of the species’ last known refuges- bottomland forests- also appeared to argue that it could be persisting undetected.  Suggestion has also been made- and seems to be backed up by observed patterns of sightings and disappearance- that any remaining birds might be nomadic, so where they are one year is not necessarily where they are the next. Such a possibility would make documenting their occurrence doubly difficult.

Like so many others, when several years ago credible evidence surfaced in Arkansas and Florida (in the latter case, right near where I had been searching myself) that Ivory-bills were still extant, I was exhaltant.  I knew it.  They had to be somewhere.  I watched the videos and listened to the recorded calls posted on the internet.  I found the videos modestly convincing, but the sounds?  Certainly.  In their cadence and phrasing and horn-like quality, it seemed to me that they could be nothing else. I had burned into my head those very sounds from 1930s recordings I had listened to years before.

And then, enter the naysayers.  It is a venerable tradition in academia that critique follows assertion- tiresome and apparently self-serving at times- but most would say essential nonetheless.  In this case several groups took on the evidence presented and negated it point by point.  The images could have been this, the sounds could have been that, statistical inference indicated no no no. 

One suggestion was that the sounds might have been those of blue jays.  I could see why one might think so, but I disagreed.  I’ve just completed, a la John Sage, eight years of surveying Connecticut’s forest birds (see this work here) in which I detected individuals via vocalizations under varying field conditions, topography and distance.  During those years, I counted the better part of two thousand jays and in the process heard what seems likely to be every variation on a jay call theme.  My ears told me that those recordings were not of jays.

And then there was the issue that one of the naysayers had not too many years before edited a volume on Connecticut birds.  In that volume, it stated that it was absolutely, positively and otherwise definitely impossible to survey quantitatively the birds of the entire state.   Well, as it turns out, I just did that, alone and on my own dime, covering over a thousand miles on foot, and not just in summer but in winter as well, and I threw in the whole state of Rhode Island for good measure.  So, assertions to the contrary aside, it was possible.  Dogged determination, persistence and belief go a long way toward making the impossible possible.  I hope traits like these will guide the serious searchers for the Ivory-billed Woodpecker in the years that follow.


It was, thus, with some dismay that I read that one of the key institutions behind re-discovery attempts, the Cornell Lab of Ornithology (Tanner's alma mater, by the way), was discontinuing its intensive field efforts to find birds.  This led me to investigate who was behind the surveys.  From the photos I located, it appeared that the teams consisted principally of young students.  Physical stamina is certainly an advantage in the daunting work required of a survey of this sort.  I discovered my own decreasing stamina limits late last summer when, during field searches for migrant Eskimo Curlews, my legs began giving out after hour upon hour of trudging along Cape Cod dune trails.  However, there is a trade-off between stamina and experience.  Back in Tanner's day, the senior Arthur Allen and Peter Kellogg were out with him during those historic Ivory-bill studies.  I regularly see how my own years of experience give me a substantial advantage over the less practiced in distinguishing subtleties, in understanding how to look and in detecting what others might miss.  I hope this generation of senior Cornell figures has, similarly to their predecessors, made a significant field contribution to the recent efforts.  

Despite professions by some of the scientific elite that the Ivory-bill is either extinct or beyond saving, my feelings remain different.  What I see from published reports is a species that appears to have persisted for a century over significant portions of its former range without any human help.  As our continent's supply of mature bottomland forest continues to grow, we may yet see this bird emerge from its present ghostly status back to that of a resilient and revered member of our wildlife community.

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