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Bill Pulliam recounts a March 2009 morning of double-knocks in western Tennessee HERE (depending on your sound system, the DKs, especially the first two, can be difficult to hear). More analysis will likely follow.
Meanwhile, "Ghost Bird," the movie, continues its showings across the country, picking up awards along the way....
I've lost count of how many examples of possible Ivory-bill double-knocks and kents are now available to hear on the Web, let alone how many total have been reported by intelligent observers over the last 5 years. Such sounds are necessary or at least valuable backup and support for claims that the Ivory-bill has been seen in recent times... but they are not sufficient by themselves as evidence for the presence of the species. The fact is that both "kents" and double-knocks are simple enough sounds that they can be simulated by other sources, and are not clearly diagnostic for Ivory-bills alone. Worse yet, we have very little historical record of Ivory-bill sounds to even base careful scientific comparison upon (no Ivory-bill double-knock recordings and just one small sampling of kent sounds recorded in a single location, at a single time period -- really very little to go on). Nor am I convinced that one can even consistently discern through analysis, mechanical or man-made sounds from bird or nature sounds. DKs in particular can vary tremendously depending on the type, age, and condition of wood. Wind and weather conditions, and obviously distance are also confounding factors; and even different recording devices may introduce different variables into the mix.
In the course of Ivory-bill searches we need to hear double-knocks and kents, find foraging signs/bark stripping and old cavities, and... above all, to tie it all together, have sightings --- clear, unobstructed (even if brief) sightings by credible observers on the ground... in those very same areas of curious sounds. Without sightings of the bird in the flesh, or feather as-it-were, the rest of the evidence pales, even as it intrigues.
I continue to put faith in certain visual reports of the past, as well as more recent times, as indication of Ivory-bill presence. Meanwhile, stung by critics early on in this saga, official agencies have become very conservative in publicizing sighting claims over the last couple years. Also early on, skeptics warned that sending dozens of people into the field with hopes/anticipation of seeing an Ivory-bill would merely insure that many more 'sightings' would indeed be recorded... and, they would be meaningless. My concern, and a far greater worry I think, with so many individuals stalking through so many areas, is that many more sightings have not occurred. We can go for many years with 2 or 4 or 6 plausible sightings each and every year; but we ought be advancing to 10 or 15 or 20-25 sightings, if search techniques have validity. And then a clear photo, a nesthole, and then film... and hey, along the way, champagne and high-fives.
The official IBWO search is screeching to a halt, not for lack of evidence, but for lack of sightings of a creature that has indeed earned the name "Ghost Bird."
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