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IVORY-BILLS  LiVE???!  ...

=> THE blog devoted to news and commentary on the most iconic bird in American ornithology, the Ivory-billed Woodpecker (IBWO)... and... sometimes other schtuff.
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Sunday, March 04, 2012

 

-- Update --

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Not much of an update (read prior post if you haven't already), but I've been listening to the Coyote tapes repeatedly, and received slightly more context about the sounds. My first impression remains the same, that these don't sound (to my ears), like what I'd expect of Ivory-bills… the pitch, tone, cadence, speed, rhythm doesn't maintain itself correctly through the tapes, even though some short bits do sound intriguing (but, I've done no technical analysis). Having said that, I can't pinpoint a good alternative candidate for the sounds either. Certainly though, a great many sources must be considered:

1) various amphibians

2) injured or 'yelping' dogs or other mammals

3) mechanical or artificial (man-made) sounds: bird calls, tools, hinges, equipment etc.

4) I'm not aware of insects that could make these sounds, but would want an entomologist to weigh in on that.

5) just among birds alone, jays, herons, waterfowl, blackbirds, hawks, escaped psittacine birds, vagrants, and perhaps more must be considered

If some of the above suggestions seem outlandish to people, one must understand that the possibility of IBWOs IS outlandish to people… to rule IN such a low probability possibility as IBWOs, one needs to consider and rule OUT all other low probability possibilities. And from what I'm told, several of the above are already considered and ruled out. Process of elimination is a somewhat weak, but necessary, way to proceed (and I would expect spectrographic analysis will rule out all but a few of the above, though not necessarily pinpoint an answer). My own guess is still that there WILL be an alternative explanation for the sounds (this is the time of year a LOT of forest critters begin sounding off!), but admittedly, with each listening I'm having a harder time surmising what it might be.

I'm curious, by the way, of what Nancy Tanner might think of the sounds, if anyone out there can draw her attention to them. Anyone else who cares to weigh in via the comments or privately through email, feel free to do so, as well.
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Comments:
Cyberthrush, thanks for this thoughtful follow-up. My experience with this audio is very similar to yours. In the field, I said something to the effect of "this doesn't sound quite right," in reference to the lack of nasality in the calls. As I've listened to the recordings again and again, the more subtle ways it resembles the Singer Tract recordings impress me more. As I've written you privately, I'm also struck by a number of similarities between my impression of the calls and some descriptions in the literature, Audubon's in particular; however, in the absence of a perfect match for the Singer Tract recordings, no audio is going to be considered conclusive. Even assuming the IBWO is extant, I think obtaining such audio is unlikely in the extreme, given the unique conditions under which Allen, Kelllogg et al. were recording.

I do think it's important to try and eliminate all possible alternatives, and I have the impression that some of what you've listed has been eliminated. I won't speak to audio analysis, something about which I have only rudimentary knowledge, but I can speak to field conditions, which argue for the elimination of some items on your list.

Mechanical and artificial man made sounds are highly improbable, if not impossible. The nearest, and very lightly travelled, road is approximately 1 mile as the crow flies from the site where the recording was obtained. We entered the public land from the only parking area that is currently usable due to high water conditions. There were no cars in the parking area. Taking the direction of the calls into consideration, the nearest possible human or mechanical source (excluding the crop dusting plane that was flying around) would be several miles away.

Similarly, the chance that it was an injured or yelping dog is extremely slim. The calls came in two extended series (with possibly a single, more distant call heard but not recorded approximately fifteen minutes before the series began.) We were in the location for over 45 minutes, and in the general vicinity for well over an hour, counting hiking in and out. The recorder was running for approximately 30 minutes, and outside of these two sequences, no similar sounds were captured.

I think I speak for everyone involved with Project Coyote in saying that critiques and alternative hypotheses are welcome.
 
I posted by mistake before fully reviewing and editing. Sorry for the grammatical error in the first paragraph. I also wanted to comment a little more on yelping dogs and other mammals, it was clear to both Frank Wiley and me that the sounds were coming from mid-canopy. We also independently concluded that the sounds were not stationary, that they were coming from two sources, one closer and more vocal, the other distant and less vocal. I think this can be heard on the audio if you listen carefully. In any event, the calls were coming from a flooded area (which is what rendered it impossible to try and approach the source.)

The only remotely plausible mammalian explanation that I can think of is squirrel, something that no one - to the best of my knowledge - has suggested and something that should be easy to confirm or reject.
 
Probably not a yelping dog.

So could well be an IBWO.

*sound of a barrel being scraped*
 
I should have added that the most obvious avian confusion species, including several of those you listed, were easily ruled out in the field, and have since been ruled out by independent reviewers.
 
So it's an unidentified sound, possibly organic in origin, but the jury is out.

Got any photographs?
Bird not there anymore?
Bird can't be seen by human eyes?
 
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