Thursday, October 29, 2009

The Mystery Remains

And the answer is...?

As of today (October 29, 2009), there have been no more encounters with the MIMDKWFTII. I've only made a few visits since June, and am probably done for 2009 as there's no money and not much free time in the near future. We made no real progress on the overall goal: Determine WTF the MIMDK is.

I do come away from the 2009 season, however, firmly convinced that the Mystery Double Knocker is a real and coherent phenomenon, not just an agglomeration of assorted misinterpreted and misconstrued unrelated ordinary occurences. Out of the whole 20 months I have been involved in this project, one or two minutes on one day haunt me the most. It was that afternoon of February 24, 2009, as the rain was ending and the grizzled squirrel hunter across the lake shot his supper. The string of double knocks that followed were utterly clear, perfect, and undeniable. Unlike my first encounter, I knew exactly what I was listening for, and what I was hearing. I was all alone, the rest of the crew having bailed because of the weather, sitting there by myself in the drizzly late afternoon gray. If my first encounter in 2008 was the Black Swan flying across the sun, this one was the Black Swan sitting on the hood of my truck. No denying its existence, no hope of talking myself out of this one. And, I knew the damn thing was just gonna fly off and disappear again.

As a loose end from my last post, some might wonder why I spent all this time analyzing my 3/18/09 recording when I expressed such strong objections to robobirders in an earlier post. Thing is, a real "meat birder" holding a video camera is not a robobirder. All that additional information that is lacking in robodata is present in the birder-videocam combo: context, apparent distance and direction, subjective impressions of quality, loudness, etc. The digital data and the analog experience are able to complement each other, without either making the other obsolete. But in reality, I think at this point in the Tennessee project the desire for "objective" documentation has as much to do with peer pressure than anything else. We have no doubt amongst ourselves about the reality and validity of the double knock phenomenon at Moss Island.

But what about all the alternative explanations for the double knocks? As far as the misinterpretation of ordinary sounds (e.g. gunshots, boat clunks, off-site mechanical sounds), in spite of how we sometimes seem to be viewed by northeasterners and west coast types, we are actually a pretty skilled, experienced, and discriminating crew. We take great care to rule these things out, and have clearly noted these double knocks as being something consistent and unusual. The various non-biological explanations also don't work with the spatial, seasonal, and diurnal pattern we have seen. Weather, construction, etc. aren't most active in the first three hours and last two hours of the day, they don't ramp up in late February and quiet down again around the end of March, and they don't cluster within the woods in the Rhodes-Hushpuckett Lakes corridor. No, the only thing that fits this is a biological source; specifically a mobile diurnal one. In other words, a bird.

What about duck wingtip collisions? Sorry, those may be able to confuse a robobirder, but they don't cut it as an explanation for the live sounds. They are an especially poor match for the double knocks that occur in series, repeatedly from the exact same direction; nor do they account for the freakishly intense loudness of the double knocks when heard from distances of about 200m or less. Really, there's only one option. It has to be a woodpecker -- a big one. Nothing else is properly equipped.

Here we come to the only alternative explanation that makes the cut: Could the Mystery Double Knocker be nothing more than a Pileated Woodpecker? Pileateds are certainly capable of making loud noises with their peckers; indeed they seem quite fond of this sort of thing, especially in late winter and early spring. They are also extremely common at Moss Island and in most other coastal plain bottomland forests in the southeastern U.S. However, no one has ever documented a Pileated making these dead-ringer-for-Campehilus double knocks; no one has actually documented a Pileated making any double knocks that are not embedded within an abundance of normal Pileated sounds. But, no one has yet specifically documented ANYTHING north of Mexico making these dead-ringer-for-Campephilus double knocks in about 70 years. Large woodpeckers have been glimpsed fleeing the scene of the (double knock) crime, but have not been seen well enough to definitely identify as Pileated or not-Pileated. It's not just the Moss Island Mystery Double Knocker, it's the North American Mystery Double Knocker.

But why not just claim Occam's Razor and call it a Pileated? Well, until someone actually sees something else making the sound, it can't be entirely ruled out. However, a lot of things don't fit. First, Pileateds are common and widespread in much of North America, not just the coastal plain bottomlands. Yet the phenomenally loud double knock has never been identified or described as part of their repertoire anywhere, by anyone. Perhaps it is an unusual display, used only rarely, and therefore only likely to be heard where they are especially abundant. Or, perhaps it is only a small percentage of individuals that engage in this display, which might also explain the spatial clustering in “hot zones.” Several things argue against these ideas. First, Pileateds are more common in bottomland hardwoods than in other forest habitats, but only by a factor of like 3-5, not by orders of magnitude. I live surrounded by hill-n-holler upland hardwood forests in middle Tennessee, where I see and hear Pileateds many times every day. Many other experienced birders live in similar proximity to the species. I've yet to hear any of these double knocks at home, where I spend far more time than I do at Moss Island. Even with all the publicity and skepticism surrounding double knocks in recent years, no one has turned up data showing any of these tens of thousands of backyard Pileateds making this sound. Believe me, if one of these things went off in your backyard, you WOULD notice! As for the “hot zones” being caused by individual aberrant Pileateds, they actually tend to be bigger than the typical home range of a Pileated in these densely-packed habitats, so you'd need multiple neighboring birds that posessed this aberrant behavior to explain the phenomenon this way. Anyway, woodpecker drums are pretty hard-wired, fixed, inborn display patterns. They're not subject to learning and they hardly vary between individuals or circumstances. It seems very unlikely there would be a distinctive, conspicuous, yet undescribed Pileated display still lurking out in the woods.

If I were in a court of law right now I'd probably be raked over the coals at this point for having produced nothing but circumstantial evidence. It's true, that's all I got, ain't nuthin' else. Until someone SEES the f'ing thing we will not really know. It's all Just So Stories in the meantime. I'm not going to commit the sin I have chastized others for and say “I don't know what it is, but I know it isn't a Pileated.” I don't think it is a Pileated, but I really just plain don't know what it is.

There only seem to be two options, however.

In the rest of my "wrap up" posts I'll talk about some of the larger implications of all this, speculate wildly about woodpeckers, and give opinions about what we should do from here onward.

Other posts in this series:

Monday, October 26, 2009

Bass Notes

Singing trees, not singing fish

While I was continuing to get skunked at Moss Island, at least on the double knocker front, "Jacob" had been circulating my 3/18 double knock recording a bit amongst other interested people. I did not expect much response, as the big projects seemed to have dismissed Tennessee a year or more before. However, in June one of the Cornell PIs did have comments, and there was a bit of an e-mail conference between him and us. His initial response was two fold: very impressive double knocks, and because of the 10 second spacing almost surely just the simulations. There was some miscommunication between Cornell and Tennessee about the particulars of the simulations and timings, but even after this was sorted out the Cornellian remained convinced that mistiming, miscounting, and anomalous sound propagation were more likely than an actual response to the double knocker. He commented that, "a response pattern of just three double knocks spaced 10 s apart is unlikely for Campephilus." My observation in February of what was essentially this exact thing (three double knocks in rapid series) in response to a gunshot appeared to be given no significance. Worthy of note, we were not operating from a presumption of Ivorybillness and did not dismiss data because it did not match a priori notions of how an Ivorybill should behave. If we have Campephilus-like (actually, Campephilus-identical) double knocks at Moss Island, that fact is of great significance to the Ivorybill quest regardless of whether or not they truly are from an actual Campephilus. I'll have more to say on that in my concluding posts in this series. In the end he concluded that the sounds I recorded were "quite obviously something else than an Ivory-billed Woodpecker." My closing response to this was, "'Obvious' is a judgement. There are many rational, well-educated people who consider it obvious that the human mind was intelligently designed, that the bird in the Luneau video is a normal Pileated Woodpecker, and that double knocks are caused by duck wingtip collisions."

Beyond these immediate discussions, though, we also talked about what sorts of responses to the double knock simulator might be expected based on what has been seen in other Campephilus species. Much remains unanswered, but doesn't it seem likely that there would be wide variability between species, times of year, and local circumstances? Imagine if you tried to predict the behavior of a Lincoln's Sparrow on the wintering grounds based on the behavior of the congeneric Song Sparrow on the nesting grounds. You would get some broad generalities right, but would be wildly in error on many important particulars.

There is one well-publicized example of the behavior of a pair of Campephilus woodpeckers in response to simulated double knocks: David Attenborough's Magellanic Woodpeckers. Bear in mind, though, that this is a nature documentary, not a piece of raw scientific data. What we see in the final video is very likely a greatly edited abstraction from a large amount of footage. Who knows how many attempts were needed before this worked, if Attenborough's little tapping on the tree with two small rocks is the only attractant they actually used, whether they might have been standing 10 meters away from the birds' nest tree, if every shot is even of the same pair of woodpeckers, etc.? This is primarily entertainment, not scientific documentation. Still, though, it is the best footage of double-knocking Campephilus that I have seen anywhere.

I have wondered ever since I first shot the 3/18 video if there is a way to determine whether the double knocks I recorded are real or simulated based purely on the properties of the sounds themselves, without involving matters of timing, location, etc. To the ear the simulator can be a good approximation to the real sound, but it is not identical. Spectrographically there are some notable and consistent differences, which I alluded to in the previous post. I already posted one sonogram of the sound of the simulator at close range; here are two more along with video clips so you can hear also. As always, click the sonogram to see a larger version:

April 9:

August 21:

And here are samples of double knocks from the same simulator recorded from increasing distances, from August 21-22:

Note that to improve legibility, I boosted the gain by 100% on the middle three and by 200% on the last one, hence there is a lot more drop in loudness than it appears. The final sample, from 600m, was recorded at dawn; the others were at midday. It shows very well the greatly improved sound propagation in the dawn stillness; remember though that it is still less than 1/3rd of the distance that I was from Scott on the morning of 3/18. Looking at the whole sequence, you see the loss of the high frequencies, the blurring out of the sharpness, especially in the second knock and at midday, and the persistence of the long trailing gunshot-like echo at lower frequencies, regardless of time of day.

For comparison, here are two examples of real double knocks. First, a Powerful Woodpecker from the Macaulay Library of the Cornell Laboratory of Ornithology, catalog number 84098:

Next, here are sample double knocks from David Attenborough's Magellanic Woodpeckers (I hope the BBC, who seem to be checking my blog regularly, do not object to this use of a tiny sample of their footage. It would seem like fair use to me):

The most obvious differences are twofold:

A. The simulations have more high-frequency sound than the real double knocks.

B. The simulations show a more pronounced trailing echo than the real thing, looking almost like little gunshots with their broad rightward smear.

The real sounds are variable in their frequency distributions, especially on the low range. The examples that show the strongest base notes are the ones by the male Magellanic when he appears to be rapping close to a cavity, presumably near a void in the tree truck. This deep base is what gives some of the knocks their hollow, resonant quality.

Look more closely at the basso profundo on the Magellanic double knocks. Notice how the vertical line marking each knock bends to the right towards the bottom. There is a delay of a few milliseconds in these base tones as compared to the higher frequencies. In the Magellanic knock with the strongest base, it looks like this delay is actually greatest not in the deepest tones, but a bit above them; it's a bowing out, not a simple rightward bend. On the Powerful sonogram, the basso profundo is much less forte. But in the clearly visible faint tails at the bottom of the knocks, we see a distinct rightward bend as well.

I should say here that I am a hack when it comes to bioacoustics. Sure I have a Ph.D., but it is in Ecology, not Physics, Acoustics, or even Music. My formal training in acoustics would have been nothing beyond college physics about 28 years ago. So I am no expert here. But I'm not a total dope, either. It seems to me that this rightward bowing on the base of the sonogram, indicating a delay in the production of the tones in the frequency range of a few hundred Hz, is likely a property of the resonance of tree trunks. I expect it is this brief delay that especially gives the real knocks their sonorous, resonant quality.

Now, look back at the simulations. They do not show this feature. The initiation of the sound is at the same instant at all frequencies, making a crisp straight vertical line on the sonogram. Whatever the resonance properties of a real tree are that produce this effect, the simulator appears to lack them. Again, I'd hypothesize that the lack of this feature is what makes the simulations sound subjectively less resonant to the ear. There is no lack of the basso profundo tones in the simulated double knocks; they just happen at the exact same instant as the higher tones and thus to the ear are absorbed within the one big sharp "whack." I would propose to add a third distinguishing feature that can potentially differentiate simulations from the real thing:

C. The simulations lack the rightward bend of the sonogram at low frequencies; all frequencies of sound are produced at the same time.

As far as utility in the field, it varies between each feature. Item A, the excess of high frequencies, will fade out rapidly in a forest so it is probably of no real value. Item B, the trailing echos, certainly might be useful. In the data I posted both here and in the previous post showing the simulations at different distances, this only becomes more prominent with attenuation, as the whole sonogram dissolves into mush. Unfortunately I do not have any recordings of known real double knocks at great distance for comparison. Item C, the rightward bending base of the sonogram, might well survive over distance. As the speed of sound in air is largely independent of frequency, this feature (straight versus bent) should be preserved for as long as the sound remains crisp enough to give a good spectrographic image. It's also worth noting that this feature might be useful for separating "real" double knocks from other sounds, such as duck wingtip collisions, construction or vehicle noises, etc.

Finally, to the Tennessee sounds from March 18th one more time. Here is the clearest one, number 3 (click to enlarge):

As would be expected in either case, the high frequencies are gone. In the base tones that remain, I see rightward bowing. In fact it looks almost exactly like the shape of the Magellanic double knock at the same frequency range. There is also not a trace of the trailing echo, or any other smearing. So for the two criteria that might be meaningful in the field at a distance, this one scores as "real" on both.

Here are the other two 3/18 double knocks, along with the audio/video again:

The first knock of #1 is fairly clear; it looks bent to me. The final note of this double knock, plus both notes of double knock #2 are very faint. Still, the faint lines do seem to show a bend.

Score for this round:

Simulations: 0
Real thing: 2

Once again, this still only indicates that the sound is not the simulator and is something else rapping on wood making a sound very much like a Campephilus double knock. As always, this does not in itself prove the presence of a real Campephilus woodpecker at the site. But it again supports the idea that the Moss Island Mystery Double Knocker is a real and coherent phenomenon, not just a random assortment of ordinary sounds being misinterpreted.

Other posts in this series:

Thursday, October 22, 2009

Simulations Galore

Virtual unreality

Regardless of all the intrigue and discussion about the double knocks I recorded on March 18, the event did not have a major impact on our strategy for the rest of the season. If they were real double knocks that occurred in response to the simulator, what did this mean? It meant that the MIMDKWTFII had executed a series of double knocks in response to a loud anthropogenic banging noise in the woods between Rhodes Lake and Willow Flat. Well, that would make the third instance of a possible double knock response to a loud human sound at Moss Island, and the second one consisting of a series of double knocks within the same small area. It would make the sixth (I think; may have miscounted) occurrence overall of double knock(s) in this area. Nothing new there; just reinforcement of the previous patterns and strategies. The one thing I did feel it provided was some measure of vindication, both at the personal level and the project level, that I and we were in fact accurately distinguishing the "real" candidate double knocks from the background sounds. But the goal remained the same and remained unattained: Get a visual on the mystery double knocker, whatever it is.

It did perhaps suggest that a targeted cavity survey within this area might be worthwhile. Given the early time of the 3/18 double knocks (4 minutes before sunrise) if it was in fact a cavity roosting bird making these sounds then it might have a roost cavity nearby. Scott and Melinda were not available in the immediate future for more field work, and I was the least experienced (and skilled) cavity searcher of the crowd. I have generally considered shotgun cavity searches a waste of time and so have never really participated in them. In late March I did try my hand at it in the area from which the 3/18 double knocks seemed to have emanated. After a day I decided I was a lousy cavity searcher and dropped it, returning to the earlier approach of just sitting quietly with camera at the ready. Of course, I saw and heard nothing. Three weeks had elapsed between the last two possible MIMDKWFTII detections in the area, no reason to expect I'd get lucky any quicker this time.

In early April, Scott and Melinda were able to get back in the field. We concentrated on the same area, essentially bounded by Rhodes Lake Road on the south, a line drawn directly north from the Turnaround on the west, Willow Flat on the north and east, and the ATV trail that crosses the Rhodes Lake sill on the southeast. Melinda and I stationed ourselves variously within this area while Scott moved through it doing a double knock simulation series every hour or half hour. After Scott had to leave, Melinda and I remained an additional day and a half with me operating the simulator while she stationed herself aboard kayak in Rhodes Lake. All told we put in three days of this routine, covering April 7-9th.

After the confusion around the 3/18 event, we instituted some improvements to our field protocol for when the double knock simulator was in use. We made sure that all listeners were in radio contact with the operator of the simulator, and he would announce one minute and 10 seconds before the beginning of each series. I always turned my video camera on when each simuation began, and kept it running for about 10 minutes afterwards. When I was the operator, I made a point of getting a time stamp on the video as well. The communication, time stamping, and recording of the simulations should be adequate to resolve any future uncertainties about whether a sound was simulated or not.

As usual, however, all this cross checking and documenting was never put to the test, because none of the three of us heard, saw, or recorded anything worthy of note during this time. It did yield an abundance of recordings of simulated double knocks from various distances, however, as well as a more personal experience with how well the sound can be heard. We also got much more skilled at operating the simulator; Melinda commented that now the majority of the simulated double knocks generated by either Scott or me sounded like good approximations to the real Campephilus sound; earlier it had been a small minority. I noted that, though it was sometimes faintly audible at 1000m, most of the time the simulator was difficult or impossible to hear beyond about 500m. Leafout was under way as well, which was doubtless affecting the propagation of sound.

Here are three sets of simulated double knocks recorded from increasing distances. These are all from after we got practiced at using the device so they are much more consistent in timing, loudness, and quality than what we had going back in March. In each case I have edited the recording to place the double knocks at 1 second intervals. First, a set by me from only a few meters away (click the sonogram for the full image):

You can also see that the double knock simulator is hardly a high-tech device; it's a plywood box, open on two sides, that you tie to the tree and whack with a couple of wooden rods. Looking at the sonogram, beyond the overall loudness note the large amount of accoustic energy up in the high frequencies as well as the long trailing echos. The simulated knocks are almost like mini gunshots. Also note (this will come up later) how sharp, clean, and perfectly vertical the line is that marks the beginning of each double knock.

Next, a series by Scott from about 200m away:

Though to the ear they still sound fairly clean and doubled, the sonograms show a great deal of "mushiness." In some cases the individual knocks are not even clearly resolved from each other. Most of the higher frequency sound has faded away to near invisibility. Another feature that shows here is that in most cases (I see it best on #2, 3, and 5) the second knock is missing the lowest tones, being concentrated more in the upper part of the range of pitch that has survived the attenuation at this distance.

Finally, a set by Scott from about 500m away:

The double knocks are still audible, though the doubleness is not always so distinct. On the sonogram they are nearly gone, however. There are just faint indistinct smudges at about the right frequency; the crisp onset of the sound and the separation between the two knocks are both pretty well obliterated.

After this excursion in early April, I was mostly on my own for the rest of 2009. Melinda and Scott had other business to attend to as the nesting season approached; my own field time reduced as well. I did not use the simulator in the field much anymore. After our saturation effort in the "hot zone" yielded nothing further we decided to give it a rest. As Melinda said when she and I were packing it in after the last morning of whacking on trees, "Elvis has left the forest." Or at least he seemed to be done with his performances for the time being.

For the rest of April and in to May, I focused on spending more time in the few areas adjoining the "hot zone" where our effort had been lacking. These were places of difficult access along the northern and eastern fringes of the WMA, close to the Obion. At the very least I wanted to be sure I had seen the whole place and spent some token effort within earshot of every hectare.

Other posts in this series:

Monday, October 19, 2009

Fun with Audio

More numbers than the mind can comfortable contain...

Back at home, I discovered that the video camera did indeed capture at least one double knock. Once I got the video loaded up on my computer, I set about seeing what I could extract from it. You may want to have the video clip open and handy for reference. Also good for reference is this map of our locations at the time (click for a larger version):

The three double knocks flagged on the video clip I posted in my last entry are the ones I am sure are there, and are the ones I heard in person. They occur at the following times (all central daylight):


They are at very even 10 second intervals, exactly as would be expected if they were the simulations. However, if Scott had started the simulations at or within a few seconds of 7:00:00, as he believes he did, and did only 5 double knocks, as he believes he did and actually did do every time I definitely heard him, then his last simulated double knock should have been at 7:00:40. Allowing about 5 seconds for the sound to propagate the mile to my location, his final simulated double knock should have reached my camera at about 7:00:45. But actually this is when the first one showed up, not the last one. The final double knock on the tape is about 20 seconds after Scott should have finished.

Did Scott start 20 seconds late? He is pretty certain he did not. But, even if he did, where are the first two simulations? At 10 and 20 seconds before the first marked double knock at 7:00:49, there are no comparable loud crisp double knocks. As the camera was pointed most directly towards the double knocks at the beginning and ending of the tape, you would expect those first two simulations to have been as loud as the last one unless something changed dramatically in that very short interval of time.

Everyone who has reviewed the tape agrees that to the ear these are very good double knocks, with quality and cadence that are a close match to the real thing. Those who have examined them include some of the PIs from the Cornell project and quite a few people who are familiar first-hand with the double knocks of tropical Campephilus species. Only the final double knock is loud enough to render clearly on a sonogram:

Double knock #3:
This is a perfect Campephilus double knock signature: two crisp sharp raps, heavy in the base tones, about 70ms spacing between the two, first knock distinctly louder than the second but both quite similar in quality. One of the things that I note about it both on the sonogram and directly by ear is the crispness of the raps. There is not a trace of "smearing" from echo or dispersion. Granted, it is not very loud, but it is loud enough to image clearly on the sonogram. It remains very hard for me to imagine how these sounds could have traveled through 1800m of forest and yet retained such sharpness. Sound waves just don't do that.

The sonograms for the other two double knocks are fainter and harder to make much of. In all these sonograms, there is a steady whine at about 500Hz; annoyingly this is just above the dominant frequency of the double knocks. This is an artifact created by the camera motor:

Double knock #1:
Double knock #2:
The video camera was pointed away from the source in these cases. I am surprised that #2 appears the faintest on the sonogram; to my ears it sounds louder, or at least more distinct than #1. It is straddling the vertical grid line at the center of the image, if you are having trouble finding it. The sonogram for #1 shows some curious faint mushy sounds at the same frequency as the double knock about a half second later; there seems to be a gap between the double knock and these mushier sounds. I wonder if these second sounds might be echos of the original sound, perhaps reverberating off the row of trees along the Obion. At this time the camera was pointed away from the source and towards these trees; echos from these trees would have arrived at the camera with about this much delay. Overall I suspect each of the double knocks was of similar intensity, and the differences in the recording are primarily a function of whether the camera was pointed towards them or away from them.

On March 17th, Scott, Melinda, and Ryan had all been together in the northwest part of the WMA while Scott was using the simulator. Melinda commented that in the entire morning's worth of simulations, only one single simulated double knock actually sounded like the real Campephilus sound, which she is familiar with from the tropics. That's one individual double knock, not one series. Both she and Scott have been struck by how much the ones I recorded, especially the loudest one at 7:01:09, do not sound like Scott's simulations and do sound like the real thing.

Is there a smoking gun somewhere on the tape that would confirm that they are not the simulations? There may or may not be. In listening obsessively through the rest of the tape, I've found what seem to be to be two very faint doubleknocky sounds earlier, at 7:00:11 and 7:00:31. They are exceedingly faint, and only Scott is pretty sure that he can hear them too. It takes headphones and careful listening to pick them out; the quality of the audio on the streaming video I have posted may not be good enough. I also believe that they do register on the sonogram:

This is an edited sonogram; in reality the sounds occurred 20 seconds apart, not 2 seconds apart.

One might wonder why I single out these particular nearly invisible dots for special treatment from among all the other nearly invisible dots. Well, it's because they are also associated with something I feel I can hear, so it's a judgement call. At or around 7:00:21 and 7:00:41 I don't hear anything, and there are no suspicious near-invisible dots on the sonogram. These two earlier faint "double knocks" have longer and more varied internal spacing than the three loud ones. Scott feels they are much more like the way his simulations actually sounded; they sound to me more like what I heard at 7:30. If Scott did his simulated series on time, then these two sounds are positioned just right to be the 1st and 3rd of his series. They would have happened at 7:00:03 and 7:00:23 by Scott's watch at his location, allowing for sound propagation time and the difference between his watch and my GPS. If these are real, they confirm that the three loud double knocks began right when the simulations should have been ending, and continued for an additional 20 seconds.

Finally from the 7:00 tape, there's this odd little sound:

It happens at 7:00:53, 4 seconds after the first loud (real?) double knock, and 42 seconds after the first faint (simulated?) "double knock." It comes just milliseconds after some splashing sounds almost surely made by my paddle. It has a quality much like a single woody knock. It would be just two seconds behind schedule to be the final simulation in Scott's series, assuming the other "faint" sounds are Scott, if he flubbed it and made a single loud knock instead of a double as happens very easily if you swing the striker too fast. Or... maybe it's just me klunking my boat with my paddle.

My recording from 7:30, with the camera pointed directly at the simulated double knocks, did not pick up anything definite. I do believe there is one of the simulated double knocks faintly resolved on it, probably the first one. Immediately after this sound, I swung the camera to the right. As I mentioned in the previous post, I was surprised that the simulations were coming from farther west (to the right) than I had expected. There's not much to see on the sonogram, but there are some smudges that seem to correspond to what I hear. The prominent vertical streak at the middle of the image is just a spurious "click;" the interesting sound is marked by the two arrows to the right of the "click:"

Here's a very small video clip of the 2 seconds of tape that contains this sound. You will hear the "click" prominently; the knock follows immediately and is less obvious.This also shows that the surface of the lake was still glassy calm, with not a hint of wind having developed yet:

To my ear this very faint sound consists of two rather widely spaced knocks, the second fainter and also higher in pitch than the first. This is something I noted about the simulations, that the pitch of the second knock frequently seemed higher than that of the first. This was not true of the loud knocks I recorded at 7:00. I have searched through the 7:30 recordings for traces of the remaining four knocks in this series. My ear picks up nothing at all. Sometimes the sonogram suggests the presence of something at about the right time, but it never matches anything audible and it is never all that distinct from many other small specks and smudges. Even the one I highlighted above is not certain in my mind; I picked it out particularly because of my own actions (pivoting the camera right after) suggest that I heard it and recognized it.

To get to the final point, in order for the double knocks I recorded to be Scott's simulations, ALL of the following things must have occurred:

1. Scott must have either miscounted his double knocks, doing more than just five, or have begun his series 20 seconds late.

2. Three of the double knocks would have to have propagated anomalously in such a way as to arrive at my location, 1800m away through the forest, sounding and looking as crisp and clean as if they were only a few hundred meters away.

3. The anomalous propagation would have to have somehow not affected the first two double knocks. There is nothing similar to the loud double knocks to be found at the times they would be expected, in spite of the camera having been pointed more nearly in their direction

4. The anomalous sound propagation had to be highly directional, so that Melinda heard nothing in spite of having a shorter path with more open space between her and the source.

Scott remains fairly certain that #1 did not happen, and the faint sounds early in the tape give some evidence that he did indeed begin on time. Even if he did begin late, the other three items require a coincidence of multiple unlikely events. It seems to me a more straightforward conclusion is that I recorded the MIMDKWFTII in the woods maybe 400m from me. The 10 second timing argues for the simulations, but everything else argues against it. When you take in to consideration that I heard an identical double knock series, including the short (10-20s) intervals between double knocks, originating from the same area just three weeks before, when there was no double knock simulator within 100km of us, then it doesn't even seem all that improbable. Of course, even if this is the case, this doesn't add any new evidence at all as to what the mystery double knocker might actually be. It just confirms that we Tennesseans have actually been hearing the "right" sound.

Other posts in this series:

Thursday, October 15, 2009

Reality and Simulation

Live or Memorex?

March 18, 2009

I woke up in a grouchy mood, still sulking about the credibility issues. I got out well before sunrise, didn't wait for Scott to get out of his tent, and drove right past Melinda's encampment to the end of the road. I grabbed my boat along with the rest of my gear and started the long portage across the sill, down the ATV trail, to the put-in on Willow Flat. All the way I was pondering whether my services were still actually needed on this project. I didn't feel like more uncorroborated detections from me alone would accomplish anything at this point; encounters by others would be much more valuable. I might have come to the end of my usefulness unless I got something on tape or anyone else got something at all.

Once I got out on the water, my mood improved. It was an absolutely perfect morning, with clear skies, calm winds, sunrise glows in the east, and birds calling everywhere. I paddled a short ways north from the put in, and then floated stationary for a bit while I got the video camera out. I had never actually paddled on Willow Flat before, and I was quite impressed with it. It was beautiful, and seemed to provide the perfect vantage points for listening to the woods to the west. I decided to shoot a video panorama from my location, just because it was such a nice morning.

Towards the end of this panorama, I heard and recorded a gorgeous, perfect series of double knocks coming from the woods to my west, at a distance I would have guessed at roughly a half a kilometer. They were, to my ears, absolutely identical to the series I had heard in February, three weeks earlier. They also seemed to be originating from the same patch of woods, just a few hundred meters farther north than the February series. As I described in the earlier post, I decided with some disappointment over the next two minutes that I had actually only heard Scott's 7:00 simulated double knock series, not the real thing. Damned simulators. Here's the entire video segment, edited only to add titles marking the time and pointing out the double knocks. The final (third) one is the easiest to hear. There's a fairly long stretch after the double knocks where you are just looking at a closeup of my trousers while I dig around for my GPS, in order to get an accurate time stamp on the video:

Even if these were just Scott's simulations, they were essentially identical to the "real" double knocks we have heard at the site over the last two years and will give a sense of what we have been chasing around.

After deciding I had only heard the simulations, I continued paddling slowly north along the slough and made no effort to pursue the double knocker. I had enough video of Scott in the woods already. I had only covered a few hundred meters more by 7:30, when the next set of simulations was due. I turned on the video camera and prepared to record these as well, just for comparison. I was assuming that Scott was working in a different area than he had originally planned; the turnaround had been at least 1500m from my 7:00 location, and there was no way that what I heard had been that far away. I figured he must have decided to work instead closer to the lake, probably starting at the camping and parking area at the northwest end of the lake and heading in to the woods from there.

When the 7:30 simulations began, I was quite surprised. They were barely audible, seeming to be extremely far away. They also were well off to the west; if Scott had been where I was guessing, he should have been more towards the southwest. This time it sounded like he really was a mile away near the turnaround. The winds remained dead calm; the conditions had hardly changed in the previous half hour. Yet these sounds were nothing like what I heard at 7:00. In addition to being much fainter, they were much "wimpier" in quality. They didn't have the booming resonance or crispness of the earlier double knocks; they just sounded like a stick whacking a tree. They also were much less even in timing. Some of them were quite slow, a "whack, whack" rather than a "BAMbam;" others were so close in timing they seemed to just be one single "smack." When I later went through the video, I could not definitely pick out any of these double knocks.

I found this quite curious. Had Scott done the 7:00 set from near the lake and then gone back west to the turnaround for the 7:30 set? If he had stuck with the original plan, could sound propagation really have been that different between the two events? In that circumstance, neither of us would have moved very much in the intervening 30 minutes, and if anything we should have been closer at 7:30 than at 7:00. There was also the difference in quality. Had Scott done a virtuoso performance on the perfect tree at 7:00 and then gone in to a slump with a bad tree at 7:30? I had never used the double knocker myself, but I had been told it required a bit of practice and was somewhat sensitive to the tree on which it was secured. Scott had not used it much before; yesterday he and Ryan had commented about the unevenness of his results. This was consistent with what I heard at 7:30; it was not consistent with what I heard at 7:00. All rather peculiar...

At 8:00 I settled in to listen again. The winds remained quite light, but the day was advancing and the nocturnal decoupled atmospheric boundary layer (also known as the morning calm) was likely beginning to break. I heard nothing; it turns out Scott had skipped this set. At 8:30 I did hear the simulations; they sounded just like what I had heard at 7:30 and again not at all like what I heard at 7:00. This started to get me wondering. At 9:00 I heard another wimpy uneven and very faint set. After this a breeze picked up and I heard nothing more.

Other than getting confused by the double knocks, I was enjoying discovering this new part of the WMA. At its far northwestern end, Willow Flat grades into a fairly extensive boneyard of dead and dying trees. This also got me thinking in another direction, about the opening up of these lakes in areas that the USGS had mapped as closed forest, and the causes of this apparent tree decline. Of course, this made me wonder it there was any relation between the localized tree decline and the MIMDKWTFII.

As often seems to happen, my return paddle was now upwind. Midday rendezvous was planned at the barn, which was a long windy paddle, long muddy portage, and short drive away. I got there a bit before noon, and waited for Scott. My earlier concerns about not reporting anything I might see or hear had presumed events that I had not managed to document. This time I had documentation on the video camera, so I tossed all the credibility worries aside, The first question for Scott was "Where were you at 7:00?"

He had in fact stuck to the original plan. He had parked at the turnaround, walked a short distance in to the woods, and done his double knock simulations right on schedule at 7:00. This put him over 1800m away from me. It was of course possible to hear the simulator from that distance; I had done just that at 7:30 that morning. But to hear it loud and crisp and sounding like it was only a few hundred meters away? That was harder to understand. Scott and I checked his watch against my GPS, finding that he was only 2 seconds behind me. Melinda arrived at the lunch rendezvous a bit later. At 7:00 she had been sitting on alert listening from the southeast shore of Rhodes Lake, near the end of the road, and had heard nothing. She was closer to Scott than I was, with a good portion of the distance between them skirting the open water of the lake. The entire path from Scott to me had been through the woods. I pointed out (repeatedly and probably annoyingly) that strange things can happen with sound propagation; still the circumstances were not quite adding up. Had I really just heard Scott's simulations, or had I in fact heard a response to Scotts simulations?

Perhaps the videotape would help sort this out. If the sounds had registered on it, we could see how closely they lined up with the times that Scott's simulations should have occurred. He was fairly certain that he had begun within a few seconds of the nominal start time at 7:00:00 CDT, and was completely certain that he had done 5 simulations at 10 second intervals. Fortunately, I had timestamped the video by putting my GPS in the frame at the end. When I returned home, I'd get the video off the camera and see what shook out.

On the drive home later that day, when I got back in to cell phone range I discovered a voicemail from "Jacob." Steve Sheridan had confessed to faking his "mystery woodpecker" photo.

Oy, what a day...

Other posts in this series:


Monday, October 12, 2009

Onward in the Fog

Kenting, kenning

Through the rest of early March, only a few more days of field work happened and none of it by me. Classic early spring weather seemed to be bringing rain, snow, and/or wind on the majority of days.

By this same time in 2008, we had tallied something like 5 or 6 double knock detections by four different observers, with less effort. For 2009, it stood at one detection by one observer, if one only counts the actual birders and does not include Beulah's reports. There seemed to be two apparently contradictory patterns that our 2009 result (singular) pointed out. First, obviously, was that the MIMDKWFTII might be present, or at least was present on one occasion, in 2009, but it was much less active than in 2008.

Second, however, it also seemed to validate the reality of the 2008 "hot zone." We had collectively made an effort to spread our time more widely in the WMA than in 2008; I for one had concentrated on dispersing myself as close to uniformly as was practical. And still, when our 2009 detection finally came, it was smack dab in the middle of the nexus of activity from 2008. So, it did finally appear that the 2008 "hot zone" was not just an illusion created by concentrated effort, but reflected a real pattern of the activity of the MIMDKWFTII. Hence, strategies and priorities were readjusted, and we were back to concentrating on the Hushpuckett-Rhodes Lake corridor with reduced (but still non-zero) effort in the other sectors.

And, of course, there was the matter of the gunshot. As much as I disliked it, there was a case to be made that if the double knocker would double knock in response to a gunshot, then there might be value in using the double knock simulator. My only public comment about this to Scott was "just make sure we all know where and when you will be doing simulations so I don't waste time tracking you."

Underneath all the strategizing, there were other issues brewing. For one, if you look back in my blog archives for March of 2009 you will see one great big massive ball of confusion that was hurtling through the online ibwosphere at the same time, which by virtue of an odd series of events wound up selecting this self-same Little Red Blog as its ground zero. This had no direct relevance to our Tennessee work, but it was consuming a great deal of my own time and thoughts, and behind-the-scenes seemed to be building to some sort of crescendo that was not necessarily going to be a positive thing. Directly on the Moss Island front I was acutely aware of the days ticking off since that grizzled squirrel hunter shot his .22 in the woods east of Rhodes Lake on the afternoon of February 24th. One can start to feel directly responsible for the followup to something like that, and take each passing acampephilitic day as a personal failing. It can also be difficult to hush the internal whispers of paranoia, the thought that the rest of the crew is beginning to doubt your reliability, veracity, and sanity, regardless of what might actually be said, done, or thought.

March 17, 2009

Finally the weather, schedules, and unreliable household vehicles had cooperated and I was back on site. I had arrived after dark the previous night; the last 36 hours before I left home had been tumultuous in that other Ivorybill arena surrounding Steve Sheridan's photograph. The distance measurements had been independently confirmed, the mystery bird was the size of a Red-headed Woodpecker, all of this was still secret. Most others who were privy to this information seemed far more charitable that I and continued trying to figure out the impossible gyrations or incredibly unlikely errors in image processing that could have created that image without malice or mendacity. Misanthropic ol' me thought the answer was simple and obvious: if the distance numbers are right then the image is faked. This had been my position for over a year; now that the "if" was satisfied we proceed to the "then." Regardless, I had a bunch of blog postings that were now at best moot and at worse blatantly misleading that needed to be tagged, flagged, and edited to reflect the new info; but as this new info was still secret it was not my place (yet) to be the whistleblower and I just had to leave them as they were. All told, under these circumstances, it had been blissful to head west into the land of no internet and no cell coverage for a 48-hour escape from the turmoil.

Scott had a birding pal of his, Ryan from Kentucky, along for the ride; between them, me, and Melinda we were four. Scott also had the double knock simulator. The plan was that he would do 5 simulated double knocks separated by 10 seconds, starting at the top (:00) and bottom (:30) of each hour. On this day he was planning to be way up in the northwest near Mitchell Lake, while I was going to be in The Spot east of Rhodes Lake, so he should be far, far out of my earshot. I drove out from the barn before sunrise, getting out of my truck at the end of Rhodes Lake Road at about 6:45 a.m. with sunrise scheduled for 7:05 a.m. I took a bit of time to gather my gear together, as I had pretty much just thrown on my clothes and jumped right in the truck from my tent without a whole lot of advance prep. Once I had my stuff collected, I set off towards the sill.

And, for the first time in my life, my "kent" alarm went off.

As is the case for many birders who grew up chasing feathery things around the southeastern U.S. in the 1970s, I had the Singer Tract Ivorybill audio recording burned into my DNA. For 35 years, whenever I had been in any kind of coastal plain bottomland forest there was always a "kent detector" running in the background of my mental processes. Considering where I had lived and some of the things I had done for a living, this process had logged thousands and thousands of hours without a single hit. Until now.

Through the fog, from the direction of the east shore of the shrub swamp, south of the sill, a distinct kent-like sound had just come. I picked up my pace and continued listening. A minute or two later, it came again, and the "kent" alarm once again tripped. It was not close, a couple of hundred meters. I was, surprisingly, not getting hyped up about this. For better or for worse, one thing we had all learned over the last few years is that there are a very large number of things that can sound kent-like. True, I had never been aware of having heard any of them before, but that was irrelevant. The kent had proven to be no more distinctive or diagnostic than the double knock. The most suspicious possibility for the culprit behind what I was hearing was a Pied-billed Grebe. There had been courting and singing grebes around Rhodes Lake for weeks. At the distance from which I had heard the kent-like sounds I could not tell whether they were coming from lake altitude or tree altitude.

I continued towards the sill at a fast walk, and heard several more of the kent-like sounds. As I rounded the bend and got onto the sill with a better view towards the apparent source, I also got the video camera running. I knew, of course, that even if the camera recorded something that was spectrographically identical to the Singer Tract kents this would establish nothing, as the Ivorybill "kent" is really just a rather generic high-pitched "honk" and can be matched very easily on a sonogram by many other things. It didn't matter; predictably, once I got a clear view towards the direction of the kents, and had the camera running, I heard no more. Nor did I hear or see a Pied-billed Grebe in that direction, but that means little.

After a sufficient time of staring across the shrub swamp into the foggy woods while hearing and seeing nothing, I headed onwards on the original plan. I hiked to a permanent deer stand that I had found earlier in the year, and enjoyed the view from it for a good portion of the morning:

While headed back for the lunch rendezvous, I debated what to do about the morning's kentings. They really didn't amount to much; on the other hand we had so little going on it seemed a shame to just dismiss anything no matter how small. So I waited until the entire gang of four was gathered and then told the story, complete with piles of caveats about not putting much significance to it. Melinda immediately came up with the Pied-billed Grebe hypothesis as well, to which I agreed, and the lunchtime chatter went off in other directions. Of course the paranoia whispers kept pointing out things like "oh yeah, THAT did wonders for your credibility." Now, the facts that none of us had ever actually heard a grebe "kent," nor had ever heard of such a thing, nor had any of us previously heard anything else "kenting" at Moss Island were, in the surreal Ivorybill parallel universe, irrelevancies.

I split the very quiet afternoon between the southwest woods and the "canoe trail." Ryan had departed after lunch, just leaving the three of us camped on site overnight. That evening we had a discussion about what the future plan should be, since Moss Island seemed to have dramatically cooled off. We talked about expanding to adjacent areas, that sort of thing; we also discussed whether there was any reason to maintain secrecy given the lack of activity this year. I did feel the need to point out that we were in fact not entirely without detections for 2009, I had heard a double knock series just three weeks before, a reminder that seemed to be met with something akin to "yeah, whatever." More internal paranoid whispers.

I had already been pondering that I was in danger of becoming the Tyler Hicks of Moss Island, the one who seems to keep getting detections when no one else does and hence becomes the target of suspicion and derision. I now had the only detection for 2009, and my two double knock series were the only reported detections of that sort for the entire state of Tennessee, ever. All others had been individual double knocks in isolation. This could become a problem. After that evening's conversation I decided that I might need to give serious consideration to actually choosing not to report anything else I might see or hear unless I got it on tape. An additional undocumented encounter would do little or nothing to change the situation, anyway.

On that note, it was off to bed, or at least off to sleeping bag. Tomorrow's plan was for Melinda to sit on the Rhodes Lake shore while I paddled Willow Flat. Scott would start at "the turnaround" on the road west of Rhodes Lake and head north into the woods, doing his double knock simulations on the :00/:30 schedule as he went. Ever forward in the quest for the Hope Eater.

Other posts in this series:

Thursday, October 08, 2009

Banging on Trees, Tilting at Windmills

Making loud noises

It turned out that Scott did not have the double knock simulators with him on this trip. He and I were both planning on heading home at midday the next day, leaving the swamp in Dave's hands. The plan we hatched was to start the morning with sits along the lakeshore. If that yielded nothing, starting at about 9:00 Scott and I would work our way southwards through the woods on the east side of the lake while Dave was stationed on the ATV trail east of the sill. Scott and I would periodically beat on trees as hard as we could with whatever we could find handy in the woods.

The morning sits yielded nothing, so we shifted to the second part of the scheme as planned. Scott and I did our thing, never really feeling satisfied with the quantity of sound we got from whacking snags with branches:

In the shots where Scott is pointing his camera at the forest floor, he is photographing an American Woodcock that was hoping to remain invisible.

When we met up with Dave at the south end of our transect, none of us had seen or heard anything of note. Dave had not been able to hear our tree whacking until just at the very end when we were only about 100m from him. Obviously we were not even coming close to the power of the real noises that I had heard easily from 500m away. In discussions about what to do next, I felt strongly that we should try to keep someone on sit in that patch of woods as much as possible, indefinitely, Given that we now had one full-timer and four part-timers on site, it seemed like a practical thing to do and still leave person-hours to be deployed in other areas.

Our next rendezvous was being planned for Sunday or Monday, March 1-2. However, on February 28th another winter storm of mythic proportions moved in to west Tennessee. This time it was snow, upwards of 18" of it in some areas, with drifts measured in feet. All roads in the area quickly became impassible in this world where sand and salt trucks are scarce and snow plows almost nonexistent. The stretch of I-40 from near Jackson to Memphis became a grand jumble of stranded cars and jackknifed trucks which was not cleared for several days; this is part of my route to Moss Island. Dave had gone to visit family in Arkansas for the weekend; he finally attempted to return to Tennessee on Sunday. He had to use his four-weel drive on the Interstate, at one point found himself pointed backwards in the median, and wound up in a hotel still in Arkansas at the end of the day. I had visions of sitting in the woods amongst balls of slush raining from the trees, as I was seeing at home where we only got 6" of snow, which made the thought of a long sit in the snow-covered swamp uninviting.

Dave and Melinda with their 4WD vehicles made it back by Monday, March 2, I with my rear-wheel drive pickup chose to wait one more day and headed out for a day trip on March 3. I was unable to spend the night on site as my wife was away from home for the week, leaving no one to tend to the various animals. On route, I took note of the rapidly-increasing numbers of gashes in the mud on the median and shoulders of I-40 as I approached Jackson; these were what was left from the great heap of snowbound trucks from three days previous. The snow drifts on the roadsides began to appear after Jackson, and as I traversed Crockett County the residual snow drifts and cornices along the roadside gave an even better imitation of eastern Colorado than usual.

On arrival at Moss Island I found the road snow-packed and icy. In Tennessee most people would read this to mean "impassable without 4WD." But after a decade in the mountain west, to me this meant "open and passable with reasonable care." The main thing I worried about was the parking turnaround at the end of the road. If it was icy enough, my 2WD pickup could have a little trouble getting traction when it was time to head home. At the end of the road I met up with Dave and he agreed to make sure I was out before leaving for the day, so I would not be stranded on an unplanned overnight with animals at home that needed tending.

I spent my entire time that day sitting in the snowy woods on the east side of Rhodes Lake. It was a cold day to be sitting motionless, with the temperature around freezing all day. Welcome to early March in Dixie. It was also an immensely quiet day, with a five-hour sit yielding only 4 Pileateds:

Dave and Melinda continued working the area through the week. No one heard or saw anything suspicious; it had been over a week since my double knock encounter. As feared and expected, followup was yielding nothing. I returned for a day trip on Friday, March 6, making the long hike from the Barn through the woods all the way to the Rhodes Lake sill. I had pre-arranged to meet up with Dave there so he could give me a ride back to my truck at the barn. Dave's available time was rapidly running out; he would be heading back towards California in just a few days. The weather had warmed dramatically (up to around 20C) and the snow was nothing but a memory. The wind, however, was quite real, and seriously hampering ear birding. My main hope was that somewhere on the hike I would see that bold white flash; but it didn't happen.

Other posts in this series:

Sunday, October 04, 2009

Here We Go Again

Phantom thunderbird strikes again...

Over the previous year I had listened to a fair number of recordings of real double knocks from known Campephili. The double knock I had just heard from across the lake was absolutely perfect, textbook, archetypal. It had been crisp, rich, resonant, woody, sonorous, dead-on for cadence, and freekin' LOUD considering that the near edge of the forest in that direction was about 500m away diagonally across the lake. As happens at these times, my mind started racing. The first thought was, "Is that Dave?" I knew Dave had a recording of Pale-billed Woodpecker double knocks on his iPod, which was connected to a portable amplified speaker thingy. He had demonstrated it to me the day before. At top volume it sounded like "pop-pop" and might be audible from 100m under perfect conditions (which light rain and a 2 m/s wind from the other direction were not). It was hard to imagine that he could be blasting it so loud and with such perfect reproduction. Besides, he and Scott had just driven past me headed back to the barn a half hour before. There's no other road. It's been raining. How the hell could he have gotten way the f' back over there in the roadless forest across the lake?


Holy crap! Exact same direction, exact same apparent distance, exact same sound. It was a double knock series! It had only been something like 10 or 20 seconds since the first one. Extremely fast decisions were needed. Do I try to get it on tape? Because of the rain I did not have the video camera at the ready. Do I try to get closer? Do I tear off into the woods on foot to try to track it down? Would a crappy recording of a distant double knock submersed in the continuing sound of raindrops on the roof of my truck really accomplish much at this point?


The third double knock, again only about 10 or 20 seconds after the preceding one, again exactly the same direction and exactly the same sound, settled the matter. I needed to get closer. I started the truck and drove to the other end of the lake as fast as I could. At the end of the road I lept out and set the camera recording in the direction the double knocks should be coming from, now only about 200m away. Nothing. Not a creak or tap to be heard.

I still had nagging doubts about the origin of the three double knocks I had heard. Strangely, it was their perfection that bothered me. I knew Scott had a double knock simulator; I didn't know if he had it with him on this trip. But how could he or Dave possibly have gotten back over there? Could they have looped around the other end of the lake, off-trail, in the rain? That just made no sense at all considering that the last time I saw them they had been hurrying back to camp to get away from the rain. By now the rain had entirely stopped, and the sun was even hinting that it might break through.

Not long after I got to the end of the road, the squirrel hunter returned to his truck, parked about 50m from mine. He started to drive out, but stopped when he saw me sitting on my tailgate, and started chatting with me. I caught the whole conversation on tape; the first part is pretty amusing in context and it's included at the beginning of the video clip below. I asked him if he had seen anyone else in the woods over there recently, which he had not. He had gotten a squirrel with the one shot I heard, and that was the only shot he had fired all afternoon. I told him I had heard some weird sounds over there and wondered if there could possibly be someone from our crew still in the woods. He confirmed he hadn't seen anyone, and couldn't remember having done anything himself other than firing his gun just the one time that would have made any loud noises.

That seemed to settle it. The Moss Island Mystery Double Knocker (Whatever It Is) was indeed back.

I stayed on watch until dark, hearing no more signs of the MIMDKWTFII. I was treated to an avian spectacle after sunset as hundreds and hundreds of ducks, mostly Mallards, streamed overhead, all in small groups, all headed the same direction, filling the sky. There's some rather indistinct footage of this on the video clip below as well. Finally in deep dusk I got in the truck and drove back to the barn. Scott and Dave were there, relaxing before dinner. They had been there all along, of course; they went directly there after I saw them drive past in the rain back at the lake. I told them my tale.

Scott commented later, as did "Jacob," that I didn't seem as excited this time as I had been in 2008 after my first (and last) encounter with a double knock series. Well, it had been a long year, and now I knew what came next. More correctly, I knew what almost certainly did NOT come next: quick followup resulting in nailing down the bird, accomplishment, satisfaction, and progress. More likely what came next was a whole lot of followup yielding a whole lot of nothing. Jaded, sure, but I think we all have gotten hard and green after the last few years.

Two parts of this encounter most interested Scott. First was the geography. I had not been entirely clear in my mind on the details of the two encounters in 2008 that were had by Cornell staff (Dave's brief glimpse and Leighton's double knock). It turns out that they were quite close to the spot from which the double knocks I had just heard had originated, as was Scott's very first double-knock-and-brief-glimpse encounter in 2008. All told, there had now been four possible detections on four different dates, by four different observers, and in two different years within about 100-200m of each other.

The other thing that really got Scott's interest was the very close proximity of the double knocks to the gunshot. There was only a minute or less and maybe 100m of distance separating the two. I would love to tell that squirrel hunter, who joked about Ivorybills completely out of the blue, that when he shot his supper he might have been standing only a hundred yards from one! It seemed like too much of a coincide-ence to just write off as a coincidence. There seemed a very real chance that the MIMDKWTFII had been prompted to do its DK thing in response to a nearby gunshot.

Scott of course now wanted to run through the woods blasting a .22 everywhere he went. On a more serious note, it strongly suggested that maybe we should give that damned double knock simulator a try. Scott may have heard a double knock in response to the simulator in 2008, I had just heard a double knock series that was possibly triggered by a gunshot. Loud man-made noises in the woods might have some merit in this quest. We would just have to decide how to make use of this possibility.

The rest of the video for 2/24/09 -- the conversation, the sunset view from my lookout, the ducks:

Other posts in this series:

Saturday, October 03, 2009

Cinematic interlude

A break from the Moss Island saga...

Go see it. Just do.

Thursday, October 01, 2009

More Troups

Call up the reserves

February 17, 2009

Other commitments kept me from being able to overnight at Moss Island for another week or so, but I managed another day trip on this date. I spent a half day and change in the Rhodes Lake area; Scott was on site as well working around Forked Lake. Whatever Beulah had seen the previous week, it was our only lead so far this year and it had been seen flying from Forked Lake towards Rhodes Lake. It was another grey and quiet winter day. The ornithological high note was a full set of Eagles over Rhodes Lake:The camouflaged creature in the second half of the clip is Scott, of course.

February 23, 2009

For a change, it was a mostly sunny day. Dave Pereksta was due to arrive around noon, planning on 2 or 3 weeks of work, entirely on his own vacation time and personal expense. He had been on the road for a week or so already, making a few birding stopovers on the way from Ventura County to Dyer County. I arrived early and covered the southwest woods in the morning, encountering a strange artifact deposited by floodwaters, then returned to the barn to rendezvous with Scott and Dave.

On my arrival at the barn, Beulah accosted me excitedly. She'd had another encounter. The previous Friday (2/20/09) she had been hiking the ATV trail that goes south from the turnaround, the trail that runs west of Hushpuckett Lake and from which I had heard my first double knock 49 weeks earlier. She had been about 100m from the spot of my first DK-hearing when she heard what she said sounded like somebody whacking a tree with a baseball bat extremely hard, twice in rapid succession. She didn't have a real distance estimate, just saying it had been quite close and had nearly made her jump out of her skin. She wasn't able to see the source of the sound.

As in so many cases, the description sounds good.. HOWEVER... I had described the double knock to her previously, using words and terms very similar to the ones she used when she described what she had heard to me. Still, the encounter sounded much like Scott's very first incident on February 28, 2008 that had launched the whole show, except lacking the glimpse of a fleeing large bird.

As before, though, whatever it was, we didn't have any other leads. After Dave arrived we divided up and headed back to the old "hot zone;" I headed down that same ATV trail again. About halfway down the trail I had what we have come to call a "Luneau moment." Ahead of me through the understory, I caught a glimpse of a fleeing dark bird with brilliant white on the hind portions of its wings. The intervening brush made judging size and distance tricky, but it somehow gave an impression of being a large bird. As I continued in that direction, I found nothing but an active assembly of Red-headed Woodpeckers. Reclassify that "impression" of being a large bird as more likely an "illusion" of being a large bird, and ticky that one as a Red-headed with grand aspirations.

At sunset we reconoitered at Rhodes Lake to compare notes and discuss the plan for tomorrow. The video clips from this day ("Luneau moment" not included, cam did not get it):

February 24, 2009

We had initially had ambitions for a moderately large-scale effort on this date, but most of our potential recruits were unable to make it, and even Melinda was not available. In the end we did marshall a team of four: me, Scott, Dave, and Allan Trently, a birder, botanist, and biologist with the Tennessee Department of Environment and Conservation based in west Tennessee. Between the four of us we represented two State and one Federal agency, though Dave was here on personal time not in his official capacity with the FWS.

After a dawn assembly at the barn, we split up. We were again focusing on the old "hot zone," primarily because we wanted to remain fairly close to each other. I took the ATV trail again, hiking about halfway down it and sitting quietly in the damp gray cold (about 1 or 2 degrees C). The birds were moderately active, but I heard no clarinets or baseball bats whacking trees, and saw no woodpeckers with white secondaries other than dozens of Red-headeds. The noontime rendezvous happened at the west end of Rhodes Lake where there are a primitive campsite and a gravel boat ramp. For the most part we had a whole lot of the same to report; Allan, however, had sort of seen something kind of interesting. He had hiked south from the trail on the east side of the Rhodes Lake sill, in the isthmus between Willow Flat and the shrub swamp below the sill. He had his own "Luneau moment," a large woodpecker seen flying off briefly that appeared as though it might have had white in un-Pileated places. He was not worked up about it, just matter-of-factly saying it might have been interesting but he didn't get much of a look at it.

Once again, it might not have been much but it was all we had. We deployed ourselves spaced about 50m apart and hiked slowly south through this same patch of woods. After about 90 minutes, with the gray skies getting grayer and more threatening, and little to show for our efforts, we turned around and repeated the exercise northwards. On the return I crossed paths with a grizzled squirrel hunter and his two dogs. The TWRA truck at the trailhead obviously made him nervous, and he immediately began to show me his credentials and his weapon to prove he was in full compliance with the game laws. I told him I didn't give a damn, I wasn't involved in enforcement, we were just doing bird surveys. We chatted for a bit (I never mentioned woodpeckers, crested or not), talked about his dogs, and continued in our opposite directions.

Videos from the the morning sit, lunchtime conference, and afternoon hike:

Back at the trailhead, Allan had to head home. Light rain was beginning as the three of us who remained decided to just spread out along the lakeshore roadside and listen. Dave and Scott took the south/east end, I drove to the west end and pulled into the boat ramp. The rain began to fall steadily, and it was not long before Scott and Dave drove past me, calling it a day and heading back to camp. I stuck it out, sitting in my truck watching the rain fall.

Around 4:30 or so, the rain began to slacken enough that I could roll my truck windows down a bit, then open the doors for better listening. About 4:45 I heard a single shot from a .22 rifle ring out from across the lake and down at the far end. Maybe the squirrel hunter had bagged his supper? Not even a minute later, as I was pondering if the rain had let up enough to get out of the truck, another sound came from across the lake just a little to the left of the direction of the gunshot:


Other posts in this series:

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