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: