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Seeking the Ivory-billed Woodpecker

"No testimony is sufficient to establish a miracle, unless the testimony be of such a kind, that its falsehood would be more miraculous than the fact which it endeavors to establish."
– David Hume, Scottish philosopher.

The past few year's flurry of excitement over reports of ivory-billed woodpeckers in the Pearl River area of Louisiana has caused a lot of people to conclude that the species is not yet extinct. Hope, the most misleading of human emotions, is running high.

Just how likely is it that the ivory-billed is still out there, breeding in some undiscovered patch of old-growth bottomland forest in Louisiana or anywhere in the Southeast?

Art by Julie Zickefoose

The odds are frighteningly small. You've got almost as much chance of seeing Bigfoot as you do of finding an ivory-billed. The most recent sightings along with a moderate host of others over the past few decades actually makes the odds worse, not better. A lot of folks take the opposite view. They fall back on the ancient adage: Where there's smoke there's fire. A close examination of all the evidence might persuade them to consider an adage only a few seconds younger: Sometimes where there's smoke there's someone blowing smoke.

What makes me so skeptical about the survival of the ivory-billed woodpecker? Before getting to the details, we need to dispose of the negative baggage that the word skeptic has been saddled with. Skeptics are neither cynics nor spoilsports. They do not carry stunted genes for wonder and awe. We are awash in wonder and awe. It is just that we prefer being awed by the truly awesome and to wonder at the truly wonderful. We aren't interested in wasting our time on the artificial, the phony, and the illusory. The defining characteristic of skeptics, the diagnostic field mark, is not the absence of wonder and awe, it is the refusal to go off half-cocked. The evidence for the continued existence of the ivory-billed is weak, unpersuasive, and anecdotal. The evidence against is, I believe, persuasive. Not perfect because it is almost impossible to prove with certainty that something does not exist, but it is strong. Some people turn the argument around. "You can't prove it is extinct," is their position, as if that somehow proves that it is not extinct. But the burden of proof is not on the skeptics, it is on the people who claim the species is still with us.

The evidence for the survival of the ivory-billed woodpecker consists almost entirely of about 50 reports spread over the past 50 years. That's a lot of reports, and they are the reason people fall back on the smoke and fire adage. Before you pull the alarm, however, it is worth taking some time to think about those reports. Before assuming that they should inspire hope, ask yourself the following questions. What are the odds that we would get 50 reports and in not one instance, not even one, would the observers manage to get a single piece of evidence? Not a photograph, a videotape, a feather, an egg, or anything else. Not one of the birds could be refound, and believe me, when someone reports an ivory-billed, the searchers converge. The chance that 50 people would see an ivory-billed and not one of them would be able to produce a photograph or see the bird a second time stretches coincidence well past the breaking point. This doesn't happen with other rare birds. Even when someone stumbles on the rarest of the rare, it is far more often than not refound, photographed, or seen by mobs of observers. Why should the ivory-billed be different?

Believers argue that the great woodpecker is shy and retiring and shuns humans. That may be true, at least partly, but many birds are shy, retiring, cryptic, and just plain hard to get a glimpse of. Over and over again, however, dedicated, enthusiastic, patient observers do see, photograph, and refind them. The stories of encounters back when there were ivory-billeds around suggest that they may be overrated as skulkers. Early in this century people stood right next to nests and photographed the birds coming and going.

"Ah," say the believers, "but there are vast tracts of remote bottomland in the Southeast that no one can get in to." They speak especially of the Big Thicket in Texas and the Atchafalaya Basin in eastern Louisiana. The problem is that it isn't true. There are some fair-sized tracts of largely uninhabited forest, but they have been carefully searched, even unto the most remote corners. Remember, people, including teams of researchers, have been looking for these birds for 50 years. Bird watchers, full of hope, have gone down and traipsed though much of the habitat. They found precisely nothing.Furthermore, most of the reports haven't come from those areas. They have been randomly scattered, many of them from areas where the chance of an ivory-billed occurring is smaller than the chance that I'll take up origami.

So the evidence, the smoke, consists almost entirely of quick glimpses of birds never seen again by people who are unfamiliar with the species or who are not bird watchers. It is poor fuel from which to try and build a fire.

What about the Pearl River report, the one that jump-started a massive search and attracted so much attention that it made the national news? I don't know what the observer saw. I wasn't there and there are no photographs. I can only work with what we have learned subsequently. It's not encouraging.

Art by Julie Zickefoose

The area was subjected to one of the most intense searches ever launched in pursuit of a bird. Teams worked through every possible piece of habitat, tree by tree and inch by inch. I know, because I was on one of the early teams and spent almost a week there. But there were lots of others. Microphones and remote cameras were installed. Holes were investigated. It would have been hard to hide a hummingbird in the area without it being spotted at least 20 times. They found nothing. Not a bird, not a feather, not an eggshell, not a hint or a whisper. Nothing. The odds that all those people whiffed on the birds are too long to calculate.

The true believers, the ones that most passionately want there to still be ivory-billeds out there somewhere, wild and free, argue that the birds were overlooked because the area is usually inaccessible and it was only the drought that made it possible to get in and see the woodpeckers. It won't wash. Yes, much of the Pearl River Management Area is wet in most years, but the area where the birds were reported is hardly inaccessible and remote. There are roads crisscrossing it. It is overrun with feral pigs, which draw hunters by the truckload. Bird watchers wander around it in every season. All those people are as likely to have overlooked a population of ivory-billeds as they are to have overlooked a tribe of elves. The problem of population is another powerful argument against the continued existence of the ivory-billed woodpecker. It has been at least 50 years since the last confirmed sightings. That's a long time. Big woodpeckers can live quite a while. We don't have any data for ivory-billeds, but we can look at its closest North American relative, the pileated, which is almost as big. The longevity record is about 12 years. Assume we are underestimating it and that ivory-billeds lived longer, and bump that up by 5 years. What that means is that there are not a couple of last, lost ivory-billeds that have been hiding for the past 50 years. It means that there have been generations of birds, birds breeding and successfully raising young. Given failures, unexpected deaths, and natural mortality, at least 10 generations and probably four times that. And there have to be enough birds to breed without inbreeding themselves out of existence. We are not talking about a couple of woodpeckers, we are talking about a bunch of them. And where have they been hiding? One bird might elude detection for a while, but not clumps of them.

Let's return to the beginning-David Hume's test for miracles. It is appropriate because a legitimate sighting of a pair of ivory-billed woodpeckers in this day and age would qualify as a minor miracle. Philosophers, especially 18th-century ones, produced dense prose, but Hume's test is not hard to tease out of the slightly convoluted wording. A simple example will help. Suppose you are told that an alien spacecraft hovered over a neighbor's yard and that little green men appeared and took blood samples from the observers (we have many such reports). Hume asks you to apply the following test: Is it more likely that the spacecraft appeared (which would require suspending all the known laws of the physical universe), or is it more likely that the person who reported it was confused, deluded, or pulling your leg? Which is harder to believe: the miracle or the alternate explanation?

In the case of the ivory-billed woodpecker, I think the evidence indisputably points to the alternate explanation. Remember, we have more reports of Bigfoot over the past 50 years than we have of ivory-billed woodpeckers, and few people have trouble dismissing those. And in both cases we have exactly the same amount of useful, believable physical evidence, which is none.

I said that I was one member of one team that went in search of the Pearl River ivory-billeds. I went with enthusiasm, but I said before we left that I did not believe we would find any ivory-billeds. I went not because I thought the birds were there, but because it is probably the last great ivory-billed hunt, a benchmark in the history of the species, and I wanted to be part of it. I'm glad I did. I searched hard, suspended my disbelief while I was in the field, met many knowledgeable and interesting people, and learned a lot.

No one wishes more passionately that the ivory-billed has survived our depredations than I do. It is one of the fantasy birds of my bird-watching youth, and in some ways I will never be able to let go of it. But hope has to be tempered with knowledge and the ability to think clearly about what we hope for and why. I am convinced that humans have a gene for wonder-the wonder gene-and a gene for belief, and a gene for hope. The emotions are too universal for it to be otherwise. We live for wonder and for the moments that move us beyond words. We revel in the impossible, seek it out as if it were the fundamental sustenance of life. We are the only animal that wants, even needs, the shock of being surprised. These are critical components of what makes us human and they make it possible for us to rise above being merely human to being better than we are. We should never let go of the wonder, the desire to believe, and the capacity to be surprised. What we have to guard against is the tendency to believe anything, to be surprised when we ought to be disappointed.

I never told anyone this, but while I was in Pearl River I saw an ivory-billed woodpecker. I was doing duty in a corner of the forest, alone, sitting against a tree eating lunch. Suddenly the bird appeared, the great white patches in the wings flashing as it landed right in front of me. The white bill was hypnotic, impossible to tear my eyes away from. Watching it I knew, not felt, but knew, what it was like to be here a thousand years ago and to watch the birds coming and going, holding dominion over all the forest. It was so real it coursed through my body like a drug and I could feel tears, not of sadness but of wonder and awe. It was the most emotional moment I have had in 30 years of watching birds, and it moved me as few things have done.

But there was no bird there.