Earth & Sky

The following individual was interviewed for today’s program. Our thanks to:

Dr. John Fitzpatrick
Louis Agassiz Fuertes Director
The Cornell Lab of Ornithology
Ithaca, NY

Interview with John Fitzpatrick:

ES: Please tell me about yourself.

JF: I’m John Fitzpatrick. I am director of the the Cornell Laboratory of Ornithology, which is located at Cornell University in Ithaca, New York.

ES: Can you please tell me about the work that the Cornell lab is doing with the ivory-billed woodpecker?

JF: We have been following up this year on the reports that came out of a large area of forest in Southern Louisiana, the Pearl River bottomlands, which is a big area of forest, almost 100 thousand acres, that separates Louisiana from Mississippi. And reports came out of there several years ago, credible reports that this bird long thought to be extinct might still be alive, mainly somebody actually watched a pair of them for ten minutes. And what we did was to capitalize on work that we had done here at the lab that uses modern technology for recording sounds, digitizing these sounds and putting them into a small disc drive to construct units that could fit in the forest, on their own, powered by an automobile battery and record the sounds of the forest for 40 or 50 days. So we went into the middle of the Pearl River bottomlands, at twelve different places, backpacked the equipment in, including the batteries, and set these recording units up to record in late January through the middle of March. And indeed all twelve of them worked, and we brought them back in the middle of March. We have now almost half a terabyte, that’s close to 500 gigabytes of digitized sound. And we’re now sending these sounds through digital detectors that are trained to recognize the sounds made by the ivory-billed woodpecker based on recordings that were done in the mid 1930s. So as we speak, literally, I heard just a few moments ago, we have almost all of the sounds running through the detectors, and we’ll be very soon able to characterize the sounds that are most closely similar to an ivory-billed woodpecker sound. And in theory we’ll be able to detect whether any of those places had an ivory-bill calling nearby.

ES: So you might be sitting on sounds made by the ivory-bill now?

JF: That’s right, as of this moment we know that they all work, they all are filled with sounds from the forest, I’ve personally listened to a bunch of the sounds and identified sounds in there. We do know that we got good recordings in the botttomlands during the appropriate months, and this is a period of time when ivory-billed woodpeckers in their historic days would have been setting up territories and making a fair amount of noise. And they had huge home ranges, so we’d know that over a six-week period we had these units set up far enough apart that we’d have a good sense that they’d pick up the birds if they’re there. So it could be that we are actually sitting on evidence for the continued existence of this bird. We don’t know the answer right now (5-2 02), but we will know it within the next couple of weeks.

ES: What does an ivory-bill sound like?

JF: The two basic sounds that woodpeckers make are vocal sounds and drumming sounds. And the vocal sounds that the ivory-bill make are very distinctive. They were high-pitched, nasal sounds that were described by those that heard them as coming out of a ten-penny horn or tin horn. Sort of a “eihk eihk eihk” sound. They’re unlike any other bird. And so what we did was, using modern software for describing sounds, breaking the sound into its wave forms, measuring its energy into different frequencies, we could actually describe the sounds of an ivory-billed woodpecker very accurately in some software, which then can co through all the sounds that we have recorded and look for that particular signature of the sound. Every sound on those discs is being compared to this signature of the ivory-bill. And those that look most similar to an ivory-bill are being stored as a separate file, so we’ll be able to go through and listen to any sounds that are being detected. I can tell you that we are getting detections, but also that there are a few sounds that red-shouldered hawks make that are triggering the detectors, we know that we are going to have to make some plain old human listening to differentiate.

ES: Could you tell me more about the function of the sounds that ivory-bills make?

JF: The tapping sounds, or really the drumming sounds that woodpeckers make are very much their far-reaching territorial displays. Ivory-bills in particular were notorious for picking very resonant, hollow parts of dead trees and doing a very distinctive double-drum, a dah-doom, and that would carry for a quarter, up to a half a mile even from the tree tops. So it’s a very distinctive sound, described by the man who did the most important study of ivory bills as being the sound of bam-bam, like an echo. That’s a territorial display. And their vocal calls are probably much more social bonding between members of the pair. Ivory bills used to live in family groups, a breeding pair and one or two offspring from the previous season live together, so they would often call to one another across the tree-tops within the group. And so those are those high nasal calls that the bird was most famous for that were well recorded by Arthur Allen in the mid 1930s. So there are group calls, and then there are these territorial drums. And there are a variety of much softer notes that are given around the nest. We certainly wouldn’t expect to pick up any of those unless we got extraordinarily lucky. I might mention that while we were recording, We ourselves, plus another group of six biologists, were out on the ground looking physically with our own eyes and ears, and this search which lasted a month on the ground yielded nothing. So right now, it’s all eyes and ears pointing toward the Cornell acoustic units to see if we have any acoustic evidence.

ES: Can you please describe these Acoustical Recording Units a little more?

JF: These are terrific new devices that were invented here at the Cornell lab. And they have an enormous potential for use in monitoring remote places. Especially monitoring remote places for rare animals that make noise. They have been used already over the last 12 months in Madagascar looking for rare lemurs. They’re currently in use as we speak in West Africa where they’re set up in long arrays for the purpose of gathering sounds for forest elephants, which can then be triangulated so that we can actually track the movement patterns and even count the numbers of elephants. They’re also being used right now at Fort Hood in Texas to do a detailed study of the sound and territorial behavior of endangered golden-cheeked warblers. So all of these studies and many more are sure to come, are basically using these things as ways of recording permanently the sounds of a given spot, and then those sounds can be put together even in two-dimensions, so that we can track the movements of animals. All of this, therefore allowing us to get a lot of information recorded at the same time from lots of different places without having to have people at all of those places. And it all is possible because of the miniaturization of computer technology, allowing us to do all of this in a very small area, and to use a very small amount of power as we go, so that we can have the same recording for many, many days on just a small source of power. So we end up gathering huge amounts of information from individual spots, and then we go gather that information and bring it back to the lab and put it together and analyze it.

ES: What were some of the difficulties in using this methods of observation?

JF: Well, from our standpoint, the biggest difficulty was that we had to get these fairly fragile units, we had to carry them out to the middle of the forest, along with a 55lb automobile battery in each case, backpacking them up to 1/2 mile 3/4 of a mile into a forest through the bottomlands of bayou country in Louisiana, so this means backpacking through knee-deep or even hip-deep bayous. So it was a physical job to get them out there, and then of course to retrieve them. But it’s walking in the woods, basically with a backpack on, and so the other thing I might mention is that we wanted to select as varied a set of places as I could that represent a very good forest. So we had to do some reconnaissance in traveling through the forests of the Pearl River wildlife management area and the adjacent Bogachito National wildlife refuge. We looked for the very best forests that we could that it looked like it could have regenerated enough to hold an ivory-billed woodpecker territory. So we had to get to know the forest pretty well to know where to put these units.

ES: Can you talk a little bit about what led to the demise of the ivory-billed woodpecker?

JF: Well, this is a very important story. In many of our views, the most profound conservation failure we did in North America in the 20th century was that we cut, literally every square meter of virgin bottomland forest, that used to be from Texas to North Carolina. There simply are no places left where the very large trees that used to be there can be found. We cut them all. And the ivory-billed woodpecker existed because of the immense distribution of this forest, the immense size of the trees. We took away its lifeblood when we took away these trees. So the big question is whether a few individuals might have survived this bottleneck that we put them through in the middle of the 20th century. Because today, in places like the Bogachito National Wildlife Refuge and the Pearl River Wildlife Management Area, these trees are coming back. They’ve been coming back in many cases for up to a hundred years. So we’re now seeing in water oaks that are four and five feet in diameter, sweetgum trees that are almost three feet across. So those are the trees that the ivory-bill used to use all the time. So we look for places where the trees are oldest. I will mention that none of the places that we saw, nor any place that anybody could see right now looks as magnificent as the original forest did, where people could stand on the base of trees that were 15 feet across. But there are forests that are back on the way. And, hopefully, the next hundred years of management will allow these forests to return to what they used to look like. And really, whether or not the ivory-bill will still exist, we certainly will hope and expect that many of these areas will be managed as if it did, so we’ll see them returning. In our case, what we were looking for was forest that had a good hardwood diversity among several different species of oaks and sweetgum and sycamore and other species of trees that have as big a diameter as possible so that it represented as old a forest as we could find. Those are the places that the ivory bill used to lurk. And we’re hoping that the few pairs might have been able to hang on.

ES: What did the ivory-bill eat, and what kind of trees did it like?

JF: Right, the ivory-billed woodpecker was a specialist on bark-chipping of big, old , dead trees because it fed on very large beetles, the larvae of several families of beetles that get, literally,to be the size of one of your fingers. The very big beetle larvae was what this bird lived on. And those are found on a very brief stage of death of trees down there. So during a period when the living part of a tree is just dying, these big beetles would infest some of the bark and the ivory-bill evolved a specialization of chipping away the bark and eating these beetles. So to be able to live with that kind of specialization on those sorts of beetle larvae, the bird needed an immense home range, and it particularly needed great, big, dead trees. So it was looking for trees that were suddenly, briefly, filled with these big beetle larvae. That’s what it would eat, and that’s would it would feed its young on. It also would eat fruits and nuts of various kinds, and as any woodpecker would do it would eat a variety of things, but its main sustenance was these big beetle larvae. So it needed those big trees to be able to do that specialized foraging behavior. I mean its beak, the beak of an ivory-billed woodpecker, was just huge compared to the beak of any other woodpecker. A great, big, ivory-colored chisel in the front of this wild-eyed, white-eyed bird is what characterized this bird. It used that beak to chip away bug chunks of bark at a sitting. So it specialized in chipping hunks of bark, looking for these big beetles. Now, when we take away the forest, or make the forest a miniature version of it, first of all, these are all young trees growing back, there are far fewer dead ones than there used to be. And the diameter of the trees, and the species of trees, even, are such that they aren’t amenable to these beetles. So, when we have a young forest that’s a hundred years old or younger, we aren’t really supplying the kind of substrate that the ivory-billed woodpecker needed for its food. We’re supplying plenty of woodpecker food though, those forests are full of woodpeckers, and the most common one there is the pileated woodpecker, which looks a bit like the ivory-bill, somewhat smaller, but it’s still a large woodpecker with a red crest. Now there’s lots and lots of pileated woodpeckers out there, and that correlates with ivory-bills habitat, because it was found that the ivory bill used to live where the pileated woodpecker was the most common. And none of us that worked the Pearl River this year have ever seen pileated woodpeckers as common as they are in that spot. So all the signs point to the woods being pretty close to being able to support ivory-bills again. The only question is whether any of them made it through the time when we cut all the trees down.

ES: In the course of your study in the Perl River bottomlands, what is something that surprised you?

JF: I guess what surprised me the most was that I had not been aware of the extant of regenerating forest that does, in fact, exist now. I grew up with the knowledge that the ivory-bill was probably extinct because we cut all the old forests down. And frankly, seeing the Pearl River first hand, acknowledging that the place is four miles across and it’s absolutely pure, dense, old forest, I was amazed and very pleasantly surprised by the fact that we do have a regenerating, primeval forest down there, even though it’ll take another few hundred years to get back to its pre-settlement condition. I was just very pleasantly surprised by how much good forest there is and how it’s being managed now by the state and federal agencies managing it. You know, that was a very pleasant surprise. I’ve never seen woodpecker densities as high as they were in that forest, anywhere that I’ve worked, and I’ve worked all over North America and South America too. This woodpecker density is the highest that I’ve ever encountered. That certainly speaks to what the ivory-billed woodpecker used to live in, namely a place with a lot of stuff to eat for woodpeckers.

ES: Why should the non-birder care about whether Ivory-billed woodpeckers still exist?

JF: Well, I have to say this. For anybody who has read at all about birds or who has any kind of love about birds, finding the ivory-billed woodpecker is like literally raising something from the dead. It’s a bird that we believed for a generation or more to have gone, and also it was just a magnificent bird, an absolutely magnificent, striking bird. Large, blazing white eyes, a huge red crest, Just a beautiful bird with it’s gleaming white beak. And it really was a symbol of the primeval forests of North America. So losing that bird meant we lost, not only this beautiful bird, but it was symbolic of the fact that we lost this beautiful old forest. So finding the bird again, besides just the thrill of seeing something come back to life, would represent a huge ray of hope that there is a chance that we could bring back the ecosystem of the southeastern, North American bottomlands, so it would just be, in lots of different respects, a major symbol of hope and rejuvenation of this habitat that everybody has thought for generations to be totally gone and that we might never see again. I guess the most important thing of all is, from anybody who loves birds, is that this bird itself has really taken on mythic proportions. It was so beautiful, it was such a rare sight. It was Audubon’s favorite bird. It inhabited these beautiful southern swamp forests and big old pine forests. It just symbolized the real wilderness of the American southeast.

ES: Can you talk a little bit about the significance of the recording of ivory-bills made by Arthur Allen back in 1935?

JF: The recording made by Arthur Allen in 1935 was made only a couple of years after this bird was literally rediscovered. It was believed to be extinct already in the 1920s. And reports emerged from this place called the Singer Tract or the Singer Forest in Northern Louisiana that this bird might still exist. So Arthur Allen went down from Cornell specifically to try and get recordings of this bird and some pictures. And when he emerged from that swamp in 1935 with these spectacular pictures, and absolutely hauntingly beautiful recordings of this bird, it caused quite a stir. It was featured in the news reports and it made National Geographic. It was a big event even at that time. And little did they know that that experience plus a couple of years afterwards his student, Jim Tanner did a study on the birds there ? little did they know that never again, for 60 years would there be an absolutely confirmed positive reports of this bird. Besides getting great recordings, it turns out that they got the last one, perhaps ever, for that species. That actually kind of launched the beginning end of archiving of natural sounds here at Cornell. In a way it formed the cornerstone for what is now a huge library of natural sounds here at the Cornell lab, the Macauley Library of Natural Sounds, which is the largest archive of natural sounds in the world. I think it’s a wonderful thing to be able to feature the diversity of sounds in the world. It makes people realize that diversity has lots of different dimensions.