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PRI's Environmental News Magazine

To the Edge and Back

Air Date: Week of June 28, 2002

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Scott Weidensaul has hiked through forests and swamps to bring back the dead – dead species, that is. He’s written a book on the search for extinct species, from the famed Ivory-billed to the secretive Semper’s Warbler. He talks with host Steve Curwood about his book "The Ghost with Trembling Wings: Science, Wishful Thinking, and the Search for Lost Species."


CURWOOD: Every hour, three or four rare plants or animals go extinct. That’s nearly 96 species a day, about 30,000 a year. But every now and then a species the world nearly forgot resurfaces. For example, just recently in Tanzania, the Wildlife Conservation Society captured rare footage of the Lowe’s servaline genet. That’s a three foot long relative of the mongoose that no one had seen for more than 70 years. Other lost species are waiting to be rediscovered and there are people who go to great lengths to find them. Scott Weidensaul is one of them.

He’s a naturalist and author of "The Ghost with Trembling Wings: Science, Wishful Thinking and the Search for Lost Species" and he joins me now. Welcome to Living on Earth.

WEIDENSAUL: Thank you.

CURWOOD: Tell me, how do we know that a species is really extinct or, as you put it, lost? I mean, what makes this final determination?

WEIDENSAUL: Well, that’s the difficult of it, actually. You can’t really tell for sure if a species is gone. Now, if it has a very limited range and it’s possible to scour that range and you can say with reasonable certainty that the species isn’t there. But, you know, you can’t prove a negative. And what happens so often is that many of these animals and plants are simply overlooked for long periods of time in the wild. And then years, decades, sometimes centuries later they reappear again. And in our history, when we’re losing so much in terms of natural diversity, it’s rather wonderful when these things suddenly re-appear again long after we’ve given up on them.

CURWOOD: Now, there are a lot of people who, when they hear that something is really extinct, set out to prove that the pronouncement is wrong. What do you suppose drives them, if so few efforts are successful?

WEIDENSAUL: Well, I think it’s a combination of a couple things, Steve. One is just the fact that we don’t want to let go of things. Sometimes we don’t appreciate something until it’s gone and you get these reports that drivel out of the wild from time to time of lost birds, lost mammals. And so, by searching for these lost animals and occasionally finding them, you know, in a sense you’re kind of restoring something that’s been lost. And people have a tendency toward obsession, some people a little bit more than others. I feel that within myself, dealing with these animals sometimes. You can just get this burr under your skin sometimes that sends you out time after time after time looking for something, whether or not you really, truly believe it’s there. Sometimes the search is as much fun as the finding.

CURWOOD: Now, what happens in those cases lost species have been found? What does it do to the surrounding community and governing bodies, or what changes in terms of environmental thinking?

WEIDENSAUL: Sometimes nothing, unfortunately. But frequently what happens, you know, there’s a progression when one of these animals is rediscovered, or plants. You know, there’s a sense of rejoicing, because something we thought was irrevocably lost has been brought back again. But then you suddenly have a reality check, because now, instead of having this mythic lost animal, now you have a conservation problem. One example here in the U.S. is the black-footed ferret, which is a beautiful weasel of the western prairies. And it was written off as extinct twice during the 20th century, once in the 1970’s and again in the early 1980’s. It was rediscovered twice.

The second time, it was rediscovered in northwestern Wyoming on cattle ranches. And each time it was rediscovered, you know, the whole mechanism of wildlife protection kind of ground into action. The U.S. Fish and Wildlife Service, state wildlife agencies, biologists crawling all over these ranches, and, you know, this did not necessarily always sit well with the folks on whose property these animals were found. Many of them at the time thought that there was just a little bit too much manhandling, a little bit too much direct intervention with these animals.

And in fact, that assessment was somewhat borne out when a canine distemper epidemic swept through the black-footed ferret colony in the 1980’s and wiped them out in the wild. And there was some speculation that that canine distemper may have been brought in by one of the very researchers who were studying the black footed ferrets. We can’t be sure about that, but some of the ranchers in that area on whose property the ferrets were found have later said, "Boy, if we had to do all over again, we wouldn’t have told anybody they were up here."

CURWOOD: From all your research and experiences, tell me, what do you feel was the most inexcusable extinction, the one that we really screwed up?

WEIDENSAUL: One of the worst examples, one of the most egregious examples, probably was the thylacine, which was the Tasmanian tiger. It’s not really a tiger. It’s a marsupial equivalent of a dog or a wolf. And this is an animal that was at the pinnacle of the food chain for a very, very long time until European colonists showed up and turned Tasmania into a penal colony and a sheep farm. And first the wool growers inflicted a bounty on them and that caused the death of an awful lot of thylacines, and then in the late nineteenth century, the Tasmanian government posted a state bounty, so that by the 1930’s the thylacine was virtually extinct.

Now, we’ve lost a lot of predators over the years. But what made the thylacine particularly a hard loss to bear is that it was the largest carnivorous marsupial in the world. This was really kind of at the pinnacle of marsupial evolution in terms of predatory behavior. There’s nothing else like it even remotely in the world. Unless somebody finds a thylacine in the wild it’s unlikely that we’re ever going to see them again.

CURWOOD: Something interesting just came up on the thylacine. There’s a group of researchers at the Australian Museum who say that they have some genetic material, they’re starting to isolate it and they think that perhaps in another decade they could somehow clone a thylacine. What do you think of that effort?

WEIDENSAUL: Well, this is actually the brave new world now for lost species resurrection. It used to be the only way to find them was to actually go out and look for survivors in the wild. But with cloning technology, with molecular technologies, there’s a chance that we could actually literally raise the dead from old tissue. And you’re absolutely right. The folks at the Australian Museum are putting a great deal of time and money to try to clone the thylacine from reserve specimens left over from the 1860’s.

It’s really very much science fiction because nobody’s ever managed that before. We’ve cloned mammals by taking live cells from live animals, but we’ve never done it with the dead cells of the long extinct animal. And yet even if they managed to do this, there are a lot of people who say that they shouldn’t be trying. There’s one group of people who say that you shouldn’t do it simply because it’s too expensive. You know, instead of taking that $80,000,000 and using it to clone one extinct species, give it to conservationists and use it to save the literally hundreds of endangered species of plants and animals that still exist in the wild in Australia.

And then there’s another group of people who say that the cloning project also sends the wrong signal to the public at large; it tells them that even for something as permanent and profound as extinction there’s a technological quick fix. And, you know, we don’t have to save endangered species, we don’t have to save endangered habitat. We’ll just save some tissue in test tubes, we’ll cryogenetically freeze it and, you know, some day later we’ll raise up some babies in a test tube.

But then, there’s also the third group of people who say that the whole thing is moot because the thylacine isn’t really extinct, that it still exists in the wild in parts of the mountains of western Tasmania which is, you know, a very rugged wilderness area. Certainly, the context is there for these animals to possibly survive.

CURWOOD: Scott Weidensaul, the subtitle of your book is "Science, Wishful Thinking and the Search for Lost Species." Could you please read us a little about the wishful thinking part of this and about what keeps the search going?


"Time and again, against logic, against sense, I would start to imagine. I could see the striped coat of the thylacine moving through the Tasmanian bush, or summon up in my mind the manic call of an Ivory Bill echoing off ancient tupelos deep in some soggy forest. Imagining leads to a germ of hope, and hope sometimes leads to belief, to obsession and piles of old maps, to fruitless expeditions and squandered life savings. All of which would seem a sad and farcical pathology, except that just often enough some lucky searcher hits pay dirt, and the world stands surprised and delighted with the discovery."

CURWOOD: How frequently does such a discovery happen?

WEIDENSAUL: It happens a lot more often than people realize. It happens, in some cases, almost on a monthly basis. It doesn’t often get a lot of attention because sometimes these are animals that are, you know, not terribly well known or people don’t get all worked up when a new species of lost fruit bat is rediscovered in Papua, New Guinea. But for those of us with an interest in the natural world, for those of us to whom the loss of a species is kind of a personal loss, these are occasions for great joy.

CURWOOD: Scott Weidensaul, you write-- and I’m quoting here-- "For many lost species there is one canonical moment that defines the hope for its survival." Did you have such an experience?

WEIDENSAUL: I had moments when your heart leaps, when you suddenly see something that you think "Oh my God, that could be it." And then a heartbeat later you realize, no, it’s just a Caribbean alainie (phonetic) or some other common species of bird. I was looking for a bird called the Cone-billed Tanager, however, in Brazil. This is a bird that hasn’t been seen since 1938. And I was in a fairly remote area of Montegrosso, fairly close to the Bolivian border, by myself, and a mixed flock of Tanagers flew through. And we’d been in the field, my friends and I, for weeks by this point, and we were a little bit burnt out dealing with bugs and heat and humidity and all the stuff that you normally deal with and so, I wasn’t thinking that clearly.

But I’m going over these birds through my binoculars and, you know, Cinnamon Tanager and a Black-masked Tanager. And then, suddenly, there was this greenish bird that looked vaguely familiar, like I’d probably seen it in a field guide somewhere but couldn’t quite put my finger on it. And there wasn’t that blinding slap your forehead and go "Oh my God" moment.

It was just that dull realization that "Oh, that could very well be the female Cone-billed tanager"-- which nobody has ever described. We only know what the male looks like. And then 30 seconds later the flock took off and disappeared, and I’m left standing there scribbling notes as fast as I can, wondering whether I should bolt off into the trackless bush in search of this bird or go back and try to find my colleagues. And as luck turned out, they showed up moments later and we went off after this bird and didn’t find it.

So I wonder, you know, to this day, what did I see? My gut tells me that, logic being what it is, I didn’t really see a Cone-billed Tanager. It might have been a juvenile of another more common species of Tanager. And yet, I can’t shake the notion that if that was, indeed, a Cone-billed Tanager that it looked exactly the way it should have looked. But I can’t prove it. And you come back to obsession here because I lie awake nights, literally, thinking about this, scheming to get back into that area with more time and better equipment and a better sense of what we’re looking for. And, you know, it gets to you in some fashion, the notion that there’s this lost soul out there, and you start thinking that you’re the one who can find it. It’s this is almost your mission, this is almost your calling in life.

CURWOOD: Scott Weidensaul is a naturalist and author of the book "The Ghost with Trembling Wings: Science, Wishful Thinking, and the Search for Lost Species." Thanks for talking with me today.

WEIDENSAUL: Thanks Steve. It’s been a pleasure.




"The Ghost with Trembling Wings: Science, Wishful thinking and the Search for Lost Species" by Scott Weidensaul.">


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