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from Gainesville, Florida Well, yeah, Conversation from the University of Florida. A discussion of social, political, scientific and religious issues of the day. Your host is Dr Michael Vegan in professor of history and ethics and assistant dean of the College of Liberal Arts and Sciences at the University of Florida.

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Hello and welcome to conversation. My guest on this conversation is Dr Lincoln Brower, professor of zoology in the University of Florida Lincoln. Welcome to our program. I want to say at the outset that I have been very impressed by your writings about the Monarch butterfly and for the benefit of my viewers.

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I'd like to rehearse something that I've learned about them. Namely, that early this fall, vast armada of orange and black monarchs began a mysterious journey down the eastern seaboard of the United States. And as their flight progress, they were joined by yet groups of other monarchs.

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Until eventually their numbers reached into the millions that they passed through cities and across plains and down rivers, uh, and along coastal waters, sometimes at 15 ft off the ground and sometimes for 80 miles a day. Until eventually they left this country and entered Mexico where, after one final meal of the nectar of autumns flowers they disappeared into the Fastness of a volcanic mountain range west of Mexico City into a secret hiding place, which very few people know.

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But you're one of those, very few, and you were there visiting them early this month. Do I tell the story correctly? Very well indeed. We just got back last Sunday night, as a matter of fact. And for the first time, we saw the butterflies coming in to the site to begin their phenomenal overwintering biology.

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Now I call that a secret site. Its presence was not known until what about five years ago? Well, it was made known in 1967 um or rather 1976. Uh, and it has not been made generally public, although numerous television shows and public announcements and journals have been made.

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And the reason that the actual sites have not been geographically given out to the public yet is because there is not a plan of tourist access to the sites. One of the reasons we were in Mexico last week with the World Wildlife Fund was to try to arrange with the Mexican government to develop a plan of access to these sites for the public, similar to that of our own national parks in this country.

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Are there not migrations of a similar kind on the west coast of the United States? And the butterflies gather on trees somewhere in California? That is correct. It's long been known in this country that monarchs in the West from west of the Colorado Rockies in the fall migrate towards specific grow in other areas along the coast of California, and this has been loan for a long time.

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But the vast numbers of them migrate all away from the east side of the Rockies all the way to the East Coast. When August and September comes on and the nights are cooler and the day length is shorter as we approach the fall equinox, when the day late day length is exactly 12 hours long and the night is 12 hours long, that appears to be the big trigger butterfly start flying south and until it was published in the National Geographic magazine by Professor Urquhart, who made the original discovery of these sites in Mexico, it was a complete mystery as to where these butterflies went, It's phenomenal, and I'm always amazed by animal migration of whatever kind.

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There seems to be a genetic trigger, as you say, that gets them started. But have we come to some conclusion about how they navigate as a pilot? I'm interested in navigation, and this is the most remarkable example of of navigation over a long distance by a very small organism.

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Well, we're talking about a butterfly being able to navigate from as far north as Canada to as far south as central Mexico and to a very small pinpoint, a pinpoint location map literally acres only in size. Exactly. I'll show you some pictures of this later, but the most phenomenal aspect of the monarch migration, which makes it unique, different from birds which are phenomenal, also is the fact that the butterflies that fly south will go to this pinpoint.

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They have never been there before. It's an inherited pattern of behavior. They will spend the entire winter there and in March, when the equinox is again upon them, the spring equinox, they reverse their urge and they fly north again. And eventually some of these butterflies that spent the entire winter in Mexico we'll get back to Canada, they'll lay their eggs, caterpillars will hatch out, the life cycle will complete itself.

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A new generation of butterflies is born, and this cycle repeats itself two or three times as the butterflies breed all over the North American continent east of the Rockies and then the great grandchildren of the ones that did the big migration. The great grandchildren are the ones that know how instinctively to get back to this overwintering site in Mexico.

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That is phenomenal because they have never been south themselves. But something in the genes passed down to them enables them to do this. What about such explanations as that birds and butterflies and other migrating species have magnetite or some kind of physical property that is attracted by the Earth's magnetic poles?

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Or something like that? Well, there's some work now going on in the University of Florida, which suggests that possibly the monarchs do contain magnetite, which may be used in some way as a guidance system for them to get to this area. But it's still difficult at this point in our understanding to know exactly how they know when they get to this site.

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We think that the well I have a map that might If I could show you a few of these slides, I could explain and more do that. Now let's put up the first of a number of pictures that we have. This is the monarch itself, right?

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Those are two butterflies overwintering on a warm day, and the next slide shows the egg. The butterflies seek out milkweed plants, and they lay their eggs one at a time on them. Now that's a poisonous plant. Isn't that is Right now. The next slide will show a very poisonous plant with a full grown caterpillar.

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Takes the caterpillar about two weeks, uh, depending on the temperature to get to that song, and then it turns into a beautiful green crystalline next slide. All right, let's move on to the next picture. Here we are. There's the crystalline, which is very difficult to find.

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Uh, now, my initial research interests on the monarch were, as you mentioned, based on the relationships of the monarch to the milk weeds. The butterflies lay their eggs on these plants, which are extremely poisonous, and it turns out if we feed one of these butterflies to a blue Jay.

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You see this in the next slide? Now we've taken a butterfly which we've raised on one of these poisonous milkweed. This is a laboratory blue Jay which eats the monarch with great relish Initially and then the next slide shows what happens in about 10 minutes. The bird is violently sickened by the poisons that the butterfly actually picked up from the plant.

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Now I want to stop you there. This bird will probably remember that and not eat another monarch. But does the species remember that doesn't know the bird. Every bird has to learn to avoid the monarch butterflies. It's all based on learning. But believe me, once A J had that experience, he won't.

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He won't want it again. All right, let's go on to the next. All right, Now this this spaghetti picture that you see here represents the distribution of all these milkweed plants in North America. There are 108 species. There's been a marvelous evolutionary unfolding of milkweed in North America, and the monarch is basically a tropical butterfly which flies north to lay its eggs on these plants, and it multiplies through the several summer generations and then in the fall, and the next slide will show the this one of the things that we're doing.

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If you look at this slide, it's a chemical thin, layer chromatography analysis, and you will see a basic pattern in that slide. If you look at each channel on the left, there's a series of blue spots, and next to that is a shorter series of blue spots.

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Now the one on the far left is the plant, and the one next to it is the butterfly that ate those plants. Those spots are cardiac like asides, which are very much like digital toxin used in the treatment of human heart disease. And it is those chemicals that make the birds sick.

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Now it turns out that the pattern of spots here is a fingerprint. We can tell which milkweed that a monarch butterfly has eaten by looking at the cardinal lied in its tissues. So what? We were really eager to find out where these monarchs were in Mexico, because here you have all the butterflies flying down to Mexico.

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Where did they come from? If we could look at their chemical fingerprints, we could tell where they came from. Now there's a long history about how ah, we found our way down to Mexico. But let me show you the slide of how they actually migrate there.

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This slide, the arrow shows the migratory routes. It's the one on the left goes to the overwintering sites, which are the black dots in California, and the ones on the right are going down to Mexico, and the next slide will show the butterflies on their way.

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And as you mentioned at the outset, this is a rather phenomenal behavior, and we were just down there last week. The next slide will show the butterflies well. You see the mountains, the Appalachian Mountains and the coast and Florida. Now butterflies come down along the mountains.

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They come out of the Great Plains. They follow the Gulf Coast. Some of them may go across the Gulf. We're not really sure. But anyway, they follow down along the mountains in Mexico, on the eastern side, and eventually they end up by that cross trans volcanic range.

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You can see a range of mountains going across there in the middle of Mexico, and it's right there in the middle of that volcanic area where the butterfly spend the winter. Mhm. All right, now we have another picture. And here's the actual site. Uh huh. Now, this is what we have called the Enchanted Forest.

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And this is a forest that it's about 10 0 300 ft high, and the butterflies fly in up that canyon to the very top of it. And then down in a sheltered valley, they spend two or three months getting through the winter. Now when they come in.

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This was incredible. Last week we saw this and let's look at the next slide, the black spots against the sky or the monarchs coming in. They've come in from Canada. They've come in from probably Manitoba, uh, South Dakota, Nebraska, Illinois, probably some from Florida, and they're assembling.

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And then the next slide shows them coming in. They come in and pulses. It's just incredible to see these against the blue sky. They swarm as it were. Well, they stream in, they stream. It's like water coming down a stream, Uh, and in pulsations. And then they come in and what they do, they keep coming and they form nuclei along the top of this ridge and the next slide will show that I think well, here they're still coming in.

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And this is a big pulse of them that you see here looks as though it was taken from an airplane. No, that was taken from the edge of the cliff as we were looking out across the beautiful fir trees in the background, the next one still coming in in the next one.

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Now, along the top of this ridge, the butterflies land in the very tops of the trees, and apparently they signal other butterflies to join them, and the next one shows butterflies coming in, and the next one shows the trees after they've built up with masses of butterflies on them, completely covered by the butterfly over.

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We've tried to estimate how many butterflies occur in these areas, and we're not sure whether it's 10 million or 100 million. Or maybe even more than that. It's There's so many. The usual sampling procedures that biologists used to measure their numbers cannot be used. What kind of trees are those first?

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It's a fir tree, right? It's a bee's religious, which is also known in Mexico as the oil mill, but they're not eating at this stage. They've eaten their last meal, haven't they? Before they have reached this point. They will not eat now for at least two or three months.

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Uh, although on their way in they do a lot of feeding you and you wanted to find out where those flowering fields were. That's right where they had their last meal. Have you found that? Well, it turns out we think that they're extremely important fields in Texas.

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In fact, if you look at a wildflower book of Texas, you'll find that the fall corresponds to the period of the great blooming composite E daisies and the monarchs are very much attracted to those. And we know that they tank up on flower nectar on the way down and build up very large fat reserves.

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In fact, about 4/5 of their entire weight will be fat, and they live on that during the winter. I see. And do they stay in that same tree where they first allowed? They don't now, this is interesting. This is now. This is where they first starting to assemble.

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And there are literally hundreds of assembling points along the ridge, butterflies zooming in, flowing in from all directions. And then as the season progresses, they dropped down into the valley about two or 300 ft below, where it's protected and the next slide may show well. Here's a little tighter shot of the butterflies, which are drawing each other closer and closer to each other, and more and more as the clusters build up and the next one shows a tight cluster and the next one.

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Now, in the very center of that picture, it's a little hard to see. But at the very head of that valley there is a colony of approximately 20 acres of monarch butterflies. One of the largest clusters were one of the largest aggregations we've ever found in this area, and the butterflies have dropped down from the ridge into this huge overwintering aggregation.

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The next slide will just show you how densely clustered they are at the peak of winter. Amazing the next one. The being inside this forest is truly an enchanting experience on a warm day, the next slide the butterflies well, on cold days, the butterflies become very quiet, isn't it?

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Gets down to freezing here and monarch butterflies cannot withstand freezing below, maybe two or three degrees below freezing, and they cannot fly below a certain temperature, either. Is that correct? And the next one. Not only do they festoon the branches, but they also festoon the trunks of tree of trees.

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That tree trunk there's at least 2 ft in diameter when they become quiescent. Is that akin to hibernation and other species? Well, it's It's not really hibernation, although it's analogous to it. They are conserving their fat. They are practically inactive. If they get knocked off, they will do everything they possibly can to crawl back up on the trees.

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They can crawl at a temperature lower than that which they can fly out, and they can struggle and warm their rings up. But every time they do that, they expend some of that precious energy. Yes, and that means they may not be able to fly that far back in the spring without running out of energy.

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And in the spring they have to fly some distance before they find flowers again. Well, they do fly a great distance. There are flowers in the area, but there are so many butterflies that they outnumber the flowers and so that they have to have a reserve to get out of there and then encounter more flowers.

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But they're not as many flowers in the spring as there are in the fall, so the name of the game and the spring is to get out of there fast and to get back. Now. If they get knocked down, they'll crawl up on tree trunks as you as you see here, anything to get up off the ground where they may be subject to freezing the next one.

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Now as it warms up and this picture is taken in March, and that's one of my laboratory assistance Willows, you house key, who's here at the university? Willow is on her way down at our camp to get water and all you have to do to find water there is follow the butterflies because at this time of year they're just flying out and droves and again, this is like water flowing down.

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And then late in the afternoon, they come back. It's just remarkable. Do they show any fear of human beings? None whatsoever, although if you catch them and release them, they go off in an escape flight and they will avoid hitting you. They have very good vision, and I have.

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All right. Is that the water? This is where they're feeding at water. Now they're gathered around a wet spot, a little stream there, and they will fill up with water and fly back into the colony. And they may have to do this once or twice during the year.

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The next one. This shows them on the way out in the spring, and here you see a different set of flowers, which are providing some nectar for the butterflies in the spring. But as the spring advances again at the Equinox in March, this is when they're on their way north, and those butterflies that you see there, this is March will be in.

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Some of them will make it to Canada, probably in late May or early June. And as they fly, they mate, and then the females encounter the milkweed plants and lay their eggs on them, and the breeding cycle begins. A new do. These same butterflies make it all the way back to their northern habitats.

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Some do. Some do we have. Only Professor Urquhart at Canada has done a massive tagging program where they actually mark individual butterflies, and he marked one in the Southeast, which was recaptured in New York state the following spring. It was not found for certain to overwinter in Mexico, but it probably did so.

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That is the best evidence we yet have, but the whole picture, if you put it together, although we don't have the exact piece, we can make out what the picture is saying. And we need that evidence eventually to complete the puzzle, which will be gotten by marking butterflies in Mexico, proving that they get back into Canada.

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Do we have any more pictures? We have a few more one of our concerns. Maybe I shouldn't even talk about this, after all the marvelous beauty of this incredible phenomenon. But like all tropical regions of the world, and in fact, like most of our own forests in this country, they are subjected to lumbering and Mexico with a with a booming, expanding, uncontrolled population.

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Growth is placing immense pressure on these forests, and the next slide will show that we're talking here about a major operation of saw wood and paper, pulp, wood, everything and what we're trying to do with the World Wildlife Fund is to negotiate an area here to protect us Enchanted Forest.

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And the next slide, I think, shows the second person from the left there is the governor of Michigan. You can, uh Governor Cuauhtemoc Cardenas says. That's the province within which this valley is situated, right that he is the governor of the province, or state of Michoacan and governor card.

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Inez is very interested in preserving the butterflies, and he arranged for us to do a helicopter reconnaissance trip there last March, which was rather an exciting trip. We covered about 800 miles of the area where we think the butterflies are overwintering. We found several new areas, but far fewer than we expected.

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So this enchanted forest is a very limited area, and it's one I think the next to slides would. This is perhaps the most incredible aspect of the whole overwintering biology. What? We're looking the governor on the right there, what we're looking at and that slide is shown in the next slide.

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No more slides. Well, I'm sorry, but anyway we were. What we were looking at was that the sky was literally blackened with butterflies in the spring. When it's warm, the butterflies become very active. They sit around in the treetops and they warm themselves, getting ready to fly.

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If a cloud comes over, they all fly into the air. All of them, millions of them in this poll, relating cloud of butterflies was above us. And when they do that, they dropped down the valley about five or 600 yards. And this is the way the spring migration gets going.

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My word. What an incredible story. I want to ask about the danger posed to the flowering fields. You think they may be in Texas because if there is destruction there, it would be just as damaging. Would it not to the butterfly populations absolutely well. See one of the reasons the World Wildlife Fund is interested in the monarch conservation is because it involves Canada, the United States and Mexico.

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Mexico is the prime overwintering site. The United States and Canada are the breeding and neck during sites, for the most part, so this has to be an integrated conservation program and that's what we're working on. And the Mexican government has been extremely cooperative, very interested, and hopefully we may have something akin to a national park within two years.

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You've been involved in this research for a long while. I know both as Stone professor of Zoology at Amherst College and as professor of zoology here at the University of Florida. Before we close this conversation, I certainly want to ask you to say something about the fabulous new collection of butterflies that we have at the university.

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I understand it makes us the largest such repository in the Western Hemisphere. Well, we are one of the major butterfly collections in the world. Now, thanks to the Allen gift, uh, this was absolutely fabulous gift to the University of Florida. And what we're hoping is that that large resource will be a magnet to attract, not butterfly well butterflies, but also two or three major butterfly experts in the future who will curate that collection and who will develop it.

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And we may have a collection here someday. Comparable to that in the British Museum of Natural History. I want to mention as well that you are the newly elected president of the and I hope I name this organization correctly. The International Society of Lepidoptera Wrists the world group of scientists who work with butterflies and that again has brought great distinction to our college of liberal arts and sciences into our university.

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What are some of the advantages to human life and the human sciences that come from butterfly research? You mentioned something about the heart? Uh, um, some chemical in the milkweed that we're able to ingest but not human beings. This is a very interesting sideline of what comes out of basic research, no matter what it is, whether it's butterflies or birds or frogs or fruit flies or rats or monkeys.

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In studying basic biology, you often come across interesting problems that bear potentially on human health and well being. And it turns out that the poisons that are in the milk weeds that the monarch can tolerate in very high concentrations are very similar to human heart drugs.

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They are chemically almost identical to them now, the ones that are used in the treatment of human heart disease, digit toxin, digitalis and lobbying, and others. Um, okay, that's only one small group of drugs. The butterflies potentially can tell us how overdoses of drugs which could harm the heart, might be corrected because the butterfly is living with with what amounts to a huge overdose.

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How does that living tissue tolerate that high dose? Another question, we can ask is the milkweed Zara literal museum of compounds like the pages of a book full of these different kinds of heart poisons. And perhaps 10 years from now, the poison that is taken up by a monarch butterfly might be the effective drug of the future for the treatment of human heart disease.

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That would be a wonderful bonus from the type of research you do. And you're quite right in pointing out the advantages that come to humankind from basic research and other species, including the smallest, such as butterflies. I thank you very much for taking me on this magical journey to Shangri La and to show all of us who have had the opportunity to see your pictures, the beautiful coloration of the orange and black monarch butterflies, your life, love as well as your life study and Dr Lincoln Brower.

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I thank you very much for being with me on conversation. Thank you, Mike. Thanks. Mm.