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				The Silence of the Birds The brown tree snake has wiped out bird life on Guam. Will a new snake virus curb the crisis?
		Select text to jump ahead in the clip: ALDA: It's a tranquil scene on the coast. A couple of guys are diving... checking out life on the lagoon floor. People are boating. Actually, I know who that is out there. She's Rachel Woodfield, a marine biologist, and she's bringing in a bag of that weed the divers were looking at. Hiya, Rachel. Hiya. Hi. Is that it, there? This is it right here. ALDA: But the weed is not as nice as it might seem. We're at Agua Hedionda Lagoon just north of San Diego on the California coast. The divers out there are trying to get rid of every last shred of this stuff that they can find. It's calledCaulerpa taxifolia. It's an invasive weed that has the potential to literally smother California's native marine life to death. We know that because it's already killed off thousands of acres of coastal life in the Mediterranean. Caulerpais a classic example of the phenomenon that we're devoting this entire program to: alien species. Remember killer bees? They're dangerously aggressive African bees introduced to Brazil in 1957. Now they've spread north into California and the Southwest and beekeepers are trying to figure out how to cope with them. South American fire ants are another alien. They attack pets and wildlife and destroy native plants. Fire ants got to Mobile, Alabama, in the 1930s probably in soil used as ship ballast. Now they're in 14 states in the Southeast. What they all have in common is that somehow they've been transported from their home habitat to a part of the world where they did not evolve, where they're aliens. It's a great thing to be an alien because in your new environment there aren't any of the predators and competitors that you originally evolved with that make your life a constant struggle. So you can really run wild and grow like crazy and take over the place. Thousands of plants, animals, insects, fish and microbes have moved around the globe to become aliens. Almost always, it's humans who do the moving. Asian hydrilla, for example was first brought to the U.S. in the '50s as an aquarium plant. Now it clogs waterways all over the South. People always have carried things with them, of course either by accident or design. But now with global trade alien species are becoming an irresistible force. In the Great Lakes, many of the most common species are aliens including the notorious European zebra mussel. Most are recent arrivals. New Zealand now has as many alien plants as native around 1,700 of each. Hawaii is the same. It's thought that right now the U.S. has about 7,000 alien species of all kinds. Is that a bad thing? Sometimes the cost is obvious. For example, 20% of California is infested with Eurasian yellow star thistle. It's toxic to horses, and cattle won't walk on it so huge areas of rangeland are now useless. But ecologists argue that the greatest costs are less tangible. When species get mixed up in this great global exchange the sets of plants and animals called ecosystems can fall apart and disappear. We're going to lk at four alien species stories from around the world. Among them, they display all the classic ingredients. There's the 19th-century Harvard professor who thought he had the key to a better silkworm. There's the disease that was blown across the Atlantic to cause havoc in the Caribbean in coral reefs and maybe among people as well. We're going diving in the Mediterranean to see firsthand the damage that Caulerpa taxifoliacan do. And first, the story of a bird, a snake and a small island in the Pacific. WOMAN: Okay, this is... ALDA: This is the National Zoo in Washington, D.C. I'm heading for the tropical bird house in the company of Kathy Brader, the keeper. So, we have these birds that are housed inside. These are all different...? ALDA: There's one particular exhibit we're interested in. Now, this is our Guam exhibit. And in here we have our Guam rail and our brown tree snake. He's curled up on the top. Oh, yeah. And he is the cause of these guys' problems on Guam. ALDA: On the island of Guam in the western Pacific the forests are eerily silent. Guam has lost all three of its unique native bird species. Six other regional species are gone; just three others are hanging on. This is the culprit. You can see all the different locks and equipment we have on there to make sure that he cannot get out. Sometimes they hide a key, you know. (laughing) Well, fortunately I don't think we have that problem with the snake. And... let's just back up here a little bit. For us to have him here, we had to have a special permit and only have males, so there's no chance of... If one did get out, they can't reproduce. Because we don't need this problem here in the United States, you know, on the mainland. ALDA: You can be sure that if the brown tree snake did manage to get out the Guam rail would make an easy meal. Guam has no native snakes so the birds developed no natural defenses against them. Horatio, as he's called, doesn't even recognize the nearby snake as a danger. It's the mealworms that interest Horatio. BRADER: We use them as a protein supplement but we also kind of use them as a treat. As a treat? Yeah. You know, no wonder these birds are extinct. Come here, Horatio. ALDA: Horatio is descended from the last 21 Guam rails that were brought in from the wild in the mid-1980s for captive breeding. ALDA: Do you hope to reintroduce them? BRADER: Yes, but there's literally millions of these snakes and we can't just go and re-release them with the snakes still being the problem. When we can solve that problem is to reintroduce these birds back into Guam. We want them in the wild. NEWSREEL ANNOUNCER: Here in the South Pacific theater air transport bucks fog, mountains and Japs in the routine performance of its duties. ALDA: It was the disruption of war that led to the devastation of most of Guam's wildlife-- birds, bats, flying foxes and small mammals. The island was occupied by the Japanese, fought over and became an important air-transport hub. Sometime in the 1940s a few brown tree snakes must have stowed away on flights maybe from New Guinea or the Solomon Islands and made it to Guam-- the first snakes ever on the island. Today, Guam is infested with brown tree snakes maybe one or two million of them-- up to 20 snakes per acre in some areas. It's the highest snake density in the world and a major nuisance for people. Their bite is only mildly poisonous-- about like a bee sting-- but the snakes short out power lines; they get into buildings and attack anything-- wildlife, pets, chickens, and children, too. Secured in double cages at the National Zoo there's a large research collection of brown tree snakes including females, collected in Guam by veterinarian Don Nichols. He's been bitten maybe half a dozen times. You need to move quickly once they know you're here but I'm just going to grab the snake by the head and secure the head, which is where all the weapons are and then pull it on out. And as you can see these are very long and slender which is adapted for life in the trees. And if my hand were a tree branch then it could actually extend its body out as much as 67% out into the air. With a lot of snakes that are not adapted to life in the trees you can actually grab them by the tail and hold them up like this and the snakes can't get to you if you hold it away from your body. But this snake can, huh? But this snake has the ability. Its muscles are so strong that it can actually come right back up like this and if I were to let go of the head it could come up and nail me, or maybe even... Or maybe even me. ALDA: Guam is still a major hub so the fear is the snake could stow away again and jump to other snake-free islands, like Saipan or Hawaii. There are rings of traps around the seaport and airport. Cargoes are checked constantly but in spite of the vigilance, there are leaks. So far the snake has been caught on eight other Pacific islands including Hawaii, where 14 are known to have arrived. One snake was even caught in Corpus Christi, Texas. It's only a matter of time before a new population gets established somewhere so the search is on for some way to control-- even eradicate-- the snakes on Guam. At the National Zoo Don Nichols and Elaine Lamirande are working on a radical idea: find a disease which just affects snakes. These samples all came from snakes that died from a virus infection. Called paramyxovirus, it regularly crops up in captive snakes which live close together. NICHOLS: This one looks a little rambunctious so I'm going to use the snake hook. ALDA: Don Nichols had the idea that paramyxovirus could be made to spread among Guam's dense snake population. Right now they're seeing how different strains of virus sent here from around the world, affect the brown tree snake. The snake gets a shot of anesthetic which takes about 15 minutes to take effect. NICHOLS: Now I give it a few jiggles and make sure there's no movement. Yeah. You can see. I still will make sure I got control of her head but she's... quite asleep at this stage. ALDA: Then a dose of one of the paramyxovirus strains is injected into the snake's windpipe causing a pneumonia-like disease within two or three weeks. Don says these viruses pose no risks for people because they're active only in cold-blooded reptiles. Our high body temperature kills the virus off. NICHOLS: Let the fluid trickle down into the lung. ALDA: So far they've tested 16 strains of the virus, looking for one that will kill the snake only after a delay, so there's time for the infection to spread to other snakes. There's no getting around the fact that this project is about killing animals-- figuring out the best way to give them a really bad case of pneumonia. That's something that an animal lover like Don is acutely aware of but for him, it's the lesser of two evils. How do you answer somebody who questions whether or not you're being cruel to them? Well, I mean it's all a matter of your priorities and I'm the first person to admit... I actually like snakes, and I like them where they belong. But these things are... are a pest species in an area and they're causing all kinds of havoc. They're threatening other islands. And it may not be the most humane way to kill them but it's the only way you can do it on a broad scale. ALDA: There was an attempt on Guam to persuade people to eat the snakes. It never caught on, and anyway no approach involving catching individual snakes is going to make a dent in a population of millions. Don is convinced that only a biological control agent that can perpetuate itself-- like a disease or a parasite-- could have much effect. But could biological control carry its own risks? Don't viruses reproduce rapidly? Don't they have a chance to mutate and attack other species eventually? My biggest concern would be whether or not it could adapt... mutate and adapt to the native lizards. ALDA: Don says that paramyxovirus has never been known to jump to lizards and of course they'll do tests before any virus release. But biological control inevitably carries risks and that's a measure of how difficult it is to tackle the problems created by alien species. The original problem occurred when some snakes got on airplanes and flew to Guam. Now, if you infect the snakes in Guam and an infected snake gets on an airplane and flies to some country where that virus could hurt those snakes isn't that a danger? NICHOLS: There is a chance of that happening. However, one of the key things is that these viral diseases are very density-dependent. In other words, high populations, dense populations-- easy for the viruses to spread around. But in the native range of these things it's very difficult to find the snakes. They're very low-density, so... It's not a zero-percent chance, I'm not saying... No, no, I mean, my mind is racing because it just seems to me that every time we do something to fix something that we did wrong 50 years ago we create a new problem for somebody 50 years from now. ALDA: The hope, of course, is that we've learned how not to create new problems. If the virus project is approved the small island of Rota, 35 miles north of Guam may hold the best hope for the return of Guam's wildlife. It's still free of snakes so there are birds here that are extinct on Guam. Over the last few years, more than 200 Guam rails bred in zoos from the 21 birds captured in the 1980s have been released here. Two-zero-eight-five. ALDA: They're breeding successfully so they can provide a wild nucleus from which Guam itself can be repopulated if Don Nichols' virus works. Guam's wildlife can never be fully restored but without snakes, it can return to something like the balance that once existed. And at the same time, the threat of similar devastation spreading to other islands can be averted.

				Green Invader Alien algae are smothering native marine life and livelihoods in the Mediterranean. And now it's in San Diego as well.
		Select text to jump ahead in the clip: ALDA: How long have you been studying thisCaulerpa? MAN: More than ten years. Ten years. ALDA: We're in a small towjust down the coast from Nice in the south of France. Alex Meinesz, a biology professor from Nice University is taking me out fishing. In those ten years, how much has it increased? ALDA: As with thousands of places like it around the Mediterranean Sea this town depends on a mix of fishing and tourism for its livelihood. On peut monter? FISHERMAN: Okay. Okay, thanks. Bonjour. FISHERMAN: Bonjour. Patrick. Patrick, Alan. Alex, bonjour. Mais alors, au commencement... ALDA: We're on the Verg family boat. The waters around here have been fished for generations-- until now, that is. They don't fish here anymore. We had to persuade them to set their net out last night just so we could film the result. And the result is this. ALDA: There's some. MEINESZ: Caulerpa. Yeah. Caulerpa. Look. PATRICK: On arrte un peu, uh? Look-- and thisCaulerpa clogs the nets and the fish see the nets, and there is no fishes. Oh, I see. So it hurts fishing... it hurts fishing just because... They see the nets. It calls attention to the nets. ALDA: The weed, calledCaulerpa taxifolia,doesn't belong here. It's a tropical plant common in the Caribbean and other warm waters. The northern Mediterranean gets cold in the winter but somehow theCaulerpais surviving and thriving-- nothing can touch it. MEINESZ: When you broke it, there comes a kind of juice out of, you see? Does that juice have anything in it that keeps away predators? Yes, absolutely that are terpenes, caulerpenynes. And this is a kind of toxic matter and a repellent matter. So the fish don't eat it. So it repels fish, and does it... so... in this area, nothing is a natural predator. No. You see all the leaves are entire. Nothing... Nothing has been eating it. No, no eating trace. Yeah. On y va? On y va. (laughing) Holy moly! He really jumps in! ALDA: Alex took us into the shallow water near the town's bathing beach. Everything below was covered by theCaulerpa:rocks, sand, mud. There's nothing else down here-- no other plants, barely a fish. It's a classic example of an alien that just takes over-- like the brown tree snake in Guam. Nothing eats it, and nothing competes with it. It's full, huh? Yeah, there's a lot of it down there. All the bottom is covered. ALDA: TheCaulerpaarrived here about nine years ago. Advancing at an inch a day, it has ruined the fishing and it'll soon clog the town beach. It's the same disastrous story spread out along a thousand miles of Mediterranean coast. Caulerpais easily spread. It's carried along in fishing nets and there are millions of small boats in the Mediterranean all with anchors. MEINESZ: A little piece like this I put this in the water after six months, you have three square meters with this little piece. Any part of this? Any part, any part. ALDA: With its rapid spread from fragments and its cold-water survival Caulerpain the Mediterranean is behaving in ways that shocked marine plant experts like Alex. After years of investigation Alex is pretty certain he knows how this disaster happened. This is the aquarium at the famous Monaco Oceanographic Museum where Jacques Cousteau was once director. In the early 1980s, the museum along with several other European aquaria started using a decorative and easy-to-grow plant in their tropical tanks. The plant was Caulerpa taxifolia. It's still used here today, as it is around the world. Alex believes that somehow some fragments ofCaulerpa were released from the tanks into the sea. A museum diver first sawCaulerpa right outside the building on the bottom in 1984. It covered just one square yard. By 1989, when Alex first saw it, it covered two acres. By 1990 it was at nearby Cap Martin next year Toulon, a hundred miles away and now it's found from Spain to Croatia. With no natural enemies to hold it back theCaulerpahas been steadily smothering Mediterranean sea life. In the shallow areas, there's normally a complex community of over a thousand different species: algae, shellfish, worms and fishes, all based on meadows of native sea grass. In the darker depths, there's a different balance with the grass giving way to red sea fans. This is the steep 100-foot rock wall off Cap Martin once a favorite spot for scuba divers. The film is from 1996, shot as theCaulerpawas taking hold. Alex has been diving here every year since theCaulerpaarrived. As the alien plant advances, it blocks out light-- from the red sea fans, for example, which die off. Alex has seen the same process repeated all over the rock wall. Did this all originate with the Monaco aquarium? Genetic analysis has shown theCaulerpais a mutant strain unique to aquariums-- including Monaco-- and not found in the wild. But we'll never know for sure how it first got loose. In the summer of 1999 our underwater cameraman swam down the rock wall at Cap Martin to record the progress of theCaulerpa. The wall is now completely covered. The last sea fans are dying. The wall is essentially a biological desert. Once again, we're looking atCaulerpa growing in an aquarium. But there's something else-- it's a kind of slug and it's eating the weed. The result: all over the tank, ghostly white fronds of weed with their toxic juice sucked right out by the slugs. The slugs are being studied in his lab at the University of Nice by Alex Meinesz. In his view, they represent the single best hope for controllingCaulerpa taxifoliain the Mediterranean. We've jumped 4,000 miles across the Atlantic to the Indian River in Florida. Alex's slugs came from here, collected by Cecilia Miles a marine biologist from Florida State University. HereCaulerpais eaten and controlled by the highly specialized slugs as it is further south all over the Caribbean. The hope is that slugs from Florida-- the northern extreme of their range-- might be hardy enough to survive the Mediterranean winter. In the summer of '99 Cecilia collected and packed a batch of Florida slugs for shipment to Alex in Nice. The slugs had their own air supply for the flight and were escorted across the Atlantic by a French grad student. See you, Cecilia. Bye-bye. Thank you. ALDA: Here you were a student ofCaulerpa... ALDA: Alex has been studying different slugs for years. The Florida batch had been in residence at Nice University for about two weeks when I visited. I study on theCaulerpasince... ALDA: His work with slugs andCaulerpa is done on a shoestring budget in a makeshift lab behind the biology building. The Monaco Aquarium connection makes this a very political subject so research grants have been hard to come by. ALDA: So you've got a chance to see who's working out. Yes, who studies biology. Come in, please, come in. So... they're in there. I don't see any slugs. Yes... here! ALDA: Oh, yeah, yeah, yeah! Now, is he eating now? Yes, I think so. So these slugs really like that toxic stuff. Yes, ah, yes. They need the toxic because they take the toxins and they stock it in them and then the fishes doesn't eat it. Oh... Oh, I see! Oh, oh, so the slugs use the toxins to keep the fish away from them! Exactly, exactly, exactly. ALDA: The slugs have other highly specific adaptations toCaulerpa. They needCaulerpacells as part of their own metabolism and they have a special tooth which matches onlyCaulerpacell structure. Alex argues that the slugs are so exquisitely adapted to their one food that releasing them into the Mediterranean to control the invasion biologically would present a very low risk. I asked him about this. How do we know the slugs that you bring in won't adapt and find some other way to live in addition toCaulerpa? When the slug have no moreCaulerpa they cannot, in one generation, say "Ah, we shall change our tooth, our mouth our toxin, to eat other things." (laughing) You understand? That takes a lot of plastic surgery! You understand? Sure, sure! When there isCaulerpa, they eatCaulerpa. No problem, no problem. When they see there is no more Caulerpa,it is too late. It is too late. ALDA: Alex's slugs may be the only way to go. All kinds of nonbiological control methods have been tried like releasing poisonous copper from underwater electrodes... or simply scraping the weed off... vacuuming it up... freezing it with dry ice... scalding it with hot water... or cutting off its sunlight. But there's nothing that's practical on a large scale except the slugs. I asked Alex again is it really smart to release the slugs into such a paradise of food? All of a sudden, they're dining out every night. They're going to Maxim's every night and they're doing pretty well. Now you're liable to have some pretty fat, happy, healthy slugs around looking for trouble. No, no. You ever have a prairie ofCaulerpa with many slugs in it and then they control theCaulerpa and it is finished, that we think. But what you want? Do you want to have a Mediterranean Sea full withCaulerpa without any control method? We must have a predator for this invader. Without predator, theCaulerpa-- that is a risk that we see now. We can see, you have see it when we snorkeling. You see with the fishermen. It covered all the bottom and expands every year. So what do we do? Do we nothing or do we try this? ALDA: If you can't get rid of it, if the slugs don't work if the slugs are too dangerous, if the slugs work but governments won't let you use the slugs what will theCaulerpado? What will happen to the Mediterranean? What happen is exactly the same that happened since ten years. It extends. It extends every year, in new country, new regions. And we think that this algae is able to colonize most of the region of all the Mediterranean Sea. ALDA: Now fast-forward two years and 7,000 miles. We're back at the California lagoon where we began this program. Just like in France, the alienCaulerpahere is untouched by any natural enemy. It's capable of smothering the native eelgrass. The patch of bright greenCaulerpa was first noticed in the year 2000 suspiciously close to a storm drain outlet. Caulerpais widely used in home aquariums so someone probably dumped one out into a drain somewhere in the area. Getting rid of theCaulerpahere and in one more spot near Los Angeles is now the responsibility of Rachel Woodfield who works for an environmental consulting firm. Where did you first find Caulerpaaround here? Right out here in the eelgrass beds. We were monitoring the success of the native eelgrass beds and came across this bright green terror growing in there. We weren't sure what it was at first. We've all heard ofCaulerpa in the Mediterranean but to make the relation that this isthekiller algae-- it took us a little while to figure it out. Was it widespread by the time you first discovered it? It had spread throughout this small harbor area. It covers about five acres. So we built this boom around it to keep all the boats out and people who might want to come in and see it and might potentially spread it. ALDA: They decided to try killing off theCaulerpa a few square feet at a time-- something it's too late for in the Mediterranean. Portable frames are covered with plastic tarps which are sealed to the lagoon floor with sandbags. The underwater tent is then given a dose of chlorine and left for a few days. Everything inside is killed-- Caulerpaand native eelgrass-- but so long as they get all theCaulerpa only eelgrass will grow back. After a year, it seems to be working. We're at a manageable point right now. We have two infestations. They're deep back inland in lagoons. There's calm water. We're able to have the luxury to put these tarps down and deal with it and keep an eye out for it before it gets offshore. Is this the major threat or the only threat right now from an alien species in this... in these waters? This certainly is not the first exotic species that this lagoon has seen. However, this is the first species that really has the potential to cause some serious, serious harm to our coastline and that is at a state that is manageable.

				The Silken Tree Eaters Scientists wage a desperate struggle to save America's forests from deadly insects.
		Select text to jump ahead in the clip: ALDA: We're in the New York City borough of Queens to witness the death of a tree. (chain saw buzzing) ALDA: One of the cemetery's prized mature maples is coming down. It was doomed anyway, and this is why. MAN: What we have here is a larval Asian long-horned beetle. If we just pull him out of here... You can see they're quite sizable. They have large mandibles well suited for the environment inside a log and chewing its way through the hardwood. ALDA: The Asian long-horned beetle is as big a threat to America's forests asCaulerpais to our marine life. In late summer each female distributes a couple of hundred eggs around several trees. The beetles arrived in the mid-1980s in wooden packing materials from China so as usual with alien species they have no natural enemies here. Right now they're just confined to the New York City and Chicago areas but already 7,500 trees have had to be destroyed. The damage is done in the spring when the larvae hatch and eat their way out emerging as adult beetles to begin the cycle again. The tree cannot survive the process. You don't see much on the outside sometimes and then when you flip it you see what type of damage this is capable of. Our goal is total eradication of this insect from North America. (chain saw buzzing) ALDA: Eradication means cutting up every infected tree picking out the larvae chipping the remains and burning the chips. And then every apparently healthy tree within 700 feet gets a dose of systemic insecticide just in case there are larvae inside. Like withCaulerpa, we still have a shot at halting this alien invasion. The dominant hardwood in the eastern American forests was once chestnut until it was almost wiped out by chestnut blight-- a fungus from Japan-- in the 1880s. As a result, oaks took over but they're being devastated by the gypsy moth from Europe. So now maples are coming to predominate. But they're one of the favorite foods of the Asian long-horned beetle. It would be the worst-ever pest of American forests. It's a pest of about 18 different species of hardwood trees in the northeast forest including all of your maples, your elms, horse chestnuts willows, poplars, birch, ash trees. So you're talking about a sizable percentage of the natural forest in the Northeast. And the possibility of spread outside of the... if you would, the ornamental situation now from a backyard pest to a forest pest, would be catastrophic. ALDA: Many people in the Northeast have firsthand experience of a continuing forest catastrophe. The gypsy moth regularly defoliates and kills large swaths of oak forest in an ever-expanding area. It's costly and destructive. It leads to large-scale pesticide use and it's plain disgusting, too. The gypsy moth has been a classic story of alien invasion for over a hundred years. This film was made 50 years after Etienne Trouvelot, a Harvard astronomer had accidentally released a group of gypsy moths from his home in Medford, a Boston suburb. He'd imported the moths from Europe in the hope of establishing an American silk industry. The first big defoliation took place in Medford in 1880 ten years after the release. There were more or less constant attempts to prevent the moth from spreading including extensive use of toxic lead arsenate sprays. But by the late 1920s it infested 40,000 square miles of New England, New York and Canada. Victory was declared several times but the gypsy moth proved unstoppable. Today, it's all over the Northeast and still on the move. From this lab on Cape Cod the U.S.D.A. continues to battle the gypsy moth as they have for a hundred years. Inside labs sealed with airlocks they keep gypsy moths and about 40 other aliens which might be the next invader. They even have some Asian long-horned beetles here. They're determined not to be caught off guard again. MAN: The gypsy moth is fully entrenched in the United States. We will never eradicate it. The goal now is to slow that natural spread. You can eliminate some pesticide use and save some dollars by not letting uninfested areas become infested sooner than they would naturally. ALDA: Historically, the gypsy moth spread westward at about 13 miles a year. In the last few years that's been slowed to about five miles a year with a program that's like a military campaign. They've managed to tap into the enemy's signaling system-- the chemical pheromone which the darker male moths follow to lead them to the females. U.S.D.A. researchers first isolated the pheromone from female moths about 30 years ago. Then a synthetic version was developed. It's contained in this little plastic tube at the head of the wind tunnel. It's a powerful attractant for any male moth that's downwind. Each spring, to detect where the moths are half a million pheromone-baited traps are set out along the front line from Wisconsin to North Carolina and also throughout the western U.S. So now it's possible to concentrate attacks in the right place the following year before infestations build up. This couldn't be done before. Today, the insecticides are much less toxic, too although they do kill other insects. Right from the start people tried biological control against gypsy moths. They understood that alien species succeed because they've escaped their natural enemies. So it seemed obvious that importing some of those enemies would be beneficial. A Massachusetts state lab was set up to breed and distribute many different predatory beetles and flies and some diseases brought in from Europe or Asia. Nothing was very successful and it's turned out to be a classic lesson in how not to do biological control. MASTRO: With gypsy moth about 40 or 50 exotics were introduced but only about 12 of those were established. Some of those are not specific to gypsy moth and that's caused a problem. ALDA: The most notorious example is this little fly calledCompsilura brought in from Italy. In a series of rapid darting attacks it plants its eggs inside gypsy moth caterpillars. Eventually, the eggs will hatch into a maggot leading to a gruesome death for the caterpillar. Compsilura'srange now extends all the way across the United States so it's far outdistanced the gypsy moth and it attacks native species throughout that range. ALDA: Compsiluraturned ou to be more interested in attacking native caterpillars than gypsy moths. As a result, some of our most spectacular native moths are greatly reduced in numbers and probably extinct in some areas. The lesson we've learned is that biological control agents must be absolutely specific to the particular pest. They've taken the lesson to heart back at the Cape Cod lab. These are gypsy moth eggs, being spread onto a nutrient base. It's the production system for the latest biological control agent-- a virus. When the eggs hatch in 180 days the cups are infected with the virus. With this timing, the virus will kill the gypsy moth caterpillars just as they reach maximum size. It's the most efficient way to produce the largest amount of virus which is now being used in aerial spraying. The virus occurs naturally. It was isolated from gypsy moths already in the U.S. and it's supposed to only attack gypsy moths. The problem is, it's expensive because it can only be produced using live gypsy moth colonies. With our century-long struggle against the gypsy moth it's clear that it's better to prevent alien species than try to cure them. But Vic Mastro believes the task is so enormous that our only hope lies in knowing ahead of time where the dangers are. MASTRO: I think the problem of introduced pests is a huge problem. I think it's as big a problem as global warming. I don't think we can exclude everything. It's just a huge, huge task. And the volume of people moving around the world and trade items is so great that you can't look at everything. But I think we can target very specific things and say we'll exclude those from introductions. ALDA: And right now, we're faced with two certain targets for exclusion. Caulerpa taxifolia and the Asian long-horned beetle are both potential gypsy moths, or worse. And in both cases, there's still time for an ounce of prevention.

				Dust Busting A Caribbean coral disease is traced to fungus-filled dust from new African farmland. Researchers also investigate a link betweeen the dust and increased asthma in the region.
		Select text to jump ahead in the clip: ALDA: The Virgin Islands. From here down to Venezuela, it's a 500-mile loop of beautiful, small islands set in a sparkling sea. They're some of the world's most popular tourist destinations to find the sun or catch a wave. Below the surface, things get even better. Coral reefs, the rain forests of the ocean delight the eye and the imagination. But here they're the setting for a most surprising alien invasion. It's a coral disease which came from another continent and a completely different environment. In the winter of 1998 I found myself being thrown around in a small boat in the company of three coral experts-- Gene Shinn and Ginger Garrison of the U.S. Geological Survey and Garriet Smith from the University of South Carolina. We're off St. John, but this is no vacation. "Caribbean," they said "We're going to shoot in the Caribbean. It'll be nice." All these great stories, sun, surf... ALDA: We found a spot that was sheltered and got ready to check out the reef. The scientists and I are going to be free-diving while our underwater camera crew will be using scuba. Free diving's a lot simpler than scuba and just fine for seeing shallow reefs like these ten or 20 feet deep. The bad weather has stirred up sediment so it's not as clear as it could be, but it's more than enough for Ginger to point out the problems. Here comes the free dive... and here's the problem. On this boulder coral, large patches, called "white plague" where the living surface has died off. GARRISON: Looking pretty slick now. ALDA: As we head back down I realize that white patches of different sizes are everywhere on the boulder coral. It's one of the Caribbean's principal reef-building corals so this is a disturbing sight, to say the least. When I see the white stuff down there, what am I looking at? Well, the white area that's surrounded by the normal-looking coral tissue that's brown is actually just the skeleton. What's happened is the disease, whatever the pathogen is has evidently killed the polyp and that tissue has sloughed off. So it's as if we lost everything except our bones so that we wouldn't have any flesh on them. ALDA: Next Ginger takes me down to check out the sea fans. There are clumps of them all around waving lazily in the swells. Sea fans are one of the soft corals-- not reef builders but an important part of the reef ecology providing shelter for many inhabitants. But the sea fans are in bad shape. This is a typical example-- chunks of the fan rotted away, with bright purple patches. Once you know the symptoms, you notice them everywhere. Garriet Smith outlines a light purple infected area. Eventually it'll die off leaving a gaping hole in the fan. Here the process has already started. This is not just a local problem-- sea fans all over the Caribbean are affected. On the reef there are fans at every stage of deterioration. This one's lost almost all its living tissue. So out we came-- cold and wet, tired depressed at the state of the reef. And as if that weren't enough... I have a blister from my flipper. ALDA: Then I realized that my companions don't care about working conditions. It's knowledge they're after. (laughing) I love it-- science! ALDA: This is a diseased Caribbean sea fan in Garriet Smith's lab at the University of South Carolina. You can see the skeleton from which the living white tissue has died back. The brown growth is some kind of secondary infection and the purple is an immune reaction that shows the coral is trying to fight whatever is attacking it. So, what is attacking it? The team's now pretty certain they've nailed it down. Here's what they did. Samples were taken from diseased sea fans from six different islands. After culturing for a few days, this is what they got... a whole mix of about a dozen fungi and bacteria. It looked to Garriet that only one was common to all the sea fans. It had the typical threadlike appearance of a fungus. Garriet confirmed that it caused the disease by deliberately infecting healthy sea fans. So now it was time to identify the fungus. It's routine nowadays to map out the DNA of organisms. T-A-G-T-A-A... ALDA: Garriet and Kim Ritchie mapped out the fungus's DNA looked it up in the databases, and got a big surprise. Sea fan disease was caused by a common soil fungus calledAspergillus. You could find it in any backyard. But how wasAspergillusgetting to coral reefs in the Caribbean? Take a look at this. This picture was shot from the space shuttle over the Atlantic. The brown stain is dust, millions of tons of it coming from new farmland in Africa. In drought years, when there are often dust bowl conditions huge quantities are swept across the ocean on the trade winds to settle on the Caribbean. Gene Shinn suspected that the dust could be delivering a constant dose of damaging material to the water and to the coral. And it could explain why coral diseases appear all over the Caribbean at the same time. Gene takes up the story. I got talked into presenting this as a hypothesis at the Oceanographic Society annual meeting last year on April Fool's Day, by the way and a lot of people took it that way and one thing's that common... They didn't go along with this idea. I had discovered that everyone who studied dust in the past the common denominator is they all got laughed at at one time or the other. And they were studying dust in the late '60s and early '70s, and there wasn't that much dust. But it's a hundredfold greater now. Is it pretty clear to you therefore that this... this rise in disease here in the coral is because of the desertification effect? Well, it was just an observation that the peak years of... for dust, like '83 and '87-- these were big years for the coral reefs and things changed. It seemed like there was a link. ALDA: To find out what the Caribbean winds contain Ginger Garrison sampled the air above St. John. The filter papers went to Garriet Smith in South Carolina. And along with dust particles he saw thousands of tiny fungal spores. So, next step-- culture the spores. A few days later, another mix of organisms and among them-- you guessed it--Aspergillus. SoAspergillusspores are flying 4,000 miles across the Atlantic settling onto the reef, and then attacking the sea fans. It's an important breakthrough in understanding coral disease and a remarkable example of how alien species can behave in unexpected ways in a new environment. Ah, wee in luck; the gods are with us. ALDA: I'm getting to be a real pro at this now. Gene Shinn is moving on to the next phase of the investigation. He's drilling a deep core sample from a large boulder coral. The aim is to look at the recent history of the reef to see if what happened from year to year can somehow be matched up with dust conditions. There you go. That's about 30 to 40 years of growth. Not as easy as it used to be. (Alda chuckles) Can you see anything on this that... that... Can you read this in any way now without... without taking it to the lab? Well, you can see these are the... this is the growth axis these lines pointing this way and that's each individual polyp and you can see the little polyps. It's like a little jellyfish that secretes calcium carbonate and so our plan is to take these segments cut them out with a diamond saw dissolve them in hydrochloric acid and then we get a residue and that residue will be... hopefully will be African dust. ALDA: It took a lot of work but eventually they were able to find African dust trapped in coral cores corresponding to the recent bad dust years. Since the breakthrough with sea fan disease the team has found a second coral type, called sea whips being attacked byAspergillus. And they're on the track of a second soil microbe which may be causing white plague the coral-bleaching disease. They've also started to look into the idea that African dust may be connected to the huge increase in asthma around the Caribbean-- up 17-fold in the last 30 years. We're going to be hearing a lot more about dust in the years to come. Come visit us at PBS Online.

Take a look at these related stories from the Frontiers Archive:

				Prairie Comeback Ecologists work to restore the quintessential American landscape.
		Select text to jump ahead in the clip: ALDA: First light on the prairie. We're in northeast Oklahoma, to witness a tradition that stretches back all of seven years but with ancient roots. It's the annual bison roundup on what was once the Chapman-Barnard cattle ranch. Stampeded into the corral by cowboys in pickup trucks are the first of over 1,000 bison also known as buffalo. 5,000 years ago, the stampede would have been started by Native American hunters using a ring of fire set in the prairie grass although probably not during a downpour like this. Today there'll be no feasts of fresh bison meat but instead a systematic checkup of each animal to make sure this precious herd stays in peak condition. In 1989, the ranch became the Nature Conservancy's Tallgrass Prairie Preserve-- the largest prairie restoration project on the continent. ( hooves thundering ) ALDA: I don't want to get, you know, unduly nervous but... they're heading for us. ( calmly ): Yeah. Yeah, well, maybe we should just step inside the thing here. ( lightly ): They like us. ALDA: Uh, no, I think we should step inside... the corral. You want to come with me or are you just going to stand out there? Oh no, no... they know me. Well, that wasn't so bad. No, no. Kind of... easy. ALDA ( shouting ): They are coming back! ( laughs ): This is... They have a very strong... Bison have a very strong herding instinct. Yes, so do I. ( laughs ) ALDA: What do they do for the land? Why... why are you so concerned about bison as far as the land is concerned? Well, in Great Plains grasslands you're looking at... Grazing and fire are really the two management forces that we're trying to put back into these landscapes. And bison were the primary... the premier historic grazer in the Great Plains. ( rifle shots ) ALDA: But the bison were too easy a target. In the 1860s, special excursion trains, riding the new railroads brought random and widespread slaughter deep into the plains. Most carcasses, killed for fun, were left to rot. Then in the 1870s, bison robes became all the rage and the collapse of the great herds began. It's almost incomprehensible, but by 1900, 60 million animals had been reduced to a few hundred total most in zoos and private herds. Settlers moved in where Plains Indians and the bison they depended on had coexisted for thousands of years. Teams of "prairie breakers," as they were known used oversize plows to expose the rich soil for the homesteaders' crops of corn and wheat. John Deere's steel plow, invented in 1835 was tough enough to bust open the tangled prairie sod itself a material strong enough to build houses with. America's great unbroken grassland-- our Serengeti-- is gone forever. Parts of the arid short-grass prairie closer to the Rockies and now used for grazing, could be prairie again. But in wheat and corn country-- the Dakotas, Nebraska, Kansas, Iowa and Illinois-- we couldn't bring the prairie back if we wanted to. The whole system of native plants and animals has simply disappeared. Except, that is, on the Chapman-Barnard Ranch. It was never plowed so every prairie plant is here, somewhere on its 38,000 acres. It seems strange to immediately start burning things up. But that's exactly what the Nature Conservancy did when they moved in. I'm about to find out why. MAN: Alan, I hate to tell you this, but the cowboy custom is the person on the right has to get the gate. Okay, I'll be a good cowboy; one second. ALDA: Extremes of heat, cold, drought and storms are normal here... not so comfortable for us modern cowboys but they kept the prairie ecosystems happy. In spite of the weather Harvey Payne, the preserve director, offered to show me the secrets to prairie restoration. Just call me "Slim. " Okay, how about "Tex? " "Tex" is good. ALDA: One secret is size. This place is big-- 50 square miles-- so there's room for different things to happen in different places. Our first stop was here, in an area that was burned in late August, about two months ago leaving enough time before winter for warm-season grasses to resprout. The bison, once they're released from the corrals will utilize this area very heavily. Because this is the new growth that they like so much? Yes, it is. They will use the regrowth from a burned area almost exclusively to all other parts. ALDA: Prairie plants have especially deep root systems so they can survive both drought and fire. When the hot fire passes above the roots below are unharmed and even stimulated by the warming of the soil. The animals will graze here all winter and into next spring. And at that point there'll be a dramatic change: All the broadleaf plants, which bison won't eat will come back very strongly because there's no competition from the overgrazed grasses. Harvey showed me the result on this patch. PAYNE: This area was burned a year ago last summer and it was used very heavily by the bison in the first growing season. The bison have grazed the grasses very closely to the ground, allowing the broadleaf plants to exhibit themselves much more dramatically. ALDA: The broadleafs produce flowers and seeds which, in turn, attract insects, birds and small mammals. Then, over a few years, the bison will find a new burn area grasses will come to dominate again and the patch will end up like this with a thick thatch of grasses, ready to burn once again. It's this shifting interaction between burned patches and bison which is the biggest secret of the prairie. It may look tranquil and settled but it's a jungle out there. Things are always changing, and for every slight alteration there's a plant, an insect, a bird... that's perfectly adapted to the new conditions. So real prairie, they've discovered here is not just grassland. It's hundreds of tiny subsystems all mixed up. PAYNE: We call this... a disturbance-dependent landscape. And those disturbances are fire and grazing primarily by bison. But that's what shaped this ecosystem. And that's what allowed the 750-plus plant species here to develop and to flourish. That's what happened to allow all the different bird species the insects, the reptiles, amphibians nematodes in the soil. ALDA: Already at the preserve you can see the richness coming back to prairie life. Prairie chickens-- grouse-- like to feed on the new growth but nest in mature grass. Sandpipers prefer the partial shelter of young grass. Rare harrier hawks follow the mice and the mice are where the best seed crops happen to be. Multitudes of insects are attracted to many different flowers. And it seems there's a dozen different flowering plants for every week of spring and summer... every different patch of light or shade or passing shower. Once these constant ripples of change were flowing across millions of square miles. But now the challenge is to maintain them over just 50. That patchwork dynamics took place on a large scale in the tall-grass prairie as an ecosystem. We're trying to reduce that scale in size to this preserve. ALDA: Here's the deliberately complicated burn pattern they're developing for the first third of the preserve so far. About 50 different patches get either a spring, summer or fall burn, about every five years. Manipulating the land like this is truly a return to an earlier age because the prairie was largely created by people. For thousands of years Native Americans set fires to attract bison to the new growth: probably more fires than were started by lightning. So over time, every plant and animal became adapted to fire and bison. Nature's machinery is perfectly tuned. Seeds caught in the bisons' thick coats, for example get spread across the land especially when the animals wallow in the dust. Eventually, the bison wallows make seasonal ponds which attract birds and snakes, which then... Well, you get the idea. We're back on the preserve, at the start of the roundup. 1,300 bison are out here somewhere... but where? Most of them are exactly where you'd expect: on the newly burned patches. It takes a week to drive the herd into progressively smaller enclosures. And every year, a few just can't be caught-- usually the strongest, most experienced bulls that can outmaneuver anything. ( men whooping and shouting ) Cows with this year's calves are the easiest to catch and that's important, because the long-term goal is to imitate ancient hunting pressure from wolves and Native Americans. So once they've built up the herd to the limit of about 3,000 on their 30,000 acres they'll sell off mainly calves. Eventually the whole herd, minus a few bulls is collected into one 50-acre pen. Then for about a week batch after batch of animals is run through the corrals. For these cowboys, it's like working with stronger faster, more aggressive cattle-- although that doesn't prevent some pretty daring moves every now and then. ( cowboys hollering and shouting ) ALDA: This year's calves are separated out to get their vital brucellosis shot. Brucellosis is a serious cattle disease and the preserve has to coexist with its cattle-ranching neighbors. The calves will rejoin their mothers later. All the rest go down the chute. Every animal has its computerized record and its place in the herd structure. So this is a simulated wild herd. But they're still wild animals nonetheless. These guys are frisky here. Okay, go ahead. Whoa, go! ALDA: The whole chute has to be higher, stronger and tougher than what you'd use for cattle. There are routine shots for parasites and other cattle diseases-- also to be good neighbors. ( electronic beep ) They've all got microchip transponders in their ears. These tags... How do you get this guy's job over here? ( laughing ) You make him mad. ALDA: Whoa! I've been a bad boy. HAMILTON: As you can see, right... right there... ALDA: Aha, yeah. HAMILTON: is the tag. It's just a small plastic tag has a microchip inside of it, so you... Who gets to put the tag on his ear? We put them in typically as yearlings or calves. Oh, I see, when they're a little more manageable. Easier to handle, yeah. And what kind of information is in that tag? HAMILTON: Basically kind of like a Social Security number. How do you decide what happens to the animals after they leave this point? Well, it's all determined beforehand who stays and who goes. By knowing the complete structure of the herd then you can sit down in the comfort of your office and figure out what the carrying capacity is for next year and the year after. As they come through then, we can identify those animals and basically, they have been flagged. So, okay, this is a 15-year-old cow. You know, this is her year to go. ALDA: Before long, I was wondering if it was my year to go. So just lean in there, don't get too close... ( gates clattering ) especially to the adults. They will sucker you in to where you think... They'll sucker me in? Yeah, yeah, you think they're at their full extent... Oh, yeah. and you'll lean in and they'll lunge out and they've got another 18 inches to go and you'll get a horn in the ear. Okay. You're on. ALDA: Oh, great... Whoa! HAMILTON: Watch out. Watch out for the equipment there. ( sensor beeps ) HAMILTON: There you go. ALDA: Did you get it? Did we get it? Got it! We got it, good. Take this, I'll see ya. I'll be at the luncheonette. ALDA: One surprise this year was finally catching up with this terrific 1,600-pound bull. ( bull snorting ) He was not happy about it. Brought in from Montana two years ago he had never got his microchip tag. He was a no-show last year. He didn't cooperate in the roundup. ALDA: Regularly introducing genetic variety with new animals like this is another key part of managing the herd. ( pliers click ) The Tallgrass Prairie Preserve is a highly successful restoration project but it's also a paradox. To stay wild it's going to need human intervention forever. And that's becoming the case with wilderness everywhere as we'll see. ALDA: We're in the middle of town here--

				Raven’s World A walk through the Missouri Botanical Garden and an exploration of world conservation issues with renowned biologist Peter Raven.
		Select text to jump ahead in the clip: now a 40-year-old classic. ALDA: Now, is this a rain forest? It is up here-- it's warmer and then it's cooler down there. So over here we can grow plants that are really from tropical rain forests and as you go down towards the west here, you get into plants that are from cooler and cooler places like the islands in the Pacific or from cloud forests. ( bird singing ) Basically, we try to build as much variety in here as we can so people can get an idea of what it's like in the tropics. Is this place mostly for people to become educated about rain forests in general or do you actually do research on these plants here? It's mainly to educate people about what the plants are like in the rain forests and other kinds of tropical forests around the world. So these plants are, in a way in an environment that they wouldn't find themselves in in the natural world? Well, the temperature and the humidity and all is about the same. I mean, one of the funny things is it's really cooler in the tropics than it is in St. Louis in the summer. So you have to air-condition it! We need to actually cool the place. To keep it tropical. ( humming begins ) What's happening? Vents are opening or something because the temperature is hitting some kind of a critical level. It'll be over in a minute. It's something like opening vents. You just have to think about temperature or mention it and the windows open. No, actually, that's what I wish. ALDA: In Raven's 30 years as director the garden's sparkling public displays have gone from strength to strength. They're comparable to the New York Botanical Garden or Kew Gardens in London. But Raven's done something else here that the public doesn't see. This is now one of the leading plant research centers in the world and the headquarters of attempts to save U. S. endangered plants. Raven has been a passionate conservationist since the '60s when, on academic field trips he saw the reality of mass extinction developing in the tropics. Mixed in with the plants being raised for display are some of the rarest plants in America saved in the nick of time from extinction. This is a medlar. It's a plant that was discovered about 12 years ago. A little tiny grove of these with just 26 individuals was discovered in central Arkansas. The whole genus, the whole kind of plant was unknown in North America before. Is there something special you can learn when you have a plant like this that seems to be unique? I mean, that's so different from it's neighbors? All that we know is that since it's very unique-- since it's so unusual-- it may have characteristics that are outstanding. ALDA: Here's a unique lobelia from Hawaii with fewer than 200 in the wild. Here's a rare member of the pea family from Tennessee and here's a groundnut with 25 little patches left in the Midwest. So why should we care about a rare medlar from Arkansas? This is a plant in the rose family which has lots of plants of economic importance: apples, plums, peaches, strawberries and so forth. So it could be that the genetics of this particular plant would be of interest in relation to economic uses of the rose family directly. But we just don't know. We're barely getting the tools to even be able to think about those questions. So in a way, letting this go would be like burning down a library that had only one copy of each book. Letting any species go is like that. ALDA: One of Raven's favorite projects here is a 15-acre Japanese garden. It's vital, he says, for Americans to learn about others and to understand what's going on out there. It's a crisis, and the prognosis is clear. RAVEN: We'll lose about half of all tropical species during the course of the next century which amount to about a third of all the species on earth. ( cracking ) ALDA: The images are by now familiar. ( thunderous thud ) Tropical forests are rapidly disappearing at the rate of about 150 square miles a day-- one percent a year. Forest is fatally attractive. The timber's worth money, and the space gives room to expand. Developing countries need both, as they follow the way we in the industrialized countries do things. Why is it important not to let species go extinct? What difference does it make? Does it make a difference to us as humans? Does it make... I mean, will we perish if a certain critical number of species become extinct? It's not that we're not going to survive. We're going to survive-- we're going to survive in whatever kind of a world we build for ourselves. The question is, shouldn't we be capable of making intelligent choices not of survival but of what kind of a world do we want? ALDA: In Raven's world people acknowledge that we're part of nature that we evolved in wild places side by side with nature's diversity and that we have no right to destroy these wonderful things. Who could disagree with such an idea, he asks when faced with the beauty of the forest? Raven helped coin the term "biodiversity" to describe the huge range of species that fit together to make ecosystems-- like tropical forest or the American prairie. The problem is, the forces arrayed against advocates like Raven are immensely powerful and, some would say, unstoppable. ( explosion ) Just look at our own short history. ( explosions ) NEWSREEL ANNOUNCER: To make a million acres bloom anew. To build an industrial empire from the wasted power of the Columbia. ( Woody Guthrie playing "Roll on, Columbia" ) ¶ Now, river, you can ramble where the sun sets in the sea. ¶ ¶ But while you're rambling, river ¶ ¶ You can do some work for me. ¶ ¶ Roll, Columbia, won't you roll, roll, roll. ¶ ¶ Roll, Columbia, won't you roll, roll, roll. ¶ ALDA: It took us only about 300 years to dam every major river from the Atlantic to the Pacific cut down all but two percent of the original forest and plow under a million square miles of prairie. ( slow cracking ) We literally took nature apart, without really understanding it. In the process we found prosperity... and pollution. But now the tinkering is becoming global in scale. Scientists agree we're changing the climate-- and what else could we be doing? I think we have to think of the dictum of the great American conservationist Aldo Leopold who said, "The first rule of intelligent tinkering is to save all the cogs and wheels. " ( laughing ) So you don't leave them out when you put them back together. When we're learning what we can do that's just the time that we ought to be concerned about saving the parts that we can do it with. Is the developing world going to catch up with us and surpass us do you think, in the ability to wreck things? How is that going to work? Well, 20% of the people in the world live in developed or industrialized countries. But we have about 85% of the world's economy use about 80% of the industrial energy have about 90% of the world's scientists and engineers. So, that's about proportional to our impact on the world's ecosystems about proportional to the amount of pollution that we produce and amount of waste that we produce and the destruction of natural environments. It is our pressure on the world that's really causing most of the damage directly or indirectly. And yet we're always worried and always preaching to the developing world that as they develop they better not develop the way we did. If everybody in the world lived as we do in the United States it's estimated it would take about two more editions of planet Earth to accommodate everybody, and we haven't got it. ALDA: People have to understand, says Raven that we humans are inseparable from the natural world-- we use it all the time. RAVEN: When New York City wanted to purify its water about ten years ago it found that it had two choices: It either could put about $5 billion in new water purification plants or it could put about $1½ billion in restoring the watersheds in the Catskills. It was an easy choice. ALDA: More often those choices are not so easy or so obvious. For example, we filled in or drained about a half of our wetlands before we fully understood how they purify water recycle nutrients, absorb floods and provide nursery grounds for marine life. There may be as many as 20 million insect species in the world. Most are in tropical forests, but many are right here at home working hard to pollinate our crops. We don't know the effects of destroying a large part of the globe's insects. And we don't know how effectively polluted oceans will continue to help regulate the global atmosphere-- which is just one of the things oceans do, as do forests. Biologists are now calling these natural processes "ecosystem services. " RAVEN: They've been estimated by some economists as worth $37 trillion or some arbitrary number like that. But actually, it's pretty easy to see that they're priceless. If we didn't have them, we'd all be dead so we wouldn't be worrying about what they were worth. It seems to me that that points to the incredible complexity of nature and of this system that we're all hooked into. When you talk about our interconnectedness that sounds like it makes it especially difficult to know what piece you can pull out without the whole thing collapsing. That's right. It's not only incredibly complex but it is our basic habitat. It's the resource or it's the area into which we evolved. You see, 400 generations ago-- just 400 generations, 10,000 years ago-- there were only a few million people in the whole world. It's really only been the invention of crop agriculture that's allowed the global population to build up to where we're cultivating an area the size of South America producing food, producing poets, musicians specialists of all kinds that create what we call civilization. But it all relates ultimately on the ability of natural systems to be able to support us. ALDA: The nightmare that Raven foresees is growing poverty and population driving a quickening pace of ecosystem destruction in developing countries. The only possible answer, he believes lies with new ideas-- especially new science-- coming from within developing countries themselves. RAVEN: One out of every four people in the world get by on a dollar a day. And the women and children in those societies have no opportunity whatever to contribute to human progress because they spend their whole time carrying fuel wood and water over great distances back to smoky, carcinogenic huts. That's a way of ensuring that the human race will not make the progress that it can. What I would like to do is to be able to build up the ten percent of the world's scientists and engineers that exist in developing countries into responsible groups in those countries that would be able to advise their governments and their people how to achieve the aims that they want: sustainability, health, relative prosperity dignified lives in which people can contribute. So a lot of our energy here at the garden and a lot of my personal energy is devoted to trying to build institutions and to empower people in developing countries to be able to take care of their own futures adequately. ALDA: And what about us in the rich countries? He says it's the same answer. We need to consume fewer of the world's resources but we can live just as well if we get smart and use science. That's the first thing. The second may be a little harder. RAVEN: If there would be a single thing that we could do in the United States that would support global sustainability in the future and the most possible options for our grandchildren and their grandchildren, it would be to bring our fellow citizens and ourselves to our senses about the fact that we live on a single planet Earth with magnificent diversity run by people in something like 200 different nations and that we all are managing this beautiful planet together. Promote a spirit of internationalism in the United States. Help people understand why it is that we depend on countries all over the earth and do something about it-- in our schools, in all of our social groups and in any way that we can. ALDA: Let's hope it works out. Otherwise this stuff may exist only in St. Louis. ( Joni Mitchell playing "Big Yellow Taxi" ) ¶ They took all the trees, put 'em in a tree museum ¶ ¶ And they charged the people ¶ ¶ A dollar and a half just to see 'em... ¶ ¶ Don't it always seem to go ¶ ¶ That you don't know what you've got till it's gone ¶ ¶ They paved paradise, put up a parking lot ¶ ¶ Woo, pa-pa-pa-pa ¶ ¶ Woo, pa-pa-pa-pa... ¶ ALDA: A few years ago, I was in southern Germany to meet a man whose life revolves around these. They're white storks. At that time, Peter Berthold was having his first successes

				Paradise Lost? Invasive species, including humans, threaten to forever alter the landscape of the Galapagos.
		Select text to jump ahead in the clip: THROUGHOUT THE ARCHIPELAGO. WITH PEOPLE CAME ANIMALS THAT WOULD NEVER HAVE MADE IT HERE ON THEIR OWN: CHICKENS, DOGS, CATS.. GOATS, PIGS, CATTLE. TODAY THERE ARE STRICT RULES GOVERNING WHERE PEOPLE AND THEIR ANIMALS CAN LIVE. 96% OF THE LAND IS NATIONAL PARK OFF-LIMITS TO ANYONE NOT ACCOMPANIED BY A GUIDE LIKE LYNN FOWLER. BUT WHILE PEOPLE CAN BE CONTROLLED THE ANIMALS THEY'VE BROUGHT WITH THEM CAN'T. WE'RE CLIMBING A PEAK OVERLOOKING SANTIAGO ONE OF THE FOUR ISLANDS ON DARWIN'S ITINERARY. Fowler: WHEN DARWIN CAMPED THERE... THAT'S ALL SANTIAGO OVER THERE? YEAH-- THERE WERE SO MANY LAND IGUANAS ON IT THAT HE COULD HARDLY FIND A PLACE TO PITCH HIS TENT BECAUSE OF THE LAND IGUANA BURROWS. ( chuckles ) BUT THEY'RE EXTINCT NOW. THEY'RE EXTINCT FROM SANTIAGO. THOSE... REALLY? WELL, HOW DID THAT HAPPEN? DOGS AND PIGS... AND RATS. THEY GO RIGHT INTO THE... THE RATS ATTACK THE IGUANAS? THEY GO IN THE LAND IGUANA BURROWS AND EAT THE EGGS AND KILL THE LITTLE HATCHLINGS. Alda: ONE OF THE GALAPAGOS NATIVES WORST HIT BY HUMANS AND THE ANIMALS THEY BROUGHT WITH THEM IS THE GIANT TORTOISE. ORIGINALLY DECIMATED BY WHALERS HAULING THEM OFF FOR FOOD THEY HAVE SINCE HAD TO COMPETE WITH PIGS AND GOATS THAT HAVE GONE WILD AND RUN RAMPANT OVER MANY OF THE ISLANDS. ( tortoise hissing ) 30 YEARS AGO, THE POPULATION OF THE CHARACTERISTICALLY SADDLE-BACKED TORTOISES OF ESPAÑOLA WAS DOWN TO JUST 13-- 12 FEMALES AND A MALE. BROUGHT HERE TO THE CHARLES DARWIN RESEARCH STATION ON THE ISLAND OF SANTA CRUZ, THESE 13 TORTOISES-- AIDED BY A SECOND MALE RECRUITED FROM THE SAN DIEGO ZOO-- HAVE SINCE PRODUCED HUNDREDS OF OFFSPRING. LAVISHLY FED AND KEPT SAFE FROM RATS UNTIL THEIR SHELLS ARE STRONG ENOUGH TO PROTECT THEM THE YOUNGSTERS HERE CAN LOOK FORWARD TO A LONG LIFE. LET ME JUST CURVE HIM IN. HERE WE GO. ( laughing ) DON'T BE SHY. HE'S HOW OLD? THIS ONE'S ABOUT A YEAR AND A HALF OLD. AND HOW OLD WILL HE GET TO BE IF HE'S LUCKY? WELL, WE CAN GUARANTEE THAT THEY LIVE BETWEEN 60 AND 90 YEARS OLD BUT HISTORY BOOKS AND STORIES THAT ARE A BIT DIFFICULT TO CONFIRM SAY ANYTHING UP TO 150, 200 YEARS. Alda: THE PROJECT OWES ITS SUCCESS LARGELY TO THIS MAN, CRUZ MARQUEZ WHO WITH HIS COLLEAGUES HAS HAD TO INVENT THE CAPTIVE-BREEDING PROCESS AS THEY WENT ALONG. A CRITICAL REALIZATION WAS THAT THE SEX OF THE HATCHLINGS DEPENDS UPON THE TEMPERATURE AT WHICH THE EGGS ARE INCUBATED... ONE'S COMING OUT, HUH? Alda: 29. 5 DEGREES CELSIUS GIVES YOU FEMALES; 28 DEGREES CELSIUS, AND YOU GET MALES. SOUNDS LIKE YOU MUST HAVE TO HAVE A PRETTY SOPHISTICATED SYSTEM HERE TO KEEP THE TEMPERATURE WHAT YOU NEED IT TO BE. WE HAVE AN INCREDIBLY SOPHISTICATED SYSTEM. WE HAVE A HAIRDRYER CONNECTED TO A THERMOSTAT HERE, ON CONTINUOUS CYCLE. Alda: DESPITE THE SHOESTRING BUDGET THE CAPTIVE-BREEDING PROGRAM HAS RESULTED IN SOME 800 ESPAÑOLA TORTOISES BEING RETURNED TO THEIR NATIVE ISLAND. MAKING THIS POSSIBLE WAS AN AMBITIOUS AND SUCCESSFUL PROGRAM AIMED AT RIDDING THE ISLAND OF GOATS THE TORTOISES' MAIN COMPETITOR FOR RESOURCES. BUT MANY OF THE ISLANDS, INCLUDING THE BIGGEST, ISABELA REMAIN OVERRUN WITH GOATS AS WELL AS PIGS. THEIR ERADICATION IS A PRINCIPAL GOAL OF PEOPLE TRYING TO PRESERVE THE ISLANDS' UNIQUE BIOLOGICAL HERITAGE-- PEOPLE LIKE THE DARWIN RESEARCH STATION'S HOWARD SNELL. WE'RE COMING IO ELIZABETH BAY OFF THE COAST OF ISABELA THE LARGEST ISLAND IN THE GALAPAGOS AND THESE ARE THE MARIELAS ISLETS. Alda: BUT FOR SOME INTRODUCED SPECIES ERADICATION IS ALL BUT IMPOSSIBLE. RATS, FOR INSTANCE, HAVE BEEN IN THE GALAPAGOS AS LONG AS SHIPS HAVE VISITED HERE. THEY APPEAR TO HAVE INVADED THE MARIELAS ISLANDS ONLY RECENTLY BUT NOW MAY BE THREATENING ONE OF THE GALAPAGOS'S MOST UNEXPECTED INHABITANTS. Snell: PENGUINS IN THE GALAPAGOS ISLANDS ARE THE NORTHERNMOST PENGUINS IN THE WORLD. SO IT'S A UNIQUE KIND OF PENGUIN. BUT UNFORTUNATELY, THE PENGUINS IN GALAPAGOS AREN'T DOING PARTICULARLY WELL. WHEN EL NIÑO EVENTS COME INTO THE ARCHIPELAGO WHICH HAPPENS EVERY SO OFTEN, THE WATERS GET VERY, VERY WARM AND THE NORMAL FISH LIFE AROUND HERE BEGINS TO DIE OFF. WHEN THAT HAPPENS, PENGUIN POPULATIONS CRASH. IN 1982-'83, THEY CRASHED BY OVER 50%. THIS LAST YEAR, '97-'98, THEY CRASHED AGAIN. AND THE THING THAT CONFUSES US IS THEY DON'T RECUPERATE AFTER THOSE CRASHES. NOW, THAT WORRIES US, BECAUSE, OF COURSE IF THE POPULATIONS CRASH EVERY SO OFTEN AND NEVER RECUPERATE THEY CAN GO EXTINCT. Alda: HOWARD SUSPECTS RATS ARE THE CULPRITS INVADING THE ROCK CREVICES WHERE PENGUINS LAY THEIR EGGS AND RAISE THEIR CHICKS. SO HE'S CONDUCTING AN EXPERIMENT TO SEE WHAT CAN BE DONE TO SAVE THE PENGUINS-- SHORT OF THE IMPOSSIBLE TASK OF RIDDING THE GALAPAGOS OF RATS ENTIRELY. Snell: NOW, WHAT WE'RE TRYING TO DO IS USE THESE ISLANDS-- THESE SMALL ISLANDS-- AS MODELS FOR THE REST OF THE GALAPAGOS. AND WE'RE REMOVING THE RATS, BY POISONING THEM FROM SOME OF THE ISLANDS AND LEAVING THEM ON OTHERS. THE IDEA IS TO TRY AND MEASURE HOW FEW RATS WE CAN REMOVE TO INCREASE PENGUIN REPRODUCTION. THAT WAY WE CAN INVEST ENOUGH MONEY TO INCREASE PENGUIN REPRODUCTION BUT NOT SO MUCH MONEY THAT WE CAN'T DO OTHER THINGS ALSO. IT'S REALLY ABOUT TRYING TO DIVVY UP LIMITED RESOURCES FOR THE CONSERVATION OF THE BIOLOGY OF THE GALAPAGOS ISLANDS. Alda: THOSE RESOURCES MAY BECOME A LITTLE LESS LIMITED IN THE FUTURE, THANKS TO THE LATEST ALIEN SPECIES TO INVADE THE GALAPAGOS ISLANDS: ECO-TOURISTS, WHO COME BY THE THOUSANDS EACH YEAR. THESE TOURISTS BRING IN MILLIONS OF DOLLARS FOR THE TOUR OPERATORS BUT UNTIL RECENTLY, LITTLE OR NOTHING FOR THE WILDLIFE. NOW THAT'S CHANGING. Man: THERE ARE ABOUT 60,000 PEOPLE A YEAR WHO VISIT THE GALAPAGOS AND I'M OF THE BELIEF THAT THOSE 60,000 PEOPLE CAN BE A MAJOR PART OF THE FUTURE IN THESE ISLANDS AND THAT COMPANIES LIKE OURSELVES WHO BENEFIT AND INDEED PROFIT FROM BEING ABLE TO BRING THESE VISITORS HERE ARE IN THE POSITION TO MAKE A DIFFERENCE. AND IN THE LAST YEAR, IN THE YEAR SINCE WE'VE BEEN HERE WE'VE RAISED ABOUT $200,000 FROM OUR GUESTS AND WHEN YOU THINK THAT WE REPRESENT FIVE PERCENT OF TOURISM TO THESE ISLANDS AND IF YOU MULTIPLY THIS KIND OF AN ACTIVITY TIMES 20 ALL OF A SUDDEN, TOURISM COULD, IN FACT, SUSTAIN PLACES LIKE THE CHARLES DARWIN RESEARCH STATION AND THE NATIONAL PARKS AND THEY WOULDN'T HAVE TO STRUGGLE SO MUCH FOR FUNDING. Alda: BUT THERE'S AN IRONY HERE. TOURISTS BRING IN NOT ONLY DOLLARS; THEY'VE ALSO ATTRACTED THOUSANDS OF ECUADORIANS TO THE ISLANDS TO WORK IN THE TOURISM INDUSTRY. TOGETHER, TOURISTS AND RESIDENTS POSE A NEW THREAT TO THE ISLANDS' ECOSYSTEM. Snell: BECAUSE THERE ARE 16,000 TO 20,000 PEOPLE THAT LIVE IN THE GALAPAGOS ISLANDS FIVE SUPPLY SHIPS RUN OUT HERE TWO OR THREE TIMES A MONTH EACH AND THERE ARE THREE 727s A DAY THAT FLY INTO THE GALAPAGOS ISLANDS. ALL OF THAT ACTIVITY BRINGS IN A TREMENDOUS AMOUNT OF MATERIAL. TONS AND TONS AND TONS OF FOOD AND CONSTRUCTION MATERIAL COME TO THE GALAPAGOS EVERY YEAR. SOMEWHERE IN THOSE PACKAGES ARE THE INTRODUCED SPECIES OF TOMORROW. IT'S NOT PURPOSEFUL NOWADAYS BUT IT'S EVERY BIT AS DAMAGING AS IF IT WAS. Alda: I'VE COME TO SEE FOR MYSELF ONE OF THE WORST OF THESE ALIEN INVADERS. CHARLOTTE CAUSTON OF THE DARWIN RESEARCH STATION IS SHOWING THE WAY. WHAT ARE ALL THESE LITTLE WHITE THINGS? OKAY, THESE ARE THE COTTONY CUSHION SCALE. IT'S AN INTRODUCED SCALE INSECT THAT WAS INTRODUCED IN 1982 INTO THE ISLAND OF SAN CRISTOBAL AND HAS SINCE THEN SPREAD TO NINE OTHER ISLANDS IN THE ARCHIPELAGO AND ATTACKS OVER 40 PLANT SPECIES. HMM... IN THE ABSENCE OF ITS NATURAL ENEMIES IT'S JUST GONE HAYWIRE. HOW WAS IT INTRODUCED? WE'RE NOT SURE. WE THINK IT WAS INTRODUCED IN SOME ACACIA TREES THAT WERE IMPORTED TO THE ISLANDS BUT THEN AGAIN, IT COULD HAVE BEEN SOME CITRUS. AND IT WAS DEFINITELY ON A PLANT AND ACCIDENTALLY INTRODUCED. NO ONE BROUGHT IT IN ON PURPOSE. Alda: THE COTTONY CUSHION SCALE IS ONE OF HUNDREDS OF NONNATIVE INSECTS THAT HAVE RECENTLY SNEAKED INTO THE ISLANDS AND CHARLOTTE IS ONE OF ONLY TWO ENTOMOLOGISTS. IF YOU HAVE TO GO AFTER THEM SPECIES BY SPECIES FIND OUT WHAT THEY DO, WHAT HARM THEY CAUSE AND THEN HOW YOU CAN PROTECT AGAINST THEM-- AND BY THE TIME YOU FIND THAT OUT ABOUT ONE SPECIES YOU'VE PROBABLY GOT ANOTHER 300 ON YOUR LIST. THAT'S RIGHT. HOW DOES THAT MAKE YOU FEEL? IT'S DAUNTING, THE PROSPECT. THE MAGNITUDE OF THE PROBLEMS THAT FACE THE GALAPAGOS ISLANDS CAN APPEAR OVERWHELMING, AND IN FACT, THEY ARE OVERWHELMING BUT THE ONE THING THAT PEOPLE THAT ARE MOTIVATED TO CONSERVE BIOLOGICAL DIVERSITY IN THE GALAPAGOS ISLANDS KEEP AT THE FOREFRONT ALL OF THE TIME IS THAT THIS IS REALLY ONE OF THE LAST OCEANIC ARCHIPELAGOS IN THE WORLD WHERE WE HAVE AN OPPORTUNITY TO MAINTAIN A PRISTINE ENVIRONMENT. THERE ARE... 95% TO 96% OF THE SPECIES THAT EVER OCCURRED IN THE GALAPAGOS ISLANDS ARE ALIVE TODAY. SOME OF THEM ARE IN A BAD STATE. SOME OF THEM MAY GO EXTINCT BEFORE TOO LONG IF WE'RE NOT SUCCESSFUL AT RESTORATION EFFORTS FOR THEM. BUT THE POINT IS, WE HAVE AN OPPORTUNITY HERE. THE WORLD, ACTUALLY-- IT'S NOT JUST ECUADOR; IT'S NOT JUST THE RESEARCH STATION; IT'S NOT JUST THE NATIONAL PARK SERVICE BUT THE WORLD HAS AN OPPORTUNITY TO PRESERVE BIOLOGICAL DIVERSITY IN A PRISTINE STATE. NOW, NOW, WHAT ABOUT THIS? WHY SHOULD ANYBODY ELSE, WHO'S NOT A SCIENTIST, CARE ABOUT PRESERVING THE GALAPAGOS? IF THE GALAPAGOS DISAPPEARS AS A UNIQUE PLACE-- IT'S RUN OVER BY INTRODUCED SPECIES-- SO WHAT? THERE'S A GENETIC... A BANK OF GENETIC INFORMATION AND IT CAN BE SQUANDERED OR IT CAN BE PRESERVED IN ITS CURRENT STATE. THE ANALOGY IS OFTEN MADE WITH A LIBRARY-- THAT YOU WOULDN'T GO INTO A LIBRARY AND WANTONLY DESTROY A WHOLE BUNCH OF STUFF TO MAKE SHELF ROOM, YOU KNOW, TO PUT KNICKKNACKS ON. WELL, HERE, WE'VE GOT CREATURES THAT HAVE BEEN COMING UP WITH SOLUTIONS TO PARTICULAR PROBLEMS FOR A LONG, LONG TIME AND THERE'LL BE PROBLEMS IN THE FUTURE THAT WILL NEED SOME OF THOSE SOLUTIONS. THEY'RE HERE; WE SHOULD PRESERVE THEM. I THINK IT'S ALSO A PLACE OF JOY AND INSIGHT INTO NATURAL PROCESSES AND YOU CAN'T REALLY PREDICT WHAT PEOPLE WILL FIND HERE IN THE FUTURE. BUT LIKE, DARWIN WAS INSPIRED BY THIS LABORATORY OF EVOLUTION AND I THINK MANY PEOPLE WILL IN THE FUTURE. AND YOU CAME BECAUSE YOU FIND IT INTERESTING. SO I THINK IT REALLY WILL CONTINUE TO BE A LAB OF EVOLUTION WHERE YOU CAN REALLY SEE THESE PROCESSES HAPPENING. THIS OTHER GUY WENT UNDER. THERE HE GOES! OH, THERE HE GOES. GREAT, BRAVO. Alda: IT WAS LATE ONE AFTERNOON AFTER LYNN AND I HAD BEEN OUT SNORKELING THAT THE MAGIC OF THE GALAPAGOS-- ITS ABILITY, AS MARTIN SAID TO PROVIDE JOY AND INSIGHT-- CRYSTALLIZED FOR ME. HERE WE WERE ON THE EQUATOR, TALKING TO PENGUINS WHOSE ANCESTORS CAME FROM THE ANTARCTIC. IN SPITE OF THE WAVES AND THE RAZOR-SHARP ROCKS WE WERE MESMERIZED. Fowler: WALKER IN FRONT. AREN'T THEY CUTE HOW THEY WALK? HE'S GOING TO GO BACK FOR SOME FISH. HE'S HUNGRY. YOU KNOW, TO GET THAT CLOSE TO PENGUINS, AND... IT'S AN EXPERIENCE I'VE NEVER HAD BEFORE AND IT'S REALLY A SENSATIONAL EXPERIENCE BUT YOU'RE OUT HERE ALL THE TIME. WHAT'S IT LIKE FOR YOU? THAT'S WHAT I SAID THE OTHER DAY WHEN YOU ASKED ME WHY I WAS STILL HERE AFTER 20 YEARS-- IT'S INCREDIBLE, ISN'T IT? SOMETHING HAPPENS DIFFERENT EVERY SINGLE DAY. YOU NEVER GET TIRED OF THESE ISLANDS. Alda: CHARLES DARWIN SPENT JUST FIVE WEEKS IN THE GALAPAGOS AMAZED, AS IS EVERY VISITOR BY THE TAMENESS OF THE ANIMALS AND BIRDS, AND BY A SENSE OF BEING IN A WORLD APART, IN TIME AND IN SPACE. BUT WHAT STAYED IN HIS MIND LIKE A SLOW-BURNING FUSE WAS THE SAME CREATURE OR PLANT TURNING UP IN DIFFERENT FORMS EVEN DIFFERENT SPECIES, ON DIFFERENT ISLANDS-- A CIRCUMSTANCE, HE WROTE IN THE VOYAGE OF THE BEAGLE "THAT STRIKES ME WITH WONDER": "IT IS THE FATE OF MOST VOYAGERS "NO SOONER TO DISCOVER WHAT IS MOST INTERESTING IN ANY LOCALITY "THAN THEY ARE HURRIED FROM IT; "BUT I OUGHT PERHAPS TO BE THANKFUL "THAT I OBTAINED SUFFICIENT MATERIALS TO ESTABLISH "THIS MOST REMARKABLE FACT "IN THE DISTRIBUTION OF ORGANIC BEINGS. "REVIEWING THE FACTS HERE GIVEN, ONE IS ASTONISHED AT THE AMOUNT "OF CREATIVE FORCE, IF SUCH AN EXPRESSION MAY BE USED DISPLAYED ON THESE SMALL, BARREN AND ROCKY ISLANDS.

				Ways of the Wild In South Africa’s game parks natural processes like fire and drought are tolerated or encouraged. Successes like saving the white rhino are one result.
		Select text to jump ahead in the clip: AN ABUNDANCE OF WILD ANIMALS FREE TO ROAM WHEREVER NATURE AND INSTINCT LEAD. IF ONLY IT WERE TRUE. BUT THE FACT IS WE FILMED EVERY ONE OF THESE SCENES INSIDE GAME PARKS. IN SOUTH AFRICA, ALL LARGE ANIMALS ARE ENCLOSED BY FENCES. EVEN IN THE GREAT KRUGER PARK OVER TWICE THE SIZE OF YELLOWSTONE THERE WAS ALWAYS A FENCE NO MORE THAN 20 MILES AWAY. SOON ANIMALS WILL BE FENCED IN ALL OVER AFRICA. THE DEMANDS OF PEOPLE FOR HOUSES, FARMS, FACTORIES, ROADS ARE IRRESISTIBLE. CONFINING ANIMALS TO PARKS MEANS ONE THING ABOVE ALL-- WE HUMANS CAN NO LONGER AFFORD TO LEAVE THINGS ALONE. THE RHINOS IN UMFOLOZI GAME PARK ARE OVERCROWDED. SOME OF THEM ARE GOING TO HAVE TO GO. BUT BIOLOGISTS HAVE DEVISED A WAY TO REMOVE THEM THAT CAUSES THE LEAST DISRUPTION. USING ANESTHETIC DARTS THEY PICK ANIMALS ONLY FROM THE OUTER EDGES OF THE PARK. FOR THE ONES LEFT IN THE CORE AREA IT FEELS LIKE A NATURAL MIGRATION HAS TAKEN PLACE. BUT CAPTURING RHINOS ALIVE IS A DANGEROUS BUSINESS. THE VET HAS TO KEEP THE DRUGGED ANIMAL OUT OF THE THICKEST COVER AND AVOID BEING CHARGED. WITH THE ANIMAL DOWN THE FIRST STEP IS A CAUTIOUS CHECK ON THE PULSE. THE REST OF THE TEAM'S NOT FAR BEHIND. IT'S AN ELABORATE OPERATION, BUT NECESSARY IF YOU CAN ONLY TAKE ANIMALS FROM PARTICULAR AREAS. WHILE THE VET WAITS, HE APPLIES ROUTINE ANTIBIOTIC TREATMENT. INTENSIVE MANAGEMENT LIKE THIS HAS PAID OFF. IN THE 1930s, THERE WERE ONLY 50 WHITE RHINO IN THE WORLD ALL IN THIS PARK. NOW THIS FINE, MATURE FEMALE WHO IS PROBABLY ALSO PREGNANT IS ONE OF 2,000 IN THIS PARK AND 5,000 MORE IN PARKS AND ZOOS AROUND THE WORLD. SHE AND HER CALF WILL JOIN THE THOUSANDS OF OTHER WHITE RHINOS THIS PARK HAS BEEN ABLE TO BREED AND SEND ELSEWHERE. THAT IS, IF THEY CAN EVER MOVE HER. AT THE ANNUAL GAME AUCTION IN THIS PROVINCE OF KWAZULU NATAL YOU CAN PICK FROM A DOZEN SPECIES-- $10,000 FOR A RHINO, $1,500 FOR A GIRAFFE-- WITH THE MONEY GOING TO THE PARK. MKUZE IS ANOTHER OF THE NATAL PARKS. I'M HERE WITH PETE GOODMAN, A BIOLOGIST AND THE COUNTRY'S LEADING ADVOCATE OF A NEW WAY TO MANAGE PARKS. "IT'S TOO SIMPLE TO MANAGE SPECIES BY SPECIES," HE SAYS. "THAT'S LIKE A FARM. INSTEAD, YOU'VE GOT TO KEEP NATURE ITSELF GOING. " WE'RE ON OUR WAY TO A NATURAL WATER HOLE. AROUND MIDDAY, IT'S A MAGNET FOR ALL KINDS OF ANIMALS. AT THE END OF THE PATHWAY THERE WILL BE A HIDE BUILT OUT OVER THE HOLE. Alda: I DON'T UNDERSTAND. IF THERE ARE AN... SHH, WE'LL HAVE TO KEEP QUIET. ( softly ): I'M SORRY. IF THERE ARE ANIMALS THAT NATURALLY DRINK AT WELLS... WE REALLY HAVE TO BE QUIET. OKAY, I'M SORRY. Alda: FORTUNATELY, I HADN'T SPOOKED TOO MANY ANIMALS SO WE WERE PRESENTED WITH A REMARKABLE SIGHT. IT WASN'T SO MUCH THE INDIVIDUAL ANIMALS THAT STRUCK ME LIKE THESE MALE IMPALA CHALLENGING EACH OTHER-- ALTHOUGH THEY WERE PRETTY GOOD-- IT WAS MORE THE VARIETY. A MALE NYALA CLEANING OFF HIS HORNS. THIS IS ONE OF HIS FEMALES. A CAUTIOUS FEMALE KOODOO. ALL THE ANIMALS WERE CLEARLY THIRSTY BUT EQUALLY CLEARLY, THEY WEREN'T BEING SATISFIED. A TROOP OF BABOONS WAS JUST AS FRUSTRATED AS WERE ABOUT A DOZEN WARTHOG. ALTHOUGH THE WATER HOLE WAS NEARLY DRY A HERD OF WILDEBEEST CAME CHARGING IN. Alda: THEY COME IN AND TAKE OVER. THEY TAKE OVER, DON'T THEY? Alda: THERE'S MORE GOING ON AT WATER HOLES THAN MEETS THE EYE. FOR EXAMPLE, WILDEBEEST CAN USE THEIR SIZE TO RANGE FAR AND WIDE FOR GRAZING AND WATER. SMALLER ANIMALS STICK CLOSER TO THE HOLE AND THAT AFFECTS THE WHOLE LANDSCAPE. Goodman: WILDEBEEST, BECAUSE THEY CAN MOVE MUCH FURTHER ARE LESS CONFINED BY THE DISTRIBUTION OF WATER. THEY CAN AFFORD TO MOVE MUCH LARGER DISTANCES TO DRINK AND MUCH LARGER DISTANCES BACK TO WHERE THEY'RE GRAZING. SO THEREFORE THEY'RE NOT BOTH COMPETING FOR THE SAME VEGETATION? THAT'S CORRECT. THESE GUYS HAVE LOST INTEREST AND THEY'RE GOING NOW? I DON'T THINK THEY'RE GOING TO STICK AROUND FOR VERY LONG. Alda: OF COURSE, THERE WERE STILL PLENTY OF ANIMALS STUCK HERE. IT'S VERY INTERESTING. THEY CAME AND THEY TOOK A LOOK BUT THE BABOONS ARE SITTING AROUND. I SAW ONE BABOON DIGGING IN THE MUD AND THEN PUTTING HER FACE DOWN INTO IT TO TRY TO GET THE LAST LICK OF MOISTURE. THEY JUST WON'T GIVE UP. NO. Alda: PETE BELIEVES THIS IS A BIG POINT. IF THE WATER HOLE DRIES UP, IT SHOULD BE LEFT DRY. SOME ANIMALS MAY NOT MAKE IT AND SURVIVAL OF THE FITTEST TAKES PLACE. Alda: WE'RE BACK IN UMFOLOZI PARK AND LEON STEYN IS GETTING READY FOR AN ACTION-PACKED NIGHT. YOU CAN APPRECIATE AT NIGHT BUT YOU CAN'T SEE VERY CLEARLY AND END UP TRIPPING OVER WIRES. SO YOU HAVE TO BE PRETTY CAREFUL. Alda: A NYALA CARCASS WILL BE THE BAIT TO DRAW IN LIONS. PREDATORS ARE ESSENTIAL TO NATURAL SYSTEMS TO CONTROL PREY NUMBERS AND MAINTAIN THE STRESS THAT PETE GOODMAN WANTS. Steyn: NOTICE THAT I'M ACTUALLY TYING IT AROUND THE BONE. IF I DON'T DO THAT THE HYENA WILL JUST TAKE THE HINDQUARTER OR WHATEVER OR THE MIDDLE SECTION AND JUST RUN AWAY WITH IT. Alda: AS NIGHT FALLS, LEON PREPARES TO BROADCAST OVER THE COUNTRYSIDE A RECORDING OF LIONS SQUABBLING OVER A KILL. ( lions growling on tape ) ANY LIONS OUT THERE WILL WANT TO SNATCH A FREE MEAL. WITHIN HALF AN HOUR, THE RANGERS HEAR GRUNTING OUTSIDE. THEY KNOW THIS FEMALE. SHE'S ALREADY WEARING ONE OF THEIR RADIO COLLARS. SHE COMES IN TO JOIN ANOTHER OLD FRIEND. THE RANGERS CALL HIM SNARLY BECAUSE HE'S SO AGGRESSIVE. LIONS WERE REINTRODUCED INTO THE PARK IN 1965 WITH JUST SIX ANIMALS SO IT'S IMPORTANT TO KEEP TRACK OF HOW THEY'RE DOING. Steyn ( whispering ): WE DON'T KNOW HOW MANY LIONS ARE IN THIS PARK. WE DON'T KNOW HOW MANY LIONS ARE IN POOR OR GOOD CONDITION. WE DON'T KNOW WHAT THE SEX RATIO IS. WE NEED TO KNOW THAT SO THAT WE CAN MANAGE THE TOTAL POPULATION. Alda: TONIGHT THEY DECIDE TO CHECK OUT SNARLY. THE HEALTH OF THE LIONS IN THE PARK IS A BIG CONCERN. WITH SO FEW ANIMALS ORIGINALLY WEAKNESS AND INBREEDING COULD HAVE DEVELOPED. A SINGLE FLASHLIGHT IS USED FOR AIMING THE DART GUN SO THE LIONS STAY CALM AND SETTLED. ( dart gun fires ) ( lion snarling ) ALL RIGHT, THE ANIMAL IS DARTED. WE'RE GOING TO WAIT FOR APPROXIMATELY BETWEEN TEN TO 12 MINUTES. WE'LL CHECK AGAIN. HE'S STILL FEEDING, WHICH IS GOOD. Alda: SURE ENOUGH, TEN MINUTES LATER, SNARLY IS OUT COLD SO THE DART DELIVERED THE CORRECT DOSE. AND WITH SNARLY, THE DOMINANT MALE, OUT OF THE WAY SEVERAL MORE ANIMALS ARE NOW ON THE BAIT. THAT'S GOOD NEWS FOR THE RANGERS BECAUSE THEY DIDN'T KNOW A PRIDE HAD ESTABLISHED ITSELF IN THIS PART OF THE PARK. NOW COMES THE TRICKY PART. ( car horn beeps ) THE RANGERS HAVE TO DRIVE OFF THE REST OF THE PRIDE. Steyn: THIS ONE'S GOING TO HASSLE US. IT KEEPS COMING IN. Alda: BECAUSE THE ANIMALS HAVE JUST STARTED FEEDING THEY'RE PERSISTENT AND VERY DANGEROUS. ( horn continues beeping ) ( lions growl ) Alda: WITH THE LIONS CROUCHING JUST BEYOND THE HEADLIGHTS THE RANGERS QUICKLY DRAG SNARLY AWAY FROM THE BAIT. WHEN HE GETS A GOOD LOOK LEON'S VERY CONCERNED AT SNARLY'S CONDITION. HE'S ACTUALLY BEEN FIGHTING SO IT ACTUALLY LOOKS QUITE BAD. HE'S TORN UP RIGHT AT THE BACK. NOW, INITIALLY, WHEN I FIRST SAW THIS ANIMAL HE WAS IN EXCELLENT CONDITION. HE'S LOSING CONDITION AS WELL. Alda: IT'S NORMAL FOR MALES TO FIGHT-- THAT'S HOW THEY WORK OUT WHO'S BOSS-- BUT IT'S THE POOR RECOVERY THAT WORRIES THE RANGERS. MAYBE THERE IS AN INBREEDING PROBLEM IN THE PARK. THERE'S JUST TIME FOR A QUICK GENERAL CHECKUP BEFORE SNARLY HAS TO BE DRAGGED BACK TO THE BAIT. SNARLY WILL COME AROUND SOON DRIVE OFF THE OTHER LIONS PROBABLY AND THEN GO HUNTING IN A FEW DAYS' TIME ALL PROVIDING THE COMPETITION AND PRESSURE THAT PETE GOODMAN ADVOCATES. Alda: STICK THIS IN? Man: AND THEN YOU JUST WALK UP THE LINE. Alda: WE'RE BACK WITH PETE GOODMAN AND I'M WRAPPING UP MY VISIT BY CAREFULLY SETTING HIS PARK ON FIRE. ACTUALLY, THIS IS EXACTLY WHAT PETE WANTS TO HAPPEN HERE. IN THE DRY WINTER LANDSCAPE, YOU CAN SEE WHAT THE TERM "SPREADING LIKE WILDFIRE" REALLY MEANS. I CAN'T BELIEVE HOW FAST THAT'S GOING. Alda: WHY DO YOU HAVE TO GO OUT AD LIGHT IT BY HAND? WHY CAN'T NATURE START THE FIRES BY ITSELF? NATURE DOES START FIRES. INFREQUENTLY, WE HAVE LIGHTNING FIRES. BUT MAN HAS BEEN A PART OF THE AFRICAN ECOSYSTEM. I DON'T THINK WE MUST FORGET THAT MAN EVOLVED IN AFRICA AND WITH THAT, HIS USE OF FIRE. Alda: THE LEADING EDGE OF THE FIRE SKIPS RAPIDLY ACROSS THE LAND WITH THE WIND BUT THE BACK END, FACING INTO THE WIND MOVES SLOWLY. HERE, THE GRASS BURNS MORE THOROUGHLY. ON TREES, THERE'S A DIFFERENT EFFECT. I NOTICE THAT THIS LITTLE BUSH OVER HERE IS VERY... IT'S NOT VERY HIGH AND IT'S STILL GREEN ON TOP. Goodman: SURE. SO THAT'S NOT KILLED, IS IT? THE TREE IS NOT KILLED. THOSE LEAVES ARE SCORCHED, AND THEY'LL EVENTUALLY DIE AND DROP OFF EVENTUALLY IN A WEEK OR SO'S TIME. BUT THEN, MOST OF THESE SAVANNA TREES ARE RESPROUTERS. THEY WILL RESPROUT. EVEN IF THEY RECEIVE QUITE AN INTENSE FIRE GOING THROUGH THEM THEY'LL RESPROUT AND CARRY ON GROWING. Alda: AS LONG AS THERE'S A FIRE HERE EVERY YEAR OR TWO FUEL CAN'T ACCUMULATE. THE FIRE NEVER GETS VERY INTENSE SO IT BRINGS A SORT OF PATCHINESS TO THE LAND. SMALL TREES ARE SCORCHED, AND THEY'LL RESPROUT. LARGE TREES COME THROUGH UNSCATHED. SOME GRASSES BURN, SOME REMAIN. IT'S THESE KINDS OF VARIED CONDITIONS THAT MAINTAIN THE DIVERSITY OF PLANTS AND ANIMALS. WHEN OUR ANCESTORS DID THIS TWO MILLION YEARS AGO THEIR INTEREST WAS TO DRAW GAME INTO THE FRESHLY SPROUTING GRASS. BUT IF WE LIKE THE DIVERSITY THAT FIRE BRINGS WE HAVE TO TAKE OVER THEIR ROLE. BY NIGHTFALL, MY FIRE HAD SPREAD OVER A COUPLE OF SQUARE MILES AND WAS PUT OUT BY AN OVERNIGHT RAIN SHOWER. IT WAS A PERFECT EXAMPLE OF THE SURPRISING THINGS IT NOW TAKES IN AFRICA TO KEEP THE WILD WILD. Alda: THIS IS UMLAZI NEAR DURBAN. IT'S ONE OF THE TOWNSHIPS SET UP UNDER APARTHEID

				Environmental Decade 10 years of work to save endangered species and restore threatened ecosystems -- coral reefs, forests, mountains, deserts, tundra.
		Select text to jump ahead in the clip: THEY ARE THE PEOPLE WHO STUDY THE WILD PLACES OF THE EARTH-- THE CORAL REEFS, THE FORESTS, THE DESERTS AND MOUNTAINS WHICH ARE HOME TO AN ENORMOUS AND STILL UNCOUNTED, DIVERSITY OF CREATURES. OF COURSE, WE ALL KNOW THAT THOSE PLACES ARE COMING UNDER INCREASING PRESSURE FROM US-- FROM HUMANS-- BUT AS WE'VE REPORTED, IN MANY PARTS OF THE WORLD A FEW HUMANS ARE TRYING TO DO SOMETHING ABOUT IT. IN 1989, HURRICANE HUGO SLAMMED INTO SOUTH CAROLINA. IT DESTROYED ALMOST EVERY NEST SITE OF THE RARE RED-COCKADED WOODPECKER WHICH NESTS ONLY IN MATURE PINES. THERE WAS AN EMERGENCY PROGRAM TO MAKE ARTIFICIAL SITES FOR THE 700 BIRDS LEFT ALIVE. IT WAS A CLASSIC DEMONSTRATION OF HOW VULNERABLE SPECIES BECOME ONCE HUMAN PRESSURE HAS HEMMED THEM IN. IN ST. JOHN, I SAW SOME OF THE CORAL DISEASES THAT ARE APPEARING WITH INCREASING FREQUENCY AROUND THE WORLD. THESE WHITE PATCHES ARE ONE SYMPTOM. Alan: WHEN I SEE THE WHITE STUFF DOWN THERE, WHAT AM I LOOKING AT? IT'S AS IF WE LOST EVERYTHING EXCEPT FOR OUR BONES SO THAT WE WOULDN'T HAVE ANY FLESH ON IT. Alda: AN INSPIRED PIECE OF SCIENTIFIC DETECTIVE WORK TRACED THE DIE-BACK OF CORAL SEA FANS TO A SOIL FUNGUS, BLOWN ACROSS THE ATLANTIC FROM NEWLY CREATED AFRICAN FARMLAND. THE SEA FANS WERE DEPRESSING, BUT THE SCIENCE WAS WONDERFUL. ( laughing ): I LOVE IT! SCIENCE! Alda: IN THE BOOMING RESORT TOWN OF EILAT ON THE RED SEA OUR STORY SHOWED HOW DIRECT WEAR AND TEAR FROM THOUSANDS OF TOURISTS' FEET IS DESTROYING THE SHALLOW REEF. BUT TO COMPENSATE, JUST DOWN THE COAST BIOLOGISTS HAVE SUBMERGED LARGE STEEL FRAMES AS THE BASIS FOR ARTIFICIAL REEFS. THE FIRST COLONIES OF MARINE LIFE HAVE MOVED IN. IN NEWFOUNDLAND THE SAD SPECTACLE OF A RARE HUMPBACK WHALE THAT HAD DIED TRAPPED IN A FISHING NET WAS TEMPERED BY THE DEDICATION OF THE BIOLOGISTS. OH, JEEZ WATCH OUT, I'M GOING IN. OH, OKAY IS THAT COMING OUT? WELL, I THINK FOR A SCIENTIST IT'S JUST AMAZING HOW THIS HUGE ANIMAL WORKS. WE ONLY UNDERSTAND IT VERY POORLY. AND IT'S A RARE PRIVILEGE TO BE ABLE TO GET INSIDE OF IT. Alda: JON LIEN, ONE OF THE WORLD'S LEADING WHALE RESCUE EXPERTS HAS RELEASED HUNDREDS OF TRAPPED WHALES IN THESE DANGEROUS, NEAR-FREEZING WATERS AT CONSIDERABLE PERSONAL RISK. IN ST. THOMAS, I MET ANOTHER DEDICATED BIOLOGIST WHO WORKS WITH SEA TURTLES. ZANDY HILLIS PATROLS NESTING BEACHES, PROTECTS NESTS AND REGULARLY CHECKS UP ON EVERY ONE OF THE ADOLESCENT TURTLES THAT HANG OUT ON THE REEF IN HER AREA. ( laughing ) Alda: IN CHINA, I MET A LONE YANGTZE RIVER DOLPHIN. Alda: CHI CHI IS THE ONLY DOLPHIN-- RIVER DOLPHIN-- IN CAPTIVITY ANYWHERE IN THE WORLD? CHI CHI IS THE ONLY BAIJI IN CAPTIVITY IN THE WORLD. I SEE. OKAY, WAIT A MINUTE. WAIT, DON'T GO AWAY. HERE, HERE... OKAY. Alda: IT'S TOUCH AND GO NOW FOR THESE ANIMALS ALTHOUGH SPECIES CAN BE BROUGHT BACK FROM THE BRINK AS HAS HAPPENED WITH THE GREAT BUSTARD. ITS GRASSLAND HABITAT HAS GIVEN WAY TO FARMLAND BUT ONCE AGAIN, A CAMPAIGN RUN BY A FEW DEDICATED ENTHUSIASTS HAS MADE ALL THE DIFFERENCE WITH YOUNG BIRDS NOW REGULARLY RELEASED BACK INTO THE WILD. YOU GRAB HIM BY THE WINGS AND THEN YOU GRAB HIM BY THE NECK? Man: IF IT'S CLOSE TO THE FENCE AND IT'S STANDING, MORE OR LESS, THEN IT'S BEST... Alda: I'M DISCUSSING HOW TO CATCH A STORK WITH ANOTHER OF THOSE ENTHUSIASTS. IF IT'S FLYING AGAINST YOU THE BEST IS YOU TAKE IT AS YOU NORMALLY TAKE YOUR WOMAN IN THE EARLY MORNING, AND THEN YOU HAVE IT. THAT'S ALL... ( laughing ) Alda: YOU'LL NOTICE HOW I STAYED OUT OF THAT ONE. STORKS HAVE BIG BEAKS. Man: AH, THIS IS MATURE BIRD. Alda: BUT THERE'S A SERIOUS PROBLEM WITH EUROPE'S STORKS. MANY BECOME EXHAUSTED ON THEIR MIGRATION SOUTH TO AFRICA BECAUSE INTENSIVE FARMING IN EUROPE HAS REDUCED THE FROGS AND MICE THEY EAT. A FEW PEOPLE RUN THIS RESCUE STATION ALONG THE WAY BUT IT'S NOT A LONG-TERM SOLUTION. ( alarm beeping ) IT WAS REMARKABLE TO SEE PEOPLE EVERYWHERE WAKING UP TO THE FACT THAT SO MUCH WILDLIFE-- LIKE EUROPE'S BROWN BEARS-- MUST BE CONSERVED BEFORE IT'S TOO LATE. MANGIA, MANGIA. Alda: BROWN BEARS, ONCE COMMON, ARE NOW CONFINED TO A FEW MOUNTAIN STRONGHOLDS. THERE'S A CAPTIVE BREEDING PROGRAM HERE BUT INBREEDING'S A DANGER, SO GENETIC ANALYSIS IS ESSENTIAL. Alda: WHERE IS HE TAKING THE BLOOD FROM? IS IT FROM THIS VEIN HERE? Man: YES, THE JUGULAR. JUGULAR... JUGULAR. Alda: THESE CHAMOIS MOUNTAIN GOATS ARE TO FORM THE NUCLEUS OF A NEW HERD TO AVOID THE KIND OF VULNERABILITY THAT ALMOST WIPED OUT SOUTH CAROLINA'S WOODPECKERS. OCCASIONALLY ONE OF THESE NERVOUS ANIMALS DOESN'T MAKE IT BUT BIOLOGISTS BELIEVE IT'S A PRICE WORTH PAYING FOR FUTURE SECURITY. OUR STORY ON WHITE RHINO SHOWED HOW INTENSIVE MANAGEMENT OF ENDANGERED SPECIES REALLY CAN WORK. THERE WERE ONCE 50 WHITE RHINO LEFT, ALL IN THIS PARK. NOW THERE ARE 2,000 HERE, AND 5,000 MORE WORLDWIDE. THEY'RE OUT OF DANGER. IN MANY PLACES, WE FOUND A NEW UNDERSTANDING OF THE NEEDS OF ENTIRE HABITATS. I CAN'T BELIEVE HOW FAST THAT'S GOING. Alda: FIRE IS ESSENTIAL IN MANY ECOSYSTEMS TO PROMOTE SEED GERMINATION, FOR EXAMPLE SO MORE AND MORE ECOLOGISTS WERE STARTING FIRES. IN THIS PROJECT SIMULATED LIGHTNING STRIKES WERE JUST THE START. Man: WHAT YOU'LL BE DOING IS SIMULATING A COW'S STOMACH ( laughter ) MAYBE A BUFFALO'S STOMACH. Alda: IT TAKES BUFFALO AND FIRE FOR SOME PRAIRIE PLANTS TO GERMINATE. OUR CAMERAS WERE HERE NINE YEARS AGO AND NOW THERE ARE JUST TEN PRECIOUS ACRES OF PRAIRIE RESTORED TO ORIGINAL CONDITION. AN ARTIFICIAL PRAIRIE DOG TOWN WAS THE SETTING FOR ONE OF AMERICA'S BEST-KNOWN RESTORATION PROJECTS. PRAIRIE DOGS ARE BROUGHT IN SO THAT THE YOUNG BLACK-FOOTED FERRETS BRED HERE CAN LEARN TO HUNT, UNDER THE BIOLOGISTS' WATCHFUL EYE. OVER A THOUSAND OF THE ONCE-ENDANGERED FERRETS HAVE SINCE BEEN RELEASED, NEAR NATURAL PRAIRIE DOG TOWNS. PRAIRIE DOGS-- ONCE REGARDED AS PESTS-- ARE ESSENTIAL TO THE FUTURE OF THE FERRETS AND IN MANY STORIES WE FOUND BIOLOGISTS EAGER ADVOCATES OF THE NEED TO CONSERVE THE LEAST POPULAR WILDLIFE. YES, SCORPIONS HAVE THEIR PLACE, WE WERE TOLD AND SO HAS EVERYTHING ELSE-- EVEN IF IT DOES ATTACK MICROPHONES. Man: GRAB THAT TAIL FOR ME. Alda: GRAB THE TAIL... DO YOU HAVE THE HEAD? OH, THE TAIL IS SHAKING! THE TAIL IS SHAKING! Alda: IN THIS STORY I LEARNED THAT EVERY SQUARE MILE OF ARIZONA DESERT SHELTERS OVER 2,000 RATTLESNAKES AND THEY JUST WANT TO GET AWAY. AND AFTER RATTLESNAKES... Alan: IT'S A GIGANTIC HEAD... Alda: THE PRODUCERS THOUGHT I SHOULD TRY SHARKS. IT'S BITING THE BOAT. THAT DOESN'T SOUND LIKE WHAT YOU SAID BEFORE ABOUT NOT BITING THINGS THAT AREN'T FOOD. WELL, THAT'S THE GREAT THING ABOUT SCIENCE-- IT'S A WORLD OF DISCOVERY. DOES IT MAKE ANY DIFFERENCE IF YOU RUB HER TUMMY? I MEAN, DOES THAT HELP HER QUIET DOWN? I DON'T KNOW. BUT, YOU KNOW IT'S A VERY, VERY COMMON PHENOMENON IN ALL VERTEBRATES THAT... OH, GEE... OH, BOY. THAT'S WHY I'M... NOW I'M PLAYING THE PART OF RICHARD DREYFUS. WHAT, WAS HE BUSY TODAY? Alda: IMPLANTED RADIOS ALLOWED THE SCIENTISTS TO FIND OUT THE SHARKS TRAVELED ROUTES EXTENDING HUNDREDS OF MILES. ARRIVA... RAPIDO. Alda: IN OUR STORIES ON UNDISTURBED ECOSYSTEMS WE SHOWED WHAT'S BEEN DISCOVERED IN RECENT YEARS ABOUT THE ASTONISHING DIVERSITY OF NATURE. RAIN FOREST STUDIES LIKE THESE NOW HAVE SCIENTISTS CONVINCED THERE MAY BE 30 MILLION DIFFERENT SPECIES ON THE PLANET. IN OUR MOST RECENT EPISODE ABOUT THIS ASPECT OF NATURE WE VISITED THE GALAPAGOS ISLANDS. IT'S ONE OF THE LEAST DISTURBED PLACES ON EARTH-- STILL LITTLE CHANGED FROM DARWIN'S TIME. THE GALAPAGOS ARE AN IMPORTANT NATURAL LABORATORY WHERE FUNDAMENTAL RESEARCH ON EVOLUTION IS CONTINUING TRACING THE ADAPTATION OF FINCHES' BEAKS TO CHANGING FOOD SUPPLIES, FOR EXAMPLE. THE ISLANDS ARE A NATURAL PARADISE. Alan: HELLO. MY PROBLEM IS I NOT ONLY SAW E. T., I ALSO SAW JURASSIC PARK. Alda: WE TOLD THE STORY OF THE MARINE IGUANAS. THEY WERE DEVASTATED IN 1997 AND '98 WHEN EL NINO BROUGHT WARM WATERS TO THE SHORES. 90% OF THE IGUANAS PERISHED WHEN THE ALGAE THEY EAT DIED OFF. THE FOOD SUPPLY HAS SINCE RECOVERED. IT WAS EVOLUTIONARY PRESSURE THAT THE SPECIES MUST HAVE GONE THROUGH MANY TIMES BEFORE. Alda: WHY DO WE SEE SO MANY SMALLISH IGUANAS HERE? THEY SOMETIMES HAVE THESE HUGE ALGAE PASTURES AND THEY JUST GET A MOUTHFUL OF ALGAE EVERY BITE. BUT HERE THEY ONLY HAVE A TINY LITTLE CARPET OF ALGAE WE FILMED ANOTHER FAMOUS STORY OF UNVARNISHED NATURE HERE IN A MASKED BOOBY COLONY. ONE CHICK VIOLENTLY EXPELS THE OTHER FROM THE NEST. ALTHOUGH IT SEEMS INEXPLICABLE, IT MAKES SENSE BECAUSE THE FEMALE CAN ONLY ADEQUATELY FEED ONE. IN THE FUTURE ARE WE GOING TO BE ABLE TO PROTECT PLACES LIKE THIS FROM THE POWERFUL HUMAN PRESSURES THAT TAKE THEIR TOLL IN SO MANY OTHER PLACES?