Return to Transcripts main page

Anderson Cooper 360 Degrees

Planet in Peril

Aired April 21, 2008 - 23:00   ET

THIS IS A RUSH TRANSCRIPT. THIS COPY MAY NOT BE IN ITS FINAL FORM AND MAY BE UPDATED.


ANDERSON COOPER, CNN ANCHOR: Nothing occurs in a vacuum in the natural world. There are ripple effects, and that is putting our planet in peril.
This journey around the globe is an investigation into the reasons our planet is changing. It's about the front lines, the places where threats aren't just forecast for the future but are happening now. Where forests are lost --

JEFF CORWIN, WILDLIFE BIOLOGIST: We're destroying nature's natural regulators.

COOPER: Where islands are discovered.

UNIDENTIFIED MALE: This island exists because of global warming.

COOPER: Where water is poisoned.

DR. SANJAY GUPTA, CNN CHIEF MEDICAL CORRESPONDENT: A lot of people live around here and are dependent on this water.

COOPER: Where endangered animals are bought and sold and killed.

CORWIN: There's a lot of animals right here that range the gamut of critical status.

COOPER: Where people are dying.

GUPTA: We're hearing that people are getting cancer from drinking water.

COOPER: This is a planet under assault. This is a planet in peril.

This documentary is the result of a year-long investigation. Dr. Sanjay Gupta, wildlife biologist Jeff Corwin and I traveled to some 13 countries on four continents to examine climate change, overpopulation, deforestation and species lost; problems which as you'll see tonight are all interconnected.

The U.N. now estimates we are losing species at 1,000 times the natural rate of extinction. That is a staggering figure. Species are disappearing in part because of the black market trade of wildlife. That's where our investigation begins tonight.

Behind a closed door in a cramped and sweltering room in a police station, an informant maps out the secret she's seen in Bangkok's infamous J.J. Market. For her own safety, we can't show her face. This is a dangerous and tricky job.

The police hope to catch dealers selling rare and endangered animals. But first, they need a plan on how to enter the market without anyone suspecting them.

UNIDENTIFIED FEMALE: Do you think if you go in from a different entrance, do you think you can find the place?

COOPER: J.J. Market, officially called Jatujak (ph) is a sprawling weekend market that attracts buyers from around the world. At first glance, it's not much different from many Thai markets. But behind the bustle, there are dark secrets.

This is one of the main hubs for illegal wildlife trafficking in Southeast Asia. Some of the animals are taken from Thailand's forests and waters, but many are stolen from places as far away as Africa and South America.

Wildlife biologist, Jeff Corwin, is helping us investigate this illegal trade. Our team puts on undercover cameras posing as tourists, checking out the market on a typical Saturday afternoon. The stalls are packed not only with people, but with animals for sale. Many of the animals look as though they're dead or close to it due to the stifling heat.

It's inhumane perhaps but selling all these animals is perfectly legal. But as we move deeper into the market, we begin to find endangered animals. These are endangered tortoises from Madagascar, selling more about $500 each.

The dealer proudly tells us it's because they're rare, there aren't many left in the world he says. They're also illegal to sell.

The cameras are not welcome in the animal market. Everywhere we find signs like this one -- "no photo." Dealers here know they have to be careful because there's an international treaty called CITES that is supposed to protect endangered species, like these two small primates called slow lorises we discovered just left of the sign in the front window. But as we'll soon find out, in Thailand there are real problems enforcing international treaties.

Inside this store, we find even more threatened species. Two South American marmosets, going for almost $2,700 each. The shop owners are suspicious, making it difficult for our cameras to get close. Not wanting to cause a stir, our team leaves.

The Thai police planning to raid these stores are from the Natural Environmental Crimes Division. They're working with conservationist Steve Galster. Galster is the co-founder of Wildlife Alliance; a conservation organization that helps train local law enforcement to recognize and protect their native species.

Galster has worked as a conservationist for more than 20 years. It is risky work. He's gone undercover in Russia, Afghanistan and throughout Africa. In each place, he's stopped wildlife trading rackets. This undercover video he shot helped convict this Russian police officer who was illegally selling tiger skins. The United Nations Environmental Program says we are now losing anywhere between 18,000 and 50,000 species of plants and animals every year. As we said earlier, that's up to 1,000 times the natural rate of extinction.

Endangered islands like tigers are killed and sold for meat, medicine and trophies. Bear paws are cut off, dried and sold as ashtrays. Sharks are pulled from the ocean, their fins cut off for soup.

Where do these animals and parts end up? Galster says the top two importers of illegal wildlife are China and America. And it's big business. The trade is estimated at between $10 billion and $20 billion a year.

Galster believes up to 1 million animals are shipped through Thailand every year. Many of them make their way through Bangkok's Jatujak Market.

Back inside the police station, the mood is tense. The police believe the wildlife traders have their own scouts looking for any signs of a coming raid.

They finally agree on a plan. The informant will take an unmarked car to the market and through a series of signals, guide to police to the illegal sellers. The officers receive their final orders and break into teams.

It's about four miles to the J.J. Market and with the informant already there, there's no way to tell if the illegal traders have already been tipped off.

(COMMERCIAL BREAK)

(BEGIN VIDEOTAPE)

COOPER: It's rush hour in Bangkok. We're riding with heavily armed Thai police and Wildlife Alliance's Steve Galster, heading toward the Jatujak, or JJ Market.

We've split into two teams. Wildlife biologist Jeff Corwin is just ahead of us. An informant and our team took these pictures just yesterday with an undercover camera -- endangered animals being bought and sold. The informant is now in the market, hoping to guide police to the illegal dealers.

Obviously, these dealers are very sensitive to anyone coming.

STEVE GALSTER, WILDLIFE ALLIANCE: Very sensitive. This is why you just saw the police take so much preparation. It just takes one leak or one person sensing there's an undercover cop and word goes all around the market and they padlock their doors, close down and they can't get anything.

COOPER: We drive into the market and the police start their work on foot. JJ is like a labyrinth. We weave through the small aisles. It's clear word of our arrival is spreading. Animal dealers are closing their shops. They know there's a provision in Thai law that makes it all but impossible for police to enter a closed store.

CORWIN: This store right here was just opened. So was this one. It's most curious that as we enter this market with these police officers, doors start to close.

COOPER: The police keep moving toward the back of the market, where they make a discovery.

GALSTER: This is an illegal warehouse right now where some of the people who are selling birds in this market, they'll store them here over the weekend.

COOPER: Authorities shut this warehouse down less than a month ago. Already, it's reopened -- stocked with birds plucked from Thailand's forests. It's illegal to sell native species.

Some of these are already dead.

GALSTER: That's right. So you see the conditions they're kept in here. If you walk in here, you're going to burn up really fast. You can see how hot I am standing outside. Upstairs here, they've got an attic, too. There's no cooling system. They're not keeping them fed. These are dead already.

COOPER: And that is all too common. U.S. Customs estimate 90 percent of the animals smuggled into America die before reaching their final destinations. Most of the animals smuggled into the U.S. are birds and reptiles sold as exotic pets.

The police keep moving and find the store that just yesterday was selling these animals -- including the endangered slow lorises. Now it's locked. The police will break into the store only if they can confirm the two slow lorises are still here. That's because they're native to Thailand and only that fact makes their sale illegal.

GALSTER: The light is on, you know, but the animals won't come over to the side, so we can't see them.

COOPER: Even if police identify animals protected under an international treaty called CITES, Thai law stipulates that only protected animals native to Thailand are illegal to sell.

CORWIN: We've got the -- the little marmosets in the back.

COOPER: And is that Thai?

CORWIN: No.

GALSTER: No.

COOPER: So there's definitely threatened animals, perhaps endangered?

CORWIN: There's a lot of animals right here that range the gamut of critical status.

COOPER: But the officers' hands are tied by their own law.

So only if they can identify a species that is from Thailand and being illegally traded can they actually break in?

GALSTER: That's right. And with regard to species from other countries, they actually have to prove that that person smuggled it in. Otherwise, the trader here -- that's why Jatujak Market is so ripe with illegal animal trade.

COOPER: So, for now, they're just going to walk away?

GALSTER: They have to.

COOPER: The Thai government does recognize it has a problem. Aligned with Wildlife Alliance, they launched a campaign aimed at educating people about the need to preserve rare and endangered species. They've also created a regional wildlife law enforcement network with neighboring countries.

CORWIN: They've got the regulations. They're signatories to all the major international treaties. But in some ways, it's like a paper tiger, because it's hard for them to actually engage the necessary enforcement.

UNIDENTIFIED MALE: A little leopard cat.

COOPER: Enforcement of international laws protecting wildlife is a problem around the world. Contradictory local laws, corruption and the low priority most governments give to protecting endangered species means the global trade of wildlife continues to thrive.

CORWIN: Hi. How are you?

COOPER: Before leaving the market, we make another stop -- at one of the stalls where we saw the endangered radiated tortoises from Madagascar.

CORWIN: These aren't Madagascar tortoises.

COOPER: By now -- no surprise -- they're gone. The rare tortoises replaced with a far more common variety. Two endangered turtles from Madagascar now hidden somewhere behind these walls. Two endangered turtles pulled from their wild habitat thousands of miles away.

Why does that matter?

What's the world without two more turtles from Madagascar?

The fact is, for some endangered species, every animal counts. And in a place like Madagascar, every species lost can have a major impact on the ecosystem.

Madagascar is an island off the southeast coast of Africa. It's incredibly rich in terms of biodiversity and there's a real battle going on there right now to protect the species on that island. It's so important, we've asked Jeff to go there to the front lines.

CORWIN: This is a place where 90 percent of the wildlife can be found nowhere else on earth.

There he goes.

This is place where only 10 percent of the natural habitat remains. This is Madagascar. It is one of the world's largest islands, isolated from mainland Africa for more than 160 million years. The small pockets of remaining forest explode with life, but you have to look closely.

If you let your eyes just sort of drift down the trunk of this tree, you'll see spots of lichen and moss and little bumps along the bark.

What's so amazing is that there is a lizard here. It's hard to see. The camouflage is that good. It is a Uroplatus gecko. It just moved.

Isn't that amazing?

It also perfectly illustrates how many of the animals here survive. They survive by being specialists. This creature is so specific to this tree, to this habitat, it cannot survive anywhere else.

UNIDENTIFIED MALE: OK.

CORWIN: And that is why Conservation International's Russ Mittermeier is here.

RUSS MITTERMEIER, CONSERVATION INTERNATIONAL: This is an (SPEAKING FOREIGN LANGUAGE) -- and this is an area that we really want to protect.

CORWIN: His group is working to protect what are called biodiversity hot spots -- regions that are both unique and threatened.

MITTERMEIER: If you're going to try to avert an extinction crisis -- which we're facing right now -- you've got to focus a lot of attention on hot spots like Madagascar.

CORWIN: Of all the animals here, the most well known is the island's primate, the lemur.

Where did you see them?

UNIDENTIFIED FEMALE: Oh, let's go this way.

CORWIN: This way?

UNIDENTIFIED FEMALE: Yes.

CORWIN: Oh, look at this.

When we come back, our journey to Eastern Madagascar to come face-to-face with an animal on the brink of extinction -- the world's largest lemur, the Indri -- and to track down one of Madagascar's most mysterious animals, one that's eluded cameras for decades.

UNIDENTIFIED FEMALE: You can see it?

CORWIN: I see it. I see. There's the Indri right there.

UNIDENTIFIED MALE: Oh, I see. There.

CORWIN: Oh, my goodness. Look at this! Look at this!

(END VIDEOTAPE)

(COMMERCIAL BREAK)

(BEGIN VIDEOTAPE)

CORWIN: Trail blazing through the Indossi Bay Forest (ph) in Eastern Madagascar...

Oh, I see it!

We are searching for one of Madagascar's flagship species of lemurs -- one on the brink of extinction.

Oh, look at the way he leapt like that!

MITTERMEIER: They're what you call vertical clingers and leapers. Rather than moving quadrepedally, they bounce from vertical support to vertical support. They can go 30 feet at a single jump.

CORWIN: Look at this guy right there! Look at him.

MITTERMEIER: That's very close. Oh, this is fabulous. This is a great view.

CORWIN: There he goes! Oh, did you see the way he hops like that?

Out of the 100 plus species of lemurs living in Madagascar, the Indri is the largest and can weigh as much as 20 pounds.

That's very -- yes, that's very eerie, very melancholy.

MITTERMEIER: And when they start in the morning, you can hear them calling all over the forest.

CORWIN: But it is only here, in this remote rainforest in Eastern Madagascar, that the Indri exists. They will not breed in captivity.

MITTERMEIER: There's no backup. There's no safety valve in terms of a captive colony. You've got to protect them in the wild. CORWIN: And if they disappear here, they are lost forever?

MITTERMEIER: They're gone forever.

CORWIN: Lost forever due to hunting and massive habitat destruction.

MITTERMEIER: This is the worst erosion you'll see anywhere on the planet. I've never seen anything like this.

CORWIN: Forests are not only essential to the survival of wildlife, they also provide stability for the landscape. Without them, the soil literally collapses.

Unfortunately, Madagascar is disappearing. Today, in the 21st century, less than 10 percent of the original pristine habitat remains to support all this life.

So the threat to Madagascar's animals doesn't just come from illegal wildlife traffickers like the ones we saw in Bangkok. It's also from the loss of habitat. Conservation International says every year roughly 350 square miles of forest are destroyed.

One of the poorest countries in the world, the World Bank estimates 70 percent of the people here live on less than $1 a day. So people will do anything to make money. And it's usually the forest that pays the price -- through livestock grazing, charcoal production, rice paddies -- anything and everything.

MITTERMEIER: The amazing thing is that in a country that's lost 90 percent of its original natural vegetation, where all that remains is packed into an area about twice the size of the State of New Jersey, and yet every time one of our Rapid Assessment Program expeditions goes out, we find literally dozens of new species -- everything from insects all the way up to new species of primates.

CORWIN: A RAP, or Rapid Assessment Program, is a novel way scientists are trying to save what forest remains here. If you discover new species, the thinking goes that government will protect the land where it was discovered. Previous RAPs have discovered over 550 new species. And that led to the protection of more than 8.6 million acres of land.

We wanted to go on a RAP, so we traveled north to the Adrafiamena Forest.

So this is your field station over here?

MITTERMEIER: Yes. The camp is over here and the forest is over there.

CORWIN: Russ Mittermeier was one of the early adopters of RAPs. As a field biologist with a PhD, Mittermeier has spent more than 30 years in the field. In the past 10 years alone, he has discovered two species of primates here in Madagascar, both of which have been named after him. Tracking through this tense jungle gives you just a quick sense of the challenges these biologists face every day as they enter this forest. They can come out here and discover a new species or they can spend 15 hours in this jungle and get absolutely skunked. It's like finding a needle in a haystack. But let me tell you, when you make that discovery, it's worth the effort.

And this, my friends, is the payoff -- a glimpse at a very unusual, very mysterious and rare species of lemur -- the black sifaka.

You are looking at one of the first videos ever taken of the black sifaka, one of the rarest lemurs in the world.

MITTERMEIER: And this is -- this is very, very exciting.

CORWIN: On the forest floor, we sit and watch as the mysterious creatures leap from tree to tree.

MITTERMEIER: Just five or six years ago, we didn't even know for sure whether there were black sifakas in this forest, and it's not a protected forest.

During the RAP expedition and many other efforts that are under way will hopefully get this set aside as a protected area in the next few years.

CORWIN: Only then will the critically endangered black sifaka have a chance of surviving. As night falls in the forest and Madagascar's nocturnal creatures come to life, we begin to make our way back to camp.

Our encounter with the black sifaka, one of the most endangered primates in the world, is a reminder of just how extraordinary Madagascar's dwindling forests really are. It's entirely possible that when we go out tomorrow, we may even discover a new species.

I had him. He slipped right through my fingers.

This creature is quite the mystery, isn't it? We don't know who this is.

(END VIDEOTAPE)

(COMMERCIAL BREAK)

(BEGIN VIDEOTAPE)

CORWIN: It is early morning, and we're on the outskirts of the Adrafiamena Forest in northern Madagascar. Conservation International's Russ Mittermeier and his team of scientists gear up for what they hope is a day of discovery.

This was the scene from yesterday. Video of the black sifaka, one of the fist times this critically endangered animal has ever been caught on tape. The scientists here are conducting what they call a Rapid Assessment Program, or RAP. It is a fast-paced inventory of threatened habitat, and it is not uncommon to discover new animal species on RAPs.

We team up with Betran (ph), a herpetologist, as he heads out to inventory the forest wildlife.

The whole point of a RAP is to move efficiently and quickly. And that can be tough in this dense forest. But sometimes it does pay off.

This is why you have to truly focus in through the branches, through the chaos of vegetation. When you do, look at this incredible gecko. That right there is the day gecko.

The day gecko, an incredibly beautiful but previously identified species. Part of the RAP is to catch the animals you find for study. But that's easier said than done when it comes to lizards.

I have got a lot of pressure riding on him here. I want to capture him without hurting him. I don't want to let him get away.

I'm being outsmarted by a vertebrate with a brain about as big as a hangnail. There we go. Ah, look at this gorgeous, gorgeous lizard. I mean, he is as emerald and as green as the foliage which basically swallows him up. But while I'm tracking down the day gecko, Betran finds two others and one of them doesn't look familiar. This may be a new animal species.

One in the bag.

We rush back to camp, where research on this mystery lizard starts quickly.

It's not large, I mean, it's actually tiny. It's an adult animal, only an inch in length. Its coloration is rather drab. It's not nearly as brilliant in color as that day gecko. But this creature is quite the mystery, isn't it? We don't know who this is.

You have to be so gentle, don't you, because his head is so fragile, to take a measurement like that, my goodness. The other thing that's cool about it is that this adult lizard has a spine, a three-chambered heart, a set of lungs, but almost microscopic in design.

If it is indeed new, the discovery would stand in stark contrast to current trends of species lost. Scientists think we are right now in what they call "the sixth great spasm of extinction in Earth's history."

In the past, ice ages, comets, natural events led to the extinction of species. This time, though, man is solely to blame. Russ Mittermeier says that's dangerous territory.

MITTERMEIER: We have to be careful not to think that we can dominate everything and control everything and fix everything by technology, because we can't. The environmental underpinnings have to be solid. We have to protect the nature upon which we ultimately depend for our own survival.

CORWIN: It will take months of intensive lab research to learn if this gecko is indeed a new discovery. But the chances are very good. More new species of animals are found in this dwindling habitat than just about any other place on the planet. And those discoveries might be the only thing that can save Madagascar's animals from disappearing forever.

There's no disputing it. Today our planet is losing species at an unprecedented rate. The great question is what is the value of a species lost? One way to look at this is to actually turn the situation upside down. Instead of looking at species lost, look at species recovery.

And to better understand this, Anderson has made his way to Yellowstone National Park, where he's exploring the recovery of one of North America's most charismatic and controversial carnivores.

COOPER: Yellowstone National Park, crown jewel of America's park system. Its beauty is otherworldly, a fully intact ecosystem. Scientists say this is the natural world as it should be. But it hasn't always been this way.

Sometimes it's hard to see the impact the loss of one species can have on an entire ecosystem. In order to demonstrate it, you sometimes have to look at the reverse, what happens when one species is reintroduced to an ecosystem.

We have come here to Yellowstone Park because in 1995, gray wolves were brought back to this park. A total of 41 wolves were brought back here over two years. And since then their numbers increased steadily and they have had a major impact on this entire area.

To get a sense of that impact, we wanted to see the animal for ourselves. It was late afternoon in the park and the light is fading fast. It's not easy to find the wolves. They are elusive and very sensitive to the presence of humans. There's a lot of running, ducking and hiding.

There's a bison which died several hundred yards from here along a little river. At night the wolves are going to come and feed on it. They were out here last night. There's a good chance they will be back tonight. So we are trying to get as close as possible. We don't want to scare the wolves off by getting too close.

UNIDENTIFIED MALE: There's a wolf right there.

COOPER: He's standing on a rock.

UNIDENTIFIED MALE: Yes.

COOPER: I see him. (END VIDEOTAPE)

(COMMERCIAL BREAK)

(BEGIN VIDEOTAPE)

COOPER: We're losing light in Yellowstone National Park, trying to get in to position to see an animal that has captured people's imagination and changed nearly the entire ecosystem of the park.

There's a bison which died several hundred yards from here, along a little river. At night the wolves are going to come and feed on it.

Do they always feed around this time?

DOUG SMITH, WILDLIFE BIOLOGIST: Yes. This is about the time they come out.

COOPER: Doug Smith (ph) is the wildlife biologist in charge of the wolf reintroduction project. We hunkered down in the sage brush for about 30 more minutes, then spot movement in the distance.

Yes, yes, yes.

SMITH: OK, great. You're officially a wolf-watcher now. And is that your first wolf?

COOPER: Yes, it is.

UNIDENTIFIED MALE: OK, great.

COOPER: That we are actually seeing wolves here is something that just 15 years ago seemed impossible. Viewed as both pests and vicious predators, wolves were the target of a government-sponsored extermination campaign in the beginning of the 20th century. Along the way, they were completely eliminated from the park.

But public perception and biological appreciation for the wolf began to change in the 1980s. Bison and elk populations exploded because there were no natural predators like the wolf to keep their numbers down.

In 1995, after a pitched battle with a nearby ranching community who were afraid wolves would kill their livestock, Doug Smith transplanted the first wolves back into Yellowstone. The reintroduction is now considered one of the greatest conservation success stories in the past few decades.

What do you think it is about wolves that surprise people, surprised everyone here, just how adaptive they are?

SMITH: Yes, I think so. They just fell right back into their old role, even though they had been missing for 70 years.

COOPER: And that role, the role of just one single species, has profoundly altered Yellowstone's entire ecosystem. It's what scientists call a trophic cascade, when one animal, usually a top predator, has a cascading top-down effect on different levels of the food chain.

It's almost a paint-by-numbers illustration of how a healthy ecosystem should work. It starts with the wolf's favorite prey, elk.

SMITH: And I was circling four wolves...

COOPER: From his observation plane earlier in the week, Doug saw wolves surround and kill a bull elk. He takes us into the shallow draw where he thinks we will find the carcass.

SMITH: There he is. There's virtually nothing left. And so he probably died right here. So these bones all around here, there's leg bones here, there's leg bones up there, were done by wolves, bears, coyotes, what we call the scavenger community.

I have not seen that beetle...

COOPER: But it doesn't stop for the big animals. A single wolf kill means even the little ones eat too.

Even things like these little beetles, these little bugs here.

SMITH: Yes. We have actually documented a team of researchers that work with us. Hundred of different species of beetles that use wolf kills. We estimate, just a ballpark figure, 2,000 elk are hitting the ground a year in this part of Yellowstone due to about seven wolf packs.

So you add all of that up for the vertebrate scavengers, the invertebrate scavengers, these bugs, that becomes a real direct effect of wolf killing in terms of the big picture of ecosystems that wasn't taking place before wolves got here.

COOPER: That trophic cascade because of the wolf's presence here doesn't stop with what it kills. There's also a ripple effect through the plant life.

This is a stand of willows?

SMITH: Yes, it is. And this stand has grown up in the last 10 years since wolves were reintroduced.

COOPER: So before when there were no wolves here, what would this look like?

UNIDENTIFIED MALE: This stand was much shorter. I can't remember exactly, but it certainly wasn't over my head like this.

COOPER: So before there were wolves here, the elk had no one attacking them, no one hunting them, so they had a lot of time to just chew on willow bushes?

SMITH: That's true, and there were a lot of more elk. So the combination of behavioral changes in the elk, getting inside of their head, worrying about wolves and fewer elk, we think have conspired to produce a flush in growth on these willows.

COOPER: And that flush in willow growth is now providing a rare and critical habitat for songbirds, cover for birds and food for beavers. Remember, all of this is because of just one animal.

How has this affected the beaver population?

SMITH: Well, they have taken advantage of it, too. Willow is a key food for them. They build dams and lodges with it. So they have responded as well.

COOPER: Can we go and try to find some?

SMITH: Yes, we can look.

COOPER: So that's a beaver lodge?

SMITH: Yes, the beavers put that lodge in here a few years ago and they dammed the creek to create this pond.

COOPER: Before the wolves, there were around six beavers in this part of the park. There are now more than 90.

What impact do beavers have? What other species do they impact?

SMITH: Well, beavers are great creators of watery habitat. So anything that uses water is going to benefit.

This is really good habitat for fish, birds, amphibians, small mammals, moose, mink, otter. This was just a meadow and now it's a pond and that creates a lot of opportunity for life.

COOPER: We came here really because we have been traveling around the world, looking at how the removal of one species can have an impact. This is sort of the reverse of how the insertion of a species can have a ripple effect.

SMITH: Absolutely. This is an important kind of lesson for the rest of the world, because carnivores across the globe have been targets of human persecution. And so we are trying to study and understand these carnivore effects on how they structure ecosystems.

COOPER: Back at the wolf kill, as the sun is setting, more of the Lamar Valley pack comes in to eat. And then there's a report of a fight in the distance between a bear and a wolf.

This is exactly what you had hoped for all along with the reintroduction.

SMITH: Yes.

COOPER: It would be this kind of active natural cycle.

SMITH: Yes, absolutely, wolves fighting with black bears is natural. And eating bison carcasses is natural. And it restores Yellowstone to what it used to be. COOPER: Doug mentioned how predator species around the world are under threat. There's no better example of that than what's happening right now in Cambodia. Jeff Corwin and I are headed there next in order to go on patrol with some rangers trying to save the last of Cambodia's endangered tigers.

They are just giving hand signals to get down. They have seen several people in the forest. They are not sure if they are poachers or if they are people just drinking in the forest.

(COMMERCIAL BREAK)

(BEGIN VIDEOTAPE)

COOPER (voice-over): Cambodia's Bokor National Park, a protected forest under threat, its green mountains surrounded by miles of clear- cut countryside. The park has an eerie quality. Its highest point is dominated by the shell of a once-lavish British-run resort.

We have come to see how poachers capture wild animals. And, in these forests, there's one predator both poachers and protectors are searching for.

GALSTER: You think the tiger is still alive?

UNIDENTIFIED MALE: Yes, I think so. If a person catch a tiger from Bokor or from where we -- it be heard.

GALSTER: You will know?

UNIDENTIFIED MALE: Yes.

GALSTER: Yes because you have a good informant network now.

COOPER: Concerned this park was unprotected, conservationist Steve Galster came here in 2001 with Wildlife Alliance.

It was then, using cameras hidden in the forest, they caught a glimpse of the park's most illusive inhabitant and what might be the last wild tiger in all of Bokor.

Every wild tiger in the world is critically important. Like the wolf in Yellowstone, its presence alters the behavior of an entire ecosystem. The World Wildlife Fund says there are only about 5,000 wild tigers left in the world.

Bokor's tiger appears to be injured, its front right paw wounded, most likely from a poacher's snare. Tigers are hunted for trophies, as well as for their body parts, prized in traditional medicine.

Bokor National Park is about 800 square miles. It's a lot of territories for these rangers to cover. There's only about 55 of them. They work in teams. There's usually at least three teams out on patrol at any one time. And they can be gone for as long as five days at a time. The rangers are paid only $30 a month by Cambodia's government. Wildlife Alliance supplements that and has armed them with guns and GPS systems. They are all that stand between the poachers and the park's wildlife.

They have just given the hand signals to get down. They have seen several people in the forest. They are not sure if they are poachers or if they're people just drinking in the forest.

Crouched down in the field, we wait as the rangers survey the situation. But the forest is dense, and it's difficult for them to see which direction the potential poachers fled.

We wait for the OK signal, and push further into the thick brush.

In the jungle, you really get a sense of just how difficult the job is for the rangers. It's very hard to move around, very -- the progress is very slow. The jungle is very dense. They follow these trails, which are essentially trails that would -- a poacher would follow.

The rangers are constantly searching for clues, picking up cigarette boxes, belt straps, anything to help track the poachers.

GALSTER: What's that, chief?

Oh, yes, look at that. Can you see it? Very nicely disguised. That is a trap.

COOPER: Since 2001, they have rescued 31,000 wild animals and confiscated more than four tons of slaughtered animals, called bush meat.

A couple of miles more into the forest, we find what we are looking for.

GALSTER: This is a whole camp. They would sleep here. They would eat here. And you see they have gone along the water here. That's so that they can bathe, wash their dishes and drink.

COOPER: No sign of people, but it's obvious the camp has been occupied recently. Scattered around, rangers find garbage, snares, even primitive religious artifacts.

In their camp, the poachers make religious offerings, trying to ensure that they have a good hunt. They used this coconut to put some incense sticks in. There's also this sort of a mini-spear with two pieces of what looks like doll's clothing. It's a mixture of animist and Buddhist beliefs.

The rangers have destroyed this very same camp before, but the poachers keep coming back.

Where does this fit into the big picture? This is a tiny little camp. Does it really make any kind of a difference if you eliminate this camp? CORWIN: Well, this camp, which maybe sustains four to eight poachers, has had an incredibly negative impact on this ecosystem. There's no species of animal that these individuals would not hunt.

COOPER: The poacher's preferred tool is the snare. The rangers confiscate roughly 7,000 of them every year.

GALSTER: Since they have been out patrolling, the animals have come back. And we have been monitoring it, taking camera trap photos in the forest, so we can see and hear the animals returning.

COOPER: However, they are not seeing the number of poacher snares decline.

GALSTER: This is a freshly laid snare.

COOPER: It's right there?

GALSTER: This is it. It is tied up to this twig here, so, if an animal comes in here, it's going to pull it, snag it. It's not going to kill it. And, so, it could sit there for a day. It could sit there for a week.

COOPER: Snares are easy to make and hard for the untrained eye to see.

In this one area of forest, the rangers have so far found seven snares. There's one actually right behind me, but you probably can't see it, because it's so well camouflaged. Here it is. It is attached to this rather thick branch here. You can see the rope goes down. This is where the trap is. I'm going to brush away its -- as I said, it's very well camouflaged.

This is where the trigger mechanism is. You can see the rope. Now I will show you how it works.

(END VIDEOTAPE)

COOPER: On the next episode of Planet in Peril, Jeff and I continue on the trail of the poachers and witness first hand the power of these endangered animals.

Dr. Sanjay Gupta investigates a place where drinking the water can mean death.

GUPTA: We're hearing that people are getting cancer from drinking water.