♪♪ BENSON: Dropped into one of the wildest places on the planet... [ Chirping ] ...I'm going to run a unique experiment.

♪♪ Using a network of remotely operated cameras... [ Whirring ] ♪♪ ...I want to explore [ Purring ] every level of this incredible jungle, in real time, for a month... ♪♪ ...a wildlife filmmaking first.

[whispering] See if we can get a wide shot of this, as well.

The multiple live feeds will allow us to experience the behaviors of the animals here, as the action unfolds.

Filming 24/7... [ Thunder crashing ] ...and suffering challenging conditions... Agh!

MELVILLE: Oh!

Oh!

BENSON: ...we'll to try to capture the lives of remarkable creatures... MELVILLE: [gasp, whispering] What's that in the trees?

BENSON: ...and experience life in this incredible green realm in a whole new way.

[ Rumbling ] [whispering] That is remarkable.

♪♪ [ Outro plays ] ♪♪ ♪♪ [ Insects chirping, creatures whistling ] [ Creature caws ] [ Insects buzzing ] [ Whirring ] [ Creatures calling ] [ Suspenseful music plays ] BENSON: I'm Will Benson, a naturalist and filmmaker.

♪♪ COX: [ Speaking indistinctly ] BENSON: And, with my team, it's taken us a week to rig a remarkable patch of Amazon rain forest with remote-controlled cameras to covertly watch the lives of the animals here.

♪♪ In my hunt for this incredible location, I surveyed maps and satellite images and, in the Amazon basin of Ecuador, I found a region of unmatched biodiversity.

♪♪ It took us four days to get here and can only be accessed by boat.

♪♪ Parts of this jungle have never been visited by humans.

It doesn't get any wilder than this.

[ Monkey calling ] A troop of very noisy woolly monkeys just climbing above us right now.

A single hectare here contains more tree species than the entire of the U.S. and Canada combined, and over 100,000 species of insect.

It's a living, breathing, green metropolis of life... [ Suspenseful chord strikes ] ...and I can't wait to meet its billions of inhabitants.

[ Purring ] [ Insects chirping, money chattering ] Across this patch of jungle, our cameras will allow us to see it all, from 3 feet below the ground to 300 feet above it.

♪♪ We've bugged an area of tangled vines inhabited by a colony of palm-sized monkeys; rigged a muddy wallow visited by mammals and exotic birds; trained our cameras on fruiting trees up in the emergent layer, that will attract hungry primates; lined the riverbank with cameras to capture the Amazon's aquatic critters; and rigged nesting sites and animal trails.

♪♪ The live feeds from the cameras are wired back to our remote monitoring stations... MEYRICK: Look at the size of that.

MELVILLE: Oh, that's huge.

BENSON: ...from where we'll follow the action across multiple areas of the rain forest as it unfolds.

♪♪ The network of cameras have been rolling, day and night, for a week, now, and we're getting into the swing of spying on the daily lives of the inhabitants of this jungle metropolis.

[ Whirring ] [ Tweeting ] The sac-winged bats blissfully fill their days alternating between sunbathing and sleeping... [ Monkey hooting ] ...while this family of saki monkeys... [ Hooting ] ...are still trying to make sense of our cameras.

MELVILLE: They look a bit bemused.

[ Laughs ] -BENSON: Yeah.

I think you would be, if a strange camera suddenly appeared in your living room one day.

[ Hooting continues ] [ Screech ] [ Hooting continues, insects chirping ] Almost nothing is known about these rare primates who live hidden among the top layer of this city of green... ...so, being able to meet their inquisitive gaze through our spy rig is an incredible moment.

[whispering] Fantastic.

[ Hooting ] Appearing somewhat overdressed in their coat of coarse fur, they use their strong hind legs to propel themselves through the branches.

[ Insects chirping ] [ Screech ] [ Hooting continues ] Getting to see these elusive sakis so early on is a great sign and we're now itching to meet the nine other species of monkey that share this tree-top neighborhood.

[ Creatures chirping ] [ Sinister music plays ] But then?

Rain.

♪♪ [ Thunder crashing ] ♪♪ The downpours here can last anywhere from a few hours to a few weeks... ...and the bad weather is threatening to bring our whole project to a soggy standstill.

♪♪ It's now rained every day for the last eight days and, um, we're waterproofed and our kits are waterproof, but the wildlife has pretty much gone to ground.

We've had minimal activity at most of our camera sites.

Um, because wildlife doesn't like getting wet and it hunkers down, waits for a bit of a sunny window to come out and forage and hunt for food.

But, you know, this is all part of the experiment, um, all part of the challenge, uh, and keep our fingers crossed that it stops raining soon, we can dry our boots out and film some wildlife.

[ Thunder rumbling ] All we can do is sit it out.

[ Suspenseful music plays ] ♪♪ And after the tenth day of rain, the clouds finally clear... ♪♪ ...and I'm thrilled when the wildlife begins to return to our cameras.

[ Whirring ] [ Creature cawing ] [ Peccary snorting ] These bristly pig-like animals are collared peccaries.

[ Snorting ] [chuckling] And it seems the alert adults have sensed they're being watched.

MELVILLE: [whispering] They're properly looking at the cameras.

BENSON: They're so aware of them, aren't they?

But, they soon realize we pose no threat and return to their daily business.

[ Lapping ] This muddy wallow is clearly irresistible to peccaries and our cameras are revealing why.

It's the ideal place for a refreshing drink and somewhere to cool off in the midday heat.

MELVILLE: Oh, look, there are some little, tiny ones.

Little babies.

BENSON: Fantastic.

[ Snorting ] Squabbling between the peccaries seems to be a regular affair... [ Squeaks ] ...but it rarely lasts long.

Day after day, we watch as the herd returns to this wallow.

[ Snuffling ] [whispering] Their really sensitive noses are great for finding seeds and... tasty morsels to eat here.

[ Rumble ] And this relentless snuffling and plodding stops trees and plants from growing in the wet soil, so it seems they've tailor-made this mucky meeting place to suit their needs just perfectly.

MELVILLE: [whispering] Oh, he's got that again.

BENSON: Okay.

[ Insects chirping ] Trail cameras on this forest floor capture incredible predators, [ Rumbling ] like puma, a notoriously elusive jaguar.

[ Purring ] [ Chirping ] [ Whistle ] With hungry mouths patrolling down here, life in the trees is a far safer option for many.

[ Whirring ] And, 10 feet up, our cameras spy one of the most vulnerable animals of all.

[ Chirp ] It's a pygmy marmoset.

[ Chirping ] Weighing less than an apple, pygmy marmosets are the smallest monkey in the world.

MELVILLE: Look at their little faces.

Just gorgeous.

BENSON: Stunning.

[ Whirring ] Their needle-sharp fingernails enable them to scamper up and down tree trunks and vines... ...leaping over 30 times their body length from tree to tree.

[ Creature croaks ] They can swivel their heads backwards to spot any potential predators.

[ Hiss-squeaking ] And it seems something has caught the eye of one of the marmosets, prompting a loud warning call.

MELVILLE: [whispering] Oh, look, he's really nervous.

He's looking around.

BENSON: There's some movement over there.

MELVILLE: Yeah.

BENSON: The technology we're using here means we have an eye at all levels of this jungle.

Zoom in there.

[ Whirring ] From one of our canopy cameras, we can zoom in and see what's triggered this alarm... [ Hiss-squeaking ] ...a great black hawk, stealthily eyeing them up.

[ Hiss-squeaking ] A very real threat for one of these snack-sized monkeys.

[ Hiss-squeaking ] The shrill call lets the hawk know he's been spotted.

[ Hiss-squeaking ] And it has the desired effect.

[ Hiss-squeaking ] His cover has been blown and he's lost the element of surprise... [ Hiss-squeak ] [ Wings fluttering ] ...allowing the rest of the marmosets to return to their playful ways.

For now.

From the moment we entered this jungle, we've been surrounded by a more dizzying array of life than anywhere I've ever experienced... [ Insects chirping ] But to see some of the more unusual creatures here, we need a few extra tricks up our sleeve.

[ Suspenseful music plays ] I think we want to make sure we've got as much coverage in this clearing as possible.

MEYRICK: Heading this way?

-BENSON: Yeah.

♪♪ We obviously know there's big populations of things like jaguar and, uh, puma here, and also scavengers, but, it's a huge area.

I think we can use a -- a cow's head as bait and we can hopefully bring some of those really cool animals towards where we've got some of our cameras set up and see some of the action for ourselves.

MEYRICK: How long do you reckon it'll take for animals to actually smell this thing and start coming in?

BENSON: I reckon things like vultures, they've got an amazing sense of smell.

Possibly, in the first day, we're gonna see animals start coming in.

And, thanks to a remarkable insect, we have the perfect setting for our experiment.

It's actually, is one species of ant that creates these clearings -MEYRICK: Yeah.

BENSON: and that has a symbiotic relationship with these trees, which are the same trees in this whole area and the ants live inside these branches.

You can see there are little in and out holes and these swellings are their nest, uh, nodule.

The ant releases a -- an acid into the soil which no other tree species tolerate, so, those trees can't grow here.

This tree tolerates it and, as a result, gets precedence to grow here.

And the common name for this species of ant is the lemon ant.

MEYRICK: Right.

-BENSON: Because, if you eat it, it tastes like lemon.

It's like the world's smallest lemon sherbet.

MEYRICK: [Chuckle] -BENSON: Give it a go.

MEYRICK: More like lime.

[ Laughter ] BENSON: With insects eaten and the lure set, everything is in place to monitor this area over the coming days, to see who arrives.

[ Insects buzzing ] [ Creature whistling ] Each evening, we spy on the animals as they hunker down among the three-dimensional tangle of branches.

[ Whimsical tune plays ] And, while this baby woolly monkey is snuggling up with Mum, there's no rest for our team.

♪♪ As the Sun dips below the canopy,... [ Whistling ] ...the jungle's night shift begins to stir.

♪♪ To see in this nighttime world, we've rigged the jungle with infrared lights.

[ Suspenseful lullaby plays ] ♪♪ But wildlife has no need for technology to operate in the Amazon's twilight zone.

♪♪ This brocket deer has a layer of ultra light-sensitive cells at the back of its eyes, allowing it to see using the faintest twinkle of starlight.

And keep watch for nighttime hunters.

MEYRICK: Oh, number one.

Is that something that's moving in the bushes?

-MELVILLE: Oh, wow!

BENSON: Like this solitary puma.

Twenty feet above the forest floor, our cameras spy a family of curious night monkeys, stirring.

MELVILLE: Oh, they're quite cute-looking.

MEYRICK: Quite cute, yeah.

-MELVILLE: [Laughing] [ Chattering ] [ Rumbling faintly ] MELVILLE: [whispering] Oh, look at the little baby ones.

MEYRICK: Incredible.

[ Chirping ] [ Chattering ] BENSON: These are the only nocturnal monkeys on the planet.

By day, they sleep in this hollowed-out tree.

But under the cover of darkness, they emerge... MEYRICK: Oh, he's coming out.

MELVILLE: Off he goes.

BENSON: ...to hunt for insects and ripe fruit in the surrounding canopy.

MELVILLE: We've got the infrared lights and we can see pretty [laughing] well, -MEYRICK: Yeah.

MELVILLE: that, actually, down there, it is pitch-black.

-MEYRICK: Yeah.

We -- Yeah, if we went out there, we'd be just completely blind.

[ Insects chirping ] BENSON: As the weeks roll on, one of the toughest parts of this filming experiment is keeping our network of cameras rolling 24/7 and, with a small team, that means working in shifts.

[ Alarm beeping ] Two of us will wake up in the middle of the night... ♪♪ ...pack all our food, water, and batteries for the next 12-hour shift, and make the exhausting hour-long hike through the dark to switch out with the other half of the team.

♪♪ But operating the cameras in the day can be just as demanding.

[ Whimsical tune plays ] Wildlife rarely appears on demand and, even with multiple cameras placed across the jungle, we can sometimes wait for days without seeing any activity, [ Monkeys screeching ] [chuckle] even when their calls are tantalizingly close.

[whispering] You can hear them.

MELVILLE: [chuckling, whispering] Yeah.

BENSON: They're still around.

[ Caw ] ♪♪ MEYRICK: Very quiet today.

There's plenty of wildlife in here, like this one.

[ Clap ] ♪♪ BENSON: Fortunately, as the Sun rises on a new day, the wildlife activity around our cameras picks up again.

[ Suspenseful country music plays ] ♪♪ Yellow-spotted turtles are regular visitors to our riverbank cameras... ♪♪ ...and this one is looking for a place to haul out.

♪♪ Easier said than done when you're wearing a heavy shell.

♪♪ ♪♪ [ Whirring ] ♪♪ When the Sun's out, these turtles bask in the heat.

♪♪ It warms their cold-blooded bodies, while the UV rays kill parasites and algae growing on their shell.

♪♪ A blissful moment of alone time.

♪♪ On these blistering days, our monitors are busy with activity.

♪♪ The peccaries are joined by animals from across the forest... [ Whimsical-suspenseful tune plays ] ♪♪ ...from piping guans... ♪♪ ...to inquisitive curassows.

♪♪ And twist-neck turtles join in on the action.

[ Whirring ] ♪♪ ♪♪ Even the nervous brocket deer has returned, braving a quick drink in the safety of the clearing.

♪♪ What appeared, at first, to be a humble muddy pool is, in fact, a hidden haven for the animals here, all thanks to the curious peccaries, who fortify this wallow with their daily visits.

♪♪ [ Whistling ] [ Chirping ] At midday, the fierce equatorial Sun bakes the canopy.

Moisture is sucked from the treetops like a giant sauna.

[ Suspenseful music plays ] [ Creature cawing ] As the mercury creeps close to 100°, it's hot work, for both the animals and for us.

♪♪ [ Woodpecking ] [ Leaves rustling ] MELVILLE: [whispering] Oh, wow, look, quickly.

♪♪ Spider monkeys!

BENSON: Wow.

♪♪ I've never seen these guys coming down out of the trees before, ever.

-MELVILLE: No.

BENSON: Spider monkeys almost never leave the safety of the treetops.

Jaguar and puma roam the forest floor and would seize any opportunity to prey on these large primates.

♪♪ It's a risky maneuver.

There he is.

He's coming to drink.

[ Woodpecking ] ♪♪ In the searing heat, this male's need for a drink has become too great.

♪♪ [ Gulping ] [ Screeching ] While the young seem oblivious to the danger afoot... [ Continues screeching ] ...the female waits nervously.

♪♪ He's dangerously exposed.

[ Lapping ] Ordinarily, spider monkeys get their water from tree holes or moisture gathered on leaves.

♪♪ Could something else be drawing them to this mud wallow?

♪♪ MELVILLE: Oh, yeah, look, there he goes.

BENSON: Wonderful.

♪♪ Really rare to be able to see this sort of behavior.

♪♪ [ Cawing ] We don't have to wait long before our cameras capture another piece of the puzzle.

♪♪ MELVILLE: [whispering] Oh, I think it's a howler monkey.

BENSON: [whispering] Yeah, it's a howler monkey.

♪♪ MELVILLE: Oh, I hope they come down.

BENSON: Yeah.

Following in the spider monkey's footsteps, the howler monkey wastes no time heading down to the muddy bank.

But it's not a drink of water he's after.

[ Suspenseful music plays ] [ Whirring ] ♪♪ [ Chewing ] ♪♪ Yeah, they're not drinking.

They're just eating MELVILLE: Yeah.

-BENSON: whole clumps of clay.

♪♪ Amazing.

MELVILLE: Like whole mouthfuls of the stuff.

♪♪ Oh, look there's two; there's two!

♪♪ BENSON: Howler monkeys are known to sometimes eat clay that's rich in minerals to help neutralize toxins from their leafy diet.

[ Gulp ] ♪♪ Their mucky meal is evidence that this watering hole contains more than meets the eye, and sheds light on why the monkeys risk life and limb to come and feed here.

♪♪ That's amazing to see.

♪♪ [ Chattering ] Despite the rewards of filming in a pristine rain forest, Agh!

the conditions are far from easy.

MEYRICK: We've been setting up remote cameras in really hard to get to places.

It's obviously muddy and slippery and we've gotta get cameras and cables and feed them back to our tent.

BENSON: Just getting power to our camera rig in a place this remote is a huge logistical challenge.

♪♪ So, the, uh, the batteries that we're using to power our remote rig are these kind of 20-kilo, 12-volt batteries, and we've got three of them that we're having to carry to and from base every day, so, the walk, alone, with this weight is killing us and, uh, it's an enterprise unto itself, and that's before you've even pressed record on the cameras.

COX: I've worked in the Serengeti, in the Arctic, in every sort of environment, up mountains, and there's nowhere quite like the jungle.

It's so difficult, in so many ways, to try and film wildlife.

The wildlife is spread between 100 meters up and a meter down in the ground and you can quite easily walk for 20 minutes here and see nothing, yet I know the facts are that I've probably passed thousands of species in that time.

♪♪ BENSON: While the Amazon's wildlife are experts at keeping themselves hidden... ♪♪ ...trail cameras reveal that powerful predators [ Rumbling ] do use this area.

♪♪ Hoping to film the behaviors of one of these apex predators, we decide to rig a location close to where the trail cameras were last triggered.

♪♪ I think this site's perfect.

I could imagine, you know, something like a jaguar could be up there, puma, lying in wait.

Amazing ambush predators, as we know, they'll potentially sit and watch things going into this cave and then, you know, you could have a -- a deer come through here.

It would have no idea it's being watched and that jaguar would be on its back before it knows about it.

So, um, it's a long shot, but I think, if we have our cameras here, we're likely to see some really exciting behavior.

As well as rigging cameras ou tside the cave, we install a camera inside, as well, to see what animals use it.

COX: So, I think we're gonna have to run the cable -- BENSON: We have no idea what could be lurking deeper inside, so we've got to be extremely cautious.

We can have some infrared lights in there, so we can have a bit of illumination.

♪♪ Getting the infrared lights in place means crawling for 40 feet through thick mud into the furthest reaches of the cave.

♪♪ Some bats flying around in there.

[ Wings fluttering ] Clearly an active spot.

♪♪ Not only is this cave the perfect home for a whole manner of jungle predators, bats are known to carry some of the deadliest diseases known to humans, so this isn't somewhere I want to hang around.

♪♪ And, with the lights installed, I make a hasty exit.

♪♪ [ Insects chirping ] [ Creature whistling ] For a zoologist, like me, there are few places more exhilarating than a rain forest after dark and the nighttime world of the Amazon quite literally pulses with life.

[ Hooting ] Our microphones across the jungle capture a chorus of nocturnal animals echoing through the understory.

[ Insects chirping ] [ Whooping ] The camera we installed in the cave is already paying off, revealing a lively colony of round-eared bats.

♪♪ And, in infrared, [ Twittering ] we can see their invisible world.

♪♪ These bats can't support their body weight standing upright, so, instead, they hang from the roof.

♪♪ Special tendons in their feet allow them to dangle with zero effort, so they can focus on more important tasks, like grooming.

♪♪ But getting up there takes a feat of precision aerobatics.

♪♪ They have to flip 180° midair and reverse into position.

MELVILLE: I guess you always see bats either flying or hanging [laughing] upside-down, backwards.

I never really thought about how they get from one to the other.

MEYRICK: How they get into that position, yeah.

MELVILLE: Bit like parallel parking.

MEYRICK: Yeah.

MELVILLE: They just slot right in.

♪♪ [ Twittering ] At the back of the cave, it looks like all the adults are in one spot and then, the young are sort of [laughing] off to the side.

MEYRICK: Yeah.

Yeah, they're really separated, aren't they?

MELVILLE: Yeah.

♪♪ BENSON: Their bizarre leaf-shaped nose focuses and amplifies their chirping echolocation calls into a narrow beam.

♪♪ It's a super-sense allowing them to navigate in the dark and locate any potential dangers.

♪♪ And we soon discover what these bats need to be wary of.

MEYRICK: Oh.

There's something on three.

Snake.

MELVILLE: Oh, wow!

-MEYRICK: There it is.

That is a big snake.

-MELVILLE: [Scoff] Look at the way it moves MEYRICK: Oh, yeah.

-MELVILLE: its head, like kind of almost sniffing through the air.

♪♪ MEYRICK: Well, it looks like he's hunting.

BENSON: Using heat-sensitive receptors on its head, the snake probes the air for any bat within striking range.

♪♪ MEYRICK: Being at the cave entrance, probably not a bad place, just waiting for a bat to fly past.

♪♪ BENSON: But this bat appears too busy cleaning its wings to have noticed.

MELVILLE: I mean, I've seen a couple of snakes around camp, but, I haven't seen one this big.

MEYRICK: No, that is a sizable snake.

He's gotta be, uh, six-foot-long maybe?

BENSON: Big enough to make this bat pay attention.

MELVILLE: He's disappeared.

Well, it's quite creepy to think, when we were setting up the [laughing] camera in the cave, it could've been in there the whole time.

[ Cawing ] [ Insects chirping ] BENSON: As the snake slinks into the undergrowth... [ Wings fluttering ] ...the colony are left in peace.

Every sunrise in the Amazon feels magical... [ Hooting ] ...a billion jungle inhabitants awakening for a new day.

♪♪ The air in this jungle is a living mist of moisture, microbes, and invisible spores, slowly decaying everything it touches.

I think I've got two belts that I've gone through here.

Both of them have been consumed by mold.

They just...don't dry.

And while our cameras are designed for these rain forest conditions, it's beginning to take its toll on them, too.

MEYRICK: The biggest challenge with the cameras and all the equipment we have here is the humidity and that affects cables; it affects cameras and you can have a camera working just fine, one moment, and then, all of a sudden, it reaches a point where it no longer works.

♪♪ BENSON: It becomes a constant struggle for us to keep the cameras and monitors running 24/7.

COX: It's already full of water.

MELVILLE: If we got another box, I'm sure we could work it out.

MEYRICK: Some camera's gone down and we've had to swap it out for a new one and that will last fine for a few days and then, that will go down, so that's a constant challenge, is to keep repairing and keeping on top of all the kit.

COX: We just brought these back from one of our positions and there's water kind of dripping out of various bits of it.

Actually, that is soaking wet in there.

[ Blows ] They are waterproof, but it's -- when it's been raining here, it's been literally a power shower, um, it's been a jet wash. MEYRICK: When it's this wet everywhere, um, cameras just don't survive.

BENSON: With only have a tight window to get the footage we need here... MELVILLE: No!

BENSON: ...we've got to keep the rig running and not let the conditions get to us.

♪♪ [ Whirring ] ♪♪ For now, the cameras are back in action and we can press on with our filming experiment.

MELVILLE: [gasp] What's that in the trees?

There's something moving there.

♪♪ BENSON: It's a troop of woolly monkeys.

MELVILLE: Very exciting.

BENSON: Yeah.

MELVILLE: [whispering] God, there's loads of them.

♪♪ [ Leaves rustling ] BENSON: Their muscular bodies enable them to move with ease among the three-dimensional layers of the canopy... ♪♪ ...and make death-defying leaps from branch to branch.

♪♪ [whispering] Very, very agile, like an acrobat.

♪♪ Our cameras are revealing that they have a secret weapon for success among these treetops.

MELVILLE: Oh, look, look how he's -- he's holding himself with that branch.

♪♪ BENSON: [whispering] He has a kind of thick pad on the inside of the top of the tail, which they can use to -- to grab onto things, but it is like another hand.

They're pretty much dangling from their tails.

It's like "Mission: Impossible."

-MELVILLE: [Chuckle] BENSON: Their tail can support their entire body weight, freeing up their hands to search for food.

♪♪ Each morning, like clockwork, we watch as the troop heads out.

♪♪ Let's see if we can follow him.

MELVILLE: Yeah.

[ Whirring ] ♪♪ BENSON: Can you move that camera one?

Let's see if there's something coming through there.

[ Whirring ] ♪♪ Led by the imposing alpha male, they travel through the canopy's interconnected sea of green and our cameras capture glimpses of their two-mile foraging mission.

♪♪ 150 feet above the forest floor... ♪♪ ...we see that the foods they're after are young leaves and fresh shoots.

♪♪ But climbing higher, still, there's an even tastier reward... [ Whirring ] ♪♪ ...soft, ripe fruit.

♪♪ Their sensitive hands allow them to feel for those which are just right for picking.

♪♪ That thick fur is amazing.

MELVILLE: Yeah.

I wonder if it's to keep the bugs away.

♪♪ BENSON: But woolly monkeys appear to be picky eaters, consuming just the juiciest and sweetest part of the fruit and discarding the rest.

♪♪ As they feast their way through the treetops, their castoffs shower the forest floor below... ♪♪ [ Crack ] where the seeds can germinate.

♪♪ MELVILLE: Oh, privileged view.

-BENSON: Yeah.

So, it seems their picky table manners actually help to plant more fruit trees here, meaning the next generation of ravenous woollies will have plenty to feast on.

♪♪ [ Whimsical tune plays ] It's been three weeks since we begun our filming experiment and our remote cameras have discovered creatures of all shapes and sizes.

[ Whimsical tune plays ] But there's one group of animals that reigns supreme... [ Buzzing ] ...insects.

[ Buzzing ] ♪♪ Over two and a half million species of them inhabit every inch of the Amazon jungle and each day is a battle against this relentless army of bugs.

MEYRICK: We're absolutely covered in them.

BENSON: Sometimes they're after our equipment.

This is what's happening to our bags.

They're everywhere.

MELVILLE: Oh!

Oh!

BENSON: Most of the time, they just want us.

[ Buzzing ] ♪♪ MELVILLE: Everything wants to lay its eggs in you or bite you [laughing] or sting you.

COX: I've just been pursued by a fly, just literally.

I went up there, came back, went up there, came back, and he just followed me the whole way.

♪♪ BENSON: It seems the wildlife, too, isn't exempt from this barrage of bugs.

♪♪ [ Buzzing ] MEYRICK: I liken it to imagining you're in a sauna and you're doing a full-body workout.

MELVILLE: [Scoffs] -MEYRICK: Every five minutes, someone pokes you with a really sharp stick.

♪♪ BENSON: For most of the inhabitants here, bugs mean food, and, for this oropendola, a juicy caterpillar is the perfect way to start the day.

Several floors below, in the tangled understory, our cameras spot that the pygmy marmosets are also working up quite an appetite.

[whispering] Let's go wider on one of these other angles.

The whole gang are out in force.

MELVILLE: [whispering] Oh, wow!

There's lots of them.

[ Ethereal-suspenseful music plays ] BENSON: Using their needle-sharp teeth, they nibble holes in the tree.

MELVILLE: Oh, wow!

♪♪ BENSON: Our close-up camera reveals that it's not the bark they're eating... [ Lapping ] ...but the sticky sap underneath... ♪♪ ...a high-energy superfood for these marmosets.

♪♪ It pools into the perfectly excavated holes, ready to be slurped up.

♪♪ MELVILLE: [chuckle] They're lapping it up.

♪♪ BENSON: Draining all the sap from one part of the tree could harm it, so the marmosets create a network of holes and just eat a little from each.

♪♪ ♪♪ This industrious colony can create up to 1,300 holes on a single tree, so getting to the sap before it drips away is busy business.

♪♪ Our cameras are revealing that the pygmy marmosets are essentially farming this delicious gum up in the canopy, a smart strategy that saves these vulnerable monkeys from making dangerous trips into the jungle to find food.

♪♪ [whispering] This is what's amazing about using a rig of cameras like this, that you can film unnoticed -MELVILLE: Yeah.

BENSON: and the wildlife will continue as if you're not there.

♪♪ [ Scampering ] [ Suspenseful music plays ] Our cameras have stealthily watched the bait for many days, now, and, after the long wait, our patience is finally rewarded.

[ Whirring ] ♪♪ [ Chirp ] [ Ethereal suspenseful music plays ] It's one of the rain forest's most infamous undertakers: a yellow-headed vulture.

Unlike most birds, they have an incredible sense of smell, allowing them to zero in on a potential meal in thick jungle from up to two miles away.

♪♪ Their entire diet consists of dead meat... [ Insects buzzing ] ...and their bald head and legs are perfectly adapted to stay clean as they pick their way through a messy carcass.

♪♪ Other species of vultures have a poor sense of smell, but the sight of the yellow-headed vultures circling has alerted them to the feast below.

♪♪ The first to join are the giants of the vulture world... [ Suspenseful music climbs ] ...king vultures.

With a seven-foot wingspan, they are top of the pecking order here.

[ Wings fluttering ] MEYRICK: Oh, what was that?

Something landed in the tree, quite big.

♪♪ MELVILLE: Must be the king vulture.

MEYRICK: That must be a king, yeah.

BENSON: With their piercing eyes and flame-red face, it's easy to see why ancient Mayans believed king vultures to be messengers for the gods.

[ Whirring ] ♪♪ Despite their foreboding appearance, vultures are incredibly cautious and a gathering like this would be impossible to film up close.

[ Buzzing ] [ Hiss ] -[Whistle] -[Hiss] Ordinarily, the domineering kings would muscle the smaller vultures off a carcass, but, today, something is holding them back.

[ Whimsical-suspenseful tune plays ] It's not quite the predatory leopard we were hoping for.

♪♪ MELVILLE: It's a tortoise!

MEYRICK: That is a tortoise.

-MELVILLE: [Laughs] MEYRICK: I wonder what he's doin' here.

♪♪ BENSON: The vultures seem as surprised as we are by this unlikely arrival at the banquet.

♪♪ MELVILLE: Maybe it's just his route through MEYRICK: Could be.

Let's see.

-MELVILLE: on his morning walk.

♪♪ BENSON: Yellow-footed tortoises are a well-known resident of the forest floor.

♪♪ MEYRICK: Yeah, he's on a mission.

Look at him.

He's heading straight for it.

BENSON: They're known to feast on leaves and fruit.

♪♪ [ Buzzing ] ♪♪ ♪♪ [ Buzzing ] ♪♪ MEYRICK: He's puttin' his nose right in there.

MELVILLE: Yeah.

♪♪ BENSON: This rarely seen behavior, of a tortoise scavenging meat, is how they supplement their diet with a bit of extra protein.

[ Buzzing ] ♪♪ ♪♪ [ Buzzing ] ♪♪ And, now it's had its fill, it returns to its fruit-eating ways.

MELVILLE: It's such a cute animal, I'm almost disappointed in the tortoise.

[ Laughter ] ♪♪ [ Buzzing ] [ Chirping ] BENSON: It's a glorious afternoon and, at the river, the yellow-spotted turtles are, again, soaking up some rays in quiet tranquillity.

But not for long.

[ Whimsical-suspenseful tune plays ] This, however, is no chance encounter.

♪♪ This butterfly has come here looking for a meal.

Unlike carnivores, that get sodium from their diet, herbivorous butterflies need to get creative about how they get it.

♪♪ Further along the riverbank... ♪♪ ...our cameras have discovered huge numbers of colorful butterflies flocking to patches of exposed clay.

♪♪ [ Whirring ] ♪♪ They use their long proboscises to lick the mud and extract any sodium from the moist soil.

♪♪ It's a beautifully organized affair, with each species color-coding themselves to feed in their own patch.

But some butterflies seek a more intense sodium hit... ♪♪ [ Chorale joins ] ♪♪ ...and, unfortunately for turtles, their tears are the ultimate source.

[ Whimsical chord strikes ] [ Whirring ] [ Chirping ] The salty moisture around their eyes and nose is irresistible.

The boldest butterflies don't even wait for the turtles to be fully out of the water.

But, they appear remarkably accepting of their fluttering companions.

Perhaps their probing proboscises clean the turtle's hard to reach places.

[ Chirping ] But even the most obliging turtles have a limit... ...compelling them to return, once more... ...to the solitude of the water.

As the nights tick by, our cameras across the forest [ Whirring ] are finding creatures that only emerge under the cover of darkness.

[ Whirring ] From the charming... -MEYRICK: It's moving MELVILLE: Oh, wow.

-MEYRICK: in the bushes.

MELVILLE: It's a porcupine!

-MEYRICK: Is it?

MELVILLE: [chuckling] Oh, look, he just fell over.

Oh, that's really sweet.

BENSON: ...to the unexpected.

MEYRICK: A crab, look.

-MELVILLE: Oh, wow, there is actually a crab.

-MEYRICK: Yeah.

How weird, to see a crab in the middle of the jungle.

BENSON: With infrared cameras, we're able to see the invisible.

[ Ethereal-suspenseful music plays ] And, along the banks of the river... ♪♪ ...they're revealing a colossal cloud of insects... [ Buzzing ] ♪♪ ...gathering over the water.

And it's not long before this buzz of activity attracts some familiar faces.

♪♪ So this is where the bats come when they leave their cave.

♪♪ They fire high-pitched chirps across the water... ♪♪ ...and, by listening to the echoes that bounce back... ♪♪ ...they can zero in on a single insect and make their strike.

♪♪ ♪♪ Even large prey items, like this huge moth, can be dispatched on the wing.

♪♪ Each bat can eat up to 3,000 insects per night and our infrared cameras are revealing the scale of this feeding frenzy.

♪♪ I, for one, appreciate their part in helping to keep the army of biting insects here in check.

[ Chirping ] [ Chirping ] [ Whooshing ] [ Whistling ] [ Poignant tune plays ] After four incredible weeks, our time here is almost at an end.

Filming "Undercover in the Jungle" has allowed us to experience the lives of the animals here in a whole new way.

That is fantastic, an animal's-eye view of this amazing forest clearing.

And, as a zoologist, it's allowed me to witness things that I never imagined possible.

[whispering] You'd never be able to get this sort of footage.

Even sitting in a hide with a long lens, you'd have to be super lucky.

MELVILLE: Yeah.

[ Thunder crashing ] ♪♪ BENSON: But it's been a humbling experience.

MELVILLE: This has definitely been one of the most mentally challenging projects I've ever done.

BENSON: The extreme conditions pushed our equipment and our bodies to their very limit... [ Buzzing ] ♪♪ ...giving us a profound understanding of what the animals must overcome to survive here.

♪♪ [ Rumbling ] ♪♪ [ Chirping ] We've had just glimpses of some creatures... ♪♪ ...and have become well-acquainted with others.

♪♪ Yet, this is just a snapshot of the magnitude of life that exists here... [ Twitter ] [whispering] What a remarkable moment to have captured.

[ Cawing ] ...and a reminder of how much there is still to learn about this magical Eden.

♪♪ ♪♪ ♪♪ ♪♪ To learn more about what you've seen on this "Nature" program, visit pbs.org.

♪♪