0:00:05 > 0:00:08As night creeps across the planet,
0:00:08 > 0:00:11and our familiar daytime world is plunged into darkness...
0:00:14 > 0:00:17..strange creatures are beginning to stir.
0:00:18 > 0:00:21This is when most animals are active.
0:00:23 > 0:00:26The drama of their nocturnal lives, hidden from our eyes.
0:00:33 > 0:00:36Now a team of scientists and filmmakers is on an expedition
0:00:36 > 0:00:38to the remotest parts of South America.
0:00:38 > 0:00:41Whoa, whoa, whoa!
0:00:41 > 0:00:43What is that?
0:00:44 > 0:00:46Armed with specialist technology,
0:00:46 > 0:00:49they will attempt to discover the secrets of the night.
0:00:49 > 0:00:52- Holy- BLEEP! - I'm getting it. I'm getting it.
0:00:53 > 0:00:55She's hunting.
0:00:55 > 0:00:57It's a journey into the unknown...
0:00:59 > 0:01:02I shouldn't really be out here alone.
0:01:02 > 0:01:05..a world where we are blind...
0:01:05 > 0:01:07Please don't leave me up here.
0:01:07 > 0:01:09I don't know what that is.
0:01:09 > 0:01:11Technology will reveal it as never before....
0:01:11 > 0:01:15Right now's the most dangerous time to be out here.
0:01:15 > 0:01:16He will attack you.
0:01:16 > 0:01:20The mysteries of life in the dark.
0:01:20 > 0:01:21Don't...run.
0:01:32 > 0:01:36Over six months, the expedition is travelling
0:01:36 > 0:01:39the length of Central and South America,
0:01:39 > 0:01:42from the pristine rainforests of the north,
0:01:42 > 0:01:44to the darkest heart of the Amazon jungle.
0:01:44 > 0:01:47They've been using their new technology
0:01:47 > 0:01:51to illuminate a world hidden from human eyes.
0:01:52 > 0:01:54Now on the final leg of their journey,
0:01:54 > 0:01:57they have come to solve more nocturnal mysteries
0:01:57 > 0:02:00in a new and very different environment...
0:02:01 > 0:02:06..the southern tip of South America - Patagonia.
0:02:20 > 0:02:23Bryson, Bryson, we're going to head off now
0:02:23 > 0:02:25and we're going to check out another ridge line.
0:02:25 > 0:02:28All right. We're going to take the other road and loop back around.
0:02:28 > 0:02:30'We're going to carry on in this direction.'
0:02:32 > 0:02:34Heading up the team of wildlife experts
0:02:34 > 0:02:36is biologist Dr George McGavin.
0:02:38 > 0:02:41We've come to the Torres del Paine National Park
0:02:41 > 0:02:43right at the southern tip of the Andes,
0:02:43 > 0:02:46and we've come here to look for the largest ranging
0:02:46 > 0:02:50land carnivore in all the Americas - the puma.
0:02:52 > 0:02:54The puma is the top predator here.
0:02:54 > 0:02:57They're a crucial part of the mountain ecosystem,
0:02:57 > 0:03:00but their behaviour has been little studied.
0:03:00 > 0:03:04We're pretty sure we know what they do during the day.
0:03:04 > 0:03:09They sleep. But what a puma does after dark is a black book.
0:03:09 > 0:03:12There is a higher concentration of pumas here
0:03:12 > 0:03:13than anywhere else on earth.
0:03:13 > 0:03:16The team will use their specialist cameras
0:03:16 > 0:03:18to build a more complete picture of their lives.
0:03:18 > 0:03:21They have never been filmed hunting after dark - ever.
0:03:21 > 0:03:28If we can do that, that'd be the holy grail of puma ecology.
0:03:28 > 0:03:31Their first challenge is to find a puma.
0:03:32 > 0:03:35That means splitting up and searching by day for possible lairs.
0:03:35 > 0:03:37Three miles from George,
0:03:37 > 0:03:41night-time camera specialist Justine Evans scans from the air.
0:03:42 > 0:03:44There's a huge, huge area.
0:03:44 > 0:03:49And there's a series of ridges and valleys, lots of lakes...
0:03:49 > 0:03:52and there's little rocky outcrops where pumas can hide away.
0:03:54 > 0:03:58Justine is guiding a third team member, biologist Bryson Voirin -
0:03:58 > 0:04:00the expedition's tracker.
0:04:01 > 0:04:05The most difficult thing about this place is actually finding a puma -
0:04:05 > 0:04:07it's like looking for a needle in a haystack,
0:04:07 > 0:04:09except this needle is moving around.
0:04:10 > 0:04:13Bryson has spent years studying nocturnal mammals.
0:04:14 > 0:04:17If he can identify where pumas are hunting,
0:04:17 > 0:04:19then Justine can return at night to film them.
0:04:21 > 0:04:23'Be careful in there.'
0:04:23 > 0:04:24You don't want to corner a puma or scare it.
0:04:26 > 0:04:29Justine, I'm seeing lots and lots of game trails here,
0:04:29 > 0:04:31so it seems like there's a lot of activity with animals.
0:04:33 > 0:04:35By working in different areas,
0:04:35 > 0:04:38the team hope to maximise their chances of finding a puma.
0:04:40 > 0:04:43I'm just looking for anything I can see -
0:04:43 > 0:04:46tracks or signs, bits or remains of animals,
0:04:46 > 0:04:49anything that will hand us a clue.
0:04:49 > 0:04:51You know, hunting animals, you have to be sneaky,
0:04:51 > 0:04:55you have to have a strategy to catch whatever you're routing.
0:04:55 > 0:04:57And if you're doing it after dark,
0:04:57 > 0:05:00you have to have a special suite of tricks up your sleeve.
0:05:03 > 0:05:07Here, the puma's meal of choice is guanaco -
0:05:07 > 0:05:09an ancient cousin of the llama.
0:05:10 > 0:05:12They are constantly alert -
0:05:12 > 0:05:15almost impossible to hunt by day,
0:05:15 > 0:05:17but at night, they are vulnerable.
0:05:22 > 0:05:24Oooh. Wait. Wait, wait, wait.
0:05:27 > 0:05:31There's a kill here. Look, just right next to me.
0:05:33 > 0:05:37That is a puma kill.
0:05:41 > 0:05:43Right under that bush.
0:05:43 > 0:05:45Now, it's been hidden.
0:05:45 > 0:05:47What they do is, they hunt for their prey
0:05:47 > 0:05:50and they jump on its back and then after it's killed,
0:05:50 > 0:05:55they can't possibly eat an animal of this size in one go.
0:05:55 > 0:05:59So they hide it under all this brush and it's completely hidden.
0:05:59 > 0:06:03They then come back over two or three evenings and eat it all.
0:06:03 > 0:06:05And that is the remains of a kill.
0:06:06 > 0:06:09So there's a guanaco. That's all that remains of it.
0:06:12 > 0:06:15There'll be no more eating here. That's just skin and bone there.
0:06:18 > 0:06:21It's proof that a puma is hunting here.
0:06:21 > 0:06:26To see the animal in action, the team must return after dark.
0:06:33 > 0:06:36Three hundred miles south, in the Magellan Strait,
0:06:36 > 0:06:39a second part of the expedition is under way.
0:06:39 > 0:06:43Wildlife cameraman Gordon Buchanan will use state-of-the-art technology
0:06:43 > 0:06:47to shed light on a marine mystery in these rich waters.
0:06:47 > 0:06:51It's probably one of the most treacherous bodies of water
0:06:51 > 0:06:56in the world, but it is also one of the most unique marine environments
0:06:56 > 0:06:58and the reason being, we've got the Atlantic
0:06:58 > 0:07:02and the Pacific coming together right at this point
0:07:02 > 0:07:07and what that leads to is a biodiversity on an epic scale.
0:07:07 > 0:07:09You've got creatures in this water
0:07:09 > 0:07:13from the very smallest to some of the planet's biggest.
0:07:14 > 0:07:17One of the largest is the humpback whale.
0:07:18 > 0:07:22Ooh, a big humpback whale just here.
0:07:23 > 0:07:25Spectacular.
0:07:25 > 0:07:26And there's more.
0:07:26 > 0:07:28Just here, maybe 300 metres away.
0:07:30 > 0:07:34Most humpback whales pass quickly through the Magellan Strait.
0:07:35 > 0:07:39This group chooses to stay here for three months of every year.
0:07:43 > 0:07:46So little is known about what takes place during the day
0:07:46 > 0:07:49under the surface of the water and absolutely nothing is known,
0:07:49 > 0:07:51really, about what takes place at night-time.
0:07:51 > 0:07:53Gordon hopes to solve a puzzle
0:07:53 > 0:07:56that has mystified the scientists that study these whales.
0:07:56 > 0:07:59They can hear them coming close to shore at night,
0:07:59 > 0:08:02but can't see what they're doing.
0:08:02 > 0:08:03Gosh, look at that!
0:08:04 > 0:08:08Gordon's specialist equipment could give them the answer.
0:08:11 > 0:08:14We have an arsenal of cameras for filming at night-time.
0:08:14 > 0:08:17We've got thermal imaging cameras, we've got infrared,
0:08:17 > 0:08:20we've got low light cameras.
0:08:20 > 0:08:23Pretty much nothing can take place at night-time
0:08:23 > 0:08:26without us being able to film it in some way.
0:08:27 > 0:08:31Using this technology to film whales at night will be a first,
0:08:31 > 0:08:33and could open up a whole new world.
0:08:36 > 0:08:38It'd be good to get into the water and find out
0:08:38 > 0:08:40what those humpbacks are doing at night,
0:08:40 > 0:08:42if they are doing anything. And that's why we're here,
0:08:42 > 0:08:45to get out there and just try and answer some questions.
0:08:45 > 0:08:48Whoa, whoa, whoa, whoa!
0:08:48 > 0:08:49Unbelievable.
0:09:04 > 0:09:08As daylight fades, 300 miles north,
0:09:08 > 0:09:12the puma team has split to search the area where George found a kill.
0:09:13 > 0:09:16This is the time the pumas are just waking up,
0:09:16 > 0:09:17going around looking for dinner.
0:09:17 > 0:09:19It's a really good time to see them
0:09:19 > 0:09:21walking along the hillsides or in the valleys.
0:09:23 > 0:09:26Tonight we've got all three teams out
0:09:26 > 0:09:29in separate vehicles and driving all the tracks,
0:09:29 > 0:09:31and we're throwing everything at it tonight,
0:09:31 > 0:09:32getting everyone out there.
0:09:32 > 0:09:36It's a large area - we need to spread out as far as we can
0:09:36 > 0:09:41and to use a variety of strategies if we're to see anything good.
0:09:56 > 0:10:00This puma will have a territory of about 25 square miles.
0:10:00 > 0:10:03- Are you ready?- Yeah. We're ready.- OK.
0:10:06 > 0:10:09They are each searching in a different part of its range.
0:10:13 > 0:10:16This is great, because we've got thermal sensing going on,
0:10:16 > 0:10:20and visible light. Diego's out the roof with a spotlight,
0:10:20 > 0:10:23and I've got the little thermal spotting camera here,
0:10:23 > 0:10:25which will reveal the heat of anything warm-blooded
0:10:25 > 0:10:27that's out there.
0:10:31 > 0:10:33Right now, we're using lights to find the pumas,
0:10:33 > 0:10:36but as soon as we see we one, we've got to turn the car off,
0:10:36 > 0:10:38turn off all the lights and switch to either infrared
0:10:38 > 0:10:41or thermal cameras that don't emit any light,
0:10:41 > 0:10:42cos lights will scare the pumas away.
0:10:44 > 0:10:47Three miles west, George is with two biologists
0:10:47 > 0:10:50who have studied the pumas here for years.
0:10:51 > 0:10:55What we're hunting for is green eye shine.
0:10:55 > 0:10:57Pumas have got very big eyes,
0:10:57 > 0:11:01and they glow bright green in a headlight beam.
0:11:01 > 0:11:04So it'll be very obvious if there's one there.
0:11:08 > 0:11:10Quick! Quick, quick!
0:11:10 > 0:11:13So something just ran out of the bushes. Where'd it go?
0:11:15 > 0:11:16Oh, I see the eye shine.
0:11:16 > 0:11:18It's moving too fast.
0:11:19 > 0:11:20Fox.
0:11:20 > 0:11:21Yeah, it's a fox.
0:11:28 > 0:11:30While Bryson and Justine continue their search,
0:11:31 > 0:11:34George leaves the safety of his vehicle
0:11:34 > 0:11:37to check out a ridge above the road with a military spotting scope.
0:11:40 > 0:11:43There was definitely, definitely eye shine over there.
0:11:45 > 0:11:46It was just by that rock.
0:11:48 > 0:11:49Right there!
0:11:54 > 0:11:56(There's one just there.)
0:11:59 > 0:12:04Yeah, it's just on the hillside. Just halfway up the slope.
0:12:06 > 0:12:08Well, it isn't a very clear sighting.
0:12:11 > 0:12:12I just saw eye shine.
0:12:14 > 0:12:18It didn't look very green. It looked greenish.
0:12:18 > 0:12:21But it definitely wasn't a guanaco eye shine.
0:12:21 > 0:12:22And it was just over there.
0:12:24 > 0:12:28If it is a puma, then I'm right on the top of this ridge.
0:12:28 > 0:12:30I mean, it's obvious he'll go.
0:12:31 > 0:12:34The animal heads down towards the road.
0:12:34 > 0:12:39George radios biologist Rodrigo, waiting in the vehicle below.
0:12:41 > 0:12:46I just thought I saw a moving spot
0:12:46 > 0:12:50'on a slight slope just southwest of here.'
0:12:50 > 0:12:52OK, perfect.
0:12:57 > 0:13:02Now Rodrigo must try to intercept the animal as it crosses the road.
0:13:02 > 0:13:04Stop, stop, stop.
0:13:04 > 0:13:05Did you see something?
0:13:05 > 0:13:08- Got binoculars? - Yeah, it's a puma, Christina.
0:13:09 > 0:13:13Absolutely 100% puma. OK.
0:13:13 > 0:13:14This is great for filming.
0:13:16 > 0:13:18Give me the radio.
0:13:18 > 0:13:19Rodrigo calls in Justine,
0:13:19 > 0:13:23who is two miles away searching on a different mountain track.
0:13:23 > 0:13:27- 'Rodrigo, how are you getting on? Over.'- We just spotted a puma.
0:13:27 > 0:13:29Quick. It's just here.
0:13:29 > 0:13:30'Perfect.'
0:13:30 > 0:13:34OK, we're on our way. Let's go. Let's move on.
0:13:37 > 0:13:40The challenge now is to stick close to the puma.
0:13:40 > 0:13:43With luck, Justine will get there in time
0:13:43 > 0:13:45to film its behaviour at night.
0:13:51 > 0:13:53In the Magellan Strait,
0:13:53 > 0:13:55Gordon is hoping to solve the mystery
0:13:55 > 0:13:58of what brings a pod of humpback whales
0:13:58 > 0:13:59so close to shore at night.
0:14:02 > 0:14:07There's so much about these animals that we don't know,
0:14:07 > 0:14:10so much about them that we'll never know
0:14:10 > 0:14:13and the reason is because most of the things they do
0:14:13 > 0:14:16are done in complete darkness.
0:14:16 > 0:14:21Gordon is relying on his thermal camera to see in total darkness,
0:14:21 > 0:14:22but there's no guarantee
0:14:22 > 0:14:25his technology will even detect the whales.
0:14:25 > 0:14:27This has never been attempted before.
0:14:27 > 0:14:30we're answering some questions, we're learning new stuff
0:14:30 > 0:14:32and we're only able to do this
0:14:32 > 0:14:34because of the technology that we're using.
0:14:34 > 0:14:39This camera, it's a thermal camera, so it sees heat sources.
0:14:39 > 0:14:41Humpbacks are incredibly well insulated.
0:14:41 > 0:14:44They've got a thick, thick layer of blubber,
0:14:44 > 0:14:46so it may well be that humpbacks
0:14:46 > 0:14:49actually don't give off a temperature signal.
0:14:49 > 0:14:52They might be the same temperature as the water. We just don't know.
0:14:52 > 0:14:54This is the first time anyone's ever tried
0:14:54 > 0:14:56to use this technology to find these animals.
0:14:59 > 0:15:02Within minutes, the camera begins to pick up
0:15:02 > 0:15:03unusual activity in the water.
0:15:09 > 0:15:12Oh, there you go! There you go. You can actually see...
0:15:14 > 0:15:18Ohhh! You can see its tail splashing in the water there.
0:15:20 > 0:15:25That's interesting - there's this huge cloud of white vapour,
0:15:25 > 0:15:28and the reason it's white is because it's hot.
0:15:28 > 0:15:33It's hot breath being expelled from these huge lungs.
0:15:33 > 0:15:36And it shows up much, much warmer than the ambient water.
0:15:38 > 0:15:40Now, you see that?
0:15:40 > 0:15:42Oh! Great.
0:15:42 > 0:15:46Huge tail splashes and clouds of water coming up from the surface,
0:15:46 > 0:15:50not just from it slapping its tail, but from its blowhole as well.
0:15:51 > 0:15:54We came out looking for behaviour,
0:15:54 > 0:15:57and this is not at all what I expected to see.
0:15:58 > 0:16:02From this distance, Gordon can only speculate what the whales are doing.
0:16:02 > 0:16:05It may be a way in lower light conditions
0:16:05 > 0:16:08for whales to communicate to each other,
0:16:08 > 0:16:11to let them know precisely where they are.
0:16:11 > 0:16:14That sound, that huge, thunderous sound of the tail
0:16:14 > 0:16:16slapping on the surface of the water,
0:16:16 > 0:16:18will carry literally for miles.
0:16:20 > 0:16:22But they also do it to stun fish.
0:16:22 > 0:16:26They'll swim through a shoal and then they'll give a huge tail slap,
0:16:26 > 0:16:28literally stunning the life out of the fish,
0:16:28 > 0:16:32and then they swim back round and hoover them up.
0:16:32 > 0:16:34This is...spectacular.
0:16:39 > 0:16:41Humpbacks need to eat one and a half tonnes of food
0:16:41 > 0:16:45every 24 hours. They must feed both day and night.
0:16:47 > 0:16:49But what brings a pod of humpback whales close to shore
0:16:49 > 0:16:51remains a mystery.
0:16:53 > 0:16:55What we've seen at night-time is whales
0:16:55 > 0:16:56moving closer in to the coast.
0:16:57 > 0:16:59What I'd love to do is to get in
0:16:59 > 0:17:01to find out exactly what they're doing.
0:17:03 > 0:17:05Look at that! Oh!
0:17:15 > 0:17:19In Torres del Paine, the puma team has found their cat.
0:17:19 > 0:17:23Now Justine wants to see just how it operates in the dark.
0:17:29 > 0:17:30- Hi. Hiya.- Hello.
0:17:30 > 0:17:31Where's the puma, then?
0:17:31 > 0:17:33The puma was...
0:17:33 > 0:17:34Upwind and high above her position,
0:17:34 > 0:17:38a herd of a guanaco are oblivious to the puma's presence.
0:17:38 > 0:17:42Yeah. This is a good scenario.
0:17:42 > 0:17:44We've got loads of guanacos over there.
0:17:49 > 0:17:52Hunting at night dramatically increases
0:17:52 > 0:17:54the puma's chance of a kill.
0:17:54 > 0:17:57It's going up over the ridge.
0:17:57 > 0:18:00By day, it's almost impossible to get close enough
0:18:00 > 0:18:02to ambush prey as alert as these guanacos.
0:18:06 > 0:18:11At night, the puma's superior eyesight gives it the advantage.
0:18:11 > 0:18:14(What's happening, Diego? Are they doing anything?)
0:18:17 > 0:18:22Justine fires up her thermal imaging camera
0:18:22 > 0:18:25and the puma's heat signature is immediately revealed.
0:18:25 > 0:18:27(Got it. I've got it.)
0:18:38 > 0:18:41(I'm getting it...I'm getting it. Ah, this is fantastic.)
0:18:44 > 0:18:45(She's hunting.)
0:18:47 > 0:18:48(Wow.)
0:18:53 > 0:18:56She's putting each paw down really carefully.
0:18:59 > 0:19:01The darkness here is almost total,
0:19:01 > 0:19:03yet the puma is utterly focussed
0:19:03 > 0:19:06on its prey more than 30 metres away.
0:19:12 > 0:19:15(It's perfectly equipped to be hunting at night like this.)
0:19:15 > 0:19:17(It's got great sense of smell and hearing.)
0:19:17 > 0:19:21(Even though the moon hasn't come up and it's really dark out there,)
0:19:21 > 0:19:24(it can still see very well.)
0:19:27 > 0:19:30Guanacos have a highly developed sense of hearing.
0:19:31 > 0:19:33The contest is so finely balanced
0:19:33 > 0:19:36that the puma must take the guanacos by surprise.
0:19:43 > 0:19:48(He's in full hunt mode - it's an amazing sight.)
0:19:54 > 0:19:58(This is an absolute gem of a situation.)
0:19:58 > 0:20:01(As long as I don't cock it up and the puma doesn't cock it up.)
0:20:11 > 0:20:12(Now, who knows what's going to happen?)
0:20:12 > 0:20:13(I've no idea.)
0:20:36 > 0:20:38The puma is about to make its move.
0:20:52 > 0:20:54GUANACOS WHINNY
0:20:56 > 0:21:00The guanacos sense the danger, and the hunt is over.
0:21:05 > 0:21:07(That was such a shame.)
0:21:07 > 0:21:09(It looked like he had got everything right,)
0:21:09 > 0:21:12(and suddenly - bang! - they were all going.)
0:21:14 > 0:21:18(It makes you realise just how hard it is for a puma to hunt.)
0:21:26 > 0:21:30Filming a puma hunt in such detail is a great start for Justine.
0:21:39 > 0:21:44George is travelling 2,000 miles north to solve another mystery.
0:21:44 > 0:21:46He's come to the Atacama desert.
0:21:48 > 0:21:51Well, the Atacama, where we are now, is probably
0:21:51 > 0:21:55one of the most inhospitable and dry places on earth.
0:21:55 > 0:21:59There are parts of the land here that have never had rain ever
0:21:59 > 0:22:02in recorded history. It's that dry.
0:22:02 > 0:22:05Almost nothing can survive here,
0:22:05 > 0:22:10but one nocturnal mammal is thriving and George wants to know why.
0:22:10 > 0:22:11I'm heading to this island,
0:22:11 > 0:22:13which is just a short way off the coast,
0:22:13 > 0:22:16and it's believed to have a colony of vampire bats,
0:22:16 > 0:22:17and that is really what I want to see,
0:22:17 > 0:22:20and they're only active, and they only fly,
0:22:20 > 0:22:22when it's totally dark.
0:22:34 > 0:22:37Oh, dolphin! Look at that. Whoa!
0:22:41 > 0:22:43They're right under us.
0:22:43 > 0:22:46Vampire bats are one of the most iconic creatures of the night.
0:22:46 > 0:22:51And the colony here is truly mysterious.
0:22:51 > 0:22:54I want to find out what on earth
0:22:54 > 0:22:57a colony of vampire bats is feeding on,
0:22:57 > 0:23:02on an island that seemingly has few other animals on it
0:23:02 > 0:23:04and it looks pretty inhospitable,
0:23:04 > 0:23:07but clearly there's enough there for vampire bats to eat.
0:23:10 > 0:23:14To help him, he's calling upon the expertise of biologist
0:23:14 > 0:23:18Marcelo Flores and wildlife camerawoman Sophie Darlington.
0:23:18 > 0:23:20Everything is actually completely fine.
0:23:20 > 0:23:24We've put everything in dry bags so all the kit's protected.
0:23:31 > 0:23:34This is a hostile landscape, littered with boulders
0:23:34 > 0:23:38and coated with guano, or bird excrement.
0:23:39 > 0:23:42I've never been anywhere like this before.
0:23:42 > 0:23:45The one thing is just the overpowering stench,
0:23:45 > 0:23:46which is just everywhere.
0:23:46 > 0:23:49Looking around it's sort of like you've landed on the moon a bit.
0:23:49 > 0:23:52It's really desolate - like a lunar landscape.
0:23:52 > 0:23:55It's incredibly bleak. Really dry, really arid.
0:23:55 > 0:23:59George's first task is to find where the bats are roosting.
0:24:00 > 0:24:03They say that the cave with the vampires in it
0:24:03 > 0:24:06is actually on the coast, so it's really important
0:24:06 > 0:24:08that we find the cave as quickly as we can,
0:24:08 > 0:24:11cos if we can't find it now, we won't find it in the dark.
0:24:15 > 0:24:18This looks very like the cave.
0:24:19 > 0:24:20Yeah.
0:24:21 > 0:24:23You're right.
0:24:33 > 0:24:35The smell is very different.
0:24:35 > 0:24:37That's not guano smell, that's something else. That's...
0:24:37 > 0:24:39- HE SNIFFS - That's not nice.
0:24:41 > 0:24:43That really is not a nice smell.
0:24:43 > 0:24:44HE COUGHS
0:24:44 > 0:24:48That's acrid. That's urea, uric acid,
0:24:48 > 0:24:50really intense urine smell.
0:24:51 > 0:24:56And the rocks are really slippy with bat droppings.
0:24:56 > 0:24:59That's just absolutely thick.
0:25:00 > 0:25:02Running down the wall.
0:25:10 > 0:25:12Oh, yeah. There's one. Just flew...two.
0:25:14 > 0:25:16(Oh, yeah, yeah, yeah. Here.)
0:25:19 > 0:25:22There's about eight vampire bats just looking straight at me.
0:25:22 > 0:25:25Nine, ten...oh, there's more up there.
0:25:25 > 0:25:27This is the first time I've ever seen a vampire bat,
0:25:27 > 0:25:30and it's, what? Six feet away from me?
0:25:31 > 0:25:32(That is amazing.)
0:25:32 > 0:25:33(Oh!)
0:25:35 > 0:25:39These tiny blood suckers don't use their eyes to find their victims.
0:25:39 > 0:25:43Their eyesight is fairly good, their hearing is good,
0:25:43 > 0:25:44they can echolocate,
0:25:44 > 0:25:47they have infra-red pits around their face
0:25:47 > 0:25:50where they can sense the really hot part of the animal
0:25:50 > 0:25:51where the blood flow is highest,
0:25:51 > 0:25:54and they have teeth that are just razor sharp,
0:25:54 > 0:25:57and they just hack off a flap of skin,
0:25:57 > 0:25:58and as the blood wells into it,
0:25:58 > 0:26:01they just suck it up with their tongue.
0:26:01 > 0:26:04And they have a little groove on their lip here
0:26:04 > 0:26:06which they press against the wound,
0:26:06 > 0:26:10and, of course, they introduce anticoagulants into the bite
0:26:10 > 0:26:14so that the saliva makes the blood flow and flow and flow.
0:26:14 > 0:26:18There's no doubting the vampire bat's supreme ability
0:26:18 > 0:26:21to locate mammals and extract their blood.
0:26:22 > 0:26:27What's eluded biologists is why this colony chooses to live here.
0:26:27 > 0:26:29What are they eating?
0:26:29 > 0:26:33What animal are they extracting the blood from?
0:26:33 > 0:26:34That's what I want to know.
0:26:35 > 0:26:37I think the only way we're going to find out
0:26:37 > 0:26:42is if we can catch one and glue a little tracker on its back
0:26:42 > 0:26:46and track it to where it's eating,
0:26:46 > 0:26:53and then we should be able to film exactly what animal it's feeding on.
0:26:54 > 0:26:58The problem is how to catch a bat, as they are roosting out of reach.
0:27:00 > 0:27:04George must return at dusk to net one as it leaves the cave to feed.
0:27:13 > 0:27:16Back in the Andes, the puma team prepares for dark.
0:27:18 > 0:27:20- OK. Ready.- Ready, ready. - We're off, we're off.
0:27:21 > 0:27:24They've had a good start, filming a puma hunting.
0:27:26 > 0:27:29Now, Justine wants to spend more time with this secretive predator.
0:27:29 > 0:27:32What we really want to find out is what pumas actually do
0:27:32 > 0:27:36during the night, and that's when they do everything
0:27:36 > 0:27:37that pumas get up to.
0:27:37 > 0:27:40And we're going to need quite a lot of luck.
0:27:40 > 0:27:43But we're hoping to see some unique behaviour.
0:27:51 > 0:27:54With dusk approaching, their plan is to spot a puma
0:27:54 > 0:27:57as it leaves its daytime lair and goes out to hunt.
0:27:59 > 0:28:01Bryson has already picked up a trail.
0:28:03 > 0:28:06Look. Fresh tracks.
0:28:07 > 0:28:08Right here.
0:28:10 > 0:28:13There's another one right there. Look at that.
0:28:13 > 0:28:15Wow. That's a good one.
0:28:15 > 0:28:17Here's a nice paw print right here.
0:28:17 > 0:28:19It's big, but it's not huge.
0:28:19 > 0:28:22You know, a full-grown adult would be a bit bigger,
0:28:22 > 0:28:24about the size of the middle of my hand.
0:28:24 > 0:28:25So it's a teenager.
0:28:25 > 0:28:27He's been walking right here.
0:28:27 > 0:28:30And that's a pretty good span between footprints.
0:28:31 > 0:28:32Yeah.
0:28:34 > 0:28:37He's a pretty good size, though. He's not little.
0:28:50 > 0:28:52We have a puma.
0:28:52 > 0:28:54There's a puma. Right here.
0:28:57 > 0:28:59(He just came out of the woods.)
0:28:59 > 0:29:01(OK, he's walking along the edge.)
0:29:01 > 0:29:03(There he is. Wow.)
0:29:06 > 0:29:07(He's right there.)
0:29:08 > 0:29:10(He's looking.)
0:29:10 > 0:29:12(Nobody move. Everybody stay still.)
0:29:15 > 0:29:17(There he is. Right there.)
0:29:17 > 0:29:19(He's walking in the brush.)
0:29:19 > 0:29:22(What's amazing is, he's not making any sound at all.)
0:29:22 > 0:29:23(I can't hear him at all.)
0:29:24 > 0:29:26(God.)
0:29:26 > 0:29:28(But he's an absolute silent hunter.)
0:29:30 > 0:29:32Pumas are at their most dangerous
0:29:32 > 0:29:36when they haven't eaten for several days.
0:29:37 > 0:29:40He's hungry and he's looking for a meal
0:29:40 > 0:29:42so I really got to be careful right now.
0:29:42 > 0:29:46The last thing I need to do is act like a prey animal.
0:29:46 > 0:29:48Under no circumstances can I run.
0:29:48 > 0:29:50That's the worst thing to do.
0:29:50 > 0:29:53The thing is, you don't hear a puma coming.
0:29:53 > 0:29:55If you're lucky, you see it.
0:29:56 > 0:29:57Should it choose to,
0:29:57 > 0:30:01this puma is more than capable of killing a fully grown man.
0:30:05 > 0:30:06(Don't...run.)
0:30:08 > 0:30:09Don't run.
0:30:09 > 0:30:10He will attack you.
0:30:13 > 0:30:14(He's just staring.)
0:30:19 > 0:30:20(Wow, God.)
0:30:28 > 0:30:29You know, this is the top predator
0:30:29 > 0:30:31and you'll be able to watch him walk out of the woods,
0:30:31 > 0:30:34look right at me, and not care at all.
0:30:36 > 0:30:37(He's walking away.)
0:30:39 > 0:30:43That is the most elegant predator I've ever seen.
0:30:45 > 0:30:47(What an incredible animal. God.)
0:30:48 > 0:30:50Wow. The dark doesn't belong to us.
0:30:50 > 0:30:52It belongs to the pumas.
0:30:52 > 0:30:56with hearing and smell and vision like his,
0:30:56 > 0:30:57he really is the king of the dark.
0:30:59 > 0:31:01The team have a cat in their sights.
0:31:01 > 0:31:05This is the opportunity they have been waiting for.
0:31:05 > 0:31:08So I'll radio Justine and see if she can get him on a thermal camera.
0:31:09 > 0:31:12Justine, this is Bryson. Come in.
0:31:12 > 0:31:13'Hi, Bryson.'
0:31:13 > 0:31:15Can you hear me? Over.
0:31:16 > 0:31:17We just found a puma.
0:31:19 > 0:31:21We're on our way to you. Over.
0:31:36 > 0:31:38Off the coast of the Atacama desert,
0:31:38 > 0:31:41George and biologist Marcelo are heading back into the cave
0:31:41 > 0:31:44to catch and tag one of the vampire bats
0:31:44 > 0:31:46as it leaves the roost to feed.
0:31:49 > 0:31:52(Because they're so closely grouped together,)
0:31:52 > 0:31:55(I think it'll be quite easy to catch one,)
0:31:55 > 0:31:59(cos in the melee, as they fly off,)
0:31:59 > 0:32:02(one of them will surely go in the net.)
0:32:03 > 0:32:05(That's my theory, anyway.)
0:32:17 > 0:32:19Oof!
0:32:19 > 0:32:21Took my head off, that one.
0:32:22 > 0:32:24- There's a few.- That one there.
0:32:24 > 0:32:25There's one there.
0:32:25 > 0:32:28Yeah, and another one flew behind you.
0:32:33 > 0:32:34Is it there?
0:32:34 > 0:32:36Got it.
0:32:38 > 0:32:39Phew.
0:32:39 > 0:32:42These bats carry diseases including rabies.
0:32:42 > 0:32:46George and Marcelo must take care when handling them.
0:32:46 > 0:32:48- Oh! They're very strong, aren't they?- Yeah.
0:32:48 > 0:32:51- You got it?- Yeah.- OK.
0:32:53 > 0:32:55- OK?- Yeah.
0:32:55 > 0:32:59What an absolute beauty. Now...
0:32:59 > 0:33:02- We'll glue it on the back, yeah? About there.- Mm-hm.
0:33:02 > 0:33:04The miniature radio transmitter
0:33:04 > 0:33:06is carefully glued onto the bat's back.
0:33:07 > 0:33:10That's it. Lovely. OK?
0:33:10 > 0:33:12And that should be it.
0:33:13 > 0:33:16George must now track the bat across the island
0:33:16 > 0:33:18before the transmitter drops off.
0:33:20 > 0:33:24This wee chap is the one that hopefully will show us
0:33:24 > 0:33:29where he and his mates are obtaining their evening meal,
0:33:29 > 0:33:32and who from, which is the key thing.
0:33:33 > 0:33:36Is its transmitter working?
0:33:36 > 0:33:39Excellent. Yeah. Very nice.
0:33:43 > 0:33:45'Yeah, I can hear you good...'
0:33:45 > 0:33:50Justine and Rodrigo are on the trail of Bryson's puma.
0:33:57 > 0:34:00I see something coming. It was the puma.
0:34:02 > 0:34:06Incredibly, the puma passes just metres in front of Rodrigo.
0:34:08 > 0:34:11I saw it. I saw it run across the road in front of you.
0:34:11 > 0:34:14That was extreme, actually.
0:34:14 > 0:34:15I'm nervous now. I'm trembling.
0:34:16 > 0:34:18It was really, really near.
0:34:19 > 0:34:22It ran off over the hill. Clearly hunting.
0:34:22 > 0:34:26And then I heard all the guanacos just alarming...
0:34:26 > 0:34:27IMITATES GUANACO
0:34:27 > 0:34:29You could hear them all just going.
0:34:29 > 0:34:32And we can't see the puma now.
0:34:40 > 0:34:42Yeah, you should go very slowly.
0:34:43 > 0:34:45- Maybe we should go round.- Yeah.
0:34:46 > 0:34:48Pumas are ambush predators.
0:34:48 > 0:34:52With proportionally the longest back legs of any big cat...
0:34:54 > 0:34:56..they can leap ten metres through the air...
0:34:57 > 0:35:01..and bring down prey with a single bite to the neck.
0:35:02 > 0:35:04Wow, we are so near.
0:35:07 > 0:35:10There, there, there! There's the puma.
0:35:10 > 0:35:11Turn round, look. Turn round.
0:35:13 > 0:35:15I can see...I saw eye shine just then.
0:35:15 > 0:35:17- Yeah?- Yeah. There.
0:35:17 > 0:35:21By the time they find the puma, it's clear he's been successful.
0:35:21 > 0:35:26I think he might have food in there. He's pulling at something.
0:35:26 > 0:35:28Pretty sure there was a kill here.
0:35:28 > 0:35:30Yeah, he's pulling at something.
0:35:30 > 0:35:32See the head going up and down?
0:35:50 > 0:35:53Wow. This is incredible. Wonderful.
0:35:54 > 0:35:57This is a one-off, unique experience.
0:35:59 > 0:36:01(It's absolutely amazing.)
0:36:01 > 0:36:04(We are right next to a puma on a kill.)
0:36:04 > 0:36:08(Literally...metres away.)
0:36:08 > 0:36:12(We are so close, we can just hear him crunching the bones,)
0:36:12 > 0:36:14(pulling at the meat.)
0:36:16 > 0:36:20He's just completely absorbed in feeding.
0:36:20 > 0:36:22Not bothered about us whatsoever.
0:36:23 > 0:36:27It's only been possible to capture these intimate moments
0:36:27 > 0:36:31of nocturnal behaviour with Justine's specialist cameras.
0:36:34 > 0:36:36He's probably going for a snooze.
0:36:41 > 0:36:43Do you hear those sounds? He's going...
0:36:43 > 0:36:45IMITATES PUMA
0:36:45 > 0:36:47(Calling the mum, calling for his mother.)
0:36:47 > 0:36:50PUMA SQUEAKS
0:36:54 > 0:36:57(Which means we actually should really have a good look round,)
0:36:57 > 0:37:00(because if the mother's turning up, we are in trouble.)
0:37:02 > 0:37:04There, there, there.
0:37:04 > 0:37:08The mother is far larger and more powerful than the juvenile.
0:37:09 > 0:37:12It's time for Justine and Rodrigo to leave.
0:37:16 > 0:37:20To film natural behaviour, Justine needs a safer way to stay on a kill.
0:37:31 > 0:37:34Two thousand miles south, Gordon is making progress.
0:37:34 > 0:37:37He's tracked a humpback whale right into the coastline.
0:37:38 > 0:37:42We've got a whale right here in against the shore.
0:37:44 > 0:37:46I heard a whale blowing right here.
0:37:46 > 0:37:49We've switched off the engine to see if we can hear it.
0:37:52 > 0:37:55Seems a strange place for a whale to be, so close to shore.
0:37:55 > 0:38:00Gordon's hoping to discover why whales come into such shallow water.
0:38:00 > 0:38:01But his hopes are dashed.
0:38:01 > 0:38:03With a humpback so close to the boat,
0:38:03 > 0:38:07it's now too dangerous for him to get in.
0:38:07 > 0:38:12Going in with a 35 tonne animal in there, it's a bit scary.
0:38:12 > 0:38:14It's dealing with a set of circumstances
0:38:14 > 0:38:16it will never have seen before,
0:38:16 > 0:38:18and we just don't know how it's going to react,
0:38:18 > 0:38:20and we can't take that risk.
0:38:22 > 0:38:26Gordon will need to wait until the whale has moved off
0:38:26 > 0:38:29before getting into the water to discover what was attracting it.
0:38:31 > 0:38:33We should hear it blow if it's close.
0:38:34 > 0:38:36Can't see anything.
0:38:38 > 0:38:41I don't think there's anything out there.
0:38:43 > 0:38:46All right, let's do it.
0:38:46 > 0:38:49Finally, the decision to dive is made
0:38:49 > 0:38:50as the whale moves away from the shore.
0:38:50 > 0:38:53We're going to get into the water here.
0:38:53 > 0:38:55There was definitely a whale
0:38:55 > 0:38:59right in the place where we were intending to go.
0:38:59 > 0:39:03We think it's gone. They are an enormously powerful animal.
0:39:03 > 0:39:07If it comes back, I think we just have to get out of the water.
0:39:08 > 0:39:11- Happy for me to get in, Richard? - Yeah, yeah. Good to go.
0:39:11 > 0:39:13Here goes.
0:39:31 > 0:39:32Even with his lights,
0:39:32 > 0:39:36Gordon can only see 10 metres in the gloom.
0:39:36 > 0:39:39It's a claustrophobic and disorientating environment.
0:39:48 > 0:39:52Beneath the surface lies a thick maze of kelp -
0:39:52 > 0:39:56immensely strong strands of seaweed up to 30 metres long.
0:40:01 > 0:40:05The closer to shore, the thicker it becomes.
0:40:10 > 0:40:13Whatever it is that's attracting the whales
0:40:13 > 0:40:16is hidden deep within this impenetrable forest.
0:40:24 > 0:40:27Like tentacles, the weed clings to anything
0:40:27 > 0:40:32it comes into contact with, ensnaring Gordon at every turn.
0:40:46 > 0:40:48He has to abort his dive.
0:40:50 > 0:40:53If Gordon is to solve the whale mystery,
0:40:53 > 0:40:55he must find another way.
0:40:58 > 0:41:01I guessed, when we got into the water at night-time,
0:41:01 > 0:41:04there was going to be some problems that we didn't foresee,
0:41:04 > 0:41:08and the big problem, the insurmountable problem,
0:41:08 > 0:41:10is this kelp.
0:41:10 > 0:41:12It's like Sleeping Beauty's forest.
0:41:12 > 0:41:14You can't get through it.
0:41:14 > 0:41:16It's impossible.
0:41:16 > 0:41:18You just get tangled up in it.
0:41:18 > 0:41:19Yeah.
0:41:20 > 0:41:22Far from a result.
0:41:41 > 0:41:44With two days left in the Andes,
0:41:44 > 0:41:47Justine still wants to spend more time with a puma.
0:41:47 > 0:41:51Her best chance is to stake out a kill.
0:41:51 > 0:41:54Condors circling high overhead are a hopeful sign.
0:42:00 > 0:42:04We've been seeing lots of condors flying, circling,
0:42:04 > 0:42:06just over the brow of this hill,
0:42:06 > 0:42:09and that can only mean one thing, that there's a puma kill around.
0:42:10 > 0:42:15If Justine is right, then the puma will be resting up nearby,
0:42:15 > 0:42:18waiting to return after dark.
0:42:18 > 0:42:22This is just going to be fantastic. This is what I've been waiting for.
0:42:22 > 0:42:25I can stake it out, I can get the hide in,
0:42:25 > 0:42:28the camera on the tripod, and just sit quietly
0:42:28 > 0:42:31and hopefully observe some behaviour.
0:42:31 > 0:42:33So far we've been driving around on the tracks
0:42:33 > 0:42:36and that's been very productive for actually sighting pumas.
0:42:36 > 0:42:38But I want to see some behaviour now.
0:42:38 > 0:42:41And I want to get to know the personality of this puma.
0:42:45 > 0:42:46In the next valley,
0:42:46 > 0:42:50Justine discovers the fresh remains of a juvenile guanaco.
0:42:53 > 0:42:54Look at that.
0:42:56 > 0:42:58That's a really fresh kill.
0:42:59 > 0:43:02You can see where it's been bitten into around the neck,
0:43:02 > 0:43:03just beneath the jaw.
0:43:05 > 0:43:07It's opened up the guts,
0:43:07 > 0:43:11but nothing's been taken from the legs or the chest.
0:43:11 > 0:43:14I mean, most of the meat's still left on it.
0:43:15 > 0:43:18So this cat's going to want to come back here.
0:43:22 > 0:43:23Moving back to higher ground,
0:43:23 > 0:43:26Justine prepares for the puma's return.
0:43:28 > 0:43:32I mean, it's essential that I'm here and ready before it gets dark,
0:43:32 > 0:43:34cos that's when the puma's going to be on the move,
0:43:34 > 0:43:38so I've got this rather alarming pop-up hide.
0:43:38 > 0:43:40This is going to be it.
0:43:40 > 0:43:43This is going to be home for the next 12, 14 hours.
0:43:44 > 0:43:46I just have to have a bit of luck now.
0:43:51 > 0:43:55Justine has filmed big cats in the wild for over 20 years,
0:43:55 > 0:43:57but has only captured glimpses of pumas.
0:43:59 > 0:44:01Now, for the first time,
0:44:01 > 0:44:05she is hoping to spend the whole night with this elusive cat -
0:44:05 > 0:44:09documenting its natural behaviour around a kill.
0:44:10 > 0:44:13Just changed from the daytime camera to the night-time camera.
0:44:13 > 0:44:16And there's a puma out there.
0:44:19 > 0:44:22Wow. It's right on the kill.
0:44:22 > 0:44:26Already. It just goes to show, doesn't it,
0:44:26 > 0:44:30that the moment it started getting dark, there came the puma.
0:44:32 > 0:44:35It's starting to feed. Excellent.
0:44:37 > 0:44:39I can see that he's a male.
0:44:39 > 0:44:43So strong, the way he's just pulling at that guanaco.
0:45:02 > 0:45:06He's walking away. Ah, there he is. He's lying down.
0:45:07 > 0:45:10And this is beautiful, to see this puma just feeding.
0:45:10 > 0:45:12And now he's just cleaning himself.
0:45:15 > 0:45:18It's amazing just seeing this behaviour.
0:45:20 > 0:45:22This is everything Justine hoped for.
0:45:22 > 0:45:25She will keep watch all night,
0:45:25 > 0:45:28her camera ready to capture footage never seen before.
0:45:36 > 0:45:40Back off the coast of the Atacama desert,
0:45:40 > 0:45:43the vampire bats have left their roost to begin a night of feeding.
0:45:45 > 0:45:49It seemed to me that the bats, when they left the cave,
0:45:49 > 0:45:54turned left, so we're now heading along the island in that direction,
0:45:54 > 0:45:58so if my hunch is right, they should be over here.
0:45:59 > 0:46:02Using the VHF receiver,
0:46:02 > 0:46:05George and Marcelo hope to track the bats to their victim.
0:46:05 > 0:46:08- Got it.- Have I heard something? - Yeah.
0:46:08 > 0:46:09Yeah? There, there.
0:46:09 > 0:46:11Very faint.
0:46:11 > 0:46:15Marcelo has identified the signal coming from George's tagged bat.
0:46:15 > 0:46:18At first it was very faint,
0:46:18 > 0:46:23but it's a lot stronger now, a "beep...beep...beep".
0:46:23 > 0:46:26And as long as you follow the bleep,
0:46:26 > 0:46:30then you'll end up hopefully right at the bat.
0:46:31 > 0:46:34Following the signal for over a mile,
0:46:34 > 0:46:36George is getting closer to discovering
0:46:36 > 0:46:39where the bats are going to feed, and on what.
0:46:42 > 0:46:45That's very strong now.
0:46:45 > 0:46:47HONKING
0:46:47 > 0:46:49Sea lions. I can hear them.
0:46:51 > 0:46:52I can hear them. Look.
0:46:58 > 0:47:01We may be one step closer to solving the mystery.
0:47:04 > 0:47:08Sea lions are a perfect food source for vampire bats.
0:47:08 > 0:47:12Now George must get close enough to the colony to see them in action.
0:47:25 > 0:47:29Further south, Gordon is getting closer to solving
0:47:29 > 0:47:33the puzzle of why the humpbacks are coming so close to shore.
0:47:37 > 0:47:39I thought I heard something back that way.
0:47:42 > 0:47:44There's a humpback fairly close by.
0:47:44 > 0:47:48I can't see it yet. I just heard it breathing.
0:47:50 > 0:47:52Right here, look - whale here.
0:47:52 > 0:47:54Oh, you can see his pectoral.
0:47:56 > 0:47:58He's going to come up again.
0:47:58 > 0:48:02Got a humpback whale just in front of us, less than 25 metres away.
0:48:03 > 0:48:06The whale is deep inside the kelp forest
0:48:06 > 0:48:07that entangled Gordon earlier.
0:48:07 > 0:48:10The camera reveals that despite the current,
0:48:10 > 0:48:13the whale is not moving.
0:48:13 > 0:48:17It can't be feeding. The kelp is too dense.
0:48:17 > 0:48:20But the whale has deliberately chosen to be here -
0:48:20 > 0:48:23and Gordon has a theory why.
0:48:23 > 0:48:27What could be happening is that the humpback whales in this area
0:48:27 > 0:48:30go into the kelp to rest.
0:48:30 > 0:48:34Imagine the effort constantly trying to deal with these currents.
0:48:34 > 0:48:36To save that effort,
0:48:36 > 0:48:40they go in towards the shore and wrap themselves up in the kelp.
0:48:43 > 0:48:45Humpbacks are active day and night,
0:48:45 > 0:48:49expending vast amounts of energy, so they need to sleep.
0:48:49 > 0:48:52But for all whales, sleep is a challenge.
0:48:56 > 0:48:58Humpback whales never truly sleep,
0:48:58 > 0:49:02they shut down one half of their brain at a time.
0:49:02 > 0:49:06For a humpback whale, breathing is a conscious effort.
0:49:06 > 0:49:09They have to think about every single breath.
0:49:09 > 0:49:12For us, it's an automatic response.
0:49:12 > 0:49:14Hear that big puff?
0:49:14 > 0:49:17That humpback is saying, "I have to breathe now,"
0:49:17 > 0:49:20so they can't afford to go to sleep entirely.
0:49:20 > 0:49:24They close down one half of their brain, rest that half,
0:49:24 > 0:49:27wake up that half, shut down the other side,
0:49:27 > 0:49:29and that way they get a full night's sleep.
0:49:32 > 0:49:33(Oh, wow!)
0:49:35 > 0:49:36Holy schmoly. Look at that.
0:49:36 > 0:49:40Whoa, whoa, whoa! Incredible.
0:49:40 > 0:49:44By wrapping themselves in the kelp, this pod has found
0:49:44 > 0:49:48an ingenious way of conserving energy while they sleep.
0:49:53 > 0:49:56I think to be this close to a humpback whale
0:49:56 > 0:49:58takes your breath away.
0:49:58 > 0:50:02There are few animals on this planet
0:50:02 > 0:50:06that are as impressive as the humpback whale.
0:50:07 > 0:50:11Gordon's night vision camera has finally been able to reveal
0:50:11 > 0:50:14what these whales are doing so close to shore.
0:50:24 > 0:50:29In the Andes, Justine has been watching the puma for six hours.
0:50:29 > 0:50:33Most night-time encounters with these predators are fleeting.
0:50:33 > 0:50:36She's lucky to immerse herself in this cat's world.
0:50:38 > 0:50:41It's just wonderful using this camera.
0:50:41 > 0:50:45I've no lights on, just sitting here in the dark,
0:50:45 > 0:50:47so it's not disruptive at all.
0:50:48 > 0:50:50I think I'm really going to see exactly
0:50:50 > 0:50:53what he wants to get up to with his kill.
0:50:55 > 0:50:57But for now, he's just having a snooze.
0:51:00 > 0:51:03Big cats spend much of their time sleeping.
0:51:03 > 0:51:08The puma only stirs as a storm front begins to move across the valley.
0:51:09 > 0:51:12It's gusting at extreme speeds
0:51:12 > 0:51:15and I'm not sure whether this hide is just going to blow over.
0:51:16 > 0:51:18Oh, my God.
0:51:21 > 0:51:23I swear the tent's going to fall in.
0:51:26 > 0:51:29Puma's got up - what's he doing?
0:51:31 > 0:51:35Can't be hunting. He's still got a good kill there.
0:51:35 > 0:51:37Oh, he's chasing something.
0:51:39 > 0:51:41Probably just trying to keep warm.
0:51:41 > 0:51:42That's great.
0:51:49 > 0:51:53For all cats, domestic or wild, play is a serious business.
0:51:53 > 0:51:56Strong winds and a clump of dry grass
0:51:56 > 0:52:00give the puma a chance to hone his hunting skills.
0:52:07 > 0:52:10He's playing with it. Just biffing it.
0:52:27 > 0:52:30It's so funny. He just looks like a domestic cat.
0:52:32 > 0:52:34It's like a secret little view on his life.
0:52:37 > 0:52:38I guess if he does this,
0:52:38 > 0:52:42sits here by the kill, just cleaning himself and sleeping,
0:52:42 > 0:52:44nothing else can come in.
0:52:45 > 0:52:48He's dominating it all night long.
0:52:54 > 0:52:56This is the sort of amazing behaviour
0:52:56 > 0:52:58that I just wanted to see.
0:52:58 > 0:53:01Just the cat alone,
0:53:01 > 0:53:04blissfully unaware of it being filmed.
0:53:04 > 0:53:06Doing what it does in the night.
0:53:08 > 0:53:12I just really feel I'm seeing the true side of the puma.
0:53:12 > 0:53:14Oh, it's wonderful.
0:53:16 > 0:53:20It's the perfect end to Justine's expedition.
0:53:20 > 0:53:23She's seen pumas hunting, feeding and playing -
0:53:23 > 0:53:26capturing unique footage of these beautiful animals
0:53:26 > 0:53:28and their nocturnal lives.
0:53:31 > 0:53:34In the Atacama desert, George has called in
0:53:34 > 0:53:37wildlife camerawoman Sophie Darlington.
0:53:37 > 0:53:41Her thermal camera will be able to capture the vampire bats feeding.
0:53:41 > 0:53:44What we need to do to nail it is see them feeding.
0:53:44 > 0:53:47- That would be extraordinary. - That's it.
0:53:47 > 0:53:50George has tracked them to a sea lion colony
0:53:50 > 0:53:51on the far side of the island.
0:53:52 > 0:53:56It could be a perfect source of blood for the bats.
0:53:56 > 0:53:58We're coming down here. Some bats would be awesome.
0:53:58 > 0:54:00That would be incredible.
0:54:00 > 0:54:03Sophie's night vision cameras should provide the answer.
0:54:04 > 0:54:07(Well, we're just waiting for the bats to arrive.)
0:54:07 > 0:54:09(We're almost set up now,)
0:54:09 > 0:54:11(so any minute now...)
0:54:14 > 0:54:16(..the vampires will be flying.)
0:54:18 > 0:54:20Soon after George and Sophie arrive,
0:54:20 > 0:54:22so do the bats, flitting close to them,
0:54:22 > 0:54:24attracted by their body heat.
0:54:24 > 0:54:26What have you got? Let's see.
0:54:26 > 0:54:27(OK.)
0:54:27 > 0:54:29There's a big bull,
0:54:29 > 0:54:33and there's been a bat flying around completely harassing him.
0:54:33 > 0:54:35Oh, yeah, I can see. Yeah, yeah.
0:54:35 > 0:54:37There's two of them now.
0:54:37 > 0:54:40Three! There's three of them.
0:54:43 > 0:54:44That was a bite.
0:54:44 > 0:54:46This is unbelievable. Look at it!
0:54:46 > 0:54:48- I knew it was there. - And there's one at the back.
0:54:48 > 0:54:51- There's more than one. - The bats are all over them.
0:54:53 > 0:54:54They're following it, look.
0:54:54 > 0:54:56There's a vampire bat...look!
0:54:56 > 0:54:58It's just following it up behind it.
0:55:00 > 0:55:02It's right on the back!
0:55:02 > 0:55:04That's just unbelievable.
0:55:06 > 0:55:09So they are feeding on sea lions.
0:55:11 > 0:55:13The bats employ a clever strategy
0:55:13 > 0:55:16when attempting to feed on an animal many times their size.
0:55:17 > 0:55:21They land close by and creep towards an area of flesh
0:55:21 > 0:55:23the creature will struggle to defend.
0:55:28 > 0:55:31They're attacking from the rear,
0:55:31 > 0:55:33and the sea lions know they're there,
0:55:33 > 0:55:35and they keep turning their heads up,
0:55:35 > 0:55:37and as the sea lion moves, they just keep following it.
0:55:37 > 0:55:40And the poor sea lions are being harassed.
0:55:40 > 0:55:42I mean, they really are aware of that.
0:55:42 > 0:55:43Look at him hopping, George.
0:55:43 > 0:55:49It dispels the myth of animals having a quiet sleep at night.
0:55:49 > 0:55:53They're not. It's torment! It's absolute torment.
0:55:53 > 0:55:57They must be exhausted in the morning.
0:55:57 > 0:55:59These bats, they're completely and utterly just going for it.
0:56:01 > 0:56:03Oh! Oh! Wow!
0:56:03 > 0:56:05One's just been hit by that wave.
0:56:07 > 0:56:08I just can't believe what I'm seeing.
0:56:10 > 0:56:15Weighing 40 grams, each bat can consume half its own body weight
0:56:15 > 0:56:19of blood in a single feed, lasting up to 20 minutes.
0:56:19 > 0:56:22Is that a hotspot there? Is that the hotspot?
0:56:22 > 0:56:24We can see the wound.
0:56:24 > 0:56:25Good grief!
0:56:27 > 0:56:29We can see the wound on the flipper.
0:56:32 > 0:56:36Only the thermal camera can reveal this extraordinary behaviour.
0:56:36 > 0:56:39The bats are going in to the rear end because that's where it's hottest
0:56:39 > 0:56:42and you can really see that on the thermal camera. They're very bright,
0:56:42 > 0:56:45which means the blood's very close to the surface,
0:56:45 > 0:56:48so easy access for the bats. An easy meal, I'd reckon.
0:56:48 > 0:56:51To see the wound, the heat signature of the wound
0:56:51 > 0:56:55left by a vampire bat on the flipper of a sea lion,
0:56:55 > 0:56:57in pitch darkness...
0:56:57 > 0:56:59That is just...
0:57:00 > 0:57:01That is truly awesome.
0:57:04 > 0:57:07It is the last of the team's mysteries solved.
0:57:07 > 0:57:09Now we know what's happening.
0:57:09 > 0:57:12That's why there's a permanent colony of vampire bats here,
0:57:12 > 0:57:15because there's a permanent colony of big, fat,
0:57:15 > 0:57:19blood-filled food bags for them.
0:57:21 > 0:57:23SEA LION HONKS
0:57:29 > 0:57:32It's the end of an incredible six months.
0:57:32 > 0:57:35The team have pushed themselves to the limit
0:57:35 > 0:57:38to capture unique footage of South America's nocturnal wildlife.
0:57:38 > 0:57:40We've seen new species.
0:57:40 > 0:57:45We've seen behaviours that haven't been seen by anybody before.
0:57:45 > 0:57:47Yes! Got it. Look at that.
0:57:47 > 0:57:49Using cutting edge technology,
0:57:49 > 0:57:53they have uncovered natural behaviour never seen before.
0:57:53 > 0:57:54That's fantastic.
0:57:54 > 0:57:58There's a whole night shift of animals going about their business,
0:57:58 > 0:58:00doing things that we just never see.
0:58:00 > 0:58:02(Wow. She's hunting.)
0:58:02 > 0:58:06They have witnessed dramas unfolding in total darkness...
0:58:06 > 0:58:07(That's incredible.)
0:58:07 > 0:58:14..and started to unlock the secrets of a hidden and mysterious world.
0:58:14 > 0:58:20Daytime is a practical desert when it comes to animal activity.
0:58:20 > 0:58:23And I suppose we're just beginning to scratch the surface
0:58:23 > 0:58:26with new technology to reveal a little bit
0:58:26 > 0:58:28of what goes on when it's dark.
0:58:51 > 0:58:54Subtitles by Red Bee Media Ltd