0:00:13 > 0:00:16It's one of the world's most appealing creatures...
0:00:18 > 0:00:20..and one of its most mysterious.
0:00:23 > 0:00:27There are around 350 pygmy hippos living in zoos,
0:00:27 > 0:00:31but in the wild, they are endangered and notoriously hard to find.
0:00:35 > 0:00:40Now, a young ecologist is taking on what might be mission impossible...
0:00:42 > 0:00:45..to unravel the secrets of an animal few have ever seen
0:00:45 > 0:00:47and about which we know so little.
0:00:50 > 0:00:55She'll spend months deep in a remote West African rainforest...
0:00:55 > 0:00:58facing its many hazards,
0:00:58 > 0:01:02as she attempts to get a glimpse of its elusive behaviour,
0:01:02 > 0:01:06understand how it uses its forest home,
0:01:06 > 0:01:07so that ultimately,
0:01:07 > 0:01:12conservationists can work out what the pygmy hippo needs to survive.
0:01:12 > 0:01:14- THEY GASP - Oh, my God!
0:01:24 > 0:01:26Meet Gloria.
0:01:26 > 0:01:30She's a three-month-old baby pygmy hippo.
0:01:30 > 0:01:35Gloria likes messing around, exploring and taking a nap.
0:01:38 > 0:01:40She lives with her mum, Wendy, in Marwell Zoo.
0:01:42 > 0:01:45But for wild pygmy hippos, life is not so rosy.
0:01:47 > 0:01:50Their forest home is disappearing at an alarming rate
0:01:50 > 0:01:53and at the moment, all we really know about them
0:01:53 > 0:01:56is what we know from captive hippos, like Gloria and Wendy.
0:01:59 > 0:02:04Australian Wei-Yeen Yap is a vet, a wildlife ecologist
0:02:04 > 0:02:06and passionate about pygmy hippos.
0:02:06 > 0:02:08They're just so gorgeous.
0:02:08 > 0:02:10How can you not fall in love with this?
0:02:13 > 0:02:16The hippos' secretive and reclusive behaviour in the wild
0:02:16 > 0:02:19makes them hard, if not impossible, to study.
0:02:19 > 0:02:21But the clock is ticking
0:02:21 > 0:02:25and Wei knows scientists must find out much more about them
0:02:25 > 0:02:26before it's too late.
0:02:26 > 0:02:29If we want to try and attempt to save them,
0:02:29 > 0:02:32then we have to know how they function
0:02:32 > 0:02:34and what they need to survive,
0:02:34 > 0:02:36in order to come up with some kind of plan.
0:02:39 > 0:02:43Pygmy hippos are on the internationally recognised Red List,
0:02:43 > 0:02:46with officially just 2,000 to 3,000 left.
0:02:46 > 0:02:50Living in a region of West Africa recently blighted by civil unrest,
0:02:50 > 0:02:52their numbers could be much lower.
0:02:57 > 0:03:00Today, pygmy hippos are found in just a few isolated pockets
0:03:00 > 0:03:03of what's left of the Upper Guinea forest.
0:03:05 > 0:03:08The largest surviving protected population
0:03:08 > 0:03:11is in Cote d'Ivoire, in the Tai National Park.
0:03:14 > 0:03:19Wei has experience of studying hard-to-find rainforest animals.
0:03:19 > 0:03:22Now, she's joined forces with local conservationists
0:03:22 > 0:03:24in an international effort to help solve
0:03:24 > 0:03:28one of the natural world's last great mysteries.
0:03:28 > 0:03:31Amazingly enough, there are some animals left in the world nowadays
0:03:31 > 0:03:34that we still don't know almost anything about
0:03:34 > 0:03:36and the pygmy hippo is one of them.
0:03:36 > 0:03:38Leading the Tai Hippo Project
0:03:38 > 0:03:40are Professor Inza Kone
0:03:40 > 0:03:42and Dr Karim Ouattara.
0:03:44 > 0:03:48It is very, very difficult to see the pygmy hippo...
0:03:48 > 0:03:50These animals are nocturnal,
0:03:50 > 0:03:56very lazy, very cryptic, so very difficult to follow and study.
0:03:56 > 0:04:02I think this is one of the challenge that Wei-Yeen will face.
0:04:04 > 0:04:07Research assistants Donatien Bele...
0:04:07 > 0:04:10and Leon Sio Toh...
0:04:10 > 0:04:13have 18 years' forest experience between them,
0:04:13 > 0:04:16but even they have only glimpsed a pygmy hippo.
0:04:17 > 0:04:20Everything with this animal is hard.
0:04:20 > 0:04:23It makes every little thing that we do manage to achieve
0:04:23 > 0:04:24really, really exciting.
0:04:28 > 0:04:31Wei's new home will be a dilapidated research station
0:04:31 > 0:04:34in the remote forest, five hours from the nearest big town.
0:04:36 > 0:04:40Building a case file on this notoriously difficult animal
0:04:40 > 0:04:43will be anything but easy.
0:04:43 > 0:04:45The pressure is on.
0:04:58 > 0:05:01Understanding more about the pygmy hippo's very secret life
0:05:01 > 0:05:03is the first step to being able to protect
0:05:03 > 0:05:05its long-term future in the wild.
0:05:06 > 0:05:09The big thing for us is to just start really simple
0:05:09 > 0:05:13and just start with getting a really basic, clear, simple idea
0:05:13 > 0:05:17of what pygmy hippo behaviour and ecology and density is,
0:05:17 > 0:05:20and what is really important to their survival.
0:05:21 > 0:05:24The enormity of this mission impossible task
0:05:24 > 0:05:26is starting to dawn on Wei,
0:05:26 > 0:05:31as she spends the first two months looking for clues.
0:05:31 > 0:05:33The water's really high at the moment,
0:05:33 > 0:05:37but we found fresh tracks all along this little exit-entry point.
0:05:37 > 0:05:40So, I've just come back to check it out again.
0:05:40 > 0:05:43It's a really perfect area for the hippos.
0:05:43 > 0:05:44You can see the river's deep enough
0:05:44 > 0:05:46that he can get fully submerged in here.
0:05:49 > 0:05:53Pygmy hippos can be just a tenth of the size of the common hippo.
0:05:54 > 0:05:57Both are amphibious, but unlike their larger cousins,
0:05:57 > 0:06:01pygmy hippos are thought to lead a solitary life -
0:06:01 > 0:06:03adults only meet to mate.
0:06:09 > 0:06:11To add to Wei's challenge,
0:06:11 > 0:06:16they are believed to hide in water by day and are most active at night.
0:06:16 > 0:06:18We've got a print here,
0:06:18 > 0:06:21which you can see the two main big phalanges
0:06:21 > 0:06:25and then the two little residual ones.
0:06:25 > 0:06:27And then further up here,
0:06:27 > 0:06:31we can see he's exited out of this river bank here
0:06:31 > 0:06:32and it's not that great
0:06:32 > 0:06:34but you can see his two phalanges again, here,
0:06:34 > 0:06:36as he's made his way up.
0:06:38 > 0:06:39I'm looking in certain places.
0:06:39 > 0:06:41I'm trying to think like a pygmy hippo
0:06:41 > 0:06:43and it seems, at the moment, to be working.
0:06:48 > 0:06:49The Tai National Park
0:06:49 > 0:06:52is the largest protected tranche of primary rainforest
0:06:52 > 0:06:54left in West Africa.
0:06:55 > 0:06:57It's home not just to the pygmy hippo,
0:06:57 > 0:06:59but to many other rare animals.
0:07:02 > 0:07:05With a staggering 140 species of mammal alone,
0:07:05 > 0:07:08the park's amazing array of flora and fauna
0:07:08 > 0:07:11has earned its World Heritage Site status.
0:07:17 > 0:07:19There are 12 different primates,
0:07:19 > 0:07:23including the vulnerable Diana monkey.
0:07:25 > 0:07:26But illegal poaching
0:07:26 > 0:07:30and gold mining is increasing the pressure on the park's wildlife.
0:07:33 > 0:07:34Cote d'Ivoire already has
0:07:34 > 0:07:37one of the highest deforestation rates in the world.
0:07:39 > 0:07:44It's lost almost 70% of its original forest cover in just 50 years.
0:07:46 > 0:07:51If you look at the original home range of pygmy hippos
0:07:51 > 0:07:54in Cote d'Ivoire, we see that most forest areas
0:07:54 > 0:08:00have just been destroyed, converted to industrial plantations.
0:08:00 > 0:08:05And when plantations are so close to the forest, this is a direct threat.
0:08:07 > 0:08:11Deforestation, plus cocoa, coffee and rubber plantations
0:08:11 > 0:08:13continue to threaten forests like Tai,
0:08:13 > 0:08:16one of the last strongholds of the pygmy hippo.
0:08:21 > 0:08:26Wei is thrilled to find what she thinks are fresh pygmy hippo tracks,
0:08:26 > 0:08:29but catching sight of who made them will be a much bigger challenge.
0:08:34 > 0:08:37Wei and the team have set up remote cameras with night vision.
0:08:40 > 0:08:43She's checking what they've captured.
0:08:44 > 0:08:48It's a fascinating home movie of the inhabitants of the Tai Forest.
0:08:51 > 0:08:53There is an African civet...
0:08:55 > 0:08:56..a water chevrotain...
0:08:58 > 0:09:00..white-breasted guineafowl...
0:09:02 > 0:09:04..and a particularly nosey sooty mangabey.
0:09:07 > 0:09:11The largest of the eight species of forest antelopes called duikers
0:09:11 > 0:09:13is the Jentink's duiker,
0:09:13 > 0:09:16endangered and nocturnal, just like the pygmy hippo.
0:09:17 > 0:09:23They tend to seem to come around the same areas as the pygmy hippos a lot,
0:09:23 > 0:09:25so where we have confirmed presence of a pygmy hippo,
0:09:25 > 0:09:30we seem to get confirmed presence of Jentink's in the same area, as well.
0:09:30 > 0:09:32We've got some leopards.
0:09:32 > 0:09:36We've got this beautiful shot of a really healthy,
0:09:36 > 0:09:40really gorgeous male, because you can see his back end.
0:09:40 > 0:09:43Leopard...
0:09:43 > 0:09:46Then...the animal Wei came to see.
0:09:46 > 0:09:49So that's...amazing.
0:09:49 > 0:09:53We've got this beautiful picture of a really quite large,
0:09:53 > 0:09:55male pygmy hippo.
0:09:55 > 0:10:00And you can see him here coming and actually sniffing the path
0:10:00 > 0:10:02and kind of going, "Well, that smells like humans,
0:10:02 > 0:10:05"I don't think I'll go down there today."
0:10:05 > 0:10:08And he gives it a really, really good sniff,
0:10:08 > 0:10:12hangs around for a quite few seconds and then decides to keep moving on.
0:10:14 > 0:10:17Footage of wild pygmy hippos is exceptionally rare.
0:10:19 > 0:10:23Now Wei knows where this male hippo is active, she hopes he'll be back.
0:10:24 > 0:10:28That's our first confirmation so we'll put something up there
0:10:28 > 0:10:31and hopefully manage to study him way more.
0:10:32 > 0:10:37In 2010, a hippo with a distinctive notch in its left ear
0:10:37 > 0:10:39was caught on a project camera
0:10:39 > 0:10:42but Wei doesn't think it's the same hippo.
0:10:42 > 0:10:46But such a distinguishing feature could help identify it...
0:10:46 > 0:10:47if it's still here.
0:10:54 > 0:10:58The team throws up a web of 12 cameras around the target area.
0:11:03 > 0:11:06Almost anything that Wei can learn from observing the pygmy hippos
0:11:06 > 0:11:08will help her build a case file.
0:11:10 > 0:11:13But Wei's ultimate goal is more ambitious.
0:11:13 > 0:11:18She hopes to physically capture a pygmy hippo and attach a GPS collar,
0:11:18 > 0:11:23which will remotely store, then send her, a comprehensive data bank
0:11:23 > 0:11:26on what the hippo's been doing, where he's been going
0:11:26 > 0:11:28and when this all happens.
0:11:30 > 0:11:32This could be ground-breaking new science.
0:11:35 > 0:11:38To test that the radio telemetry system is working,
0:11:38 > 0:11:42she's heading 20m up into the canopy, where the signal should be clearest.
0:11:56 > 0:11:58Hi, Bogui? I'm not getting any signal.
0:11:58 > 0:12:01'Just keep walking unless you hear that I have a signal.
0:12:01 > 0:12:05- 'I'll let you know.'- OK, thanks.
0:12:05 > 0:12:11Ivorian PhD student Elie Bogui is the man on the ground with the collar.
0:12:11 > 0:12:14Hi, Bogui? I've got a pretty weak signal...
0:12:14 > 0:12:18'So, if we mark that, that's our distance.'
0:12:18 > 0:12:19OK.
0:12:19 > 0:12:21With the collar working correctly,
0:12:21 > 0:12:25there's time to appreciate the new perspective.
0:12:25 > 0:12:27Once you've been working in the jungle for a while,
0:12:27 > 0:12:31you get really stuck visually with just not seeing any horizon
0:12:31 > 0:12:33and feeing really enclosed all the time.
0:12:33 > 0:12:36It's actually a really big deal, psychologically.
0:12:36 > 0:12:39It kind of makes you realise a whole different parallel universe
0:12:39 > 0:12:40existing in the forest.
0:12:43 > 0:12:45I think when I was coming up,
0:12:45 > 0:12:48I disturbed a little group of pied colobus over there.
0:12:48 > 0:12:52They seemed to be pretty curious and pretty freaked out by a big primate
0:12:52 > 0:12:54climbing one of their trees.
0:12:55 > 0:12:57So, they're staying a lot less conspicuous now,
0:12:57 > 0:13:01which is interesting cos there was some red colobus
0:13:01 > 0:13:03over in that clearing, over there.
0:13:03 > 0:13:05They didn't seem bothered at all.
0:13:07 > 0:13:10Up here, it's perfect hornbill height.
0:13:10 > 0:13:12There's hornbills and instead of seeing them
0:13:12 > 0:13:14flitting over a clearing for half a second,
0:13:14 > 0:13:18you get to actually see them moving from tree to tree.
0:13:18 > 0:13:23And somewhere, deep below the forest canopy, are pygmy hippos.
0:13:28 > 0:13:30In order to collar a hippo,
0:13:30 > 0:13:33first, she'll have to catch one.
0:13:33 > 0:13:36It won't be easy, but Wei is undeterred.
0:13:36 > 0:13:38- FRENCH:- Pardon.
0:13:40 > 0:13:44She and the team are building a series of humane traps
0:13:44 > 0:13:45close to the hippo's trail.
0:13:55 > 0:13:59Wei is throwing herself into the task.
0:13:59 > 0:14:01TRANSLATION FROM FRENCH:
0:14:17 > 0:14:21Wei isn't afraid of a challenge - she even tried to learn French
0:14:21 > 0:14:23just for this mission.
0:14:23 > 0:14:24..et la porte...
0:14:35 > 0:14:37..a crossbeam, pour ca...
0:14:37 > 0:14:40'No-one speaks any English.
0:14:40 > 0:14:44'I took to learning French as quickly as possible.
0:14:44 > 0:14:47'I'm probably saying completely ridiculous things a lot of the time.'
0:15:06 > 0:15:1013 weeks into the mission, stage one of the plan is complete.
0:15:12 > 0:15:15There are four traps built and ready for action.
0:15:19 > 0:15:22Then disaster strikes.
0:15:26 > 0:15:29Wei falls ill. It looks like malaria...
0:15:30 > 0:15:32..a potentially fatal disease.
0:15:34 > 0:15:37Despite drug treatment, she isn't getting any better...
0:15:37 > 0:15:43and the nearest big hospital is an 11-hour drive away.
0:15:43 > 0:15:46I'm probably going to have to get some tests run
0:15:46 > 0:15:51and just make sure there's nothing else going on, which really sucks,
0:15:51 > 0:15:54because the traps are built and ready to go,
0:15:54 > 0:15:58our trapping date's set for the next few days and...
0:15:58 > 0:16:01it's all a real big bummer.
0:16:03 > 0:16:06Wei is finally persuaded to go to hospital,
0:16:06 > 0:16:10where it's confirmed she has both malaria and a stomach bug.
0:16:16 > 0:16:18She's hospitalised for several days,
0:16:18 > 0:16:20by which time the capture team has arrived,
0:16:20 > 0:16:22but is now behind schedule.
0:16:25 > 0:16:28Veterinary anaesthetist Dr Tim Bouts
0:16:28 > 0:16:31and postgraduate student Gabriella Flacke are now eager to get started.
0:16:33 > 0:16:36This is ketamine, which goes here. The ketamine...
0:16:36 > 0:16:38It's nearly 30 years since anyone attempted
0:16:38 > 0:16:42to anaesthetise wild pygmy hippos.
0:16:42 > 0:16:44Your dose for Medetomidine?
0:16:44 > 0:16:4720mg, and 300...
0:16:47 > 0:16:50Tim is experienced in captive pygmy hippo sedation
0:16:50 > 0:16:54but he knows that this part of the capture process is the most risky.
0:16:56 > 0:16:58If you speak with someone in Ivory Coast,
0:16:58 > 0:17:01they said last time it happened, all the pygmy hippos died.
0:17:01 > 0:17:02I am sure it wasn't like that,
0:17:02 > 0:17:05but this is the general feeling here on Ivory Coast.
0:17:05 > 0:17:07So, the fact that they allowed to do this
0:17:07 > 0:17:09was a big step for the Ivorians.
0:17:09 > 0:17:12Always test it on yourself first.
0:17:12 > 0:17:13And this one then fits,
0:17:13 > 0:17:16if you really have to breathe for the animal.
0:17:16 > 0:17:17That fits at the back...
0:17:17 > 0:17:20We are well prepared, we can do everything here.
0:17:20 > 0:17:22We've got emergency drugs if something goes wrong.
0:17:22 > 0:17:25It's always in the back of our mind but we shouldn't shy away of it,
0:17:25 > 0:17:31because the possible benefits of this project are just immense.
0:17:31 > 0:17:35Sedation is the only way to get a GPS collar onto a pygmy hippo.
0:17:45 > 0:17:47With Wei back on her feet,
0:17:47 > 0:17:51the unexpected delay means they now have only eight days to catch
0:17:51 > 0:17:54one of the world's most elusive animals...
0:17:56 > 0:17:57..and the clock is ticking.
0:17:59 > 0:18:00The door only comes up to this high
0:18:00 > 0:18:03so you can actually shoot straight through this.
0:18:03 > 0:18:04That would be fantastic.
0:18:04 > 0:18:07And it's easy enough to have someone else distract him on the other side.
0:18:07 > 0:18:10Yeah, we'll need to have probably two people to distract
0:18:10 > 0:18:13- and then hope that I don't shoot the person on the other side.- Yeah.
0:18:13 > 0:18:15You wedge it against this side and...
0:18:15 > 0:18:17It's the first chance to check the traps are still working
0:18:17 > 0:18:19since Wei was sick.
0:18:19 > 0:18:22It's just this trap that's really, really fiddly,
0:18:22 > 0:18:23cos it was the first trigger we built.
0:18:23 > 0:18:26This trap, unfortunately our first trap, was real trial and error
0:18:26 > 0:18:30so it's not the nicest and smoothest mechanism.
0:18:30 > 0:18:32There are lots of parts where things can break,
0:18:32 > 0:18:34just purely because they've been weathered.
0:18:34 > 0:18:39It's a huge thing to have a trap not work if a hippo walks through it.
0:18:39 > 0:18:42And there's no way they'll walk through it again, ever.
0:18:42 > 0:18:43A bit more.
0:18:45 > 0:18:46Merci.
0:18:50 > 0:18:53- Do you guys want to see this working?- Yes, please.
0:18:53 > 0:18:56OK, who wants to be the hippo?
0:18:56 > 0:18:58- Tim? - TIM LAUGHS
0:18:58 > 0:19:01OK, I look most like it!
0:19:01 > 0:19:03Ce pas necessaire.
0:19:03 > 0:19:04OK?
0:19:07 > 0:19:09Be careful. Be really careful.
0:19:09 > 0:19:11So I just walk through it now?
0:19:11 > 0:19:12Yeah.
0:19:16 > 0:19:18Voila! Voila!
0:19:18 > 0:19:20- That was quick!- OK.
0:19:20 > 0:19:22HE SPEAKS FRENCH
0:19:22 > 0:19:25It's a relief, but Karim knows that the pygmy hippo
0:19:25 > 0:19:28can be a wily and wary opponent.
0:19:28 > 0:19:33It is our first time we try the trap with pygmy hippos.
0:19:33 > 0:19:39We have no idea now that this will work
0:19:39 > 0:19:41but we hope it will work.
0:19:51 > 0:19:55It's six in the evening and time to set the traps for the first time.
0:19:56 > 0:19:59Wei is trying several different types of bait,
0:19:59 > 0:20:03all designed to lure a hungry hippo.
0:20:03 > 0:20:06So this is just salt, a lot of sea salt,
0:20:06 > 0:20:09mineral salts mixed in with clay...
0:20:11 > 0:20:15..so it's forming an artificial salt lick
0:20:15 > 0:20:18which most herbivores find really, really tempting...
0:20:24 > 0:20:28Hippos are known in captivity to eat cassava, bananas, apples, oranges,
0:20:28 > 0:20:30the whole lot, but we have also been trying
0:20:30 > 0:20:33other very commonly found vegetables here,
0:20:33 > 0:20:37like avocados, plantain and yam.
0:20:37 > 0:20:42Wei is keen to rid the yam of as much human scent as possible.
0:20:42 > 0:20:44The pygmy hippo may not have great eyesight
0:20:44 > 0:20:48but its nose is literally its biggest asset.
0:20:48 > 0:20:53If it gets a whiff of humans, it could run a mile.
0:20:53 > 0:20:56It's all set. Ready to go.
0:20:56 > 0:20:59Let's go, give the hippos a chance.
0:20:59 > 0:21:01Yep, he'll be waking up from his bed now.
0:21:03 > 0:21:06Hopefully, he's silly enough to decide
0:21:06 > 0:21:07or curious enough to decide
0:21:07 > 0:21:09to walk through and eat some yam.
0:21:09 > 0:21:12THUNDER CRASHES
0:21:20 > 0:21:23The downpour is welcome.
0:21:23 > 0:21:26As the rainy season approaches, it's thought that pygmy hippos
0:21:26 > 0:21:30become more active, which might play to Wei's advantage.
0:21:40 > 0:21:42At dawn, Wei gets a shock.
0:21:44 > 0:21:47She knows there might be a pygmy hippo in one of the traps
0:21:47 > 0:21:50on the other side of the river, but the fallen tree trunk
0:21:50 > 0:21:55they've been using as a bridge has disappeared in the downpour.
0:21:55 > 0:21:59There's no way the whole team can get across with all their capture kit.
0:21:59 > 0:22:01The river had risen so high
0:22:01 > 0:22:04that the way that we were using to cross
0:22:04 > 0:22:06was completely and utterly submerged,
0:22:06 > 0:22:09to the point where I got lost on the river bank for about half an hour,
0:22:09 > 0:22:12trying to figure out where my entry point was.
0:22:14 > 0:22:16But she can't leave a potentially distressed hippo
0:22:16 > 0:22:18stuck inside the trap.
0:22:19 > 0:22:21There's only one way to find out.
0:22:27 > 0:22:33Swimming across the river brings its own dangers, but Wei is determined.
0:22:33 > 0:22:36Crossing rivers is not exactly nice at 5am in the morning
0:22:36 > 0:22:38when you're checking traps,
0:22:38 > 0:22:41but if it needs to get done, it needs to get done.
0:22:41 > 0:22:43A lot of other researchers just don't go into the forest
0:22:43 > 0:22:45when it is like that,
0:22:45 > 0:22:47but unfortunately we don't have that choice.
0:22:47 > 0:22:51If we've set a trap, we can't exactly leave an animal in it.
0:22:51 > 0:22:53There's no pygmy hippo in the traps yet,
0:22:53 > 0:22:55but with more rain to come,
0:22:55 > 0:22:59Wei needs a new plan if the river stays this high.
0:22:59 > 0:23:02My only choice this morning was to swim it,
0:23:02 > 0:23:06but it's not an option for the rest of the crew.
0:23:06 > 0:23:10And getting all our collars and immobilisation gear and guns
0:23:10 > 0:23:13and CO2 canisters and IV fluids and everything...
0:23:13 > 0:23:16and ultrasound machines across...
0:23:16 > 0:23:19So, I'm not sure what we're going to do.
0:23:24 > 0:23:27It's vital that the team can get across the river,
0:23:27 > 0:23:31so the decision is taken to build a bridge.
0:23:41 > 0:23:45The pygmy hippo's forest home is crawling with other hazards.
0:23:53 > 0:23:58Driver ants are one of the most aggressive animals in the forest.
0:23:58 > 0:24:01Living in vast nomadic colonies of up to 20 million,
0:24:01 > 0:24:05workers carve out marching paths, flanked by larger soldiers
0:24:05 > 0:24:09with powerful jaws, who attack anything in their way.
0:24:11 > 0:24:14Oh, God!
0:24:14 > 0:24:16Ah!
0:24:16 > 0:24:18They call them manya here.
0:24:19 > 0:24:22And you get ant swarms and if you step into them,
0:24:22 > 0:24:26there are a certain type of manya that really, really hurt!
0:24:27 > 0:24:29And once they bite, they don't let go,
0:24:29 > 0:24:31so you've got to rip them out,
0:24:31 > 0:24:34which is what I'm doing through my pants.
0:24:34 > 0:24:35I would, if I was by myself,
0:24:35 > 0:24:38probably rip my clothes off right now.
0:24:38 > 0:24:42A swarm of manya can kill a scorpion in a matter of minutes.
0:24:45 > 0:24:47That's why you wear socks over your pants...
0:24:47 > 0:24:52and I stupidly didn't wear my socks over my pants today.
0:25:01 > 0:25:03It's 6am the next day
0:25:03 > 0:25:07and Donatien & Leon are on early morning trap-checking duty.
0:25:08 > 0:25:11We're sort of waiting right now,
0:25:11 > 0:25:14in extreme suspense, trying not to stress out.
0:25:16 > 0:25:20The time frames that we're having to work with
0:25:20 > 0:25:22put the pressure on quite a lot.
0:25:22 > 0:25:24But there's nothing we can do about it.
0:25:24 > 0:25:27It's up to the hippo...and chance!
0:25:32 > 0:25:34Merci, Leon...
0:25:37 > 0:25:41Wei can only hope that Donatien brings better news.
0:25:47 > 0:25:49HE SPEAKS FRENCH
0:25:49 > 0:25:51OK. Merci, Donatien...
0:25:52 > 0:25:54There's definitely a sense of disappointment,
0:25:54 > 0:25:57but I suppose we need to get used to the fact that
0:25:57 > 0:26:00the majority of mornings, this is what's going to happen
0:26:00 > 0:26:04and so it's, push it aside
0:26:04 > 0:26:06and let's get on with today.
0:26:08 > 0:26:13To further understand Wei's elusive opponent, Karim arranges a visit
0:26:13 > 0:26:16to the elders of several local villages.
0:26:16 > 0:26:19Sharing valuable knowledge between the communities
0:26:19 > 0:26:21and scientists is fundamental to the project.
0:26:24 > 0:26:27Here, they are regaled with stories of an animal of mystery,
0:26:27 > 0:26:31myth and legend.
0:26:31 > 0:26:37If people see the tail and if you laugh, you can go crazy.
0:26:37 > 0:26:40You know, you've got people that are over 70 years, 80 years,
0:26:40 > 0:26:43that remember what it was like when there was rainforest everywhere
0:26:43 > 0:26:46and seeing pygmy hippos was really normal.
0:26:52 > 0:26:54In the second village, the elders tell them they believe
0:26:54 > 0:27:00the pygmy hippo was once human, so people have a duty to protect it.
0:27:00 > 0:27:04This is how they keep in mind the pygmy hippo.
0:27:07 > 0:27:10It's not just in Europe, it's not just in Australia, where we go,
0:27:10 > 0:27:12"Oh, they're so cute, we should save them."
0:27:12 > 0:27:16It's also charismatic and has a lot of meaning here, as well.
0:27:24 > 0:27:27Back in the forest, there's still no sign of any pygmy hippos
0:27:27 > 0:27:31at the traps, but the cameras rigged in and around them
0:27:31 > 0:27:33reveal an interesting development -
0:27:33 > 0:27:37a host of other forest animals venturing inside.
0:27:42 > 0:27:45Rather worryingly, they also witness thieves in the night.
0:27:47 > 0:27:50Brush-tailed porcupines make off with the yams
0:27:50 > 0:27:52intended to lure the pygmy hippo.
0:27:57 > 0:28:01All the team can do is keep re-baiting the traps.
0:28:06 > 0:28:09It's day four before Wei gets even a glimmer of hope.
0:28:11 > 0:28:14She's viewed video footage through a small viewfinder of a camera
0:28:14 > 0:28:18outside trap one, which seemed to show something exciting.
0:28:57 > 0:29:00SHE LAUGHS EXCITEDLY
0:29:01 > 0:29:04Celebration soon turns to disappointment,
0:29:04 > 0:29:06when Wei takes a closer look at the images.
0:29:09 > 0:29:11Unfortunately, when we went back to the computer,
0:29:11 > 0:29:13we realised the door had actually triggered.
0:29:13 > 0:29:15We can't figure out what exactly happened there
0:29:15 > 0:29:18or what triggered that trap.
0:29:18 > 0:29:21Look, it's really obvious the doors are down and it can't be....
0:29:21 > 0:29:23So, he wasn't able to go through the trap,
0:29:23 > 0:29:25but it IS a pygmy hippo
0:29:25 > 0:29:28and he IS visiting the trap.
0:29:28 > 0:29:29Can definitely see he's a male.
0:29:29 > 0:29:32Yeah...and pretty relaxed.
0:29:32 > 0:29:34Whether he would have gone through that day or not
0:29:34 > 0:29:37if the trap had been open, we'll never know.
0:29:37 > 0:29:39But the fact is, is that he's coming back to that area
0:29:39 > 0:29:43on a constant basis so that's really, really exciting.
0:29:55 > 0:29:59Two nights later, the male hippo returns...
0:29:59 > 0:30:00Ah...
0:30:00 > 0:30:03..but again, doesn't set foot inside.
0:30:08 > 0:30:12Time is running out to entice him into the trap.
0:30:12 > 0:30:14The capture team leaves in just two days.
0:30:15 > 0:30:17I've done everything I can,
0:30:17 > 0:30:22but now I have absolutely no idea what the magic ingredient
0:30:22 > 0:30:24is to get this hippo to walk through this trap.
0:30:34 > 0:30:37And now it's the last evening.
0:30:38 > 0:30:41- Which trap was this?- The bamboo.
0:30:41 > 0:30:42Yeah, makes sense.
0:30:43 > 0:30:46Wei and the capture team are spooling through the footage
0:30:46 > 0:30:48from the previous night.
0:30:48 > 0:30:49HE SPEAKS FRENCH
0:30:49 > 0:30:51- Ah! - THEY GASP
0:30:51 > 0:30:53- Oh, my God!- Oh, my God.
0:30:53 > 0:30:55Come on...
0:30:55 > 0:31:00Yeah, but look how close he is and he doesn't go in there!
0:31:00 > 0:31:03- Oh, he's eating the sweet potato! - Oh, yes!
0:31:03 > 0:31:05No, no, wait...
0:31:05 > 0:31:08Oh, yes! He's eating the yam.
0:31:08 > 0:31:10Yes, he's eating the yam!
0:31:10 > 0:31:12Oh, so close and yet so far!
0:31:12 > 0:31:15That is SO awesome.
0:31:15 > 0:31:19Wei is thrilled and with good reason.
0:31:19 > 0:31:22It's a rare opportunity to see in close-up a creature
0:31:22 > 0:31:27that only a handful of scientists have ever observed in the wild.
0:31:27 > 0:31:31She also now knows that the bait works,
0:31:31 > 0:31:33even though the hippo doesn't venture far enough inside
0:31:33 > 0:31:35to trigger the trap.
0:31:35 > 0:31:36In the trap.
0:31:36 > 0:31:38He's still very, very cautious,
0:31:38 > 0:31:41but he's got his entire head, up to about his shoulders,
0:31:41 > 0:31:43inside the trap.
0:31:43 > 0:31:45Even when he's reaching for the further yam,
0:31:45 > 0:31:47he's kind of grabbing it and bringing it closer to him
0:31:47 > 0:31:49and eating it there.
0:31:49 > 0:31:50He's sniffing the human smells.
0:31:50 > 0:31:53I think that's why he picks it up at first and he's like, "Huh..."
0:31:53 > 0:31:56- Yeah, actually...- And he's nervous.
0:31:56 > 0:31:59He is nervous, yeah, cos he's really sniffing there.
0:32:01 > 0:32:03With the traps already set for the final night,
0:32:03 > 0:32:07Wei can only hope that he'll be brave enough to venture further in.
0:32:18 > 0:32:22When dawn arrives, it brings fresh disappointment.
0:32:24 > 0:32:27The male pygmy hippo did return
0:32:27 > 0:32:29but he didn't go inside trap one.
0:32:29 > 0:32:31The footage reveals why.
0:32:37 > 0:32:41Those porcupine thieves strike again,
0:32:41 > 0:32:46so that when the hippo does arrive, there's no food left to tempt him in.
0:32:51 > 0:32:54It's a huge disappointment for Wei and the team.
0:32:55 > 0:32:58For now, their capture plans are scuppered...
0:32:58 > 0:33:02but Wei hopes she'll see more of the big male hippo in the future.
0:33:02 > 0:33:05We've had beautiful footage of him
0:33:05 > 0:33:08interacting with the trap three times now, which is great.
0:33:08 > 0:33:13He's the first hippo that we really got a clear understanding of
0:33:13 > 0:33:16his core range that we got a lot of signs for.
0:33:16 > 0:33:19It was the first trap we built and he has had the most time
0:33:19 > 0:33:23to have us disturbing his area and getting used to that.
0:33:28 > 0:33:31After four months, time has run out for Wei.
0:33:33 > 0:33:35She and the capture team must head home
0:33:35 > 0:33:36but they will return.
0:33:38 > 0:33:40In the meantime, Donatien and Leon
0:33:40 > 0:33:43will continue to monitor the forest for signs.
0:33:53 > 0:33:56CROWD CHANTS
0:33:56 > 0:34:00- CROWD:- Hippo, hippo!
0:34:03 > 0:34:05Wei is back in Cote d'Ivoire
0:34:05 > 0:34:09and today, she's celebrating Hippo Day with children from villages
0:34:09 > 0:34:13around the forest and the rest of the Tai Hippo Project team.
0:34:15 > 0:34:18It's Karim and Inza's initiative to educate the next generation
0:34:18 > 0:34:21about Cote d'Ivoire's most mysterious mammal.
0:34:23 > 0:34:26It's also a good excuse for a party.
0:34:26 > 0:34:31These children are the future decision-makers,
0:34:31 > 0:34:35they are future researchers, so it is really important for us
0:34:35 > 0:34:41to drive them slowly towards nature conservation issues.
0:34:42 > 0:34:44KARIM SPEAKS IN OWN LANGUAGE
0:34:51 > 0:34:54Karim hopes that inspiring children to care about the hippos
0:34:54 > 0:34:57and their forest home is the most effective way
0:34:57 > 0:35:00to spread the word about saving the pygmy hippo's habitat.
0:35:01 > 0:35:06For us, if you have your child come home and say,
0:35:06 > 0:35:10"OK, Dad or Mum, we learn a lot about the pygmy hippos
0:35:10 > 0:35:13"and they are disappearing."
0:35:13 > 0:35:19So, we expect that this message is more strong when a child tells you
0:35:19 > 0:35:21that you have to stop what you are doing.
0:35:21 > 0:35:26This is our vision, that the population will start themselves
0:35:26 > 0:35:28to say, "OK, we want to protect our forest
0:35:28 > 0:35:31"because we know how it is important for our future."
0:35:46 > 0:35:49Back in the forest, the end of the rainy season brings with it
0:35:49 > 0:35:52an abundance of seasonal riches for the animals.
0:35:55 > 0:36:00Western pied colobus monkeys feast on ripening bean pods,
0:36:00 > 0:36:03ripping open the tough casings with their sharp canines
0:36:03 > 0:36:05to reach the seeds inside.
0:36:13 > 0:36:15During the wet season,
0:36:15 > 0:36:18Donatien and Leon continued to bait the traps with yam,
0:36:18 > 0:36:20but left the doors open
0:36:22 > 0:36:25The cameras were also left up to keep tabs on any action.
0:36:28 > 0:36:30And now Wei is about to see the results.
0:36:33 > 0:36:35Oh, exciting!
0:36:35 > 0:36:39Let's just hope the camera traps haven't let us down.
0:36:39 > 0:36:40She's not disappointed.
0:36:41 > 0:36:44The big male that came so close to triggering the trap
0:36:44 > 0:36:47appears to be used to walking through it.
0:36:50 > 0:36:52But that's not all.
0:36:52 > 0:36:56A smaller, clearly female hippo is also now on the scene.
0:36:57 > 0:37:01We definitely have two different individuals walking through bamboo,
0:37:01 > 0:37:04so the big male and there's definitely been a female,
0:37:04 > 0:37:06which is really exciting.
0:37:06 > 0:37:08It raises more questions about territoriality
0:37:08 > 0:37:11and the solitariness of the species.
0:37:12 > 0:37:15It's a very important development.
0:37:15 > 0:37:19Pygmy hippos are thought to be highly solitary,
0:37:19 > 0:37:21keeping to their own distinct core ranges
0:37:21 > 0:37:24and only coming together to mate.
0:37:24 > 0:37:27That may explain the female's presence...
0:37:27 > 0:37:29but only time will tell.
0:37:32 > 0:37:36That night, Wei scours the incredibly rare footage
0:37:36 > 0:37:39for any clues to the hippos' behaviour...
0:37:39 > 0:37:42and finds something commonly seen in captivity,
0:37:42 > 0:37:45but almost never witnessed in the wild.
0:37:45 > 0:37:48There was a time we went out to check the traps
0:37:48 > 0:37:53and we saw fresh spray all over the side of the exit.
0:37:53 > 0:37:56So, we know one of the hippos has been and actually marked our trap,
0:37:56 > 0:37:59but I think we can actually see that happening.
0:37:59 > 0:38:04So, can't see it perfectly but he stops and shifts his right foot over
0:38:04 > 0:38:07and turns his body angle and then you can actually...
0:38:07 > 0:38:09I've actually mashed up the volume,
0:38:09 > 0:38:13you can hear this, like, "chugga-chugga-chugga",
0:38:13 > 0:38:17as his crazy tail is smushing urine and faeces all over the trap!
0:38:17 > 0:38:19So that's really awesome, you know,
0:38:19 > 0:38:21to be able to see a sign in the field
0:38:21 > 0:38:25and kind of go, "I think I've actually got footage of it!"
0:38:25 > 0:38:27HIPPO SPRAYS
0:38:33 > 0:38:38This type of spray-marking is unique to pygmy and common hippos.
0:38:38 > 0:38:41It's thought to be the way a pygmy hippo communicates its presence
0:38:41 > 0:38:43within its home range.
0:38:43 > 0:38:47But Wei is considering a second theory about navigation.
0:38:47 > 0:38:54My hypothesis that wherever we see spray on a hippo's path,
0:38:54 > 0:38:57we pretty much start looking for some kind of turn off or crossroad
0:38:57 > 0:39:02or a new kind of right or left-hand turn or a bifurcation
0:39:02 > 0:39:06going off in two different directions and we usually find one.
0:39:08 > 0:39:12While Wei continues to put the pieces of the pygmy hippo puzzle together,
0:39:12 > 0:39:15a new capture team has arrived.
0:39:15 > 0:39:16Wei will work with them
0:39:16 > 0:39:22but will also follow her own leads to advance the field work.
0:39:22 > 0:39:25So little is known that even the smallest detail could be crucial
0:39:25 > 0:39:28in building a conservation plan to save the species.
0:39:30 > 0:39:34Whilst the capture team waits to see if the hippos return to the traps,
0:39:34 > 0:39:36Wei is on a different mission.
0:39:38 > 0:39:40Investigating a report of a hippo den.
0:39:44 > 0:39:47First, she needs to check that there's no-one at home.
0:39:50 > 0:39:54Pygmy hippos are thought to make their dens in river bank hollows,
0:39:54 > 0:39:59like this, created by fast-flowing water as it hits a bend in the river,
0:39:59 > 0:40:03under the roots of primary rainforest trees.
0:40:03 > 0:40:06All right, we're all clear!
0:40:08 > 0:40:12Some ecologists believe that the decline in pygmy hippo numbers
0:40:12 > 0:40:15is directly related to the loss of these trees.
0:40:22 > 0:40:25An improvised waterproof camera on a stick
0:40:25 > 0:40:28will enable Wei to probe deep inside the interior.
0:40:28 > 0:40:31Oh! Something slimy...
0:40:32 > 0:40:35It's another extraordinary first.
0:40:35 > 0:40:37It's believed that no-one has ever filmed
0:40:37 > 0:40:40inside a pygmy hippo den before.
0:40:40 > 0:40:42OK, there is definitely no hippo around.
0:40:44 > 0:40:49This one goes much deeper than the other dens she's seen.
0:40:49 > 0:40:53I would never have guessed the extent of the actual den.
0:40:53 > 0:40:56They're always pretty small, you know,
0:40:56 > 0:40:57good enough to hide a hippo in,
0:40:57 > 0:41:00but this just is on a whole other level.
0:41:00 > 0:41:02And there's another surprise -
0:41:02 > 0:41:05strange vertical markings on the bank.
0:41:05 > 0:41:07I can actually see scrape marks.
0:41:08 > 0:41:12Right at the surface, you can see these marks
0:41:12 > 0:41:14going down into the water,
0:41:14 > 0:41:17where you've got this perfect clay wall.
0:41:17 > 0:41:22The scrape marks suggest an intriguing new possibility.
0:41:22 > 0:41:23We know they've got those big canines,
0:41:23 > 0:41:25we've kind of always gone,
0:41:25 > 0:41:27"Oh, maybe it is for fighting, maybe it's for territoriality,
0:41:27 > 0:41:29"maybe it's for breeding..."
0:41:29 > 0:41:33Um, maybe it's for carving out riverbanks.
0:41:33 > 0:41:36It's the first time anyone's found evidence that hippos
0:41:36 > 0:41:40might actually play an active role in excavating their dens.
0:41:42 > 0:41:45But that's not all.
0:41:45 > 0:41:46That is going in so deep.
0:41:49 > 0:41:53The first entrance connects to a second.
0:41:53 > 0:41:55I'm at the end of the pole.
0:41:55 > 0:41:58The tunnel measures an incredible nine metres -
0:41:58 > 0:42:00the length of two cars.
0:42:01 > 0:42:03That is going deep this way, as well.
0:42:03 > 0:42:07And three metres away from the bank, the camera pops up
0:42:07 > 0:42:09in a hippo-sized air pocket.
0:42:09 > 0:42:13It means, basically, that this hippo can dive under
0:42:13 > 0:42:16and then resurface in an area where they can sit happily,
0:42:16 > 0:42:21breathing, completely enclosed, completely safe and hidden.
0:42:21 > 0:42:23And it's huge.
0:42:23 > 0:42:26A single animal shouldn't need something as huge as this,
0:42:26 > 0:42:28so whether they kind of use it to raise young,
0:42:28 > 0:42:30especially when they're super, super little...
0:42:30 > 0:42:33Whether they pair in these dens -
0:42:33 > 0:42:36I mean, we don't know and considering the size of it,
0:42:36 > 0:42:40now I'm kind of wondering whether that could be a possibility.
0:42:43 > 0:42:46Bit by bit, Wei is unearthing new insights
0:42:46 > 0:42:51into the secret life of her pygmy hippos.
0:42:51 > 0:42:54But as she starts to uncover their secrets by day,
0:42:54 > 0:42:58they are giving her and the capture team the slip by night.
0:43:04 > 0:43:06Neither the big male, nor the female,
0:43:06 > 0:43:09has been seen on camera for more than a month.
0:43:15 > 0:43:18Then, while out searching for tracks,
0:43:18 > 0:43:21she and Donatien stumble across something disturbing.
0:43:21 > 0:43:23Oh...
0:43:23 > 0:43:25Quoi?
0:43:33 > 0:43:36It raises a chilling possibility
0:43:36 > 0:43:39that the big male and the little female
0:43:39 > 0:43:42may have fallen victim to poachers.
0:43:45 > 0:43:48It's a reminder that although the Tai forest is protected,
0:43:48 > 0:43:51its animals do get hunted illegally.
0:43:57 > 0:43:59Karim has brought Wei to a bushmeat market,
0:43:59 > 0:44:01on the border with Liberia.
0:44:11 > 0:44:15While hunting forest animals is outlawed in Cote d'Ivoire,
0:44:15 > 0:44:18just over the river in Liberia, it's perfectly legal.
0:44:20 > 0:44:22Hunters sell their goods to traders,
0:44:22 > 0:44:26who then ship the animals across the river border to this informal market.
0:44:30 > 0:44:33So, you see here you have mainly monkeys.
0:44:34 > 0:44:38- This one seems to be Diana monkey. - C'est Diana?
0:44:38 > 0:44:42Yes. With the teeth.
0:44:42 > 0:44:47This one is a sooty mangabey. Yes, sooty mangabey.
0:44:47 > 0:44:49With this one...
0:44:49 > 0:44:52it's a Campbell's monkey. It's very fresh.
0:44:54 > 0:44:55- Oh, wow, it's really fresh.- Yes.
0:44:57 > 0:44:59No, no, no.
0:45:01 > 0:45:03Straight through the heart.
0:45:03 > 0:45:06So, that's got to be less than two hours.
0:45:06 > 0:45:11- Probably this morning, yes. - Because of the rigor.
0:45:11 > 0:45:13Wei is confronted with many of the species
0:45:13 > 0:45:17she has seen in the rainforest being sold here as food.
0:45:18 > 0:45:21Both Wei and Karim are dreading finding hippo meat.
0:45:24 > 0:45:27A local monitoring team checks the market for all animals that,
0:45:27 > 0:45:29like the pygmy hippo,
0:45:29 > 0:45:33are on an internationally banned list of endangered species.
0:45:33 > 0:45:37So, she said she started in June
0:45:37 > 0:45:44and from June to now, they recorded no pygmy hippo.
0:45:44 > 0:45:49If they do find an animal on the list, it gets sent back unsold,
0:45:49 > 0:45:52in the hope that the no-profit message gets through.
0:45:52 > 0:45:56Officially, we have a lot of law to protect the animals,
0:45:56 > 0:46:01but in practice, we need more action.
0:46:01 > 0:46:06Wei wants to ask a Liberian trader whether hunters target pygmy hippos.
0:46:06 > 0:46:10Do you know how they try to hunt the pygmy hippopotamus?
0:46:12 > 0:46:15Do people try any more, or is the animal too hard?
0:46:15 > 0:46:17They will try, if they can get it.
0:46:17 > 0:46:20- And there is like specialist hunters?- Yes.
0:46:20 > 0:46:25Do they make pits or do they make traps?
0:46:25 > 0:46:28Some set traps, some use gun.
0:46:28 > 0:46:29- Do people really like the meat... - Yes.
0:46:29 > 0:46:31- ..of the pygmy hippo?- Yes.
0:46:31 > 0:46:34More than the duiker?
0:46:34 > 0:46:37- More than that. - More than le singe - monkey?
0:46:38 > 0:46:41So, they will pay quite a lot of money if there's a hippo?
0:46:41 > 0:46:43Yes.
0:46:43 > 0:46:46There are no pygmy hippos in this market
0:46:46 > 0:46:50but discovering hippo meat is popular - at least over the border -
0:46:50 > 0:46:51is a reality check for Wei.
0:46:53 > 0:46:56But she also understands that, for local people,
0:46:56 > 0:47:00forest animals often represent their only source of protein.
0:47:00 > 0:47:03The worst thing you can do is come here and start crying and yelling
0:47:03 > 0:47:06and telling everyone here that their way is not OK.
0:47:07 > 0:47:10I will probably go and have a little cry when I get home,
0:47:10 > 0:47:14about the animals' eyes that I've looked into today.
0:47:16 > 0:47:22If you imagine that each week, we have this quantity of bushmeat,
0:47:22 > 0:47:25that means the pressure is very high on the forest,
0:47:25 > 0:47:27high on the animals
0:47:27 > 0:47:31and we don't know how long this can continue.
0:47:34 > 0:47:37CHIRPING
0:47:43 > 0:47:47Sadly, Wei's chances of capturing the big male or female hippo
0:47:47 > 0:47:48have run out.
0:47:49 > 0:47:52This morning, the capture team had to leave,
0:47:52 > 0:47:55but Wei is determined to carry on as best she can.
0:47:56 > 0:47:58She's back at the traps where, ironically,
0:47:58 > 0:48:00there are signs of activity.
0:48:06 > 0:48:07Then, at last,
0:48:07 > 0:48:09she finds a hippo calling card.
0:48:09 > 0:48:11Donatien!
0:48:12 > 0:48:14Oh!
0:48:22 > 0:48:24We've got fresh spray
0:48:24 > 0:48:27in one of their really frequently sprayed spots.
0:48:27 > 0:48:29We've got a really, really nice fresh poo sample,
0:48:29 > 0:48:31which is the first in a really long time.
0:48:31 > 0:48:35Once analysed, the poo will give Wei crucial insights
0:48:35 > 0:48:38into pygmy hippo diet and genetic profile.
0:48:40 > 0:48:44She can only hope that her nocturnal visitor was caught on camera.
0:48:48 > 0:48:50She expects it to be the big male,
0:48:50 > 0:48:51as this is his core range.
0:48:53 > 0:48:54It's really impossible to tell,
0:48:54 > 0:48:56especially when they're this close up to the camera.
0:49:07 > 0:49:10When the female first turned up in the male's core range,
0:49:10 > 0:49:12up to six months ago,
0:49:12 > 0:49:14Wei wondered if it was for mating.
0:49:14 > 0:49:19But her reappearance suggests it could be more significant.
0:49:19 > 0:49:22We're going to go around and see if we can figure out where she went,
0:49:22 > 0:49:24where she came from, what she's actually been doing
0:49:24 > 0:49:27and see what's going on.
0:49:35 > 0:49:38We've got brand-new fresh prints from last night,
0:49:38 > 0:49:42so same hippo, same spray, this lay-on.
0:49:42 > 0:49:46We might put another camera trap right here, as well.
0:50:03 > 0:50:06Oh, my God. We're stepping all over signs, everywhere!
0:50:06 > 0:50:08Getting caught in trees, ah... Getting too excited!
0:50:11 > 0:50:13They follow the female's trail.
0:50:17 > 0:50:20But the clues run out at the edge of the water.
0:50:25 > 0:50:27The wily pygmy hippo has vanished,
0:50:27 > 0:50:30eluding them once again.
0:50:30 > 0:50:32But after weeks of seeing no hippos at all,
0:50:32 > 0:50:34it's a huge relief.
0:50:34 > 0:50:37It's such a shame the capture team has already left
0:50:37 > 0:50:39but Wei gathers what evidence she can.
0:50:39 > 0:50:40Really interesting morning.
0:50:40 > 0:50:43Today is the first time they've started showing signs
0:50:43 > 0:50:47back in the areas we've known about in the past.
0:50:47 > 0:50:50They put up another camera to see if she returns tonight.
0:50:55 > 0:50:59The next morning brings exciting news.
0:50:59 > 0:51:01- Ha!- Oh!
0:51:09 > 0:51:10Ah, c'est bon!
0:51:10 > 0:51:15It's the female, coming from the same direction as last night.
0:51:15 > 0:51:17She kind of goes the exact opposite way
0:51:17 > 0:51:20to what we've always known the male to go.
0:51:20 > 0:51:23Um, so it's really interesting.
0:51:25 > 0:51:29The big male has also been known to walk this trail.
0:51:29 > 0:51:32It seems that the two of them are sharing the route
0:51:32 > 0:51:36through this area, so it's possible they may encounter each other.
0:51:38 > 0:51:42This time, the female has left a more significant trail of clues behind.
0:51:50 > 0:51:54Wow, she's really going nuts, marking away!
0:51:54 > 0:51:57One theory Wei has about the volume of evidence is that,
0:51:57 > 0:52:01like cats, hippos may leave a trail of pheromones in the area
0:52:01 > 0:52:03they feel most comfortable in -
0:52:03 > 0:52:05the core of their home range.
0:52:05 > 0:52:08And when they actually come back into those areas
0:52:08 > 0:52:10and smell their own pheromones,
0:52:10 > 0:52:12it produces an actual physiological response.
0:52:12 > 0:52:15So, like a drug that alters their own biochemistry,
0:52:15 > 0:52:18they kind of go, "Ahhh," and relax.
0:52:18 > 0:52:22And then that forces them to become happy and mark even more.
0:52:22 > 0:52:26If the female IS marking and regularly using this same area
0:52:26 > 0:52:29as the big male, then it may mean that pygmy hippos
0:52:29 > 0:52:31are less solitary than previously thought
0:52:31 > 0:52:35and indeed might share core ranges.
0:52:35 > 0:52:39Wei needs evidence that the big male is still in the area.
0:52:42 > 0:52:44ANIMAL CALLS
0:52:51 > 0:52:52The next morning,
0:52:52 > 0:52:55she's back out to see if the big male has made an appearance.
0:52:55 > 0:52:58(Please work.)
0:52:58 > 0:53:00She scans the footage from the cameras
0:53:00 > 0:53:02on the trail the female is using.
0:53:03 > 0:53:05The first two draw a blank...
0:53:05 > 0:53:07but then there's a surprise.
0:53:07 > 0:53:10There we go! It's the big male!
0:53:15 > 0:53:17It's good to see him again.
0:53:18 > 0:53:22Let's watch that again. I haven't seen him in months.
0:53:22 > 0:53:25Wei now has proof that the male and female
0:53:25 > 0:53:29have been on the same trail within a day of each other.
0:53:29 > 0:53:32They obviously are very, very aware that each other are there,
0:53:32 > 0:53:35that there's no doubt, at all,
0:53:35 > 0:53:38that they're co-existing in an overlapping habitat
0:53:38 > 0:53:39without realising.
0:53:39 > 0:53:43They're walking directly along the same lay-ons
0:53:43 > 0:53:45and sniffing each other's poo
0:53:45 > 0:53:49and coming just a day later and things like that.
0:53:49 > 0:53:51You've just got to be patient and you've got to just
0:53:51 > 0:53:55keep slowly fitting pieces of the puzzle together.
0:54:01 > 0:54:03It's Wei's final night here.
0:54:04 > 0:54:09Tomorrow, she will leave the forest and the pygmy hippos behind.
0:54:09 > 0:54:10She's unearthed a host of insights
0:54:10 > 0:54:13into the secret life of the pygmy hippo,
0:54:13 > 0:54:16including intriguing evidence that the male and female are sharing
0:54:16 > 0:54:20at least part of the same core range.
0:54:20 > 0:54:22Maybe they den together and maybe they forage together
0:54:22 > 0:54:25and maybe they do everything as a pair
0:54:25 > 0:54:27and maybe that's actually more the norm for this species
0:54:27 > 0:54:30than the other way round or they might be an anomaly.
0:54:33 > 0:54:35And now Wei wants to check something else from the camera
0:54:35 > 0:54:38left on inside trap one during the rainy season.
0:54:41 > 0:54:45One of the hippos seen inside the trap has a notch in its left ear.
0:54:47 > 0:54:50And it's exactly the same ear mark that we've seen in a hippo
0:54:50 > 0:54:52from a study done in 2010.
0:54:53 > 0:54:56It's not the big male, as his left ear is full,
0:54:56 > 0:54:58but she's yet to check the female.
0:54:58 > 0:55:02I'm just going to go through all the confirmed female shots
0:55:02 > 0:55:05and just see if I can see any other markings on her.
0:55:05 > 0:55:06That's her right ear...
0:55:08 > 0:55:10..but that is definitely a full ear.
0:55:15 > 0:55:17This means that there are not two
0:55:17 > 0:55:20but THREE hippos in the same small area
0:55:20 > 0:55:24and, interestingly, there could be two males.
0:55:27 > 0:55:30We've never heard anything about males hanging out in the same area.
0:55:32 > 0:55:35The only way to find out is to analyse the only image
0:55:35 > 0:55:38where both ear and genitalia are just visible.
0:55:38 > 0:55:40I'm going to have to look at it a few times
0:55:40 > 0:55:42to see whether there's an ear notch or not,
0:55:42 > 0:55:46but there's definitely a penis that wiggles in the corner there.
0:55:46 > 0:55:47If you don't have a great image,
0:55:47 > 0:55:50it actually is really hard to tell the difference
0:55:50 > 0:55:53and you have to stare at it a billion times.
0:55:53 > 0:55:54If that is actually an ear mark,
0:55:54 > 0:55:59which I am starting to convince myself more and more of right now,
0:55:59 > 0:56:03it's confirmation that the ear mark individual is in fact a male.
0:56:05 > 0:56:08It raises a tantalising possibility -
0:56:08 > 0:56:12two males sharing the same trail as the female.
0:56:13 > 0:56:17And that would be a significant new development to our understanding
0:56:17 > 0:56:20of how pygmy hippos live in the wild.
0:56:24 > 0:56:25Who knows what their relationship is,
0:56:25 > 0:56:29but two males existing in the same core range is huge.
0:56:29 > 0:56:34And what's more, Wei now knows that this second large hippo,
0:56:34 > 0:56:37first seen in 2010, has survived in this forest
0:56:37 > 0:56:39for at least three years.
0:56:40 > 0:56:43And that's a very hopeful sign for the future
0:56:43 > 0:56:45of this pygmy hippo population.
0:56:51 > 0:56:54Wei has spent six months in the forest with the team,
0:56:54 > 0:56:56building a pygmy hippo case file.
0:56:57 > 0:57:02In just one small area, she's uncovered some intriguing evidence.
0:57:02 > 0:57:04Ha!
0:57:04 > 0:57:06Her findings raise significant questions about
0:57:06 > 0:57:11whether the pygmy hippo is as solitary as previously thought.
0:57:11 > 0:57:14She also found clues that they may use their canines
0:57:14 > 0:57:16to improve their dens.
0:57:17 > 0:57:20And she's significantly increased the amount of footage
0:57:20 > 0:57:24that exists of wild pygmy hippos,
0:57:24 > 0:57:27the findings from which offers hope
0:57:27 > 0:57:32and will now push this critical research further forward.
0:57:37 > 0:57:39Wei's time here is at an end,
0:57:39 > 0:57:44but she's full of confidence about the future of the Tai Hippo Project.
0:57:44 > 0:57:47The biggest cool thing about this Hippo Project
0:57:47 > 0:57:51in Cote d'Ivoire, specifically, is that they are Ivorians
0:57:51 > 0:57:52that are super passionate,
0:57:52 > 0:57:55that are also super enabled and empowered
0:57:55 > 0:57:58to be in a position to really have an impact.
0:57:58 > 0:58:02Everything we've learned so far will just keep helping to unravel
0:58:02 > 0:58:05more and more the secrets of this really mysterious animal
0:58:05 > 0:58:08and hopefully give us a better chance at helping to save them.