0:00:14 > 0:00:20Think of African elephants and most of us will picture open savannah
0:00:20 > 0:00:25where the largest land mammal mingles with lions, giraffes and gazelles.
0:00:34 > 0:00:38In fact, a third of Africa's elephants live here...
0:00:38 > 0:00:40in dense, dark rainforests.
0:00:45 > 0:00:49Forest elephants stand just two metres at the shoulder, are more
0:00:49 > 0:00:53slightly built and have pinker tusks than those on the savannah.
0:00:54 > 0:01:00Little else was known about them until one remarkable woman began eavesdropping on their lives.
0:01:00 > 0:01:06Andrea Turkalo is no ordinary scientist.
0:01:06 > 0:01:12By living alone in remote jungle, she's learnt more about these hidden giants than anyone else on earth.
0:01:18 > 0:01:21This has placed a huge burden on her shoulders.
0:01:21 > 0:01:27Forest elephants are now under greater threat than their savannah cousins.
0:01:27 > 0:01:31But Andrea could be in a unique position to help them.
0:01:31 > 0:01:36She's learnt their language and understands what they're thinking.
0:01:36 > 0:01:39She can even hear when they're in trouble.
0:01:41 > 0:01:49Incredibly, she believes that, if we listen carefully enough, they might tell us what they need to survive.
0:02:00 > 0:02:05The only thing most scientists see of forest elephants is what they leave behind.
0:02:10 > 0:02:14Counting dung piles has been the crude way of guessing how many there are.
0:02:20 > 0:02:27Their real secrets are hidden away in the vast rainforest that stretches over the Congo Basin.
0:02:36 > 0:02:42But, in a small corner of the Central African Republic, there is a window into their lives.
0:02:49 > 0:02:51This is Dzanga Bai.
0:02:53 > 0:02:55A vast natural clearing...
0:02:55 > 0:02:58and a Mecca for forest elephants.
0:03:09 > 0:03:13The forest provides all the food they need,
0:03:13 > 0:03:16so what is it that draws them out of the shadows?
0:03:23 > 0:03:28The clearing contains a vital ingredient that's lacking in their diet.
0:03:34 > 0:03:39Volcanic rocks lie close to the surface, and the salts they contain
0:03:39 > 0:03:44neutralise toxins ingested with rainforest leaves and bark.
0:03:50 > 0:03:57Generations of elephants have come here to prospect for these minerals and settle their stomachs.
0:04:19 > 0:04:27Blowing down, they churn up the mud, then take a mouthful of the mineral-enriched waters.
0:04:42 > 0:04:46As soon as they've mastered their trunks, they're hooked.
0:04:49 > 0:04:54It may be that these mineral salts are also vital for the elephants' growth and fertility,
0:04:56 > 0:05:00which is why as many as three thousand elephants visit Dzanga each year.
0:05:03 > 0:05:07They'll try any tactic to control the best areas of the Bai.
0:05:27 > 0:05:31Dzanga Bai is not the only clearing where they can get these salts,
0:05:31 > 0:05:35but it's certainly one of the biggest and most frequented.
0:05:40 > 0:05:45When Andrea Turkalo first came here, she had an instinct that this place
0:05:45 > 0:05:49could help her unlock the secret lives of forest elephants.
0:05:54 > 0:05:59I knew immediately that this was an extraordinary place, because to
0:05:59 > 0:06:01see wildlife in the open in the forest is literally impossible.
0:06:01 > 0:06:06I went there first in 1987 just to see the place and actually slept there.
0:06:06 > 0:06:09And all night there were these extraordinary elephant sounds
0:06:09 > 0:06:11because elephants don't sleep like we do.
0:06:11 > 0:06:15There was just this symphony of elephants.
0:06:15 > 0:06:19And in the morning they were still there and it was obvious that this
0:06:19 > 0:06:23was probably one of the most special places for them in the Congo Basin.
0:06:30 > 0:06:32Andrea now understands what the symphony means.
0:06:32 > 0:06:36She can even hear an individual elephant's voice.
0:06:39 > 0:06:43But back then, she was faced with a huge problem.
0:06:45 > 0:06:53Each elephant visits for just a few hours - at best, a few days - so Andrea only had snapshots to go on.
0:07:14 > 0:07:18She might not see them again for months or years.
0:07:18 > 0:07:25From this constantly changing cast of characters, how could Andrea work out the big picture?
0:07:56 > 0:07:59There was another challenge.
0:07:59 > 0:08:03Andrea wasn't a trained scientist,
0:08:03 > 0:08:08but she had been a teacher in the Bronx, one of New York's toughest neighbourhoods,
0:08:08 > 0:08:12and she was single-minded enough to commit herself long term.
0:08:24 > 0:08:29She left her family and friends and set herself up in the middle of nowhere.
0:08:35 > 0:08:39At the beginning, I can honestly say there were a lot of things I was afraid of.
0:08:39 > 0:08:42I wasn't really comfortable in the dark.
0:08:42 > 0:08:46You're always in contact with insects and that was something I didn't like, but if you're
0:08:46 > 0:08:49going to stay here, you have to get used to that and deal with it.
0:08:54 > 0:08:59Andrea's had to turn her hand to everything, building a camp
0:08:59 > 0:09:03from scratch and surviving on minimal creature comforts.
0:09:12 > 0:09:17She's also had to place her trust in the local BaAka pygmies.
0:09:17 > 0:09:21They come from an ancient tribe who have always lived in this forest.
0:09:21 > 0:09:24They have helped her to adapt.
0:09:31 > 0:09:35All my employees come from the local BaAka tribe.
0:09:35 > 0:09:38They have great forest skills, they keep me out of harm's way
0:09:38 > 0:09:44and they see things long before I am aware of them.
0:09:51 > 0:09:57Every day, Andrea sets off with her loyal helpers on the 45-minute walk to the Bai.
0:10:00 > 0:10:04It's a routine she's stuck to for 20 years.
0:10:22 > 0:10:29Today, like any other day, she has no idea who, or what, she might see.
0:10:29 > 0:10:31ANDREA: Oh my God, it's Gookie.
0:10:31 > 0:10:33I can't believe she's come back.
0:10:37 > 0:10:42I haven't seen her in about six months and she's still able to keep up with her group.
0:10:42 > 0:10:44And she's still walking.
0:10:48 > 0:10:51It's not uncommon for calves to be born with disabilities.
0:10:53 > 0:10:57What's unusual is that Gookie has survived for so long.
0:11:02 > 0:11:08Unlike on the savannah, there are no large predators here, which might explain why.
0:11:09 > 0:11:14But life in the forest for a disabled calf is by no means easy.
0:11:16 > 0:11:20What really amazes me about this individual is, if you think about walking in the forest,
0:11:20 > 0:11:23the mother must come to obstacles like fallen trees,
0:11:23 > 0:11:29so she's evidently accommodating the female with the handicap
0:11:29 > 0:11:30because she's keeping up with the group.
0:11:30 > 0:11:33Otherwise she would just get lost in the forest, left.
0:11:43 > 0:11:47This place never ceases to amaze me... the things you see.
0:11:52 > 0:11:58Even though Andrea sees individuals only rarely, she's been able to piece together their life stories.
0:12:05 > 0:12:08She couldn't have reached this extraordinary position
0:12:08 > 0:12:12without first learning how to pick out faces from the crowd.
0:12:16 > 0:12:22By mid-afternoon, the crowd can be 140 strong.
0:12:22 > 0:12:27To keep track of so many individuals, Andrea drew pictures of their ears,
0:12:27 > 0:12:31which get ripped and torn in distinctive ways as they move through the jungle.
0:12:38 > 0:12:41She had over 4,000 identity cards
0:12:41 > 0:12:47before she realised her phenomenal memory was taking over.
0:12:55 > 0:13:00I think the big breakthrough was when you realised you knew the elephants, you felt empowered.
0:13:00 > 0:13:03You could just go out there and look and you knew them,
0:13:03 > 0:13:07like you would see someone on the street in your hometown and recognise them.
0:13:11 > 0:13:18Now, her encyclopaedic mind holds details of countless unfolding family sagas.
0:13:23 > 0:13:32During the hours she spends at the Bai, she notes all the arrivals, and crucially, who greets whom.
0:13:35 > 0:13:38It's late afternoon, and Andrea has noticed
0:13:38 > 0:13:43two related elephants who've arrived from different parts of the forest.
0:13:43 > 0:13:48ANDREA: This is Mimi One, who's the matriarch of this group.
0:13:48 > 0:13:50Mimi One knows that Mimi Two is there.
0:13:50 > 0:13:54Yeah, they're heading right towards each other.
0:13:54 > 0:13:58Here we go, there's a nice greeting going on right now.
0:13:58 > 0:14:03Some very low frequency, yeah, now they're trunking each other.
0:14:03 > 0:14:07Yeah, yep, that's a mother and daughter.
0:14:07 > 0:14:10So some of these greetings are very subtle and if you know the
0:14:10 > 0:14:12individuals then you can predict them.
0:14:15 > 0:14:20By understanding these relationships, Andrea's made an important discovery.
0:14:23 > 0:14:28In the forest beyond the Bai, it's rare to see more than one elephant at a time.
0:14:28 > 0:14:32People assumed they lead solitary, independent lives.
0:14:35 > 0:14:39Andrea believes that, even though relatives might not stay together in
0:14:39 > 0:14:42the forest, they do appear to know each other's whereabouts.
0:14:47 > 0:14:54I think there was a general misconception about forest elephants only having small family groups.
0:14:54 > 0:14:58But they do have extensive networks and they should because,
0:14:58 > 0:15:00we know that about savannah elephants,
0:15:00 > 0:15:04why shouldn't forest elephants still maintain these social groups?
0:15:04 > 0:15:09Dzanga Bai, as well as offering medicinal salts,
0:15:09 > 0:15:14appears to be an important venue for elephant family reunions.
0:15:16 > 0:15:23Andrea is beginning to understand why the BaAka call this place 'The Village of Elephants'.
0:15:26 > 0:15:32But even the BaAka don't understand how the elephants appear to second guess each other's movements...
0:15:32 > 0:15:36how they know when other family members will be at the Bai.
0:15:43 > 0:15:44To get to the bottom of this,
0:15:44 > 0:15:48Andrea has had to start thinking like an elephant...
0:15:52 > 0:15:56..tuning in to this forest world as they do.
0:16:21 > 0:16:24A heavy storm prevents Andrea being at the Bai,
0:16:24 > 0:16:28but even from her office, she can hear the elephants calling.
0:16:30 > 0:16:35For two decades, she's spent more time with elephants than with her friends and family.
0:16:35 > 0:16:39But even so, she's only witnessed a fraction of what they do.
0:16:44 > 0:16:48Forest elephants spend only 5% of their lives at the Bai -
0:16:48 > 0:16:51mostly at night when Andrea's not there.
0:16:57 > 0:17:00THUNDER
0:17:10 > 0:17:14It's at night, when they're visible only by starlight,
0:17:14 > 0:17:18that the elephants are at their most sociable...
0:17:18 > 0:17:20and most vocal.
0:17:24 > 0:17:27It's also when Andrea is most worried for them.
0:17:29 > 0:17:36Huge reunions out in the open place forest elephants in grave danger.
0:17:36 > 0:17:41Every year, one in ten of Dzanga's elephants is taken by poachers.
0:18:02 > 0:18:06Andrea's no longer here just to study them...
0:18:06 > 0:18:09she feels a growing duty to protect them.
0:18:22 > 0:18:26She believes their conversations are rich in meaning,
0:18:26 > 0:18:30and that one way to help is to listen to what they're saying.
0:18:32 > 0:18:36Today, she's adding to her vocabulary.
0:18:36 > 0:18:41And to get a better view of the clearing, she's working from a viewing platform.
0:18:42 > 0:18:47We're up pretty high, I think we're up about maybe seven metres
0:18:47 > 0:18:50and you can see one end of the Bai from the other.
0:18:52 > 0:18:57And you see all the entrances to the Bai, so I'm able to keep track of all the individuals that come in.
0:18:59 > 0:19:03From up here, she can compile a kind of elephant phrase book
0:19:03 > 0:19:08which links particular behaviour to the calls they make.
0:19:08 > 0:19:15What I'm doing is I'm trying to capture vocal sequences between elephants in the clearing
0:19:15 > 0:19:18in order to build up an elephant lexicon,
0:19:18 > 0:19:21what these vocalisations mean.
0:19:21 > 0:19:26Because I know the individuals, I can also anticipate these vocal events.
0:19:33 > 0:19:36Someone's lost.
0:19:36 > 0:19:38It's probably a juvenile lost its family.
0:19:46 > 0:19:49An elephant's hearing is phenomenal.
0:19:49 > 0:19:52They can hear much deeper sounds than we can.
0:19:55 > 0:19:58Technology is helping Andrea to record these very low frequency calls
0:19:58 > 0:20:01that are normally inaudible to humans.
0:20:05 > 0:20:07Yeah, Milo's checking out this female.
0:20:11 > 0:20:13She's doing a very nice rumble.
0:20:17 > 0:20:24Elephants often do that while the female's being checked out by a male, they do this real low rumble.
0:20:24 > 0:20:27Andrea can now identify ten different types of call.
0:20:30 > 0:20:36She's even discovered that each family has a distinctive voice.
0:20:36 > 0:20:39BABY ELEPHANT CRIES
0:20:39 > 0:20:42Oh, separated from its mother.
0:20:47 > 0:20:49Oh, the mother is coming, here comes the mother -
0:20:49 > 0:20:51the mother hears the baby crying.
0:20:51 > 0:20:54Here she is, she's vocalising.
0:20:54 > 0:20:59There's a lot of low frequency going on now, reassuring the calf.
0:20:59 > 0:21:03And probably the calf is learning the family's
0:21:03 > 0:21:04specific calls.
0:21:12 > 0:21:18Back in camp, Andrea can analyse the recordings and start to see the pattern of each elephant call.
0:21:21 > 0:21:23This is a clip that I've pulled off.
0:21:23 > 0:21:27It's to illustrate the distress call in a young calf.
0:21:27 > 0:21:29And it's crying,
0:21:29 > 0:21:33and it makes this sort of very low, mournful sound and what you'll see
0:21:33 > 0:21:38next in the tape is the response of two young sub-adult females.
0:21:38 > 0:21:41They approach the calf and then they discover each other and this
0:21:41 > 0:21:44looks like a small greeting, but then they go back and follow
0:21:44 > 0:21:49the calf, who's probably heard from its mother in the meantime and is approaching its mother.
0:21:53 > 0:21:59Each sound recording gets turned into a spectrogram, giving Andrea a detailed picture of the call.
0:21:59 > 0:22:03This is the calf's call and then you have these very low
0:22:03 > 0:22:05frequency calls here.
0:22:05 > 0:22:10I mean, you definitely see the calf calling, you see the mouth open,
0:22:10 > 0:22:12but to know who's making those low frequency calls is difficult.
0:22:12 > 0:22:18But, because the calf turned around and went in the other direction, I would assume it's the mother
0:22:18 > 0:22:22and it recognised its mother's voice and now it's approaching its mother.
0:22:22 > 0:22:26If you collected enough of these distress calls of calves of a certain age,
0:22:26 > 0:22:32you could compare them to see if this is your typical distress call.
0:22:32 > 0:22:35Andrea has developed an amazing skill.
0:22:37 > 0:22:42By learning their language, she can interpret what they're doing.
0:22:45 > 0:22:50This is a greeting between three members of the same family.
0:22:55 > 0:22:57They're all vocalising.
0:22:59 > 0:23:04They've all recognised each other and they've all grouped together and you see their ears are flapping
0:23:04 > 0:23:08and they're trunking each other and they're very excited to be together again.
0:23:08 > 0:23:13So I assume that they were separated for a bit of time because of
0:23:13 > 0:23:18the energy involved in their vocalisations.
0:23:18 > 0:23:22Their rumbles can travel over a mile through dense vegetation.
0:23:22 > 0:23:28Even though family members are spread out, they can hear an invitation to meet up.
0:23:31 > 0:23:35Part of the call is inaudible to our ears, it's infrasonic,
0:23:35 > 0:23:38but a lot of it is audible and that's what we're hearing.
0:23:38 > 0:23:43But these low frequencies are the ones that travel the farthest through the forest.
0:23:43 > 0:23:46If they're having this greeting and there are individuals related to
0:23:46 > 0:23:48them in the nearby forest, they're going to hear it.
0:23:48 > 0:23:52And a lot of times you see other members of their family show up.
0:23:54 > 0:24:00If their social networking is this powerful, they might even be able to warn each other of danger.
0:24:17 > 0:24:21The following morning, the Bai is eerily quiet.
0:24:23 > 0:24:29THEY CONVERSE IN LOCAL DIALECT
0:24:29 > 0:24:31He's saying that
0:24:31 > 0:24:36he's found blood on the trail and there's a lot of elephant tracks.
0:24:36 > 0:24:42Days like this remind Andrea how vulnerable these elephants are.
0:24:42 > 0:24:45I can see blood right here.
0:24:45 > 0:24:49He ran here but we can see tracks all around here... there's more here...
0:24:53 > 0:24:55more here...
0:24:57 > 0:25:00So you can actually see where the elephant has trampled the earth.
0:25:00 > 0:25:01He's probably panicking.
0:25:01 > 0:25:04- And he looks pretty big... - SPEAKS LOCAL DIALECT
0:25:05 > 0:25:08You can see a track right here.
0:25:08 > 0:25:12Pretty big male, that's the track of the front leg.
0:25:12 > 0:25:15Most forest elephants have tusks.
0:25:15 > 0:25:18The biggest adults carry the most ivory.
0:25:21 > 0:25:28OK, This is a big patch of coagulated blood, it's pretty fresh so it's from this night.
0:25:28 > 0:25:31And there's also a track... Now they're saying it might be a female.
0:25:31 > 0:25:35Where we are now is only about probably 30 metres from the Bai.
0:25:35 > 0:25:39But we suspect the elephant was probably shot on the other side and ran because we didn't hear any
0:25:39 > 0:25:43gunshot in the night and, generally, somebody will hear a gun if it goes off.
0:25:47 > 0:25:53Dzanga Bai is within a National Park, so all Andrea can do is report the incident to forest guards.
0:26:02 > 0:26:06It's a hard place to police, but Andrea's very presence in the
0:26:06 > 0:26:10area does make events like this less frequent than they'd otherwise be.
0:26:15 > 0:26:19Andrea wants local people to understand the value of elephants,
0:26:19 > 0:26:22not just as intelligent, interesting animals,
0:26:22 > 0:26:24but because, in their secret wanderings,
0:26:24 > 0:26:29elephants influence the shape and richness of the forest itself.
0:26:41 > 0:26:46The richer they make the forest, the more food there is for everyone.
0:26:47 > 0:26:53The most obvious way they do this is by engineering pathways through the tangle of vegetation.
0:26:56 > 0:27:03Over time, elephant feet have created wide trails, highways that run for
0:27:03 > 0:27:08hundreds of miles through the forest, and which link key resources.
0:27:13 > 0:27:18We're walking along a pretty well-worn elephant track and occasionally
0:27:18 > 0:27:22the areas open up like this because of the existence of this tree.
0:27:22 > 0:27:28This is a particularly favoured tree of elephants, it's Duboskia.
0:27:28 > 0:27:33And generally the forest opens up here because elephants come here and they eat the fruits.
0:27:33 > 0:27:35It's a very fibrous fruit and we find it
0:27:35 > 0:27:38in about 90% of the elephant dung throughout the year.
0:27:38 > 0:27:42So there's always a Duboskia tree fruiting
0:27:42 > 0:27:46but they also tend to scrape the bark off and eat that.
0:27:56 > 0:27:58Their trails are used by many other animals.
0:28:01 > 0:28:07Western Lowland gorillas eat the same kinds of fruit as elephants,
0:28:07 > 0:28:11so elephant paths are like signposts to food.
0:28:30 > 0:28:34But there's one type of fruit that only the elephants can get to.
0:28:38 > 0:28:44Omphalocarpum fruits are encased in a tough shell, making them virtually impossible to crack.
0:28:52 > 0:28:55Elephants have the perfect tool for the job.
0:29:09 > 0:29:16They may devour everything, but the seeds of all the fruits they eat pass unharmed through the gut.
0:29:20 > 0:29:29As they travel, the elephants replant the seeds, creating avenues of their favourite fruit trees.
0:29:31 > 0:29:39Where there's a lot of elephant activity, areas open up and sedges and grasses can take hold.
0:29:50 > 0:29:53They are fundamental to the gorillas' diet.
0:29:53 > 0:29:59These great apes would find life much harder without the elephants.
0:30:02 > 0:30:05But the relationship isn't an amicable one.
0:30:18 > 0:30:22Elephants don't like other animals sharing the clearings they created.
0:30:28 > 0:30:34As they dig for minerals, they actually maintain and expand these Bais.
0:30:34 > 0:30:38Over centuries, elephants have made hundreds of small
0:30:38 > 0:30:43clearings in the forest, but none compares to the importance of Dzanga.
0:30:48 > 0:30:51It's now the dry season, one of the busiest.
0:30:51 > 0:30:55And for Andrea one of the most fascinating times at the Bai.
0:31:00 > 0:31:03It's when most of the big bulls show up.
0:31:11 > 0:31:14This is Triple Bite.
0:31:14 > 0:31:19Over the years, Andrea has watched him grow from an adolescent
0:31:19 > 0:31:21into one of the most dominant bulls in the clearing.
0:31:26 > 0:31:28But he hasn't been here for nearly a year.
0:31:31 > 0:31:37He has travelled hundreds of miles to reach Dzanga, where he knows he can find females.
0:31:44 > 0:31:51It's not just the females that sense the tension rippling across the Bai when the big males arrive.
0:31:51 > 0:31:56That's Gonya Five chasing Sitatunga.
0:31:58 > 0:32:04For the younger bulls especially, this can be a very exciting time.
0:32:04 > 0:32:07The young elephants they come and they're very feisty
0:32:07 > 0:32:11and they'll just run around in the Bai for the entire afternoon.
0:32:11 > 0:32:15He's like a young male in puberty so he's learning how to be a man.
0:32:25 > 0:32:30Unlike on the savannah, elephants rarely see each other in the forest.
0:32:35 > 0:32:41This clearing offers rare moments of contact, time for the bulls to get to know each other
0:32:41 > 0:32:43and learn each other's strengths.
0:32:56 > 0:33:00And everything they do is copied by the youngsters.
0:33:14 > 0:33:16A lot of learning going on here,
0:33:19 > 0:33:20sort of like a schoolyard.
0:33:23 > 0:33:26Elephants are so much like humans.
0:33:26 > 0:33:33We learn to be human, we end up being socialised, and elephants undergo the same process.
0:33:34 > 0:33:38Andrea calls this "Bull School",
0:33:38 > 0:33:42a time and place to learn their position in elephant society.
0:33:45 > 0:33:49When I started this study I had no idea about how conscious they were
0:33:49 > 0:33:52and yes, they do have good memories and they have personalities.
0:33:52 > 0:33:58And watching an elephant grow from childhood to adulthood has been astonishing to see the changes
0:33:58 > 0:34:01and how much they really have to learn to become an elephant.
0:34:07 > 0:34:11Andrea has revealed something even more significant about Dzanga Bai.
0:34:15 > 0:34:20This clearing is the place where elephant culture is passed on.
0:35:20 > 0:35:26Understanding the central importance of Dzanga Bai places an even bigger burden on Andrea's shoulders.
0:35:28 > 0:35:32Her presence here is not just preventing elephant deaths,
0:35:32 > 0:35:36but the possible disruption of their entire way of life.
0:35:43 > 0:35:46She wants to protect the elephants, but she has to work
0:35:46 > 0:35:51within a culture that has very different attitudes and priorities to her own.
0:35:54 > 0:35:56For centuries the local BaAka
0:35:56 > 0:36:01have hunted forest wildlife for food and Andrea is pragmatic about that.
0:36:07 > 0:36:10Traditionally, the forest for them has been
0:36:10 > 0:36:12their life source, where they find everything they need.
0:36:12 > 0:36:17You know, they eat elephant meat. That's not a mystery to me.
0:36:20 > 0:36:24Andrea steers a difficult course between her feelings
0:36:24 > 0:36:28for the elephants and respect for the BaAka's traditions and needs.
0:36:31 > 0:36:33A lot of them will go into the forest for two or three months
0:36:33 > 0:36:38of the year where they'll gather honey and certain seeds that they eat.
0:36:38 > 0:36:42I've made their work schedule very flexible because if they want to go
0:36:42 > 0:36:47into the forest they can tell me, and I'll say fine.
0:36:47 > 0:36:50That's a very important part of their culture,
0:36:50 > 0:36:55and they need to teach that to their children because ultimately it may be the only way they'll survive.
0:36:59 > 0:37:06Not many employers would be this flexible, but she believes it's the only way.
0:37:08 > 0:37:11You have to be there for them when they really need you
0:37:11 > 0:37:14because otherwise they won't be there for you when you need them.
0:37:14 > 0:37:19And I think that's really sustained me here in many ways, that connectedness to people here.
0:37:24 > 0:37:27Andrea treats her BaAka workers like family,
0:37:27 > 0:37:30making regular trips to buy them supplies.
0:37:48 > 0:37:51The local village is only eight miles from Andrea's camp,
0:37:51 > 0:37:56but the round trip on rough, dirt tracks takes a whole day.
0:38:17 > 0:38:21It's impossible to grow anything in camp because elephants raid the crops at night.
0:38:21 > 0:38:25The heat and humidity means that nothing stays fresh for long.
0:38:30 > 0:38:36This is smoked fish and if you buy it smoked you can keep it up to two weeks in camp without refrigeration.
0:38:36 > 0:38:38I don't eat smoked fish.
0:38:38 > 0:38:41I mean it's an acquired taste.
0:38:44 > 0:38:48Protein is difficult to come by.
0:38:48 > 0:38:51What there is tends to come from the forest.
0:38:53 > 0:38:56Local people are allowed to hunt outside the national park,
0:38:56 > 0:39:00but laws control which animals can be taken as bush meat, and how many.
0:39:03 > 0:39:08Even so, Andrea knows there's elephant meat under the counter.
0:39:20 > 0:39:25The guards that patrol the forest do their best to contain this black market.
0:39:27 > 0:39:31More commonly, they pick up people who have taken too many animals
0:39:31 > 0:39:34or who have the wrong licences for their weapons.
0:39:39 > 0:39:42Most people are just trying to feed their families.
0:39:47 > 0:39:52Elephant meat is a delicacy, but it's rarely on the menu.
0:39:52 > 0:39:55They are hard to kill with a normal shotgun.
0:39:58 > 0:40:01And Andrea's work is making a difference.
0:40:03 > 0:40:09When I first started working with the BaAka, I think we all had this vision that they know the wildlife.
0:40:09 > 0:40:13But they didn't know elephants in the way that they've gotten to know them with me.
0:40:13 > 0:40:18But because now they've spent many years observing elephants first hand their ideas have totally changed.
0:40:18 > 0:40:23In fact one of them said to me one day, "Madame, these aren't elephants, these are people,"
0:40:23 > 0:40:26and it was very touching to me to hear that.
0:40:32 > 0:40:40Sadly, local opinions are increasingly affected by bigger changes sweeping across the region.
0:40:45 > 0:40:48Andrea's seeing more and more elephants entering the Bai.
0:40:50 > 0:40:53She thinks they're being pushed into Dzanga,
0:40:53 > 0:40:57as commercial logging disrupts their extensive network of paths.
0:41:04 > 0:41:09What's more, ivory is back in demand.
0:41:09 > 0:41:14And the tusks of forest elephants are most sought after.
0:41:15 > 0:41:22They are pinker and much denser than those of savannah elephants, resulting in a "rose ivory"
0:41:22 > 0:41:26that's highly prized for carving.
0:41:26 > 0:41:29Its value is astronomical.
0:41:29 > 0:41:34A pair of tusks raises 90,000 on the black market.
0:41:39 > 0:41:42It's no wonder some local people get drawn into poaching.
0:41:49 > 0:41:53Human conflict in neighbouring countries floods the area with weapons.
0:41:58 > 0:42:06The guards confiscate many of them, but there are plenty more and they're largely pointing at Dzanga.
0:42:16 > 0:42:23It's the easiest place to find and kill forest elephants, unless, of course, Andrea is there.
0:42:25 > 0:42:28I will react immediately to any threat.
0:42:28 > 0:42:32I can be out at the clearing having a nice afternoon and then I hear gunshot and I'm gone,
0:42:32 > 0:42:37I'm back to camp, on the radio trying to get guards motivated.
0:42:37 > 0:42:43In many ways, Andrea is the only person standing between the elephants and mass slaughter.
0:42:46 > 0:42:51After years of wanting to be here, she now dare not leave.
0:42:55 > 0:43:02Even trips to the local town could endanger the elephants, because she's under surveillance too.
0:43:04 > 0:43:08Her absence from the Bai never seems to go unnoticed.
0:43:13 > 0:43:18The poachers are very localised, I mean, they live in the village, I know them, they know me.
0:43:18 > 0:43:21So when I'm driving out of town they see me.
0:43:21 > 0:43:23People are going "Andrea" by the side of the road,
0:43:23 > 0:43:26so they know I'm leaving and that's a worry because there
0:43:26 > 0:43:30have been incidences where there is poaching when I've been gone.
0:43:45 > 0:43:47This video was taken when I wasn't at the Bai.
0:43:47 > 0:43:51It was taken by one of the assistants and he told me about this bull.
0:43:51 > 0:43:54This is an elephant Andrea knows well.
0:43:54 > 0:43:58But he now has a line of wounds across his flank.
0:43:58 > 0:44:03He's a young bull, he's about 35 to 40, his name is Hezy.
0:44:05 > 0:44:10The wounds are definitely bothering him. You see this often in elephants when they've been wounded.
0:44:10 > 0:44:12They'll spend a lot of time either
0:44:12 > 0:44:14throwing water on themselves or mud.
0:44:16 > 0:44:20Cos those wounds are pretty deep, I mean they
0:44:20 > 0:44:25pierce the epidermis, which is about half an inch thick.
0:44:25 > 0:44:29Andrea can tell from the pattern of wounds this was not the result of a fight.
0:44:32 > 0:44:34That many wounds, I'd say a Kalashnikov.
0:44:37 > 0:44:41Hezy has returned to the likely scene of the crime,
0:44:41 > 0:44:46perhaps because it's also the best place to treat his wounds.
0:44:46 > 0:44:50But since this video was taken on May 13th we haven't seen him,
0:44:50 > 0:44:56so, he might have even died, might have developed an infection from the wounds he sustained.
0:45:06 > 0:45:13With the stakes becoming higher, even Andrea cannot live in such remote forest without protection.
0:45:19 > 0:45:23She needs to share the weight of responsibility,
0:45:23 > 0:45:25and a chance has come.
0:45:32 > 0:45:40She's been asked to help with a pioneering study at the other end of the elephants' range.
0:45:40 > 0:45:46It means, for a few weeks, she will have to leave the elephants at Dzanga Bai.
0:45:51 > 0:45:58Forest elephants inhabit a huge area stretching over two million square miles.
0:45:58 > 0:46:02But there could be fewer than 125,000 left.
0:46:14 > 0:46:17This is Gabon...
0:46:21 > 0:46:24..where the African rain forest meets the ocean.
0:46:27 > 0:46:31It's considered to be one of the last safe havens for forest elephants.
0:46:31 > 0:46:38It couldn't look more different from Dzanga.
0:46:43 > 0:46:50Beyond the endless beaches there's a mosaic of savannah, forest and swamp.
0:46:54 > 0:46:57It's a new experience for Andrea.
0:47:01 > 0:47:05She's used to seeing groups of over 100 elephants together.
0:47:06 > 0:47:11Here, just seeing one is a challenge.
0:47:11 > 0:47:15You don't see many, but when you do see them they're doing extraordinary
0:47:15 > 0:47:18things that I've never seen before in my life.
0:47:38 > 0:47:42Elephants have adapted to this diverse range of habitats,
0:47:42 > 0:47:46even snorkelling across flooded channels and swamps.
0:47:50 > 0:47:53This place gives me a lot of hope in terms of
0:47:53 > 0:47:57elephant conservation, just because the elephants aren't accessible.
0:47:58 > 0:48:03People can't hunt in these swamps and so that is a refuge for them.
0:48:05 > 0:48:11However, there's no clearing like Dzanga to see elephants and monitor what they do.
0:48:14 > 0:48:18Researchers have had to find a different way to tune into their lives.
0:48:27 > 0:48:33Andrea's joined Peter Wrege, from the Elephant Listening Project at Cornell University.
0:48:33 > 0:48:39He's an expert in acoustic research, something he hopes will reveal more about forest elephants.
0:48:39 > 0:48:43So, this is the hard drive to store the data and then this is
0:48:43 > 0:48:49the computer, microcomputer, that's actually processing the sound.
0:48:49 > 0:48:55He's putting up remote listening devices to eavesdrop on them.
0:48:55 > 0:49:00But he needs Andrea's help because only she can translate their calls.
0:49:01 > 0:49:08We're still in kindergarten in learning exactly what their vocalisations mean and the social
0:49:08 > 0:49:14context in which they occur, and this is where Andrea is so vital to what we're doing
0:49:14 > 0:49:18now, is that she knows the behaviour of the elephants very, very well.
0:49:20 > 0:49:23These recording units contain state of the art microphones,
0:49:23 > 0:49:27specially designed to pick up low frequency calls.
0:49:31 > 0:49:36They can be left running for three months, 24 hours a day.
0:49:39 > 0:49:43Each one records rumbles from over a square mile of jungle.
0:49:43 > 0:49:47- It's better than CCTV.- That's OK.
0:49:47 > 0:49:53So, we're finished, ready to go. It's absolutely a kind of spying on elephants, listening in
0:49:53 > 0:50:00on their conversations in order to understand what they're doing, how many there are, where they're going.
0:50:05 > 0:50:12Peter already has 33 of these bugging devices deployed in the rain forests of Central Africa.
0:50:12 > 0:50:18Now, he needs Andrea's help to decode the latest recordings.
0:50:21 > 0:50:24ELEPHANTS RUMBLE
0:50:28 > 0:50:31- It's pretty deep. - Hmm.- The different rumbles tell
0:50:31 > 0:50:35Andrea how many elephants are present and what they're doing.
0:50:38 > 0:50:41OK, that for me, this first call
0:50:41 > 0:50:44may be an adult female
0:50:44 > 0:50:47and this might be a response to that call.
0:50:50 > 0:50:51Let's try this one then.
0:50:59 > 0:51:02- This is a young animal again. - Young animal.
0:51:02 > 0:51:07Just by listening, she can tell which members of the family may be vocalising and why.
0:51:08 > 0:51:13Would you call those all protest calls, or you said also sometimes they just get separated...
0:51:13 > 0:51:15No, I think they're lost calls, I think they're separated.
0:51:15 > 0:51:20So you can, you're actually hearing a difference between a protest and a lost?
0:51:20 > 0:51:22Yes, those sound like to me lost calls.
0:51:22 > 0:51:27It starts low and it goes up. The structure looks
0:51:27 > 0:51:29- the same.- Yeah, well that's one of the problems.
0:51:29 > 0:51:35I need to know more from your ear what do I need to be looking for to make that distinction.
0:51:40 > 0:51:47Andrea's knowledge will help Peter create a visual record of specific elephant calls.
0:51:48 > 0:51:53He can then refer to this library and learn even more about elephant life here.
0:51:57 > 0:52:00You don't have anything before that, do you, recorded?
0:52:02 > 0:52:04Oh, I'm sure I do.
0:52:04 > 0:52:06This is clipped out.
0:52:06 > 0:52:08- It almost sounds like mating. - Really?
0:52:08 > 0:52:12Yeah, because you've got a lot of these high pitched things going in.
0:52:13 > 0:52:18Without even seeing elephants, it's possible to translate
0:52:18 > 0:52:21their rumbles into information about breeding success.
0:52:26 > 0:52:30They've also revealed the dangers elephants face.
0:52:34 > 0:52:40Before his study began, Peter was told there was no poaching in the area.
0:52:41 > 0:52:44That's not the case.
0:52:44 > 0:52:48These, I'm pretty sure are high powered rifle shots.
0:52:53 > 0:52:56So, these devices also spy on the poachers.
0:52:58 > 0:53:05By pinpointing hotspots of illegal hunting, guards could target areas more strategically and efficiently.
0:53:05 > 0:53:07Lot of frogs.
0:53:07 > 0:53:10Yeah, those are definitely guns.
0:53:10 > 0:53:16And again, this is a bit strange because the intensity changes.
0:53:20 > 0:53:23CRACKING SOUND ON TAPE
0:53:27 > 0:53:29- That's a tree.- Really?
0:53:29 > 0:53:32That's a tree. This first thing right here, this
0:53:32 > 0:53:36first sound you hear, it's the crack and then it's the ki ki ki ki.
0:53:38 > 0:53:39I don't know, Andrea.
0:53:39 > 0:53:42No, I'd put money on that one.
0:53:42 > 0:53:44CRACKING SOUND
0:53:44 > 0:53:46Hear that?
0:53:46 > 0:53:49CRACKING SOUND CONTINUES
0:53:49 > 0:53:51And that's the whole thing going down.
0:53:51 > 0:53:53It might get hung up on something.
0:53:53 > 0:53:55True, a lot of trees out there.
0:53:55 > 0:53:59Yeah, it's very complicated, tree fall.
0:53:59 > 0:54:0420 years in the forest has taught Andrea what to listen out for.
0:54:04 > 0:54:09And Peter knows the value of her extensive memory bank.
0:54:09 > 0:54:12I'm very concerned actually about
0:54:12 > 0:54:17the huge knowledge that Andrea has about these elephants.
0:54:17 > 0:54:22I find it phenomenal what she remembers.
0:54:22 > 0:54:30No-one else comes anywhere close to what she has, so I think it is critical that we basically
0:54:30 > 0:54:33kind of extract this information from her brain.
0:54:34 > 0:54:41This experience has shown Andrea how her knowledge could help elephants across their whole range.
0:54:43 > 0:54:45But she will always feel a strong connection to the individuals
0:54:45 > 0:54:50back at Dzanga that have been her life for so long.
0:54:55 > 0:55:01I probably think about these elephants during my waking hours about 90% of the time.
0:55:01 > 0:55:05I'm very concerned about them. I mean I feel it's my moral responsibility to be there.
0:55:08 > 0:55:13Hopefully when I get back, you know, the numbers will be the numbers I'm expecting to see.
0:55:22 > 0:55:26When Andrea returns to Dzanga there's depressing news.
0:55:28 > 0:55:31More poaching has been reported in the area.
0:55:33 > 0:55:39The demand for ivory is now threatening the very existence of forest elephants.
0:55:47 > 0:55:49Recent data has shown we've maybe lost between
0:55:49 > 0:55:5440 and 50% of the population in the Central Africa area.
0:55:56 > 0:56:00So there's increasing pressure on this area where there are still animals left over.
0:56:02 > 0:56:06Dzanga Bai continues to be a magnet for forest elephants,
0:56:06 > 0:56:09and a privileged window into their lives.
0:56:15 > 0:56:17That's Marnie.
0:56:17 > 0:56:19Oh, there's a new calf.
0:56:24 > 0:56:29For the next 60 years, this calf could return time after time to take
0:56:29 > 0:56:34the salts, meet up with family and to find a mate.
0:56:40 > 0:56:43That's nice. That's a new baby for today.
0:56:44 > 0:56:47He's trying to figure out what to do with his trunk.
0:56:54 > 0:56:59But if Andrea were to leave, who knows what upheavals he and his family would face?
0:57:17 > 0:57:20I'm not an optimist about the future for animals here.
0:57:20 > 0:57:24So I mean, I get a little bit emotional about it,
0:57:24 > 0:57:31but the reality is, these animals if they're not protected they're going to be poached.
0:57:35 > 0:57:41For two decades, she has carried this responsibility on her shoulders.
0:57:42 > 0:57:45But she cannot stay here for ever.
0:57:48 > 0:57:51I've been here for 20 years and I'm beginning to feel my age.
0:57:51 > 0:57:58I think I'll stay here as long as I can walk and I can get support to do what I do because I love this place.
0:57:58 > 0:58:01There's a lot of downsides to my job, but coming here every day
0:58:01 > 0:58:06is what makes it all worthwhile and just seeing them right here.
0:58:09 > 0:58:16Maybe the pioneering study in Gabon will eventually take the pressure off her.
0:58:16 > 0:58:22And the remote listening devices will become her ears in the forest,
0:58:22 > 0:58:27allowing elephants to tell us of the dangers they face,
0:58:27 > 0:58:32as they continue their conversations through the jungle.
0:58:46 > 0:58:50Subtitles by Red Bee Media Ltd
0:58:50 > 0:58:54E-mail us at subtitling@bbc.co.uk