0:00:30 > 0:00:34In the great Tree of Life,
0:00:34 > 0:00:39one branch of the mammals has a particular fascination for us, for we belong to it.
0:00:42 > 0:00:44Primates.
0:00:52 > 0:00:56Primate hands provide a firm grip.
0:00:56 > 0:01:00And forward facing eyes accurately assess distance.
0:01:06 > 0:01:10Both are crucial for a lifestyle that began in the trees.
0:01:17 > 0:01:22Intelligence among primates can excel that of all other animals.
0:01:29 > 0:01:32Primates can solve difficult problems...
0:01:34 > 0:01:36..develop thoughts and ideas...
0:01:38 > 0:01:42..and build long-lasting relationships.
0:01:44 > 0:01:50But most importantly, primates remember what they learn during their lives.
0:01:52 > 0:02:00This film reveals how intelligence helps our closest relatives to tackle the many challenges of life.
0:02:30 > 0:02:34There are more than 350 primate species on Earth.
0:02:41 > 0:02:46Since they first appeared over 65 million years ago,
0:02:46 > 0:02:51these clever animals have become adapted to an extraordinary range of habitats.
0:02:57 > 0:03:00The Awash region of southern Ethiopia.
0:03:05 > 0:03:09A harsh, remote scrubland.
0:03:14 > 0:03:19But primates have learned how to make it their home.
0:03:30 > 0:03:36Hamadryas baboons are waking up from a night spent high on the cliffs.
0:03:40 > 0:03:47These monkeys live in groups up to four hundred strong, with no single leader.
0:03:47 > 0:03:55Theirs is a very complex society, made up of dozens of small harems, each governed by a male.
0:03:58 > 0:04:02Every morning they leave the safety of the cliffs to find food.
0:04:12 > 0:04:15Top-ranking males lead the way.
0:04:18 > 0:04:22They can be very severe with their females if there is the slightest misdemeanour.
0:04:40 > 0:04:46Despite their individual strength, hamadryas baboons prefer to travel as a troop.
0:04:46 > 0:04:48It's safer that way.
0:05:01 > 0:05:05On this particular morning, something stops them in their tracks.
0:05:14 > 0:05:19Another troop is using these cliffs as a barracks.
0:05:29 > 0:05:32More than a thousand baboons can overnight here.
0:05:32 > 0:05:35And a rival faction is heading directly their way.
0:06:05 > 0:06:10In the chaos of warfare, males settle old scores.
0:06:17 > 0:06:21This is also their best chance of stealing females.
0:06:52 > 0:06:56When the fighting is over, the harems reform.
0:07:01 > 0:07:06Lead males punish any of their females who had dared to stray.
0:07:19 > 0:07:24Strict discipline is essential if order is to be maintained.
0:07:35 > 0:07:38It's a harsh social system
0:07:38 > 0:07:43but it works for hamadryas baboons here on these arid plains.
0:07:51 > 0:07:56In other parts of the world, primates have had to organise
0:07:56 > 0:08:01their societies in a different way to cope with different challenges.
0:08:05 > 0:08:09Mid-winter in the Japanese Alps.
0:08:13 > 0:08:19The Kamicoche Valley is the haunt of the most northerly-dwelling monkeys.
0:08:26 > 0:08:33To live here you must be able to survive temperatures which plunge to minus 20 centigrade.
0:08:44 > 0:08:46The Japanese macaque.
0:08:57 > 0:09:04Dense thick layers of fur help to insulate these snow moneys in this testing environment.
0:09:09 > 0:09:12But they still feel the cold.
0:09:19 > 0:09:23At this time of the year, food is scarce.
0:09:27 > 0:09:30But macaques are adaptable and clever.
0:09:36 > 0:09:42The troop has learnt that this river stays ice-free the year round.
0:09:47 > 0:09:51This female knows it's a good place to gather insect larvae
0:09:51 > 0:09:55from under the rocks, using her versatile hands and nimble fingers.
0:10:04 > 0:10:08In winter, this troop spends most of its time searching for food.
0:10:15 > 0:10:19The same underground forces that prevent this river from freezing
0:10:19 > 0:10:22bring great comfort to others.
0:10:28 > 0:10:31The Japanese Alps were built by volcanoes.
0:10:31 > 0:10:35Many of them are still active.
0:10:35 > 0:10:42And in a region called Hell's Valley, some snow monkeys have found the perfect winter resort.
0:10:49 > 0:10:52A thermal spa,
0:10:52 > 0:10:56where the water temperature is a blissful 41 degrees centigrade.
0:11:19 > 0:11:23Everyone wants in, but primates being primates,
0:11:23 > 0:11:26there are pool-side politics.
0:11:36 > 0:11:39This is an exclusive members-only club.
0:11:39 > 0:11:42INFANT SCREECHES
0:11:42 > 0:11:46Only the highest-ranking females and infants are allowed in.
0:11:50 > 0:11:56Everyone obeys this male, who guards the pool and vets the entrants.
0:12:06 > 0:12:13These youngsters, born of the right bloodline, don't know how privileged they are.
0:12:19 > 0:12:24Lower ranking individuals are literally left out in the cold.
0:12:31 > 0:12:35Japanese macaque society is very divided.
0:12:37 > 0:12:40There are those that have.
0:12:40 > 0:12:43And those that have not.
0:12:51 > 0:12:59And that is a harsh division, because the sixty degrees that separate the steaming water
0:12:59 > 0:13:01from the freezing surroundings
0:13:01 > 0:13:05can make the difference between life and death.
0:13:14 > 0:13:19But by far the majority of primate species
0:13:19 > 0:13:22live in warm tropical forests.
0:13:28 > 0:13:32Among them are the largest of all.
0:13:38 > 0:13:44Gorillas live in stable family groups with just a single leader,
0:13:46 > 0:13:48a silverback male.
0:13:57 > 0:14:02This one, here in the Congo basin, is the guardian of his family
0:14:02 > 0:14:06which includes five females and their infants.
0:14:15 > 0:14:19He has the responsibility of protecting them from the dangers
0:14:19 > 0:14:22that abound on the forest floor where they feed.
0:14:30 > 0:14:37To sustain his huge size, he must consume up to thirty kilos a day.
0:14:39 > 0:14:46It's mostly plant food, but western gorillas also enjoy a sprinkling of termites.
0:14:51 > 0:14:57The youngsters need to eat far less than their father, so they've got time on their hands.
0:15:03 > 0:15:08They like to play for the same reasons we do...for fun.
0:15:08 > 0:15:11And it helps build long-lasting relationships.
0:15:13 > 0:15:16Their protector keeps a watchful eye on them.
0:15:26 > 0:15:28But then...
0:15:30 > 0:15:33..it's time for his siesta.
0:15:42 > 0:15:45DISTANT GRUNTING
0:15:48 > 0:15:51Something shatters the peace.
0:15:58 > 0:16:01This silverback's territory is one of the best.
0:16:01 > 0:16:05But it has borders with at least eight other gorilla groups.
0:16:15 > 0:16:17DISTANT GRUNTING AND CHEST BEATING
0:16:19 > 0:16:25The sound of chest-beating travels more than a mile through the tangled under-storey.
0:16:35 > 0:16:38It's a territorial drum-beat.
0:16:41 > 0:16:45Everyone must know who is boss around here.
0:16:59 > 0:17:04Other smaller primates are rather more secretive.
0:17:05 > 0:17:10One of the most unusual is found in Sulawesi, Indonesia.
0:17:15 > 0:17:21It lives among the aerial roots of this strangler fig.
0:17:28 > 0:17:33Its ancestors were daytime hunters, but they found that there was less
0:17:33 > 0:17:37competition if they looked for food in the twilight.
0:17:46 > 0:17:50Now they only stir after dark.
0:17:59 > 0:18:02Nonetheless there's a lot of insect food around.
0:18:19 > 0:18:22The spectral tarsier.
0:18:29 > 0:18:32Tarsiers are the only totally carnivorous primates on Earth.
0:18:37 > 0:18:40They've hardly changed in 45 million years.
0:18:43 > 0:18:47Their huge eyes can see in even the faintest light.
0:18:52 > 0:18:58These eye-balls are so wide they can't swivel in their sockets -
0:18:58 > 0:19:01tarsiers have to rotate their heads.
0:19:03 > 0:19:07Their mobile ears can detect the faintest sounds.
0:19:10 > 0:19:14And their powerful legs enable them to jump 40 times their own length.
0:19:22 > 0:19:25The family group fans out to hunt.
0:19:30 > 0:19:32Prey is not hard to find.
0:19:59 > 0:20:02But the tarsiers must be watchful.
0:20:02 > 0:20:09For a primate just five inches tall, life in the forest is full of danger.
0:20:12 > 0:20:16- The male sounds the alarm. - CHIRPING
0:20:24 > 0:20:27And everyone retreats.
0:20:52 > 0:20:54SHRILL CHIRPING CALLS
0:20:54 > 0:21:00Back in their family tree, the senior male and female send out piercing calls.
0:21:07 > 0:21:09These calls guide any stragglers home,
0:21:09 > 0:21:13and there they renew the family bonds.
0:21:18 > 0:21:22Good communication is one of the hallmarks of primate society.
0:21:28 > 0:21:30WHOOPING CALLS
0:21:30 > 0:21:35Few communicate more musically than lar gibbons
0:21:35 > 0:21:38in the forests of Thailand.
0:21:38 > 0:21:40RHYTHMIC WHOOPING
0:21:54 > 0:21:58Their songs carry for many miles across the canopy,
0:21:58 > 0:22:02proclaiming that this piece of forest is theirs.
0:22:34 > 0:22:40Most primates have excellent colour vision, and colour too can be used in communication.
0:22:45 > 0:22:48Adult Phayre's leaf monkeys might seem rather drab.
0:22:54 > 0:22:56But not so their newborn.
0:23:03 > 0:23:06Bright orange fur makes the babies very conspicuous,
0:23:06 > 0:23:10so the adults can easily keep an eye on them.
0:23:17 > 0:23:21Close friends and relatives are eager to help the mother with baby-sitting.
0:23:21 > 0:23:25It's a good chance for the younger ones to practice parenting.
0:23:32 > 0:23:36As a result, a baby is never left on its own for long.
0:23:43 > 0:23:47When it's a few months old and more independent,
0:23:47 > 0:23:51it will turn the colour of its mother and blend in with the group.
0:23:57 > 0:24:01But until then, it can't be ignored.
0:24:16 > 0:24:22Smell is of particular importance to the primates that live in Madagascar -
0:24:22 > 0:24:24the lemurs.
0:24:26 > 0:24:30They have pointed snouts and wet noses.
0:24:33 > 0:24:36These are ringtail lemurs.
0:24:48 > 0:24:54The males have sharp pads on their wrists with which they scratch the trunks of young trees.
0:24:58 > 0:25:05Glands on their wrists impregnate the cut bark with a pungent smell that acts as a territorial marker.
0:25:09 > 0:25:13Females make smelly marks in their own way.
0:25:14 > 0:25:19This one's scent carries another signal as well as the territorial one.
0:25:19 > 0:25:24It tells males that she's coming in to heat.
0:25:28 > 0:25:33But she will only be sexually receptive for 24 hours or less.
0:25:40 > 0:25:43So tensions run high among the males.
0:26:05 > 0:26:08Amid the commotion, some males sneak off.
0:26:11 > 0:26:18They have anointed their tails with scent and waft it towards her in an attempt to persuade her to mate.
0:26:18 > 0:26:21She's ready...
0:26:21 > 0:26:23but fussy.
0:26:33 > 0:26:39This male adds more of his wrist gland perfume to his tail.
0:26:48 > 0:26:52It seems to work, for they leave the party together.
0:26:59 > 0:27:02And he wafts his way to victory.
0:27:28 > 0:27:32A willingness to mate is a relatively straightforward message.
0:27:35 > 0:27:39But primates are capable of much more complex communication.
0:27:46 > 0:27:49It starts between a mother and her baby.
0:27:53 > 0:27:56The rainforests of Sumatra.
0:28:05 > 0:28:09This female orang-utan is forty-two years old.
0:28:09 > 0:28:14Her third child, a six year old daughter, is still with her.
0:28:20 > 0:28:24Orangs look after their children for longer than any other primate...
0:28:24 > 0:28:26except ourselves.
0:28:26 > 0:28:30It will take her nine years to teach her youngster
0:28:30 > 0:28:35everything she needs to know about this complex tree-top world.
0:28:38 > 0:28:42She must learn how to collect ants and termites.
0:28:52 > 0:28:57How to identify at least 200 kinds of edible plants...
0:28:57 > 0:29:00and how to avoid the poisonous ones.
0:29:03 > 0:29:06And how to judge when fruit, like this durian,
0:29:06 > 0:29:09has ripened to perfection.
0:29:25 > 0:29:30Her child must be able to judge which branches can carry her weight.
0:29:37 > 0:29:41And which insect nests are safe to raid.
0:30:02 > 0:30:08Building up a complete guide to the foods of the forest is a long process.
0:30:28 > 0:30:32Her lessons, of course, aren't limited to food.
0:30:32 > 0:30:36There are other crucial skills she must learn if she is to survive in the tree tops.
0:30:38 > 0:30:44Building a secure nest in which to spend the night, for example, takes years of practice.
0:30:48 > 0:30:52And this is, of course, a rainforest.
0:30:52 > 0:30:54THUNDER RUMBLES
0:30:57 > 0:31:01So all orangs must learn how to make a shelter early in their lives.
0:31:24 > 0:31:32It rains almost every day, so this six year old has already had plenty of practice.
0:31:43 > 0:31:47She might live to be fifty years old and if she too becomes a mother,
0:31:47 > 0:31:52she'll pass on all this expertise to her own children.
0:32:03 > 0:32:07Remembering your lessons is a vital part of primate life.
0:32:17 > 0:32:20It's not just learning how to exploit your environment.
0:32:22 > 0:32:26Just as important is knowing when to do so.
0:32:33 > 0:32:36This is Africa's Cape peninsula.
0:32:36 > 0:32:41It's the furthest south that monkeys have managed to settle.
0:32:51 > 0:32:57There's a wide range of plant food here, but because the soil is so poor in nutrients,
0:32:57 > 0:33:02Chacma baboons find it difficult to get the range of sustenance they need,
0:33:02 > 0:33:04however much they eat.
0:33:16 > 0:33:21So they have had to become quite adventurous in what they will tackle.
0:33:30 > 0:33:34The waters around the Cape are among the richest in the world.
0:33:46 > 0:33:50And the wily baboons have become tidal experts.
0:34:04 > 0:34:11If you rely on the tides to expose your food, you have to work to fairly tight schedules.
0:34:27 > 0:34:35Every two weeks, on the lowest spring tide, there's a chance to collect something really special.
0:34:58 > 0:35:03What they've been waiting for is hidden among the fronds of seaweed.
0:35:15 > 0:35:17Shark eggs.
0:35:41 > 0:35:46Each one is only a tiny mouthful, but there are lots of them
0:35:46 > 0:35:49and they're so nutritious it's worth the trouble.
0:35:54 > 0:35:56But the baboons can't stay long...
0:35:56 > 0:35:59the tide is turning.
0:36:03 > 0:36:09So now they switch their attention to the main course of the day... mussels.
0:36:11 > 0:36:17This delicacy is exposed every day, by every tide.
0:36:23 > 0:36:28Baboons have powerful jaws and huge canines...
0:36:28 > 0:36:30ideal for cracking shells.
0:36:36 > 0:36:40Timing is an essential skill if you are to harvest
0:36:40 > 0:36:46all the food that becomes available at one time or another around a coast.
0:36:55 > 0:37:02Some foods, however, are only available to those who have skilful hands and sharp intelligence.
0:37:04 > 0:37:08On the coast of Costa Rica, among the mangroves,
0:37:08 > 0:37:12live some of the most intelligent monkeys in the whole of the Americas.
0:37:17 > 0:37:21White-faced capuchins.
0:37:21 > 0:37:25They too have learnt to work the tides.
0:37:29 > 0:37:32They are after clams.
0:37:35 > 0:37:41But capuchins are quite small and don't have the brawn to open such shellfish.
0:37:44 > 0:37:48But they do have the brain,
0:37:48 > 0:37:52and they've devised an ingenious way to solve the problem.
0:37:54 > 0:37:57They hammer the clams.
0:38:04 > 0:38:08They are not trying to crack the shells, all this pounding
0:38:08 > 0:38:14and rolling has another purpose, to tire the muscle with which the clam is holding itself shut.
0:38:45 > 0:38:50Eventually the clam can hold out no longer,
0:38:50 > 0:38:52and the capuchin gets its reward.
0:39:17 > 0:39:22Trial and error may have been sufficient to solve this particular problem.
0:39:30 > 0:39:36But one of their cousins in Brazil has taken things a step further.
0:39:57 > 0:40:05Brown-tufted capuchins combine manual dexterity with considerable intelligence.
0:40:08 > 0:40:14And they have learned to use tools, hammer stones with which to open palm nuts.
0:40:17 > 0:40:21Some of the stones are nearly half the weight of the monkey.
0:40:31 > 0:40:36Without a tool, opening these nuts would be an impossible task.
0:40:39 > 0:40:44Tool-using was a major breakthrough in primate evolution.
0:40:54 > 0:41:01And nowhere is it more convincingly displayed than here in the forest of Bossou in Guinea, West Africa.
0:41:04 > 0:41:07PANTING AND WHOOPING
0:41:38 > 0:41:46Chimpanzees in this small community of thirteen individuals use tools in a variety of ways.
0:41:58 > 0:42:04The most delicate is the way they use a twig or leaf stem
0:42:04 > 0:42:05to dip for ants.
0:42:54 > 0:42:59Some of their skills are unique to this particular group.
0:43:03 > 0:43:08One of these involves stripping a palm leaf frond
0:43:08 > 0:43:13and using it like a pestle to mash up the nutritious palm heart.
0:43:32 > 0:43:35This four-year old is learning fast.
0:43:35 > 0:43:37She needs to.
0:43:37 > 0:43:40If chimpanzees haven't learned particular skills by the age of 8,
0:43:40 > 0:43:43they never seem able to acquire them.
0:43:52 > 0:43:56The most impressive skill of all, which involves nimble fingers,
0:43:56 > 0:44:02hand-eye coordination and intelligence, is nut cracking.
0:44:17 > 0:44:21Chimpanzees have gone a stage further than capuchins.
0:44:21 > 0:44:27They have learned how to carefully position the nut on an anvil and to judge how much force to use
0:44:27 > 0:44:33in order to crack the shell but not smash the kernel to pieces.
0:44:34 > 0:44:39Their use of tools is both efficient and precise.
0:44:47 > 0:44:53This eleven year old female has an anvil, but can't find a hammer.
0:45:06 > 0:45:10She approaches a male to see if he will lend her his.
0:45:26 > 0:45:29He obliges.
0:45:33 > 0:45:37Chimpanzees can show great kindness
0:45:37 > 0:45:39and compassion.
0:45:49 > 0:45:51Sharing.
0:45:55 > 0:45:57Experimenting.
0:46:00 > 0:46:01Empathy.
0:46:05 > 0:46:06Planning.
0:46:11 > 0:46:13Intelligence.
0:46:17 > 0:46:21Teaching, and learning.
0:46:32 > 0:46:37Behaviour so characteristic of us higher primates.
0:46:45 > 0:46:52We are the most inventive and innovative of all primates.
0:46:52 > 0:46:57Just one branch of a large and extended family.
0:46:58 > 0:47:01A family which has refined the ability
0:47:01 > 0:47:06to develop and pass on individual learning to the next generation.
0:47:21 > 0:47:28A family which is built on strong bonds between mother and baby.
0:47:43 > 0:47:47A family with which we share so much.
0:48:25 > 0:48:28To film the very best primate behaviour,
0:48:28 > 0:48:33the Life team had to use all their primate ingenuity and adaptability.
0:48:46 > 0:48:52And in doing so, they discovered an extraordinary affinity with our extended family.
0:48:57 > 0:49:04Especially with a great ape with who we share almost 99% of our genes,
0:49:04 > 0:49:07the Chimpanzee.
0:49:07 > 0:49:13He was completely asleep just then, so you just, just rocking to the side as if he might just fall off
0:49:13 > 0:49:19the branch, you could see his lips were twitching like he was in a deep dream, that was really beautiful.
0:49:30 > 0:49:34Chimpanzees are our closest relatives.
0:49:36 > 0:49:43Justine Evans spent almost a month with them in the forest of Guinea to film their use of tools.
0:49:44 > 0:49:46The chimps have disappeared off down there,
0:49:46 > 0:49:50they're gonna cross over into another area of forest and hopefully start using some tools.
0:49:50 > 0:49:54Go and use tools, that's what we're here for.
0:49:56 > 0:49:59Chimpanzees have to accept you.
0:49:59 > 0:50:04If they don't want to be filmed, they'll simply disappear.
0:50:07 > 0:50:13Justine needed the expert guidance of Tatyana Humle, a primatologist
0:50:13 > 0:50:16who's spent more than ten years studying these individuals.
0:50:16 > 0:50:23So when we see them always keep calm and don't stare straight into the eyes.
0:50:23 > 0:50:26Have you ever had problems with them coming right up being aggressive?
0:50:26 > 0:50:30No, never, never. I mean it's pretty rare, so...
0:50:30 > 0:50:34I don't know what to expect cos I've never seen them in the wild before so it's a first for me.
0:50:34 > 0:50:40So just always stay, stay calm and if one of them walks by really close, just ignore them.
0:50:40 > 0:50:44One particular young male might throw sticks,
0:50:44 > 0:50:46ignore him as well, it's like he's like a kid
0:50:46 > 0:50:50and he just wants attention so he'll just keep doing it.
0:50:50 > 0:50:57We've got to put these face masks on in case we pass on any infectious diseases.
0:50:57 > 0:51:01Quite a few chimps have died in the past from respiratory diseases
0:51:01 > 0:51:04in other study sites, so it's very important.
0:51:15 > 0:51:19Justine was finding her way with the chimps.
0:51:19 > 0:51:22But it would take time.
0:51:26 > 0:51:29It's never easy anticipating their behaviour.
0:51:31 > 0:51:34I'm trying to get ready really quickly because we're expecting
0:51:34 > 0:51:37some chimps to come down the path straight ahead of me.
0:51:39 > 0:51:41It'd be lovely if they'd merge out into this clearing,
0:51:41 > 0:51:44cos it's really difficult to see through all this foliage.
0:51:46 > 0:51:50Tatyana and her team were invaluable,
0:51:50 > 0:51:54they introduced Justine to the chimps' different habits and characters.
0:52:08 > 0:52:15Soon the natural inquisitiveness of the chimps overcame any worries they might have had of Justine.
0:52:20 > 0:52:25In fact, they seemed fascinated by her, and the tools of her trade.
0:52:31 > 0:52:37But it was their use of tools that Justine was here to film.
0:52:39 > 0:52:42And this was her first good opportunity.
0:52:46 > 0:52:50As I filmed them fishing for ants I was amazed by their dexterity.
0:52:52 > 0:52:57But holding focus in such low light really tested my own coordination to the limit.
0:53:11 > 0:53:13Now she's moving away.
0:53:13 > 0:53:15She's moving.
0:53:15 > 0:53:20It's been all go today, it's not over yet,
0:53:20 > 0:53:22if we can get out of here into an open,
0:53:22 > 0:53:26more open area we'll actually have enough light to film by
0:53:26 > 0:53:29cos the sun's still up, but I don't know.
0:53:31 > 0:53:36Although Justine's main goal was to film tool use,
0:53:36 > 0:53:40there was another piece of behaviour she really wanted to capture.
0:53:47 > 0:53:54Buttress root drumming had never been filmed here before but she was always just a bit too late.
0:53:54 > 0:53:57Back at yet another buttress in the hope that we might
0:53:57 > 0:54:01get some sort of buttress drumming, but it's started raining
0:54:01 > 0:54:03which is an absolute pain.
0:54:06 > 0:54:09It's a waiting game.
0:54:12 > 0:54:17Just staking out a couple of really big trees that have got very large buttress roots
0:54:17 > 0:54:20in the hope that a male will come down and drum on them.
0:54:20 > 0:54:25The drumming always happens somewhere else, and apparently,
0:54:25 > 0:54:28it's usually the males that sort of sneak off to go and do it,
0:54:28 > 0:54:31it feels like a bit of a long shot at the moment.
0:54:31 > 0:54:34I've have to have some patience.
0:54:36 > 0:54:40The thing about chimps is that, like most primates, you can't always predict
0:54:40 > 0:54:45what they're going to do, when they're going to do it, or where.
0:54:48 > 0:54:52You've just got to keep with them.
0:54:54 > 0:55:00A different type of sound brought Justine back to her main mission.
0:55:00 > 0:55:03CRACKING
0:55:09 > 0:55:11Nut cracking.
0:55:18 > 0:55:22This was the key sequence Justine was here to film.
0:55:31 > 0:55:35Filming the chimps using tools made me realise just how close to them we are.
0:55:44 > 0:55:48I felt so similar to them.
0:55:57 > 0:56:00By the end of our filming trip I was able to recognise
0:56:00 > 0:56:05most of the individuals in the group and had begun to understand their different personalities.
0:56:34 > 0:56:36For me, the most poignant moment of all
0:56:36 > 0:56:41was when the male the scientist called Clay lent a female his tools.
0:56:50 > 0:56:53I know that primates are very social animals
0:56:53 > 0:56:56but seeing this act of generosity was something that I'll never forget.
0:57:09 > 0:57:13DRUMMING AND WHOOPING God, buttress drumming.
0:57:13 > 0:57:18Just before we left, the chimpanzees finally put on the display that I'd been hoping for.
0:57:27 > 0:57:29WHOOPING
0:57:29 > 0:57:31DRUMMING
0:57:57 > 0:57:59In the great Tree of Life,
0:57:59 > 0:58:03we and chimpanzees went our separate ways about six million years ago,
0:58:03 > 0:58:08but they remain our closest living relatives.