0:00:02 > 0:00:05The world is full of extraordinary animals...
0:00:08 > 0:00:10..but how well do we really understand them?
0:00:12 > 0:00:14How do they really think and feel?
0:00:15 > 0:00:20To find out, a team of spy creatures is going undercover.
0:00:22 > 0:00:26They not only look like part of the family, they behave like them, too.
0:00:29 > 0:00:32Armed with the latest camera technology...
0:00:32 > 0:00:34they are going to travel the globe...
0:00:35 > 0:00:40..to understand the true nature of the animals they meet...
0:00:40 > 0:00:42and reveal how intelligent they really are...
0:00:46 > 0:00:48..how badly behaved they can be...
0:00:50 > 0:00:53..how important friendship is to them...
0:00:55 > 0:00:59..and if it's possible that they can truly love each other.
0:00:59 > 0:01:04What they discover will change our perception of animals for ever.
0:01:07 > 0:01:11Perhaps they are more like us than we ever believed possible.
0:01:22 > 0:01:25Animals often have strong family bonds,
0:01:25 > 0:01:29but how important are the other relationships in their lives?
0:01:33 > 0:01:37The Kalahari Desert of Africa, home to the meerkat.
0:01:42 > 0:01:46Here, everyone helps each other and life revolves around the queen,
0:01:46 > 0:01:48the only female to have babies.
0:01:52 > 0:01:57She can have six in a litter and three litters in a year,
0:01:57 > 0:01:59so her many offspring are everywhere.
0:02:02 > 0:02:03They need a lot of looking after.
0:02:06 > 0:02:10But, fortunately, she has plenty of friends to help -
0:02:10 > 0:02:12up to 50 of them.
0:02:16 > 0:02:19And today she has one more.
0:02:23 > 0:02:24A spy meerkat.
0:02:26 > 0:02:30She is here to film the unique friendship that exists
0:02:30 > 0:02:32among these highly sociable animals.
0:02:36 > 0:02:41But this is a tight-knit community - they don't welcome strangers.
0:02:52 > 0:02:55She is the biggest meerkat they've ever seen,
0:02:55 > 0:02:58and requires serious examination.
0:03:02 > 0:03:06She's been made to smell like the colony, so this reassures them.
0:03:14 > 0:03:17Each day, different volunteers set up a creche,
0:03:17 > 0:03:21giving all the child support a mother could wish for.
0:03:21 > 0:03:24They share roles, including sentry duty.
0:03:26 > 0:03:30It demands concentration, and it's easy to lose focus.
0:03:39 > 0:03:43And sometimes it's good to have someone watching your back.
0:03:44 > 0:03:46Being a sentry is a risky business,
0:03:46 > 0:03:49as they are easy targets for predators.
0:03:49 > 0:03:51But with young pups to protect,
0:03:51 > 0:03:54they take greater risks by climbing higher.
0:03:54 > 0:03:57Here, they can see predators earlier,
0:03:57 > 0:04:00but are vulnerable to birds of prey.
0:04:00 > 0:04:03Their self-sacrifice is about to be tested.
0:04:10 > 0:04:13But this is no ordinary cobra.
0:04:13 > 0:04:14It's a spy cobra.
0:04:16 > 0:04:20With no regard for her own safety, she prepares to face the snake.
0:04:39 > 0:04:41SNAKE HISSES
0:04:41 > 0:04:44She reacts as she would to the real thing,
0:04:44 > 0:04:47bravely protecting the colony with no thought for herself.
0:04:53 > 0:04:56Her aim is to harass the snake into leaving,
0:04:56 > 0:04:59but with spy snake holding its ground,
0:04:59 > 0:05:02the meerkat calls for reinforcements.
0:05:02 > 0:05:05MEERKAT CALLS
0:05:05 > 0:05:08This is where fraternity comes into its own.
0:05:24 > 0:05:28An intimidating wall of meerkats face up to spy cobra.
0:05:39 > 0:05:43They push their luck as far as they dare, goading the snake to strike.
0:05:50 > 0:05:55Real snakes tire easily, so it's a matter of wearing it down.
0:06:00 > 0:06:02But one meerkat
0:06:02 > 0:06:05senses there's something different about this serpent.
0:06:08 > 0:06:10It may look and move like a real snake,
0:06:10 > 0:06:13but it shows no sign of leaving.
0:06:20 > 0:06:23Spy snake has been well and truly rumbled.
0:06:31 > 0:06:33Satisfied he's harmless,
0:06:33 > 0:06:37the meerkats go back to what they enjoy best -
0:06:37 > 0:06:40relaxing among friends.
0:06:43 > 0:06:47And there's a more approachable spy creature to spend time with.
0:06:49 > 0:06:52Even the pups get their own introduction.
0:06:58 > 0:07:00She's part of the gang now,
0:07:00 > 0:07:04perfectly placed to film more of the meerkats' close alliances.
0:07:14 > 0:07:18The extremes of the Canadian Arctic present different challenges.
0:07:24 > 0:07:26These wolves are all related,
0:07:26 > 0:07:30but it's the close friendships between them that really count.
0:07:34 > 0:07:35In this harsh world,
0:07:35 > 0:07:38it's vital they work together to find and catch food,
0:07:38 > 0:07:41and the mother needs support in bringing up her cubs.
0:07:54 > 0:07:57A new spy creature attempts to join the pack.
0:07:57 > 0:08:01WOLF CUB WHINES
0:08:01 > 0:08:05Spy wolf cub may not last long.
0:08:05 > 0:08:07Wolves kill strange cubs.
0:08:18 > 0:08:21She considers how to deal with him.
0:08:22 > 0:08:25Then pees on him instead.
0:08:28 > 0:08:30Not the most fragrant welcome,
0:08:30 > 0:08:32but smelling of wolf is an advantage
0:08:32 > 0:08:34if you want to make friends with wolf cubs.
0:08:40 > 0:08:44He soon gets a cub's-eye view of the family.
0:08:55 > 0:08:57At five weeks old,
0:08:57 > 0:08:59the cubs need more than just mother's milk,
0:08:59 > 0:09:01so the wolves must go hunting.
0:09:01 > 0:09:04They rally the pack.
0:09:04 > 0:09:07This is when friendships really matter and everyone must take part.
0:09:07 > 0:09:09THEY HOWL
0:09:09 > 0:09:11The cubs are left behind.
0:09:11 > 0:09:14They have the den to keep them safe
0:09:14 > 0:09:17and a new friend to keep a spying eye on them.
0:09:21 > 0:09:25In the height of the Arctic summer, mosquitoes become a problem.
0:09:27 > 0:09:29A few might be a nuisance...
0:09:32 > 0:09:35..but a plague can be devastating.
0:09:37 > 0:09:40These bloodsucking insects can weaken and even kill.
0:09:43 > 0:09:46Already the cubs are suffering.
0:09:54 > 0:09:56Only the den offers some sanctuary.
0:09:59 > 0:10:01The father has been out scavenging
0:10:01 > 0:10:04and returns to see the growing swarm.
0:10:10 > 0:10:12This is not a place for young cubs any more.
0:10:18 > 0:10:21So, without waiting for the rest of the pack,
0:10:21 > 0:10:23he decides they must be moved,
0:10:23 > 0:10:26but the nearest alternative den is five miles away.
0:10:27 > 0:10:30He sets a punishing pace. Wolves travel fast...
0:10:32 > 0:10:34..and the cubs are struggling.
0:10:39 > 0:10:41The smallest soon drops behind.
0:10:46 > 0:10:50After running for over two miles, he's had enough.
0:10:54 > 0:10:57The father conceals him in a temporary hideaway,
0:10:57 > 0:10:59somewhere to regain his strength.
0:11:04 > 0:11:07With the little cub safe, he continues his journey.
0:11:11 > 0:11:12After five miles,
0:11:12 > 0:11:14the father finally slows the pace
0:11:14 > 0:11:17and the remaining two cubs reach the new den.
0:11:17 > 0:11:19There are far less mosquitoes here.
0:11:24 > 0:11:26The cubs are now in need of a good meal.
0:11:26 > 0:11:30Without hesitation, the father sets off to find one.
0:11:34 > 0:11:38Spy cub is still at the old den as the mother and the pack arrive back.
0:11:43 > 0:11:46They soon realise the cubs are missing.
0:11:50 > 0:11:51The mother calls for her cubs.
0:11:51 > 0:11:54WOLF HOWLS
0:11:57 > 0:11:59The pack spread out, looking for scent trails.
0:12:00 > 0:12:02Everyone is working together.
0:12:14 > 0:12:16After searching for eight long hours,
0:12:16 > 0:12:19at last they find the new den.
0:12:25 > 0:12:28But they soon realise one cub is missing.
0:12:32 > 0:12:35The pack howls for the lost cub.
0:12:37 > 0:12:41They won't give up searching until everyone is reunited.
0:12:46 > 0:12:49As the mother sets off with the rest of the pack,
0:12:49 > 0:12:51she entrusts her cubs to her closest friend.
0:12:55 > 0:12:57She acts as a surrogate mother
0:12:57 > 0:13:01and produces milk so she can help out in times of need.
0:13:04 > 0:13:06Even with all the pack involved,
0:13:06 > 0:13:11finding the lost cub in this vast wilderness will be challenging.
0:13:11 > 0:13:17WOLF CUB HOWLS
0:13:24 > 0:13:27The African savanna creates its own challenges
0:13:27 > 0:13:31and it's given rise to some strange and unique partnerships.
0:13:33 > 0:13:36When male warthogs leave the family home
0:13:36 > 0:13:40they find company with similar lost souls.
0:13:40 > 0:13:42They hang around in gangs,
0:13:42 > 0:13:45rooting for food and indulging in their favourite pastime -
0:13:45 > 0:13:46mud bathing.
0:13:54 > 0:13:57It's the perfect place for some male bonding.
0:14:00 > 0:14:04But since they left the family, this is a sight they rarely see -
0:14:04 > 0:14:06a young warthog on its own.
0:14:14 > 0:14:19Spy warthog may soon discover just how friendly they really are.
0:14:26 > 0:14:28He's certainly creating some interest.
0:14:40 > 0:14:44It's been a long time since this male has met a young warthog.
0:14:52 > 0:14:54Nuzzling is a greeting.
0:14:54 > 0:14:58Warthogs use their sensitive noses to recognise each other.
0:15:08 > 0:15:11Remarkably, he seems to be welcome here.
0:15:22 > 0:15:26He's now a junior member of the gang.
0:15:26 > 0:15:29But they are not the only friends he needs to make.
0:15:35 > 0:15:38These lively characters are banded mongoose.
0:15:44 > 0:15:47And they and the warthogs are the best of buddies.
0:15:47 > 0:15:52Their partnership is one of the most surprising in nature.
0:15:56 > 0:16:00When the warthog lies down, it's a signal to the mongoose.
0:16:01 > 0:16:04It means he wants to be groomed.
0:16:12 > 0:16:16The mongoose sets to work, removing dry or flaky skin
0:16:16 > 0:16:20and ferreting out parasites like ticks and fleas.
0:16:26 > 0:16:30They may act as skin therapists, but they don't go easy on their clients.
0:16:36 > 0:16:41It's for their own good, and the mongoose get a meal as payment.
0:16:44 > 0:16:47And they reach the parts that the warthogs fail to reach.
0:16:59 > 0:17:04When they finally finish, some very happy customers are left behind.
0:17:08 > 0:17:10Who's next?
0:17:14 > 0:17:18They seem to think that spy warthog is in need of a full body treatment.
0:17:19 > 0:17:21They await the signal.
0:17:26 > 0:17:28He assumes the grooming position...
0:17:33 > 0:17:35..and the mongoose set to work,
0:17:35 > 0:17:39giving him an intimate perspective of an extraordinary partnership...
0:17:40 > 0:17:44..although his skin must offer slim pickings.
0:17:56 > 0:17:59Warthogs aren't the only African animal with unusual friends.
0:18:04 > 0:18:09Every lake and river has a resident population of hippos.
0:18:09 > 0:18:11They too are social creatures,
0:18:11 > 0:18:13but they are also territorial.
0:18:22 > 0:18:26Spy hippo is going where few others dare to go.
0:18:32 > 0:18:33He needs to be cautious.
0:18:46 > 0:18:50His subjects are notoriously bad-tempered...
0:18:50 > 0:18:53and they could be anywhere.
0:18:58 > 0:19:01It's never a good idea to get on their wrong side.
0:19:09 > 0:19:12Spy hippo has been given a warning.
0:19:15 > 0:19:18He must avoid sudden movements.
0:19:21 > 0:19:24As he gets closer, ear wiggling shows confidence.
0:19:30 > 0:19:33Facing one of Africa's most dangerous animals,
0:19:33 > 0:19:36spy hippo must hold his ground.
0:19:38 > 0:19:42The pod is made up of females looked over by a single male.
0:19:43 > 0:19:46Fortunately, females are less aggressive.
0:19:50 > 0:19:54Spy hippo is already capturing some of the closest views
0:19:54 > 0:19:55that have ever been seen.
0:20:01 > 0:20:05But hippos spend much of their time below the surface.
0:20:06 > 0:20:08As the hippos dive...
0:20:10 > 0:20:12..so must spy hippo.
0:20:14 > 0:20:17He mimics their movements.
0:20:18 > 0:20:22Rather than swim, hippos walk underwater.
0:20:28 > 0:20:33Through the murk, spy hippo glimpses an extraordinary sight.
0:20:37 > 0:20:41Fish are shadowing the hippos' every move.
0:20:41 > 0:20:43These are barbs.
0:20:44 > 0:20:46They usually feed on the riverbed
0:20:46 > 0:20:49but when the hippos appear, they shoal around them.
0:20:55 > 0:20:58As spy hippo moves closer,
0:20:58 > 0:21:01it's clear that their skin is a maze of cuts and scratches.
0:21:03 > 0:21:06These fight marks easily become infected
0:21:06 > 0:21:08and parasites can also invade.
0:21:12 > 0:21:14This is where the fish come in.
0:21:16 > 0:21:20Together they set up an underwater clinic,
0:21:20 > 0:21:23with the hippos as willing patients.
0:21:26 > 0:21:28The barbs may be skin specialists...
0:21:29 > 0:21:33..but they'll try a bit of dental hygiene, too.
0:21:49 > 0:21:51After having a full body treatment,
0:21:51 > 0:21:54the hippos seem to enter a trance.
0:22:10 > 0:22:12Back in the Arctic,
0:22:12 > 0:22:15the lost wolf cub has been waiting for three long days.
0:22:19 > 0:22:21Only spy cub has been keeping watch.
0:22:26 > 0:22:28His howls are becoming desperate.
0:22:28 > 0:22:32WOLF CUB HOWLS
0:22:37 > 0:22:40He is both hungry and tired.
0:22:40 > 0:22:42He now needs the pack more than ever.
0:22:46 > 0:22:49Many miles away, the pack is still searching,
0:22:49 > 0:22:52but the cub's calls are lost in the vastness of the tundra.
0:22:59 > 0:23:01The mother has set her own course,
0:23:01 > 0:23:04sensing the urgency of the danger he's in.
0:23:12 > 0:23:15But at least her other cubs are safe.
0:23:18 > 0:23:21WOLF CUB HOWLS
0:23:21 > 0:23:24The cub's calls can carry for over a mile,
0:23:24 > 0:23:27but only if the wind is in the right direction.
0:23:30 > 0:23:33The mother can only follow her instincts,
0:23:33 > 0:23:35she has so little to go on.
0:23:42 > 0:23:43In desperation,
0:23:43 > 0:23:47her cub leaves his only protection to go searching for her.
0:23:52 > 0:23:54He howls into the canyon.
0:23:54 > 0:23:56It echoes his cries.
0:23:56 > 0:23:59WOLF CUB HOWLS
0:24:04 > 0:24:06It seems her cub did the right thing.
0:24:09 > 0:24:14WOLF CUB HOWLS
0:24:14 > 0:24:18WOLF HOWLS
0:24:26 > 0:24:29WOLF HOWLS
0:24:33 > 0:24:36He heads off in the direction of his mother's howls.
0:24:44 > 0:24:47It's taken three days of searching,
0:24:47 > 0:24:49but she's found him.
0:24:54 > 0:24:59There's no time for celebration, she must get him back to the den.
0:25:14 > 0:25:17Now the whole pack can welcome him back.
0:25:24 > 0:25:26The teamwork isn't over yet,
0:25:26 > 0:25:29as the cubs are still hungry.
0:25:29 > 0:25:34The father makes good, as he returns bearing gifts.
0:25:44 > 0:25:45As the cubs tuck in,
0:25:45 > 0:25:49he seems oblivious to the trouble he's caused,
0:25:49 > 0:25:53but with everyone working together, the precious cub was found.
0:25:57 > 0:26:01Pack life was once thought to be about dominance and submission,
0:26:01 > 0:26:06but what's actually more important are their deep bonds of friendship.
0:26:14 > 0:26:18Among our closest animal relatives, friendships are equally important,
0:26:18 > 0:26:21but they are also far more political.
0:26:25 > 0:26:26In Senegal,
0:26:26 > 0:26:29spy bushbaby is concealed in a tree stump
0:26:29 > 0:26:33to film a group of chimpanzees visiting a jungle water hole.
0:26:41 > 0:26:43They are the only chimps t o bathe like this
0:26:43 > 0:26:46and they have their version of a members-only spa.
0:26:48 > 0:26:51Here, they get relief from the oppressive heat,
0:26:51 > 0:26:55but it's also a place to socialise,
0:26:55 > 0:26:58a chance for the youngsters to play and make friends.
0:27:02 > 0:27:06They also admire their reflections.
0:27:06 > 0:27:09Chimps are one of the few animals that can recognise themselves.
0:27:14 > 0:27:18Who you are is important in chimp society.
0:27:22 > 0:27:25And friendships forged at this young age
0:27:25 > 0:27:28make all the difference in later life -
0:27:28 > 0:27:30that's when position really matters.
0:27:33 > 0:27:36Here, elders must be treated with respect...
0:27:40 > 0:27:42..and youngsters must know their place.
0:27:45 > 0:27:48When the big males arrive, family time is over.
0:27:49 > 0:27:53This is when friendships get political.
0:27:59 > 0:28:02First in has choice of the best spot -
0:28:02 > 0:28:04the deepest part of the pool.
0:28:07 > 0:28:09But not for long.
0:28:09 > 0:28:11A senior male pulls rank.
0:28:16 > 0:28:19Each new male is aware of his position
0:28:19 > 0:28:21and where his friendships lie.
0:28:22 > 0:28:24These two don't get on,
0:28:24 > 0:28:27but this one's a very good friend.
0:28:27 > 0:28:31So everyone shuffles around depending on who they are
0:28:31 > 0:28:33and who they are friends with.
0:28:40 > 0:28:43The most important likes to make an entrance...
0:28:45 > 0:28:48..and claims the prime spot.
0:28:52 > 0:28:56Once places are properly allocated, it's time for some male grooming -
0:28:56 > 0:29:00a chance to confirm friendships and alliances.
0:29:01 > 0:29:05These bonding moments reduce stress and improve their health.
0:29:07 > 0:29:11Like humans, chimps yawn sympathetically -
0:29:11 > 0:29:14a sign of closeness and empathy among familiar friends.
0:29:17 > 0:29:20This is now strictly a male-only spa,
0:29:20 > 0:29:24so mothers must find other ways to entertain the kids.
0:29:32 > 0:29:35Or let them entertain themselves.
0:29:39 > 0:29:44A five-year-old finds another of the spy cameras...
0:29:44 > 0:29:48a filming device based on the fruit of the baobab tree.
0:29:52 > 0:29:55Perfect for an improvised ball game.
0:30:00 > 0:30:03But balls have a habit of going astray...
0:30:08 > 0:30:12..and where it's landed is strictly out of bounds.
0:30:15 > 0:30:18It wouldn't be wise to try to get it back.
0:30:22 > 0:30:25But it's giving spy baobab a unique view of chimpanzees
0:30:25 > 0:30:28at their most relaxed.
0:30:34 > 0:30:37A time when they can get rid of ticks or fleas.
0:30:47 > 0:30:49Or just chill out.
0:30:58 > 0:31:00With his ball out of play,
0:31:00 > 0:31:02the five-year-old finds other things to do.
0:31:04 > 0:31:06But one brave female
0:31:06 > 0:31:10is prepared to risk joining this male exclusive club.
0:31:11 > 0:31:15She's rightly nervous but a male reaches out a hand of friendship.
0:31:17 > 0:31:21She's a high-ranking female and this gives her special privileges...
0:31:24 > 0:31:27..ones that also apply to her baby.
0:31:32 > 0:31:34But the mother is still cautious -
0:31:34 > 0:31:36some males aren't so tolerant.
0:31:40 > 0:31:43The mother retreats, but for her daughter
0:31:43 > 0:31:45the water is just too tempting.
0:31:49 > 0:31:52Her cheekiness doesn't go unnoticed.
0:31:58 > 0:32:01But a kiss reassures her
0:32:01 > 0:32:03and confirms her special status.
0:32:06 > 0:32:10This little chimp is already indulged more than most youngsters
0:32:10 > 0:32:13and is likely to rise to a high position.
0:32:16 > 0:32:18For the males and their gentlemen's club,
0:32:18 > 0:32:20bath time is over.
0:32:30 > 0:32:33The others waste no time.
0:32:33 > 0:32:37As everyone rejoins the pool party, friends can play once more.
0:32:41 > 0:32:44The five-year-old finally gets his ball back
0:32:44 > 0:32:46and takes an accidental selfie.
0:32:54 > 0:32:58Among chimps, friendships keep the community together,
0:32:58 > 0:33:03and these exclusive baths have become the hub of their social life.
0:33:09 > 0:33:11Back in the Kalahari,
0:33:11 > 0:33:15the meerkats have a far more egalitarian view of friendship.
0:33:17 > 0:33:21And there is one friend who now seems totally at home -
0:33:21 > 0:33:24spy meerkat.
0:33:24 > 0:33:28She is filming the details of life in the creche.
0:33:28 > 0:33:31Among meerkats, it is the focus of their social life.
0:33:33 > 0:33:37Here, the babies learn to make friends and discover who's who.
0:33:40 > 0:33:45As childminders change all the time, the babies soon meet everyone.
0:33:53 > 0:33:55As the youngsters groom each other,
0:33:55 > 0:33:57they establish their own bonds of friendship.
0:34:01 > 0:34:04They also learn the secrets of how to get along.
0:34:05 > 0:34:08The childminders also clean out the den
0:34:08 > 0:34:12and even make decisions on when the pups should be moved.
0:34:12 > 0:34:16This happens when nest parasites become just too much.
0:34:16 > 0:34:18Moving day is a big event
0:34:18 > 0:34:21and the process must happen quickly.
0:34:22 > 0:34:27To stay with them, spy meerkat needs some help.
0:34:32 > 0:34:35He hitches a ride on a mobile termite mound,
0:34:35 > 0:34:38complete with its own stabilised camera.
0:34:50 > 0:34:52With so many pups to care for,
0:34:52 > 0:34:55it's easy for one to be left behind.
0:34:57 > 0:34:59He's the smallest of the litter
0:34:59 > 0:35:01and he's hardly ventured from the den before.
0:35:11 > 0:35:13He faces plenty of unexpected pitfalls.
0:35:17 > 0:35:21Spy meerkat is following the rest of the gang.
0:35:21 > 0:35:25And these pups move confidently with the adults in charge.
0:35:33 > 0:35:36In the rush, they didn't check the numbers.
0:35:39 > 0:35:43But with the pups out in the open, it's wisest to keep going.
0:35:50 > 0:35:55The little pup is now even further behind.
0:35:55 > 0:35:58It's a long trek for such tiny legs.
0:36:05 > 0:36:07And the heat is taking its toll.
0:36:11 > 0:36:14When spy meerkat arrives at the new den site,
0:36:14 > 0:36:16everyone is already assembling.
0:36:20 > 0:36:24The cubs are introduced to their new accommodation.
0:36:31 > 0:36:34Now they have time for a headcount.
0:36:35 > 0:36:37They realise one has been left behind.
0:36:38 > 0:36:42All alone, he has no idea which way to go.
0:37:19 > 0:37:22His childminder hasn't let him down.
0:37:32 > 0:37:35Ultimately, everyone must be accounted for.
0:37:40 > 0:37:45Meerkat society works because everyone cares for everyone else.
0:37:45 > 0:37:48It's an ethos that begins when they are just pups.
0:37:50 > 0:37:53Those out foraging soon track down the new den.
0:37:58 > 0:38:01The mother is reunited with her babies
0:38:01 > 0:38:03and her helpers can rest at last,
0:38:03 > 0:38:06having done their best for the good of the colony.
0:38:17 > 0:38:21The need to protect young has given rise to unlikely friendships.
0:38:23 > 0:38:26Murchison Falls in Uganda.
0:38:28 > 0:38:31This is spy crocodile.
0:38:37 > 0:38:38Like a real croc,
0:38:38 > 0:38:42he's just as manoeuvrable in water as he is on land.
0:38:48 > 0:38:50He needs to be -
0:38:50 > 0:38:54where he's going is difficult and dangerous to reach.
0:39:00 > 0:39:02And in this special place,
0:39:02 > 0:39:07spy crocodile is going to film a very brave little bird.
0:39:14 > 0:39:16These are water dikkop,
0:39:16 > 0:39:19a type of stone-curlew.
0:39:20 > 0:39:24They may be small, but they like to live life dangerously.
0:39:27 > 0:39:29CROCODILE GROWLS
0:39:29 > 0:39:33Their nearest neighbour is a crocodile
0:39:33 > 0:39:35and their nest is right next to hers.
0:39:38 > 0:39:41Few would dare to shepherd a crocodile,
0:39:41 > 0:39:45but the fearless dikkop protects her nest by marshalling the croc away.
0:39:51 > 0:39:56The dikkop only gives up when the croc is safely in her own nest.
0:39:58 > 0:40:02Filming the action around the nest are some spy crocodile hatchlings...
0:40:02 > 0:40:04CROCODILE HATCHLING CALLS
0:40:04 > 0:40:07..and the crocodile guards them as her own.
0:40:12 > 0:40:16It seems insane for the dikkops to nest so close,
0:40:16 > 0:40:18especially when a second croc arrives.
0:40:23 > 0:40:26Nesting crocs are intensely territorial.
0:40:31 > 0:40:34This is too much for any dikkop to handle.
0:40:44 > 0:40:47But the rival is quickly dispatched.
0:40:53 > 0:40:58The dikkop settle, a moment of calm as the croc guards her nest.
0:41:04 > 0:41:06But it doesn't last.
0:41:06 > 0:41:10In the heat of the day, the croc heads for water.
0:41:13 > 0:41:17It's a moment not lost on this monitor lizard.
0:41:23 > 0:41:26Nile monitors eat both crocodile eggs
0:41:26 > 0:41:28and those of the dikkop.
0:41:33 > 0:41:37But it's the croc's unprotected nest that interests him now.
0:41:41 > 0:41:45Except for the spy hatchlings, the monitor has the place to himself.
0:41:50 > 0:41:53He's soon digging for the buried treasure.
0:42:00 > 0:42:03And gets a taste of a spy hatchling.
0:42:07 > 0:42:09But the real eggs are what he's come for.
0:42:11 > 0:42:13The dikkop steps into action again.
0:42:15 > 0:42:19If she can stand up to a croc, a four-foot lizard is nothing.
0:42:25 > 0:42:28She even tweaks the dragon's tail.
0:42:30 > 0:42:33Dikkops must be among the pluckiest birds on Earth.
0:42:37 > 0:42:40The male at the nest joins the battle.
0:42:41 > 0:42:44They are a formidable team.
0:42:44 > 0:42:48It's a risky strategy, as the dikkop's nest is now exposed...
0:42:52 > 0:42:54..and the monitor won't give up easily...
0:42:56 > 0:42:58..so the mother returns to her nest.
0:43:05 > 0:43:10With both bird and egg thief holding their ground, it's a stand-off.
0:43:14 > 0:43:17Time to call for reinforcements...
0:43:17 > 0:43:19DIKKOP CALLS
0:43:19 > 0:43:22..and the crocodile hears the call to arms.
0:43:33 > 0:43:36The monitor is totally outclassed.
0:43:38 > 0:43:41And this is why it was worth nesting here.
0:43:45 > 0:43:50They may be friends of convenience, but here most crocodile nests
0:43:50 > 0:43:53have their own resident pair of fearless dikkops.
0:43:58 > 0:44:03In North America, prairie dogs also have some unexpected neighbours.
0:44:05 > 0:44:09Spy prairie dog discovers who these squatters are.
0:44:12 > 0:44:14They are burrowing owls.
0:44:14 > 0:44:16OWL CALLS
0:44:16 > 0:44:20They make good use of any available free housing.
0:44:22 > 0:44:24They may be uninvited guests,
0:44:24 > 0:44:27but they still make the best of neighbours.
0:44:28 > 0:44:30The owls hunt mainly insects,
0:44:30 > 0:44:33so they are no risk to the prairie dogs
0:44:33 > 0:44:36and they also help watch for predators.
0:44:36 > 0:44:40In turn, the owls use the prairie dogs' alarm system,
0:44:40 > 0:44:44so their close relationship works for both of them.
0:44:44 > 0:44:45In the pupping season,
0:44:45 > 0:44:49the prairie dogs are on high alert, watching for danger.
0:44:49 > 0:44:53RATTLING
0:44:53 > 0:44:56And rattlesnakes are one of the enemy.
0:45:03 > 0:45:05RATTLING
0:45:05 > 0:45:09But this snake is another spy creature.
0:45:09 > 0:45:11PRAIRIE DOG CALLS
0:45:11 > 0:45:14The prairie dog sends out an alert.
0:45:14 > 0:45:16He has a special word for "snake".
0:45:21 > 0:45:23But rather than panic,
0:45:23 > 0:45:26the prairie dogs and owls stay where they are.
0:45:28 > 0:45:31Theirs is a very measured response based on how dangerous
0:45:31 > 0:45:33the threat really is.
0:45:37 > 0:45:40And as spy snake shows no sign of moving closer,
0:45:40 > 0:45:42they simply keep an eye on it.
0:45:44 > 0:45:47There are plenty of other threats to be worried about.
0:45:48 > 0:45:51HOWLING
0:45:53 > 0:45:55A coyote.
0:45:59 > 0:46:01They have their own name for it, too.
0:46:02 > 0:46:06They shout it out to alert the whole colony.
0:46:06 > 0:46:10PRAIRIE DOG CALLS
0:46:10 > 0:46:14But like the snake alarm, it doesn't create immediate panic.
0:46:17 > 0:46:21Each chirp lasts just one tenth of a second,
0:46:21 > 0:46:23but it's packed with subtle meaning
0:46:23 > 0:46:26so that everyone can know the nature of any threat.
0:46:28 > 0:46:29In fact,
0:46:29 > 0:46:34prairie dogs have the most complex animal language ever discovered.
0:46:34 > 0:46:36Nouns define the type of predator.
0:46:40 > 0:46:44Adjectives describe if the threat is near or far.
0:46:48 > 0:46:51And adverbs explain how fast it's moving.
0:46:53 > 0:46:56The chirps for a walking coyote are further apart
0:46:56 > 0:46:58and cause little reaction.
0:47:01 > 0:47:05The quicker chirps for a running coyote demand immediate attention.
0:47:06 > 0:47:09Now it's time to panic.
0:47:09 > 0:47:11QUICK CHIRPING
0:47:18 > 0:47:21The coyotes head off for an easier meal.
0:47:24 > 0:47:28When they are gone, the prairie dogs sound the all clear.
0:47:28 > 0:47:32PRAIRIE DOG CALLS
0:47:35 > 0:47:38Their language allows prairie dogs to stay above ground
0:47:38 > 0:47:41until the last possible moment,
0:47:41 > 0:47:45while the owls just have to watch what the prairie dogs do.
0:47:47 > 0:47:51Time for a traditional celebration - the jump-yip.
0:48:26 > 0:48:29Friendships help guard against danger,
0:48:29 > 0:48:33but sometimes you have to make friends with the enemy themselves.
0:48:39 > 0:48:43The langurs of India are among the most agile of all monkeys.
0:48:53 > 0:48:56Spy monkey is also capturing the quiet moments,
0:48:56 > 0:48:58when friendships are really made.
0:49:06 > 0:49:09Grooming is used to calm tensions,
0:49:09 > 0:49:12build trust and cement relationships.
0:49:17 > 0:49:21They even try to make friends with spy monkey.
0:49:27 > 0:49:30Stray dogs live alongside the langurs,
0:49:30 > 0:49:33scavenging on food that people leave for the monkeys.
0:49:35 > 0:49:38They aren't the friendliest of neighbours.
0:49:39 > 0:49:42They see monkeys as competition for food
0:49:42 > 0:49:45and will even kill a monkey if it gets on their wrong side.
0:49:47 > 0:49:49So for their own safety,
0:49:49 > 0:49:51the langurs try to make friends.
0:49:56 > 0:49:59But the dogs aren't easily won over.
0:50:06 > 0:50:07To ingratiate themselves,
0:50:07 > 0:50:11the monkeys use the same technique they use with each other.
0:50:12 > 0:50:15But grooming a dog is like playing with fire,
0:50:15 > 0:50:20especially when you don't understand the body language.
0:50:20 > 0:50:21DOG BARKS
0:50:21 > 0:50:26But if they can make friends, they are less likely to get hurt.
0:50:26 > 0:50:29Here, it's a matter of keeping your friends close
0:50:29 > 0:50:32and your enemies closer.
0:50:32 > 0:50:36Fortunately, most dogs just want to be loved,
0:50:36 > 0:50:40and they soon succumb to the monkeys' unsolicited advances.
0:50:40 > 0:50:43Grooming brings other rewards -
0:50:43 > 0:50:46a tick makes a juicy treat.
0:50:46 > 0:50:49They even start taking liberties.
0:50:51 > 0:50:55This personal valet service diffuses aggression
0:50:55 > 0:50:57and helps everyone to get along.
0:50:59 > 0:51:02For a puppy, there's a different reward -
0:51:02 > 0:51:04monkeys make the perfect playmates.
0:51:41 > 0:51:44Like the langurs, intelligent animals have subtle
0:51:44 > 0:51:47and sometimes manipulative friendships.
0:51:48 > 0:51:50And those of chimps
0:51:50 > 0:51:53show the greatest connections with our own lives.
0:51:56 > 0:52:00Filming the Senegal chimps requires an array of spy cameras.
0:52:02 > 0:52:06As well as spy bushbaby, spy tortoise is also here.
0:52:13 > 0:52:18And spy tree stump offers discreet coverage.
0:52:18 > 0:52:21There can be ten different cameras deployed at any one time.
0:52:23 > 0:52:27A chimp hears something that suddenly changes the mood.
0:52:27 > 0:52:29It's the sound of prey.
0:52:31 > 0:52:33They move into hunting mode.
0:52:47 > 0:52:51This is when rivalries and position are put to one side.
0:52:54 > 0:52:57Everyone is now working together.
0:53:01 > 0:53:05It's their bonds of friendship that allow them to hunt as a team.
0:53:08 > 0:53:10They glimpse their quarry.
0:53:16 > 0:53:18It's a large troop of baboons.
0:53:22 > 0:53:25They plan to encircle them and take them by surprise.
0:53:27 > 0:53:29They set off in different directions,
0:53:29 > 0:53:31moving silently as they go.
0:53:35 > 0:53:37Each takes up a different position.
0:53:45 > 0:53:48Standing on two legs gives a better view.
0:53:57 > 0:54:00When everyone's in place, they stop.
0:54:03 > 0:54:05One flushes the baboons.
0:54:08 > 0:54:11THEY CALL
0:54:13 > 0:54:15But their escape is blocked.
0:54:18 > 0:54:20It's just as they planned.
0:54:23 > 0:54:25There's no way out.
0:54:38 > 0:54:41To the victor the prize...
0:54:41 > 0:54:43or so they say.
0:54:44 > 0:54:46But it's not that simple.
0:54:52 > 0:54:54For this youngster, it's all too tempting.
0:54:58 > 0:55:01He sneaks down to beg for a bite.
0:55:01 > 0:55:03This is not the etiquette.
0:55:03 > 0:55:07He must learn that the victor eats first.
0:55:07 > 0:55:10His mother saves him from further social embarrassment,
0:55:10 > 0:55:12and perhaps worse.
0:55:17 > 0:55:22Then a ritual with huge significance begins.
0:55:23 > 0:55:26The successful hunter starts to share.
0:55:29 > 0:55:32The giving of meat reinforces their friendships,
0:55:32 > 0:55:36meaning everyone will contribute in future hunts.
0:55:39 > 0:55:45Such generosity releases the brain's feel-good hormone oxytocin,
0:55:45 > 0:55:48making everyone feel content.
0:55:48 > 0:55:51One chimp is tempted to jump the queue...
0:55:53 > 0:55:56..but only close friends get away with taking liberties.
0:56:00 > 0:56:04Everyone ultimately gets at least a morsel.
0:56:07 > 0:56:10Even the baby chimp, who was rather too eager.
0:56:17 > 0:56:21The friendships, cooperation and sharing that chimps show
0:56:21 > 0:56:26is the foundation on which all complex societies are laid.
0:56:35 > 0:56:37Now that everyone's feeling good,
0:56:37 > 0:56:40it's a chance to play and relax once more.
0:56:40 > 0:56:44There's nothing better than hanging out with friends.
0:56:50 > 0:56:55In the animal world, friendships lie at the heart of the community.
0:56:56 > 0:56:59From friends among equals...
0:56:59 > 0:57:01to friendships in adversity.
0:57:02 > 0:57:05From friends of convenience...
0:57:05 > 0:57:09and those for self-preservation...
0:57:09 > 0:57:11these many different animal relationships
0:57:11 > 0:57:15mirror the complexities of our own.
0:57:19 > 0:57:23Next time, our team of spy creatures investigates how and why
0:57:23 > 0:57:28animals misbehave, sometimes in spectacular fashion.