0:00:30 > 0:00:33DOG BARKS
0:00:48 > 0:00:51Meat - the muscles of mammals -
0:00:51 > 0:00:54is the richest, most energy-packed food you can get,
0:00:54 > 0:01:01and we human beings have set aside great areas of the countryside just in order to produce it.
0:01:01 > 0:01:04In this case - mutton.
0:01:04 > 0:01:08And there is other meat to be had here too -
0:01:08 > 0:01:10rabbits.
0:01:14 > 0:01:20We sometimes eat these as well, but today rabbits are more in danger from another hunter...
0:01:22 > 0:01:25..a stoat
0:01:29 > 0:01:32It's tiny - less than a foot long.
0:01:33 > 0:01:37But nonetheless, it's a skilled and determined killer.
0:02:12 > 0:02:19Its fangs, stabbed into the rabbit's neck, have crushed the back of its skull.
0:02:19 > 0:02:23The rabbit weighs ten times as much as the stoat
0:02:23 > 0:02:26but the stoat prefers to eat in privacy.
0:02:41 > 0:02:46It's those daggers at the front of the jaw that killed the rabbit.
0:02:46 > 0:02:49Now triangular blades farther back, like secateurs,
0:02:49 > 0:02:53help the stoat to cut meat away from bone.
0:02:53 > 0:02:58Those two kinds of teeth are the hallmark of all meat-eaters - small
0:02:58 > 0:03:00and large.
0:03:01 > 0:03:04There are two great tribes of carnivores.
0:03:04 > 0:03:07There are the cats...
0:03:11 > 0:03:14..and there are the dogs.
0:03:23 > 0:03:26Both are skilled in the art of stalking.
0:03:40 > 0:03:44And both have a lethal pounce.
0:03:54 > 0:03:57The serval is so athletic,
0:03:57 > 0:04:00it can sometimes bring down birds.
0:04:02 > 0:04:05It's one of the smallest of the cats.
0:04:05 > 0:04:09And this is the biggest - the Siberian tiger,
0:04:09 > 0:04:12ten feet long from nose to tail.
0:04:15 > 0:04:20The earliest fossils of meat-eating mammals, about 50 million years old,
0:04:20 > 0:04:23have been found in North America.
0:04:23 > 0:04:27It seems that they lived up in the trees, hunting birds.
0:04:27 > 0:04:31One of their descendants, the marten, still does.
0:04:44 > 0:04:48Its claws are long but they can be partly retracted,
0:04:48 > 0:04:50which helps to keep them sharp,
0:04:50 > 0:04:53and they give it a superb grip.
0:05:15 > 0:05:20But other prey sometimes tempts it down from the trees.
0:05:25 > 0:05:30And it's on the ground that most meat-eaters today go hunting.
0:05:34 > 0:05:39Dogs - descendants of those North American tree-dwellers -
0:05:39 > 0:05:44soon spread round the world and, as they did, so their bodies changed
0:05:44 > 0:05:46to suit their new homes.
0:05:46 > 0:05:49This is the Sahara.
0:05:49 > 0:05:55The dog that lives here is the smallest of all the foxes - the fennec.
0:05:57 > 0:06:00Its huge ears help it to avoid overheating.
0:06:00 > 0:06:04Here, it's so dry that moisture is very precious
0:06:04 > 0:06:07and the fennec doesn't waste it on sweat.
0:06:07 > 0:06:12Instead it cools its blood by circulating it through capillaries
0:06:12 > 0:06:17close to the surface of its immense ears which act like car radiators.
0:06:17 > 0:06:22But these enormous ears also help it detect the tiniest sounds -
0:06:22 > 0:06:25even faint scrabblings in the sand.
0:06:33 > 0:06:37The larva of a beetle is full of juice -
0:06:37 > 0:06:41just what the fennec needs, for it's seldom able to drink.
0:06:52 > 0:06:56The desert viper is very small, as snakes go,
0:06:56 > 0:07:00but it's a bigger meal than the beetle grub.
0:07:01 > 0:07:05It's also a much more dangerous one.
0:07:11 > 0:07:14First, those poison fangs
0:07:14 > 0:07:17must be put out of action.
0:07:39 > 0:07:45The snake's venom will only kill if it gets into the bloodstream,
0:07:45 > 0:07:49so, providing the fennec has no cut in its mouth,
0:07:49 > 0:07:52the poison in its meal will cause it no harm.
0:07:52 > 0:07:56Dogs in a COLD climate have a rather different shape.
0:07:56 > 0:08:01Long ears would get frostbitten, so the Arctic fox has very short ones.
0:08:01 > 0:08:07Its fur is particularly long with a dense under-layer that keeps it warm even in the worst Arctic weather.
0:08:11 > 0:08:14It's also white - good camouflage.
0:08:21 > 0:08:28In summer, it changes its coat to a thinner, darker one. FOX CALLS
0:08:28 > 0:08:33Summer is breeding time and this pair's cubs are already half-grown.
0:08:39 > 0:08:42There's no shortage of food at this time of year.
0:08:42 > 0:08:49In fact, there's a glut. Sea birds are nesting on the cliffs in thousands.
0:08:58 > 0:09:03The guillemots, high up on their ledges, are, for the most part,
0:09:03 > 0:09:05beyond the foxes' reach.
0:09:05 > 0:09:11But the foxes know that the chicks can't stay perched up there for ever.
0:09:11 > 0:09:14They have to fly down to the sea.
0:09:16 > 0:09:19But this is their first flight
0:09:19 > 0:09:22and the sea is a long way away.
0:09:26 > 0:09:29Some don't get that far.
0:09:51 > 0:09:54Food for the cubs.
0:10:13 > 0:10:16And STILL they come.
0:10:29 > 0:10:34There's far more food now than the foxes and their cubs can eat.
0:10:34 > 0:10:38Indeed, there's sometimes even more than they can carry.
0:10:47 > 0:10:51But these good times won't last for ever.
0:10:51 > 0:10:54So now the Arctic fox does what many dogs do -
0:10:54 > 0:10:57it buries the surplus.
0:10:57 > 0:11:02And in this cold climate, the meat will stay tolerably fresh for months.
0:11:10 > 0:11:15Birds are not the only sea-going animals that come to land to breed
0:11:15 > 0:11:17and assemble in great numbers.
0:11:17 > 0:11:21On the south-western shores of Africa, in Namibia,
0:11:21 > 0:11:24there are huge breeding colonies of sea mammals.
0:11:29 > 0:11:33You might think that these fur seals
0:11:33 > 0:11:38would be particularly sensitive to danger that comes from the sea.
0:11:38 > 0:11:42But, in fact, they are most easily alarmed
0:11:42 > 0:11:45if you approach them from the land,
0:11:45 > 0:11:50and, since I don't want to scare them, I have to move with great care.
0:11:54 > 0:11:57(Their pups are just up here.)
0:12:03 > 0:12:06(And they STILL haven't seen me.)
0:12:13 > 0:12:15These little pups
0:12:15 > 0:12:19are only a day, or maybe two days, old.
0:12:20 > 0:12:25It's so hot that their mothers have gone to sea to cool off,
0:12:25 > 0:12:28so their babies are now unprotected.
0:12:28 > 0:12:32But I had better retreat before someone raises the alarm!
0:12:33 > 0:12:37From here, I've got a splendid view
0:12:37 > 0:12:40of almost the entire colony,
0:12:40 > 0:12:44so, if attackers come from the land,
0:12:44 > 0:12:47they'll come down there.
0:12:47 > 0:12:50All I have to do now is wait.
0:13:11 > 0:13:14It's a brown hyena.
0:13:21 > 0:13:24Hyenas, most of the time, feed on carrion -
0:13:24 > 0:13:28but they will certainly take a defenceless seal pup.
0:13:49 > 0:13:52PUP CRIES
0:14:15 > 0:14:18SEALS CALL
0:14:25 > 0:14:30The carcass is brought back to be shared with the family.
0:14:32 > 0:14:35All dogs communicate by smell
0:14:35 > 0:14:39but none do so more eloquently than hyenas.
0:14:41 > 0:14:45Their scent comes from a pouch beneath the tail
0:14:45 > 0:14:48and proclaims WHO they are and HOW they are.
0:14:50 > 0:14:54They also use scent to post notices around their territory.
0:14:54 > 0:14:59An individual will put one up every quarter of a mile or so.
0:15:04 > 0:15:08And this is one of their message posts.
0:15:08 > 0:15:11The smear at the top there
0:15:11 > 0:15:13comes from the anal gland
0:15:13 > 0:15:16of one of the hyena family.
0:15:16 > 0:15:19And that smell fades very rapidly
0:15:19 > 0:15:23and is a message to other members of the group,
0:15:23 > 0:15:27saying, "I was here half an hour ago, or quarter of an hour ago,
0:15:27 > 0:15:31"so there's no point in searching THIS patch for food."
0:15:31 > 0:15:34But beneath it, there's a second one
0:15:34 > 0:15:39which was milky white when it was first pasted on.
0:15:39 > 0:15:42Its smell is long-lasting
0:15:42 > 0:15:47and it's intended to be a message to other clans of hyenas, saying,
0:15:47 > 0:15:50"Keep out. This land is ours."
0:15:53 > 0:15:58So their noses enable the hyenas to divide up the desert
0:15:58 > 0:16:04between their clans and so ensure that no source of food is neglected.
0:16:06 > 0:16:10These dogs crop their territory in a very different way -
0:16:10 > 0:16:14racing along special paths through the undergrowth.
0:16:14 > 0:16:19They live in the forests of the Amazon and run in a strict order -
0:16:19 > 0:16:24the females in front, headed by the most senior, the males behind.
0:16:24 > 0:16:29They prefer wet country around the banks of the numerous rivers.
0:16:29 > 0:16:32But they are not common anywhere.
0:16:32 > 0:16:36These are the most mysterious, the least known of ALL dogs -
0:16:36 > 0:16:39the South American bush dog.
0:16:41 > 0:16:47The leading females sprinkle their scent as high as they can.
0:16:57 > 0:17:00The males do no more than cock a leg.
0:17:01 > 0:17:05Their bodies are also adapted to their environment.
0:17:05 > 0:17:09Short legs make it easy to run through the undergrowth,
0:17:09 > 0:17:13and they have skin between their toes which helps them swim.
0:17:13 > 0:17:17They're the only dogs with webbed feet.
0:17:20 > 0:17:24The rodents whose paths through the bush they often use
0:17:24 > 0:17:31are also their prey. But they'll pounce on water-living creatures as well, if and when they find them.
0:17:32 > 0:17:35The trouble with that
0:17:35 > 0:17:40is that very few water-living animals have any scent.
0:17:40 > 0:17:45When THESE dogs hunt, they must use their eyes as much as their noses.
0:17:57 > 0:18:00And if you want to look for things underwater,
0:18:00 > 0:18:04you have to be prepared to get your face wet.
0:18:18 > 0:18:22The pack may accept rules about their running order,
0:18:22 > 0:18:26but at meal times, it's a free-for-all.
0:18:26 > 0:18:29DOGS GROWL AND SQUEAL
0:18:33 > 0:18:38The luxuriant Amazonian forest may appear to be full of food,
0:18:38 > 0:18:42but, in fact, meat here is hard to come by.
0:18:42 > 0:18:45Not so on the open plains of Africa.
0:18:54 > 0:18:59Here, there is more meat than anywhere else in the world,
0:18:59 > 0:19:02so, not surprisingly, there are dogs here too -
0:19:02 > 0:19:05hunting dogs.
0:19:06 > 0:19:09But wildebeest are BIG animals.
0:19:09 > 0:19:16To bring one down, these dogs have to hunt together as a team - sometimes as many as 50 of them.
0:19:17 > 0:19:21They're the most successful of all hunters.
0:19:21 > 0:19:2580% of their chases will end in a kill.
0:19:50 > 0:19:55Once they've selected the victim, they work together to bring it down.
0:20:10 > 0:20:15They have only their teeth to get a grip on their prey.
0:20:15 > 0:20:19They don't have swivelling wrists with a sideways grip.
0:20:19 > 0:20:25Their claws, unlike cats', are not retractile, so they're blunted as a result of so much running.
0:20:25 > 0:20:28They kill in silence.
0:20:28 > 0:20:34Too much noise would attract the attention of lions, who are big enough to drive them off a kill.
0:20:34 > 0:20:41That's also why they bolt down as much meat as they can as quickly as possible.
0:20:45 > 0:20:48Their bellies full, they return
0:20:48 > 0:20:53to the pups and the females back at the dens, maybe several miles away.
0:21:02 > 0:21:05The pups can hardly wait.
0:21:09 > 0:21:12PUPS SQUEAL
0:21:18 > 0:21:23They beg for food by frantically licking the mouths of the adults.
0:21:23 > 0:21:29All these pups are the offspring of the senior pair - the alpha male and female.
0:21:29 > 0:21:32Normally, no others will breed.
0:21:32 > 0:21:39So the returning hunters are either the pups' uncles and aunts or brothers and sisters.
0:21:40 > 0:21:44They squabble among themselves - as youngsters do.
0:21:48 > 0:21:51But they also give food to one another -
0:21:51 > 0:21:55as they will do throughout their lives.
0:22:00 > 0:22:03The adults share domestic duties,
0:22:03 > 0:22:08the young females helping their mother - the alpha female -
0:22:08 > 0:22:11to look after her latest litter of pups.
0:22:44 > 0:22:49So dogs, by and large, are sociable animals,
0:22:49 > 0:22:54a fact that people who live up here in the north of North America
0:22:54 > 0:22:58have taken advantage of since early times,
0:22:58 > 0:23:02training them to pull their sledges as a team.
0:23:02 > 0:23:06And up here, too, lives the biggest of all the dog family.
0:23:06 > 0:23:09And it, too, lives in packs.
0:23:16 > 0:23:19If animals are to work in a team,
0:23:19 > 0:23:23they need to be able to communicate with one another.
0:23:23 > 0:23:27And sometimes it's possible for YOU to communicate with THEM.
0:23:30 > 0:23:33HE HOWLS
0:23:49 > 0:23:52HE HOWLS AGAIN
0:23:58 > 0:24:02DISTANT HOWLS
0:24:02 > 0:24:05IT HOWLS
0:24:09 > 0:24:12RESPONDING HOWL
0:24:19 > 0:24:24Wolves howl to warn neighbouring packs to keep their distance.
0:24:24 > 0:24:31But they also do so to reunite their own pack if it's got scattered after a long hunt.
0:24:31 > 0:24:33And as they assemble again,
0:24:33 > 0:24:37they visibly delight in one another's company.
0:24:46 > 0:24:53This pack, too, like that of African hunting dogs, is ruled by an alpha pair who are the only ones to breed.
0:24:53 > 0:24:59But there's also a strict hierarchy among the other members - one for males and one for females.
0:24:59 > 0:25:04This is reinforced daily by mouth-licking, crawling and mounting.
0:25:04 > 0:25:09These rituals become intense just before the pack leaves on a hunt.
0:25:09 > 0:25:14It's a bonding session that reminds each hunter of its place in the team.
0:25:14 > 0:25:17Invaluable in the struggle to come.
0:25:19 > 0:25:22And off they go.
0:25:28 > 0:25:32Those distant dots are their targets...
0:25:33 > 0:25:38..elk - the North American equivalent of the European red deer.
0:25:47 > 0:25:50Snow drifts will make the chase difficult.
0:25:50 > 0:25:57A wolf's pads are particularly broad but in really deep snow, the elks' long legs give them the advantage.
0:25:57 > 0:26:02In such country, there is little chance of taking them by surprise.
0:26:02 > 0:26:06So the chase is likely to be a long and exhausting one.
0:26:18 > 0:26:20One of the stags is flagging
0:26:20 > 0:26:24and the pack have managed to separate it from the herd.
0:26:24 > 0:26:28Another sprints past close by and confuses things.
0:26:33 > 0:26:37Most of the wolves stick to their original quarry.
0:26:37 > 0:26:43They have, after all, been harrying it for some time and it may be tiring.
0:26:43 > 0:26:46But it's got away.
0:26:48 > 0:26:53Another wolf is chasing the stag that ran by them earlier.
0:27:01 > 0:27:04But that escapes too.
0:27:04 > 0:27:08Only one in ten wolf hunts is successful.
0:27:14 > 0:27:16The weather worsens.
0:27:16 > 0:27:21It's a week since the wolves fed. They're getting desperate.
0:27:32 > 0:27:36They have no alternative but to continue to follow the herd.
0:27:48 > 0:27:55Now they have a real chance. A female has become isolated and is close to the end of her strength.
0:28:00 > 0:28:03She can go no further.
0:28:03 > 0:28:08But even now, TWO wolves are not strong enough to bring her down.
0:28:16 > 0:28:18But then the rest of the pack arrive.
0:28:18 > 0:28:21Now she has no chance.
0:28:31 > 0:28:33The herd moves on.
0:28:45 > 0:28:50The herds of North America are rivalled in size by those in Africa.
0:28:50 > 0:28:56And it's here in the Old World that the other great group of hunters first appeared.
0:28:56 > 0:29:00This is the original home of the cats.
0:29:03 > 0:29:10There's no problem at all in finding the hunters that dominate THESE hunting grounds...
0:29:14 > 0:29:16..lions.
0:29:16 > 0:29:22With all this meat walking around, they're taking no notice whatsoever.
0:29:22 > 0:29:27The fact of the matter is most lions do most of their hunting at night.
0:29:27 > 0:29:30The daytime's a bad time.
0:29:30 > 0:29:37It's very hot. Now it's near the middle of the day and the lions have found a nice cool place to rest.
0:29:37 > 0:29:41And during the day, too, it's so bright,
0:29:41 > 0:29:45their prey can see them - hunting is very difficult.
0:29:45 > 0:29:49Much better to hunt during the darkness of the night.
0:29:52 > 0:29:58Their eyes are more sensitive than ours, but neither they nor I can see THESE lights.
0:29:58 > 0:30:03They're infra-red and visible only to our special cameras.
0:30:03 > 0:30:07WHISPERS: Lions hardly ever roar in the day.
0:30:07 > 0:30:10It's very much a night-time thing.
0:30:10 > 0:30:12And now in the darkness,
0:30:12 > 0:30:15there are a number of them roaring
0:30:15 > 0:30:17just around here.
0:30:17 > 0:30:23There are two, I know, within three or four yards of where I am now.
0:30:23 > 0:30:26And there's a third
0:30:26 > 0:30:29perhaps 20 yards over there,
0:30:29 > 0:30:35though it's difficult to tell because it's pitch black except for just faint moonlight.
0:30:35 > 0:30:41Three of them belong to the same pride and they are communicating,
0:30:41 > 0:30:43telling one another where they are.
0:30:43 > 0:30:46LIONS ROAR
0:30:58 > 0:31:04Those are not aggressive roars. They are communication roars.
0:31:04 > 0:31:08But they are quite enough to chill the blood
0:31:08 > 0:31:10in the blackness of the night...
0:31:10 > 0:31:14LIONS ROAR
0:31:14 > 0:31:20..especially when you know that the lions making them are within a few yards of you
0:31:20 > 0:31:22but you can't see them!
0:31:23 > 0:31:26A hunt is beginning.
0:31:26 > 0:31:30The shine in their eyes comes from our infra-red lights
0:31:30 > 0:31:36reflected by a mirror-like membrane at the back of their eyes.
0:31:36 > 0:31:42That, and pupils that open far wider than ours, enables them to see eight times better at night than we can.
0:31:42 > 0:31:45The big male is going too.
0:31:52 > 0:31:55The cubs are bringing up the rear.
0:32:36 > 0:32:40The slightest noise could stampede the zebras.
0:33:03 > 0:33:06ZEBRA CRIES
0:33:06 > 0:33:09LIONS GROWL
0:33:14 > 0:33:18The lioness's jaws are clamped in the zebra's throat.
0:33:18 > 0:33:20They're throttling it.
0:33:23 > 0:33:26Now there is food for all -
0:33:26 > 0:33:30so much, in fact, that there's very little squabbling.
0:33:49 > 0:33:54Dawn - and the pride are still lounging around with full bellies.
0:34:03 > 0:34:09The zebra know that - for the moment, at least - there's no danger.
0:34:12 > 0:34:16Considering how powerful and aggressive lions can be,
0:34:16 > 0:34:21life within the pride is remarkably peaceful and harmonious.
0:34:22 > 0:34:29Just as they hunt together, so they also help one another in bringing up the young.
0:34:29 > 0:34:34A nursing mother will allow cubs belonging to others to take her milk.
0:34:34 > 0:34:37The lionesses in a pride are nearly always sisters,
0:34:37 > 0:34:42but, even so, such co-operation and tolerance is remarkable
0:34:42 > 0:34:45and very unusual indeed among cats.
0:34:54 > 0:34:57Most cats are solitaries,
0:34:57 > 0:34:59living and hunting by themselves
0:35:00 > 0:35:05These are the cubs of a single mother - a cheetah.
0:35:07 > 0:35:14She has a heavy responsibility. Neither her sisters nor the cubs' father help in bringing them up.
0:35:14 > 0:35:18Finding food for them - and for herself - is not easy.
0:35:28 > 0:35:31She moves off...
0:35:31 > 0:35:34and they follow.
0:35:34 > 0:35:39But they're likely to be more of a hindrance than a help.
0:35:52 > 0:35:54Impala are grazing nearby.
0:35:54 > 0:35:59They move away as she approaches but they don't panic.
0:35:59 > 0:36:03Unless a cheetah is within 30 yards, they can outrun her.
0:36:03 > 0:36:07She knows that too and doesn't want to waste her energy.
0:36:07 > 0:36:11She won't charge unless she gets really close.
0:36:13 > 0:36:19The cubs seem to realise that an attack is imminent and settle down to watch.
0:36:19 > 0:36:22Is she close enough?
0:36:50 > 0:36:52They're beginning to drift away.
0:36:57 > 0:37:00She starts her sprint.
0:37:16 > 0:37:18Now she's running flat out.
0:37:18 > 0:37:25She's bounding so swiftly that her feet are off the ground for almost half the time. She's almost flying.
0:37:34 > 0:37:37The race is over.
0:37:37 > 0:37:40The slowest will not compete again.
0:37:49 > 0:37:53Cheetahs are the fastest thing on four legs.
0:37:53 > 0:37:56Their backbones are so supple
0:37:56 > 0:38:01that their hind legs can reach forward on either side of the front.
0:38:01 > 0:38:03She's so slim and agile,
0:38:03 > 0:38:07she can rival a gazelle in dodging and swerving.
0:38:29 > 0:38:33Unusually, another has come to share her prize.
0:38:33 > 0:38:37It's probably a grown-up cub from last year's litter.
0:38:37 > 0:38:40She wouldn't tolerate anyone else.
0:38:51 > 0:38:54Her slim athletic build is now a liability -
0:38:54 > 0:38:59heavier animals like lions could push her off her kill.
0:38:59 > 0:39:02So she and her cubs eat fast.
0:39:02 > 0:39:07All big cats are widely distributed, but one is particularly adaptable.
0:39:07 > 0:39:11It lives in tropical rain forests from the Congo to Vietnam,
0:39:11 > 0:39:14in deserts from Algeria to Iran
0:39:14 > 0:39:18and here in the rocky hills of northern India.
0:39:18 > 0:39:21Prey is scarce here.
0:39:21 > 0:39:25By far the most abundant are the domestic animals
0:39:25 > 0:39:32that those other great meat-eaters - human beings - keep to consume themselves.
0:39:32 > 0:39:35GOATS BLEAT
0:39:58 > 0:40:02The villagers know that this cat usually hunts at night,
0:40:02 > 0:40:09so every evening they drive the goats into this thorn-walled enclosure to keep them safe.
0:40:20 > 0:40:23Even a BIG cat won't be able to cross THIS.
0:40:30 > 0:40:34It's now absolutely dark
0:40:34 > 0:40:37and all I have to help me is a torch.
0:40:38 > 0:40:42Beyond its beam, there is absolute blackness.
0:40:43 > 0:40:47So I feel pretty vulnerable,
0:40:47 > 0:40:51because this big cat can move at night in total darkness.
0:40:51 > 0:40:54It could be anywhere.
0:40:55 > 0:40:59But we DO have infra-red cameras in this village
0:40:59 > 0:41:02so if it does come, we will see it.
0:41:23 > 0:41:28And this thatched hut is our technical operations control centre!
0:41:30 > 0:41:37We've got three cameras stationed around the village, each with its own monitor,
0:41:37 > 0:41:41so whichever way the raider comes, we should see it.
0:41:47 > 0:41:51I can scan each one of them.
0:41:54 > 0:41:58There it is - a silent, moving shadow.
0:42:05 > 0:42:08It's a leopard -
0:42:08 > 0:42:13a female - and she's moving down the main path through the village.
0:42:43 > 0:42:46That's our hut!
0:42:48 > 0:42:55She's just beyond the curtain across the doorway - within a few yards of me.
0:42:58 > 0:43:01But I'm not what she's looking for.
0:43:04 > 0:43:06She's leaving.
0:43:06 > 0:43:11The flock has survived without loss for another night.
0:43:25 > 0:43:27Of all the big cats,
0:43:27 > 0:43:32the leopard is perhaps the best stalker - and the least seen.
0:43:32 > 0:43:36In Africa, it hunts gazelles.
0:44:03 > 0:44:07Each paw is placed with the utmost care.
0:44:15 > 0:44:17IT SNORTS
0:44:25 > 0:44:28SHORT, SHARP COUGHS
0:44:28 > 0:44:30ALARM CALLS
0:44:34 > 0:44:39No dog can equal the stealth with which cats can stalk,
0:44:39 > 0:44:44nor the swift efficiency with which they dispatch their victims.
0:45:10 > 0:45:14I'm in the frozen north and this is the trail
0:45:14 > 0:45:17of the biggest of the cats - the tiger -
0:45:17 > 0:45:21and the biggest of the tigers -
0:45:21 > 0:45:23a Siberian tiger -
0:45:23 > 0:45:27surely the most formidable hunter of all.
0:46:03 > 0:46:07Until human beings devised weapons for themselves,
0:46:07 > 0:46:12this was the most powerful killer on Earth - the top predator.
0:46:14 > 0:46:18Few creatures could escape it. Nothing could threaten it.
0:46:18 > 0:46:21But that has now changed.
0:46:23 > 0:46:26Hunting animals need hunting grounds,
0:46:26 > 0:46:31and that, inevitably, brings them in conflict with humanity.
0:46:31 > 0:46:34Once, there were tigers all over Asia -
0:46:34 > 0:46:37from Sumatra and Bali in the south,
0:46:37 > 0:46:41India in the west, up to Siberia in the north.
0:46:41 > 0:46:45But sadly, over much of those areas,
0:46:45 > 0:46:47the tiger has disappeared.
0:46:50 > 0:46:53And even THIS one
0:46:53 > 0:46:56is in captivity.
0:47:01 > 0:47:05Big cats like the same sort of meat as human beings -
0:47:05 > 0:47:08as well as eating human beings!
0:47:08 > 0:47:13So it's scarcely surprising that the two don't co-exist very easily.
0:47:18 > 0:47:22But once, these magnificent meat-eaters
0:47:22 > 0:47:25were the lords of the land...
0:47:31 > 0:47:35..the ultimate in lethal grace and beauty.
0:48:28 > 0:48:35I don't really know why it is that lions don't jump into a Land Rover with no doors on its sides
0:48:35 > 0:48:39and take out the people who are sitting in there.
0:48:39 > 0:48:44But they don't, and that's the thought you want to hang on to
0:48:44 > 0:48:49if you have no doors to your Land Rover and lions all around you!
0:48:50 > 0:48:53Most big cats are nocturnal hunters
0:48:53 > 0:48:59so, until now, we've only witnessed a fraction of their lives.
0:48:59 > 0:49:05Scientific studies and daylight filming have pieced together evidence of the night action
0:49:05 > 0:49:11but our understanding of the nocturnal life of all the big cats has been, at best, tantalising.
0:49:12 > 0:49:15The leopard is a stealthy, solitary hunter.
0:49:15 > 0:49:22It's rare for an individual to kill by day and rarer still for us to be able to film it.
0:49:25 > 0:49:29The leopard's territory may cover 25 square kilometres
0:49:29 > 0:49:36and, even with the cover of darkness, it's thought that less than 5% of hunts are successful.
0:49:36 > 0:49:41We can only try to interpret the evidence left in the morning.
0:49:41 > 0:49:46But there ARE people very practised in this particular art.
0:49:47 > 0:49:52For many years, field biologist Philip Stander
0:49:52 > 0:49:57has worked with the Ju'hoan bushmen to study the leopards of Namibia.
0:49:58 > 0:50:03This leopard can be within five metres, perhaps behind that bush,
0:50:03 > 0:50:06and in this habitat, we will never see it.
0:50:06 > 0:50:11But with the bushmen's skill, we learn much from the tracks.
0:50:11 > 0:50:13We know that it's an adult male.
0:50:13 > 0:50:19There's a vast amount we can learn on the animals, just from tracking.
0:50:19 > 0:50:24More than 100 kills have been interpreted in this way.
0:50:28 > 0:50:34The bushmen can read the prints so accurately that they can follow the leopard's approach to its prey -
0:50:34 > 0:50:38even see how he dug his paws into the sand before his final pounce.
0:50:45 > 0:50:51The tiger, too, is a nocturnal ambush hunter with a large territory.
0:50:51 > 0:50:57But in the Indian forest, there is even less chance of finding footprints in sand
0:50:57 > 0:51:00or evidence of a nocturnal attack.
0:51:01 > 0:51:06Once again, ANY film of a tiger hunt in daylight is rare.
0:51:23 > 0:51:29Ullas Karanth is a tiger expert who follows the animals in the forest
0:51:29 > 0:51:35by combining modern technology and a traditional ally - the elephant.
0:51:37 > 0:51:42Radio telemetry enables tracking of animals that are secretive
0:51:42 > 0:51:47and which are active at night, and which use very dense cover.
0:51:47 > 0:51:50The tiger does all these things.
0:51:50 > 0:51:55The cover's very dense so you don't get much visual observation.
0:51:55 > 0:51:58Radio tracking has revealed
0:51:58 > 0:52:03how tigers use their territory, and guided researchers to kill sites.
0:52:03 > 0:52:08The team has made a first step into the night. These photographic traps
0:52:08 > 0:52:15provide a snapshot of the tiger's nocturnal movements, and stripe patterns identify individuals.
0:52:15 > 0:52:21Yet, without more complex technology, we're still very much in the dark.
0:52:21 > 0:52:23And what of lions?
0:52:23 > 0:52:28We've observed and filmed daylight hunts for many years,
0:52:28 > 0:52:33but always in the knowledge that most of their kills are at night.
0:52:33 > 0:52:39Only after decades of research has the strategy of lion hunts emerged.
0:52:39 > 0:52:43It's less a form of team-work, as was once thought,
0:52:43 > 0:52:48and more an exercise in individual risk analysis by each lioness.
0:52:55 > 0:53:00This is how the pride spends most daylight hours.
0:53:00 > 0:53:05Generally, hunting happens after the sun has set.
0:53:06 > 0:53:09But to follow the action into the night,
0:53:09 > 0:53:11we needed to see in the dark,
0:53:11 > 0:53:18with cameras so sensitive that they could get pictures in moonlight or even starlight,
0:53:18 > 0:53:23or sometimes to use a completely different light source - infrared.
0:53:23 > 0:53:30The technology for doing that was developed by a very different kind of human hunter,
0:53:30 > 0:53:35but film-makers, like Justine Evans, have now become expert in its use.
0:53:35 > 0:53:39The technology to film animals at night
0:53:39 > 0:53:44has all come from the military, and there is quite a lot of similarity
0:53:44 > 0:53:51between the way we approach difficult, shy animals and the way the military operate.
0:53:51 > 0:53:57You need to assess the area you're working in,
0:53:57 > 0:54:04you need to think of tactics, how to get close to something that doesn't want you to get close to it.
0:54:04 > 0:54:09It can be intense working at night. No-one gets used to the dark.
0:54:09 > 0:54:14I think it's natural for all of us to feel quite fearful.
0:54:14 > 0:54:16If I turn this infrared light out,
0:54:16 > 0:54:21which is actually illuminating the picture that you're seeing,
0:54:21 > 0:54:24and I turn on this tiny torch,
0:54:24 > 0:54:29this is the sort of level of light I'd use to see the controls.
0:54:29 > 0:54:31You're seeing more than I can see
0:54:31 > 0:54:37because you've got an infrared camera which is sensitive to this.
0:54:37 > 0:54:41Justine's experience of nocturnal filming
0:54:41 > 0:54:43has been built up since 1996,
0:54:43 > 0:54:49when she first went to Africa with the inventor of the low-light camera,
0:54:49 > 0:54:52wildlife cameraman Martin Dohrn.
0:54:52 > 0:54:57We assumed we'd be able to film most of it in natural moonlight
0:54:57 > 0:55:02but we discovered that, on bright, moonlit nights, nothing happened.
0:55:02 > 0:55:06The lions just slept, and so did their prey.
0:55:06 > 0:55:10It wasn't until it got really dark and stormy and moonless
0:55:10 > 0:55:13that things started happening.
0:55:13 > 0:55:17The worse the weather, the more carnage.
0:55:17 > 0:55:21This made the work even more demanding,
0:55:21 > 0:55:24but the behaviour it revealed
0:55:24 > 0:55:26was quite extraordinary.
0:55:30 > 0:55:34I started filming a group of ten lions
0:55:34 > 0:55:36that were all very young.
0:55:36 > 0:55:40They had a specialisation - digging up warthog.
0:55:40 > 0:55:43Because there were ten of them,
0:55:43 > 0:55:48one would dig and the rest would sleep, and they'd take turns.
0:55:48 > 0:55:50Eventually, they'd get to it,
0:55:50 > 0:55:54and then ten mouths would just reach in
0:55:54 > 0:55:58and this pig would disappear in ten directions!
0:55:58 > 0:56:01That was a vulnerable situation.
0:56:01 > 0:56:05What's now clear is that lions and other predators
0:56:05 > 0:56:09have a quite different sense of purpose in the night.
0:56:09 > 0:56:15What's very natural for them is equally unsettling for us humans.
0:56:15 > 0:56:20It's a strange feeling if you sit down somewhere at night
0:56:20 > 0:56:25and you don't have your back to something solid, like a tree,
0:56:25 > 0:56:27you feel vulnerable from behind,
0:56:27 > 0:56:32and you can feel unnerved by the sounds around you.
0:56:32 > 0:56:38You can't see, and you think that other animals CAN see you.
0:56:38 > 0:56:43Since Justine first filmed her lions with the Starlight camera,
0:56:43 > 0:56:48infrared technology has evolved to take us deeper into the night.
0:56:52 > 0:56:54In this series,
0:56:54 > 0:56:59we've filmed nocturnal hunters and behaviour never seen before,
0:56:59 > 0:57:04from jungle streams in Ecuador to bat caves of Texas.
0:57:04 > 0:57:06And this is just the beginning.
0:57:06 > 0:57:09As the technology develops,
0:57:09 > 0:57:13and we gain more techniques and experience in working at night,
0:57:13 > 0:57:19the behaviour that has until now been hidden will be revealed.
0:57:19 > 0:57:25There's much more to discover in the nocturnal life of mammals.
0:57:56 > 0:57:59Subtitles by Red Bee Media Ltd