Wild Asia: At The Edge

The snow leopard's kill is three days old and all but eaten.

Even so, it struggles to save the last of its precious meat.

The snow leopard is the top predator in a spare and unforgiving land

It drags what was once a bharal.

Both snow leopard and bharal

live in the world's greatest mountains, the Himalaya.

Predator and prey endure at the vertical limit of mammalian life on Earth.

Here, only rock is in abundance.

Every Himalayan life is precarious.

Sixteen thousand feet up, a lung full of air contains

only half the oxygen of a breath taken at sea level.

At any time of year, the temperature can plummet far below freezing.

And the wind never stops

Despite the cold, the sun burns fiercely through the thin atmosphere.

Despite permanent ice on the peaks, water is scarce.

The Rumbak valley in India's Hemis National Park

is usually only dusted by snow.

It lies under the greatest rain shadow on earth.

Clouds from the south dump all their moisture

as they collide with the mountains.

The air that reaches Rumbak is dry and cold.

The snow leopard hates to share its kill.

The cat hunts alone in the twilight and at night.

Only very rarely does it reveal itself to its prey or to humans.

Stealth and mystery are its greatest weapons.

Even for the snow leopard, a healthy bharal is no easy kill.

Bharal are at home on the shear cliffs

where a predator in pursuit of prey risks plummeting to its own death

Bharal are one of six different Himalayan species

of mountain sheep and goat.

They graze all over the mountains,

but the key events in their lives happen in this vertical landscape.

To extract maximum oxygen from the thin air,

Bharal blood is rich in red cells.

Short legs reduce heat loss and lower the centre of gravity.

Bharal hooves are soft and rubbery for grip.

Its gut generates heat as it digests. Hollow hair fibres retain that heat.

The bharal's top coat is perfect camouflage.

Like the Bharal, the snow leopard is a specialist mountaineer.

It too has short legs.

It's ears and testicles are drawn deep into its multi-layered fur coat.

In extreme cold, it will wrap itself in its lush tail.

December in Rumbak valley is the time of the Bharal rut.

For most of the year mature males live apart from the main herd.

Now they follow the scent of females who are almost ready to breed.

For two weeks, mating will be the bharals' obsession.

Female bharal are half the weight of large males.

They come into season only four weeks after weaning this year's infants.

Penis mouthing is both threat and promise.

Size is important to Bharal.

Not just penises, but horns and body mass.

Males move quickly from display to direct contest.

A winner shows his dominance by mounting the loser.

A younger male submits by rubbing his face under the big male's tail.

During the rut, males study female urine.

Taste and smell tell him when she's ready to mate.

The dominant male posture for a female he detects is ready.

Pursuit begins.

Females always run from their suitors.

More nimble, they head for the cliffs.

It takes a large and skilful male to trap a female on his own.

By forcing potential mates to pursue her,

the female usually ensures her offspring are sired

by the biggest, strongest animals.

Soon the whole herd occupies the rutting cliffs.

Even if they failed to establish dominance, males still try to mate.

But to pass on their genes, they must fight dangerous battles.

A lone female is pursued by a group of males.

No one male takes control. And none will back down.

On another part of the cliff,

the dominant male goes unchallenged.

For his partner, courting is exhausting but safe.

Success at last.

The big male will mate with the female many times over the next two days.

He will threaten and fight off any competition.

Four hours on, the brawl over the lone female continues.

During the rut, Bharal take huge risks. They neglect to eat and drink.

Mating leaves the herd exhausted and some injured.

The rut provides an opportunity for the snow leopard just when it needs it.

Prey has become scarce with small animals in hibernation for the winter.

The snow leopard breeding season in January requires

adults to hunt less while they search for mates.

Tired and crippled Bharal will nourish the cat over this difficult time.

Higher up the valley,

a young Tibetan wolf has been driven from the pack into which he was born.

He comes upon a pack of three.

Lacking the individual power of big cats,

wolves must work together to kill larger prey.

The lone wolf is desperate to join a pack.

Very carefully, the outsider introduces himself.

A pack that can kill large prey with three

has no need of a fourth mouth to feed.

But the young wolf will continue to shadow the pack.

In the vast Himalaya,

it could be many hungry weeks before he finds another that might aspect him

Humans have lived in Rumbak for hundreds of years.

The Himalaya is an intersection of great cultures and nations.

It's a terrible place to farm.

Especially in winter,

families depend on the milk and meat of domestic animals.

Their dung is essential fuel.

The farmers' Bhuddist code demands they don't kill wild animals.

But that belief is sorely tested.

Domestic stocks are an easy opportunity for predators.

High above, the wolf pack has killed a mule.

They make the most of the carcass.

It may be many days and miles before the pack kills again.

Feeding, the packs' strict hierarchy is clear.

The dominant wolf shows its status by raising its tail.

The others submit by rolling on their backs.

The lone wolf can only watch. Like the magpie, he is a scavenger.

Well fed, the pack leaves.

The young wolf waits until they are far away.

Movement of animals between packs is essential to prevent inbreeding,

but for individuals it's traumatic.

The outsider is justifiably wary.

If the pack finds him on the carcass, he may be killed.

The young wolf could survive on small prey and scraps.

But he will never breed unless he joins a pack.

He will never stop trying.

A Bearded Vulture waits for the lone wolf to leave.

First to the kill are yellow billed choughs.

The Bearded vulture is in no hurry.

It will circle the carcass many times to ensure the wolf is long gone.

With a wing span over 9 feet there's no quick getaway.

In the Himalaya, many species of bird scavenge meat.

But the bearded vulture has an advantage over all its competitors.

It eats bone.

While it will sometimes take flesh,

it prefers the shards scattered by the wolves.

To digest its hard diet, the bird's gut is highly acidic.

It can swallow bones up to 10 inches long.

Late winter. The streams begin to thaw.

Insect larvae have survived beneath the ice

where only the Dipper is tough enough to hunt them.

It has extraordinary strong toes to hold itself against the current.

Air trapped beneath its plumage protects the bird against the cold.

In spring, people plant barley and peas.

They get a single crop each year from the small parts of the valley floor

they can irrigate by diverting streams.

The crop will be just enough for each family to feed itself

and its animals through winter.

As the days lengthen, many animals climb.

The upper slopes are no longer barren.

Bharal devour the first green grazing of the year.

The females are two thirds of the way through their pregnancies.

Straight after the rut, the older male Bharal left the females

and young to form separate herds.

Female Bharal have their own hierarchies.

Dominant females get right of way on the cliffs

and better access to food.

More plentiful grazing means they now have the energy to fight.

And sometimes, even to play.

On the slopes above, the male bharal herd faces colder weather.

They test each other in preparation for the next rut.

But spring battles are less serious than contests to come.

The male herd grazes on the tough,

less nutritious plants that grow in the upper valley.

The split from the main herd ensures large males

don't compete with pregnant females for the best food.

This spring, a male wolf lingers in the upper reaches of Rumbak valley.

Wolves prefer to hunt in the open

where they can wear down their prey over a long chase.

The wolf would struggle to bring down an adult Bharal male on his own.

But the female and young bharal herd across the valley is a good prospect.

For the wolf, there is no point following the bharal onto the cliffs.

He lacks the agility to kill there.

In the Himalaya, a large proportion of the land is straight up and down.

Whenever threatened, bharal flee to this vertical world.

But here, the snow leopard is just as agile as its prey.

A female wolf waited while her mate tested the bharal herd.

Usually they would hunt together. But the female rests often.

She is wary and seldom moves from a small territory.

Her teats are extended.

She has priorities other than hunting.

Her seven pups were born blind and helpless.

Now they're five weeks old,

they spend most of the day outside the hole in the ground which is their den.

Wolf pup games help build the strength