the weirdest in this world of the strange.
Vampyrotuthis, the vampire squid from hell.
Disturb it, and it only retreats a little distance.
Go after it, and it has a special defense.
To see what it does, you must switch off the lights.
The vampire squid has lights of its own.
Bioluminescent bacteria shine from pockets on its arms to confuse its predators.
Are those eyes?
In fact, there are spots at the end of its mantle.
A bite there would leave the head unscathed.
The threat diminishes and Vampyro Toothis disappears into the blackness.
It spends its days hiding 400 metres down, but as night falls it ascends up to the reefs to look for food.
Its graceful shell contains gas-filled flotation chambers that control its depth.
It's powered by a jet of water squirting from a siphon.
But it travels shell first, so it can't see exactly where it's going.
Its nearest living relatives are squid and octopus, which over evolutionary time, have both lost their shells.
And the octopus has become one of the nautilus' major predators.
It's a master of disguise.
The nautilus keeps well clear of them.
Its small tentacles carry highly developed chemical sensors which can detect traces of both predators and prey.
It uses its water jet to dig in the sand.
Because it devotes so little energy to swimming, it only needs a meal once a month.
And just as well.
Dawn is approaching, and it has to puff its way back to deeper waters.
And there are snakes here, too.
Lots of them.
These are banded sea crates.
They lay their eggs on land, but they hunt here in the water.
They're too slow to catch fish in a straight chase, so they seek prey that is hiding in the nooks and crannies of the coral.
Their bite is highly venomous and paralyzes their victims.
And on this reef, the snakes do not hunt alone.
Shoals of yellow goatfish and trevally are seeking similar prey and they attract the snake's attention.
As one group of hunters searches the reef, they're joined by the other.
At least 30 snakes have now joined the caravan.
The big fish scare the prey into cracks, and there, the snakes can catch them.
And anything fleeing from the crates will swim straight into the mouths of the waiting trevally.
There's nowhere to hide.
As the raiders scour the reef, more and more snakes join the hunt.
This cooperation between snakes and fish, spectacular though it is, has only recently been observed, for it only happens on the most remote reefs in Indonesia.
Perhaps such hunting alliances were once a common sight, but today no more than 6 of Indonesia's reefs are in their pristine state.
Incredibly, 80% of all insects live in jungles.
Fewer more successful than the ants.
There can be 8 million individuals in a single hectare.
But jungle ants don't have it all their own way.
These bullet ants are showing some worrying symptoms.
Spores from a parasitic fungus called cordyceps have infiltrated their bodies and their minds.
Its infected brain directs this ant upwards.
Then, utterly disorientated, it grips a stem with its mandibles.
Those afflicted that are discovered by the workers are quickly taken away and dumped far away from the colony.
It seems extreme, but this is the reason why.
Like something out of science fiction.
The fruiting body of the cordyceps erupts from the ant's head.
It can take three weeks to grow.
And when finished, the deadly spores will burst from its tip.
Then, any ant in the vicinity will be in serious risk of death.
The fungus is so virulent, it can wipe out whole colonies of ants.
And it's not just ants that fall victim to this killer.
There are literally thousands of different types of Cordyceps fungi and remarkably, each specializes on just one species.
But these attacks do have a positive effect on the jungle's diversity, since parasites like these stop any one group of animal getting the upper hand.
The more numerous a species becomes, the more likely it will be attacked by its nemesis, a cordyceps fungus, when all the geese have gone.
Further south, other, bigger predators prowl the tundra.
Wolves.
For them, finding food on the plains is an even greater challenge.
Not only is their prey seasonal, it's also hard to find.
They've been searching for days without a sign.
Somewhere in this immense landscape, there is food for them.
This is it, caribou.
Traveling 30 miles a day, they can cover nearly 2000 miles.
During the summer months, the wolves will starve if they don't find the caribou.
But it's no easy task to locate prey that never stops traveling.
Fighting flies and the quest for new pasture drives the migration ever onwards.
A wolf has finally picked up the trail.
The caribou are close.
At last, a chance.
The hunt is on.
The wolf panics the herd, and the weak and young are singled out.
The calf is separated from its mother.
A snow leopard, the rarest of Himalayan animals.
It's a female returning to her lair.
These are the first intimate images of snow leopard ever filmed in the wild.
She greets her one-year-old cub.
Her den is well chosen.
It has exceptional views of the surrounding cliffs.
On these treacherous slopes, no hunter other than a snow leopard would have a chance of catching such agile prey.
A female with young makes an easier target.
Her large paws give an excellent grip, and that long tail helps her balance.
Silently, she positions herself above her prey.
She returns with nothing.
In Western Australia, these dolphins have taken on an even tougher challenge.
The fish have taken refuge close to the beach, where the water is only a few centimeters deep.
Tail-slapping is a method dolphins often use to stun their prey.
But it doesn't seem to work here.
The fish are tantalizingly close, but they're still out of reach.
So the dolphins try another technique.
Vigorously pumping their tails, they work up some speed.
And then they hydroplane.
Their momentum carries them right through the shallowest waters and onto the fish.
Now they're in real danger of being stranded.
But fortune favors the brave.
Younger dolphins lie alongside, watching.
But so far, only eight individuals here have mastered this daring technique.
The cats are hungry, and the elephants seem to sense it.
Oh, shoot.
Lions don't usually hunt elephants, but desperate times require desperate measures.
This herd contains calves, easier targets. how to reach them.
The adults encircle their young.
It's an impenetrable wall of gray. a few exhausted stragglers are still arriving.
One of them is alone.
No.
But it's too big for the lions to tackle.
This one looks a little smaller.
A solitary lion stands no chance.
But the whole pride is here.
There are 30 of them, and they're specialist elephant hunters.
Exhausted from his swim, the bear must regain his strength.
The next day, a sea fog shrouds the island.
The wallaces sense that they're in danger.
Using the fog as cover, the bear approaches the herd.
The adults close ranks around their young, presenting a wall of blubber and hide.
He tests the banner, but it stands firm.
It appears that the world's largest land carnivore has met his match.
There must be a chink in the armor somewhere.
Not here.
This female walrus is shielding her pup if he can just prise her off.
The bear's claws and teeth can't penetrate her thick hide.
With the herd retreating to water, the bear must move quickly.
Having failed with one, he heads straight for another.
The chance of his first meal in months is slipping away.
He seems increasingly desperate.
It's now or never.
He must avoid the stabbing tusks if he's to win.
The flailing walrus is immensely powerful and drags the bear away from the shallows towards the safety of the herd.
It slips from his grasp.
Sailfish, three meters long, are closing in on prey.
They will only use just enough energy to make their kill, never wasting a fin stroke.
Nearly a hundred sailfish have surrounded a single school of baitfish.
It's very rare to see so many of these hunters in one place.
To herd their prey, the predators raise their huge dorsal fins.
A mistimed strike by one sailfish could fatally damage another, but each continually changes its color, from blue to striped, to black.
That warns its companions of its intentions and also confuses the prey.
As the shoal is driven nearer the surface, it comes within the range of the seabird.
Out here in the open ocean, there is nowhere for the baitfish to hide.
Sailfish live a high-octane life.
To survive, they must find prey daily.
So their entire existence will be spent on the moon.