Hunting and Escaping The Trials of Life

DULL CROAKS

These great skuas bonxies here in Shetland

are among the most aggressive and ferocious of birds.

They're attacking me now because I'm approaching one of their nests where there are chicks.

They rob other birds of their food, actually in the air.

And they are extremely skilful hunters. They're killers!

Their hungry chicks, waiting in the nest for food,

make them especially determined.

They seek their prey in the huge colony of sea-birds nesting on the cliffs nearby.

KITTIWAKES CALLING

Few creatures in the world are not forever caught up in duels,

like those being fought out here,

duels that have shaped their bodies and govern their daily behaviour.

The skua's tactic is to cruise so close to the cliff

that the kittiwake parents are frightened off their nests, leaving the chicks unprotected.

The kittiwake chicks are almost full-grown, and the skuas want them to feed to THEIR young.

That bird actually caught an adult kittiwake in mid-air.

The skuas go first for the liver.

With crops stuffed full, they will be able to feed their chicks today.

Many different kinds of birds, having spent most of the year out at sea,

come to these cliffs in the spring to nest.

Each has its own favoured territory.

In parts where there is turf and soil, puffins dig their nest holes.

Sitting beside them, they are relatively safe.

If danger looms, they can duck inside their holes.

It's when they're in the air that they are really vulnerable.

Here, the greater black-backed gull is on patrol.

It's substantially bigger than the lesser black-back.

It has a wing-span of over five feet

and the manoeuvrability of a fighter aircraft.

The puffins, with wings and feet that also serve in swimming

and diving, are less agile in the air.

Flying in flocks reduces an individual's risk,

but that's not always possible.

With the puffin almost swallowed, the gull has at last got a meal.

Or has it?

The murdering robber has been robbed.

There are other animals that spend most of their life at sea,

but come to land for a few weeks each year

seals and sea-lions.

These are South American sea-lions off the coast of Patagonia.

They can't give birth while they're swimming, as whales and dolphins do.

They have to come ashore.

In dense groups, they are a great temptation to any hunter that can reach them.

Their nursery beach seems secure.

On the landward side are cliffs, on the other side is the sea.

But the sea itself can harbour enemies.

A killer whale, 30-feet long, eight tons in weight.

Every year, the same group of about a dozen of them assemble off the sea-lion nursery to hunt.

For sea-lions to venture into deep water here is dangerous.

It's much safer to stay in the shallows if they can.

In one or two places, channels allow the whales to get really close to the beach.

Those are the danger spots.

To get off the beach, the killer has to thrash its body.

No other whale deliberately beaches itself like this,

or has perfected this method of getting back to sea.

As long as the sea-lions stay well up the beach,

you might think they'd be safe.

But the hungry whales are very daring.

Now several of the whales are hunting in a group.

That sea-lion was keeping just ahead of one of the whales,

but was caught by another it probably hadn't seen.

This savage beating may be to separate hide from flesh.

But very often, the successful hunter takes its victim out to sea without even killing it.

And there it plays with its catch as if it were exulting in triumph.

To get all the food it needs, a killer whale must catch at least three sea-lion pups a day,

and every day throughout the breeding season, this group of skilled hunters do just that.

The Indian fishing cat hunts at night.

A bit larger than a domestic cat, it feeds on all kinds of prey,

from mice and rabbits to frogs and birds.

But its speciality is fish.

This pair have found an ideal opportunity

a drying river where the fish have been concentrated by the shrinking water into a pool.

Even so, it's not easy.

It requires stealth, lightning reflexes, endless patience,

and perfect co-ordination between eye and paw.

These cats have brought such skills to perfection.

Slugs, you might think, are hardly a challenge to a hunter.

Very few things want to hunt them. This is one the thirst snake.

Its hunting technique is simplicity itself.

The slug's slime which makes it so unappetising

provides the trail which the snake follows.

But swallowing such a slimy mouthful isn't easy.

The snake dislocates its lower jaw

and twists it forward so that it snags the slug with its teeth.

Then a yawn puts the lower jaw back into position.

Not all the hunted give in easily.

Many have ways of deterring hunters that try to make a meal of them.

An American opossum may think this frog will make an easy mouthful. It's quite wrong.

First, the frog inflates its lungs

so that it looks as big and as formidable as possible.

-Then it lets off an amazing alarm.

-CROAKING SCREAM

The whole performance is more than enough to put off the possum.

In Australia, dingoes too can be put off by bluff.

A frilled lizard.

The frill is nothing but skin,

but it disconcerts the dingo long enough

to allow the lizard to escape.

This, however, is no bluff.

Hunters like this viper carry poison to kill their prey.

And the hunted use it too, as a deterrent.

This tomato frog, when threatened,

exudes a milky poison that would make any aggressor very ill indeed.

The problem about poison as a defence is that,

by the time you've convinced your attacker you're not worth eating, it has mauled or killed you.

So many animals that have poison advertise the fact in advance. Look at this little creature.

It's a spotted skunk.

Like the bigger striped skunk that also lives here in the southern United States,

it has glands that squirt a liquid that smells so appalling it can make you sick.

I'm going to press my luck a bit!

It doesn't want to squirt needlessly, so it gives a warning.

It's an eloquent display of gymnastics to back up its warning spots.

How better could you call attention to the spray-gun under your tail?

I'm not going to get any closer because I don't want to be sprayed!

Salamanders also put on gymnastic displays to declare that they have chemical weapons.

In their case, it's in their skin.

Having jerked convulsively into an extraordinary contortion, they stay there, transfixed.

This one's warning colours are on its belly only,

so when danger threatens, it throws itself on its back.

And this one has its poison in a line of sacs along its flanks which it can release

by the drastic method of sticking its ribs through its skin, tearing them open.

Some poisonous bugs carry their "keep-off" signs like banners on their legs.

And these add an additional trick. They keep together in a swarm.

If a bird misguidedly takes one, it won't peck at the others with that nasty taste in its mouth.

Black and yellow is a colour code that is widely understood.

It's used not only by wasps but by salamanders and snakes, and caterpillars like this one.

These long hairs are also poisonous.

The caterpillar walks around with the confidence of the well-armed.

Some only PRETEND to be well-armed.

This may look like an ant with a sting,

but the ant body is a mask on a harmless, edible, plant-hopper.

This little creature looks like a spider, and so does this.

In fact, both are fruit-flies.

They have neither poison-fangs nor stings, and could be eaten.

Here is a real spider.

It signals with its palps and legs, as it would to another spider.

And the fly responds by waving its black and white wings in a similar way

It's mimicking the spider's "keep away" sign.

And it works!

You can also protect yourself by concealment.

Insects are the great masters at doing this.

A stick? No, an insect.

This is its head, with its front legs stretched up beside it.

You can recognise it for what it is only when it walks.

A band of moss, perhaps?

No, another insect, but lying so flat against the twig that it seems almost a part of it.

Only its antenna lifted above the twig,

and a slight adjustment of position, give the game away.

Dead leaves lie all over a forest floor,

so an insect mimicking them can wander undetected over a wide area.

It's a kind of bush cricket.

And this insect mimics living leaves.

Its vivid green leaf-covers are veined like real leaves.

Green flanges sprout from its legs.

Few of those that are hunted among leaves can have a better concealment than this.

Thorn bugs.

Like many bugs, they produce excretions that are collected by ants.

Ants seem to know which are thorns and which are bugs.

But two can play at that game.

What could look more innocent than this orchid blooming in the Malaysian rainforest?

Its flowers are bright, proclaiming the sweetness of their nectar and attracting insects.

But even in such a lovely thing, danger can lurk.

Sitting on it, exactly matching the colour of the orchid petals, is a mantis. It's facing left.

It's waiting, motionless, for the butterfly.

Beside the entrance of a termite hill,

a pile of refuse tipped out from the nest by termite workers.

On it, another hunter, lurking in disguise.

It's an assassin bug.

It throws particles of refuse on to its body

not to hide from its prey, termites, which are blind

but to hide from birds and other creatures that might eat IT.

Its cloak of droppings, however,

may conceal it from the termites by giving it a protective smell.

The industrious workers are unaware that there's an enemy there, until it's too late.

Mimicry doesn't always deflect attention. Sometimes it attracts it.

A death-adder from Northern Australia.

And this could be its next meal a skink, searching for worms.

Perhaps this is what it's seeking.

In fact, it's the tip of the death-adder's tail.

That was a near miss!

Lures can also be used in defence.

A blue tit, hunting for food, may overlook a camouflaged hawk moth.

But if it investigates, the moth suddenly exposes its hind wings.

The eye-spots don't alarm THIS tit, but they induce an attack.

Instead of getting a lethal peck on its head, the moth is struck harmlessly on its wing.

Eye-spots give this caterpillar an almost snake-like appearance.

And these tentacles, which release a nasty smell, heighten that resemblance.

Could this really be an imitation of a snake's forked tongue?

Could the caterpillar be mistaken for a snake when it is only inches long? We can only guess.

And this is an even greater mystery.

It's a frog and, like most frogs,

is hunted by snakes.

The centres of these eye-spots carry poison glands,

but the snake couldn't see them from the front.

So just how does having a face on its bottom protect the frog?

No-one knows.

Big eyes undoubtedly attract attacks.

As this frog has real ones, it needs to conceal them rather than display them.

It lives in bromeliad plants,

a favourite hunting-ground for small snakes.

By reversing into the heart of the plant, it conceals everything except the top of its head

which is protected by a special helmet, a bony shield.

So, many animals have developed techniques for preventing other animals from eating them.

High-speed sprints, jinking runs, distraction displays, near-perfect camouflage,

even taking on disguises that make them look like hunters themselves.

But there is one animal against which none of these is a defence,

one hunter which is invariably successful this one.

Beneath this log is an immense ball of ants.

Its outer surface is a lacy veil formed by individuals clinging to one another's legs.

Altogether, there are about three quarters of a million. They are army ants. This is their bivouac.

A raiding force of workers escorted by a guard leaves the bivouac.

They are almost blind, but they are following a scent trail

laid down by scouts who are foraging ahead.

Few things are safe from them, not even a giant spider.

The sting of a scorpion is useless against such tiny aggressors. They're too small to hit,

and too numerous.

A wasps' nest is a major prize.

The adult wasps, even though they have powerful stings, can't repel the ants,

and they watch helplessly as their colony is pillaged.

The fat grubs are hauled from their cells, butchered, and carried off.

The bigger victims are cut up for easier transport,

and carried back to the queen and the workers.

A caterpillar's camouflage did not save it.

A ring-shaped segment from a millipede is caught on a spike.

In some places, the soldiers form living bridges across which the porters run.

The bite of the ants' jaws and the sting in their tail is so painful you daren't get close.

So studying them is very difficult.

We know very little of what goes on in the heart of such a bivouac.

But this optical probe may help us find out.

The bivouac has an internal structure, with walls made by the ants clinging together.

You have to be careful. Even though the probe has been greased, some soldiers manage to run up it.

Here is the nursery, full of young developing grubs.

After two weeks or so in camp, the eggs that the queen has laid in such numbers are hatching.

The grubs need feeding, and the entire army once more starts to march.

The workers carry the baby grubs.

Soldiers, huge jaws agape, guard the sides of the route.

The army makes temporary camp each night

until, after about two weeks, it bivouacs and repeats the cycle.

The most powerful hunters in the bird world are hawks and eagles.

But the Harris hawk, in the deserts of New Mexico, has a particular skill it hunts in groups.

The team of half a dozen or so assembles in the morning

and begins to search the countryside.

Their look-out posts are the great pillars of the saguaro cactus.

The cacti are splendidly tall,

but they don't appear to be very comfortable.

And the prickly pear is hardly any better.

A pack rat!

In this thorny tangle, it's hard to get a clear sight to pounce.

Some of the hawks go down to try and chase the rat out.

Since the rat is so much quicker on the ground than they are,

they'll only catch it if there are several of them.

They've lost the rat, but found bigger prey, a cottontail rabbit.

The two on the ground chase it out.

Those perching now get a clear sight.

Once the kill is made, the entire team gathers,

and each bird tears off a share.

One bird by itself is unlikely to have made such a kill in such country as this.

But were the birds working in a team with a plan? Probably not.

Individual birds do not regularly play the same role.

Each reacted to the movements of the rabbit, and benefited from its companions doing the same.

In the forests of the Ivory Coast in West Africa live animals that are our closest relatives.

Chimpanzees. A peaceful scene of jungle harmony.

You don't normally think of THEM as hunters,

more as gentle vegetarians, munching fruit and picking leaves.

But if you follow them in their true home, these forests in West Africa,

you discover that they ARE hunters.

What's more, they hunt in teams and have a more complex strategy

than any other hunting animal except...

-CHIMPANZEE SHRIEKS

-..except, of course...man.

One of the hunters, the experienced male, is sitting right there.

This is the time they hunt the wet season.

Their regular prey is monkeys, but they're selective.

A Diana monkey, a big species, and one they seldom tackle.

A spot-nosed monkey.

Red colobus. They're much better jumpers than chimps,

and being half their weight,

they go on much thinner branches, so in theory a chimp can't catch them.

They must work as a team, and half a dozen males in this group of 60 regularly do so.

This is one of them. From his walk, it's clear that the search for prey has started.

The other members of the team are not far away.

They've been following the monkeys for about 20 minutes, looking for an opportunity.

The technique they'll almost certainly use is that one of them will drive the colobus ahead of him

and there will be others on either side

the blockers who make no attempt to catch the monkey.

Then there are chasers who grab the monkey if they can,

and finally a male who goes ahead to ambush it,

so bringing the whole trap closed.

The monkeys are now getting alarmed.

A driver's going up to prevent the group from settling

and to drive them towards an area where they are more easily trapped.

That's one of the blockers that has quietly come ahead of the colobus

and is half-way up the tree.

He's deliberately making himself conspicuous.

They're all in position.

The drivers and blockers have gone up, and the one who will close the ring has gone up too.

The colobus will be very lucky if they escape now.

CHIMPS SHRIEKING

They've got one!

PIERCING SCREAMS

The hunters are tearing it apart.

Everyone hunters in the trees, spectators on the ground

is screaming with excitement.

And now the kill is brought down so that the females and others can share it.

And there's the reward for that long chase the divided body of a colobus monkey.

These blood-stained faces...

may well horrify us.

But we might also see in them the faces of our long-distant hunting ancestors.

And if we are appalled by that mob violence and blood-lust,

we might also see in it the origins of the team-work

that has, in the end, brought human beings many of their greatest triumphs.