Opportunists The Life of Mammals

I am looking at one of the most striking and instantly identifiable animals in the world.

A single one is worth about a million pounds.

Famously fussy in their feeding, less than 1,000 survive in the wild.

Millions are spent conserving them. Yet, increasingly, if you want to see one,

you have to come to a zoo, like this one in Atlanta.

It's a giant panda.

When it comes to food,

the giant panda is the ultimate specialist.

It eats bamboo and virtually nothing else.

Few animals can live on such a diet.

Bamboo is tough, fibrous and very indigestible.

With no competition, pandas thrived -

until the bamboo forests in their native China started to disappear.

Then, with no other food to fall back on, their population crashed.

So the giant panda lives its life on the edge.

But there are other feeding strategies.

Instead of being a specialist, you can be a generalist, an omnivore,

prepared to eat pretty well anything you can find - animal or vegetable.

That strategy has led to some animals that are the most successful and charismatic of all.

So what does it take to be an omnivore, and who are they?

Omnivores are the most adaptable animals in the world,

and there is no better example of this than the North American racoon,

which is as varied in its diet as the panda is specialised.

This remarkable mammal has adapted to more types of habitat than almost any other.

The skills that have enabled it to do so are many,

but there is one which it shares with all omnivores -

the ability to make the most of any opportunity.

The racoon owes much of its success to its inquisitive nature,

but it also has a special trick up its sleeve -

extremely sensitive hands.

Touch is the racoon's most powerful sense.

To process the information it gets from its hands,

it uses an unusually large proportion of its brain -

about the same as humans use for sight.

Scientists believe that a racoon - through touch -

can construct a picture of its surroundings

that is as complex as that which we perceive with our eyes.

You might say that the racoon sees with its hands.

It can feel the difference between a rock and a clam in a split second.

If it touches a crayfish, which is armed with powerful pincers,

then second sight is very valuable.

Their extraordinary sense of touch is not even affected by temperature.

Unlike human beings,

racoon hands keep their sensitivity even in the coldest water,

allowing them to forage in rivers and streams whatever the season.

Racoons have been around for nearly two-and-a-half million years,

but the first opportunists appeared much earlier than that.

Being able to eat pretty well anything

was by no means the basic condition of mammals.

The very first of them - contemporaries of the dinosaurs, small insignificant creatures -

had such tiny teeth, they probably ate little but insects.

But specialist omnivores did eventually appear among the prehistoric mammals.

One lived here in South Dakota,

though then, of course, the climate and vegetation was very different.

It's called Dynohyus, and some experts have likened it

to a kind of killer warthog.

This animal was as big as a rhino.

It had a large hairy crest running down its spine,

a long snout and a formidable set of teeth.

Dynohyus died out about 20 million years ago,

but its teeth can tell us what it ate.

At the back, it had massive, flat molars that could grind up almost any kind of vegetation.

But it wasn't a specialised vegetarian

because the teeth at the front

didn't have those sharp, chisel-like teeth that an antelope has.

Neither was it a specialised meat-eater

because the teeth at its middle jaw

are not the slicing, sharp teeth of a lion. But they ARE formidable.

So are the big tusks at the front.

In fact, what you have here is a generalised tool kit

that enabled the animal to deal with almost anything.

Dynohyus may be extinct, but teeth like these

are typical of all living omnivores today.

The forests of Sulawesi in Indonesia are haunted

by a rare, elusive animal that looks almost as prehistoric as Dynohyus.

To find food here, this animal uses not touch but another super-sense -

the one possessed by all omnivores.

The thud of a large pangi fruit hitting the ground

might attract the attention of an animal nearby,

but sounds don't travel far in these thick forests.

Scent, however, can drift on breezes and be detected from great distances

by an animal with a really sensitive nose.

And this creature certainly has that.

It's a babirusa, and its sense of smell

is probably as good as that of any omnivore, alive or dead.

There are several of them here,

attracted by the smell of the ripe pangi.

Males have teeth in their top jaw that grow up and through its snout.

The size of these tusks is a good indicator of strength,

so they determine who gives way to whom.

The pangi fruit may smell good,

but there's a problem - it contains a poison.

The babirusa, however, knows how to deal with that.

It visits a clay lick.

Clay containing the right sort of medicine is not common

and these licks are few and far between.

A large one like this attracts babirusa from miles around.

These are the only places where this rare animal is seen in any numbers.

The clay contains a mineral

which helps to neutralise the toxins in the pangi.

Babirusa, like most omnivores, live in relatively small groups,

for they specialise in picking up odd bits and pieces,

which seldom occur in sufficient concentration to sustain a herd.

So the clay lick, for the babirusa,

is a time when individuals that lead relatively lonely lives

get to know one another.

Young males get a chance to test their strength.

The nose, for any pig, is its greatest asset.

A multi-purpose tool which not only locates food, but digs it up as well.

Wild boar, the European cousin of the babirusa,

are unrivalled foragers.

They are the least fussy of feeders.

Worms make a tasty snack,

but pigs know very well that there's plenty of other food here.

It's just a question of finding it.

Their memories carry the smells and images of all sorts of things

that they've previously eaten and assessed.

Keeping an open mind means that nothing will be overlooked.

Certainly not a decaying pigeon.

Foraging in the woodland is not difficult in summer,

but what happens when the ground is hidden beneath a blanket of snow?

Food is now very scarce.

The carcass of an animal killed by the hard winter is a valuable prize,

but the pigs must continue foraging in the normal way

to maintain their strength.

They are not just ploughing through the snow at random.

They are still guided by their nose, for smell travels through snow.

And there's an interesting smell... right here.

And here.

By following their noses, pigs can keep active throughout winter.

Other opportunists use a different tactic.

They spend the winter asleep in underground dens and appear when the spring brings better weather.

This is the Asiatic racoon dog.

Its legs are so short that it has difficulty in moving through snow -

which may be one reason why it hibernates.

It, too, eats almost anything.

The females, in particular, need to do so for they produce large litters

and supplying all her babies with milk makes great demands on a mother.

She has produced 15 pups.

They ALL need to put on considerable weight to survive the winter -

and they will only be helped by their parents for eight short weeks.

Their first food is their mother's milk.

But very soon they need solid food as well

and that, too, has to be provided by Mother.

While she goes off to forage, the male stays to look after the pups.

Surprisingly - given the size of his family -

he does virtually nothing to help feed them.

The female is coming back. She has caught a small rodent.

Unlike many canids, racoon dogs do not regurgitate food for the babies

and, since mouths hold less than stomachs,

this limits the amount of food she can bring back.

As a consequence, she has to provide her cubs with milk for twice as long as any other dog does.

She'll make a number of journeys every day,

but most of the things she brings back

are only enough for a single pup.

This time she has brought an egg.

The pups haven't yet learned how to deal with such a strange object.

Is it worth eating and, if so, how?

Yes, it is!

And the pups won't forget.

Before long, they must start foraging for themselves,

with their parents alongside to give them some guidance on what is edible.

They don't always get it right.

They must learn fast, for each will have to get as fat as its mother

if it is to survive the long sleep through winter -

and not all of the litter will do so.

Racoon dogs store food as fat,

but another omnivore has a different tactic.

Chickens - one of mankind's favourite prey,

which he keeps in unnatural concentrations

to provide himself with fresh meat and eggs all the year round.

In farmyards like this, chickens are easy targets

for any opportunist determined enough to find its way in.

If there is a weak link in the defences, a fox will find it.

FRANTIC SQUAWKING AND CLUCKING

Foxes are frequently blamed for killing more than they need.

But do they really deserve such a bloodthirsty reputation?

No. A fox will not waste what it kills -

providing it's not disturbed.

But it must act quickly if it's to make the most of such an opportunity.

Few realise that foxes bury their surplus food.

They are saving it for when times get tough.

A vixen will bury carcasses all over her territory.

Later, she will use her memory and her keen sense of smell

to find them again and dig them up.

The fox is not a wanton killer,

but an intelligent opportunist who thinks ahead.

Some opportunities are both brief and seasonal.

There is an abundant source of food in this cave,

but only for a few weeks and it lies right in its far depths.

Down here, it is totally dark

and we can only see what goes on by using infrared cameras.

Darkness, of course, is not a problem for bats

who navigate by echolocation.

But for any other animal, getting around down here

presents a serious challenge.

And there's another major obstacle.

The droppings produced by the vast assemblage of bats

creates an atmosphere thick with ammonia and fungal spores

that can be fatal to those that inhale them.

This guano accumulating on the cave floor sustains more than fungus.

There is a living carpet of flesh-eating beetles and larvae

which, together, make short work of anything they can get hold of.

In fact, this is about as hostile an environment

as you will find anywhere on the planet.

Yet that doesn't deter one unfussy, enterprising opportunist - the skunk.

Indeed, skunks seem almost at home here.

They even indulge in courtship -

as can happen when a male blunders into a female in the pitch dark.

But what is it that tempts them down into this repellent place?

The answer is baby bats.

At this age, they are unable to fly

and, in such a jostling crowd, many lose their footholds and fall.

On the ground, the babies are in great danger.

The skunks can see nothing whatever,

so the fallen bats may survive

if only they can regain the safety of the rock wall.

But so many bats fall that the skunks blunder into quite enough

to make their visit worthwhile.

In the darkness, the skunks can't be sure which end of the bat is which

so, to avoid getting bitten,

they roll the bat on the ground to subdue it.

It is not just skunks that make the most of this seasonal offering.

The touchy-feely racoons are here, too.

In fact, it might seem to be just the place

for an opportunist that can see with its hands.

Exactly which sense the skunks and racoons use to find the bats in the pitch-black cave, no-one knows.

Smell seems unlikely, given the overpowering stench of ammonia here.

And how could a skunk or a racoon possibly hear the distress calls

of a single bat above the deafening squeaks of several million others?

The most likely answer is that they use a combination of touch and luck.

Both racoons and skunks must rely on, literally, bumping into the bats.

This bonanza will only last for about a month.

Then these opportunists will revert to more reliable sources of food.

Elsewhere in the world, however,

making the most of seasonal abundancies is a way of life.

Up here in Alaska during the summer, a whole succession of different food become available.

And there's a spectacular animal here that's prepared to sample each and every one of them.

No one dish is available for long, so you have to make the best of it.

And top of the menu right now is salmon!

It is the favourite food of the largest and the most formidable

of all omnivores - grizzly bears.

Salmon are plentiful now but, six months ago in the middle of winter,

conditions were so harsh that it was impossible for a large animal to get enough to eat.

All a bear can do then is to sit it out and try and conserve as much energy as possible.

To see how they cope with these enormous seasonal changes,

we must go back six months.

In October, grizzly bears went into a deep sleep.

Their temperature drops several degrees

and their pulse rate decreases to about ten beats a minute.

They do not eat, drink or defecate, but they do occasionally stir.

During hibernation, a bear burns up almost a million calories...

..virtually emptying its energy reserves.

By spring, the bears have lost nearly a third of their body weight.

To avoid starvation, they must now find food, and quickly.

Their diet will be driven by a clearly defined seasonal cycle.

Now, in April, they eat roots.

Roots are followed by grass.

It's easy food,

but they'll move on to the next course if something big shows up.

A whale carcass could last a month. By May, fresh meat is on the menu.

Mid-summer, and they're back on the salmon.

This bear has been out of hibernation for about four months.

Surprisingly, it has not gained any weight. It may even have lost weight.

But if it is to survive the coming winter, now is the time when it really has to pack on the pounds.

Salmon - one of the most important sources of food for bears -

is now available in quantity

as the fish migrate in thousands up the rivers to spawn.

Chasing them uses a lot of energy, but the rewards are great.

Salmon are rich in protein and fat.

So valuable is this source of food

that a bear that hasn't got a salmon of its own

will spend considerable energy in trying to steal someone else's.

In a good salmon year, a bear can catch a dozen a day,

giving a huge boost to its energy reserves.

But some parts of a fish are more nourishing than others.

If there are lots around, the grizzlies will eat only brains...

and caviar.

This behaviour piles on even more calories.

Even when there are no salmon to be caught,

bears can still find food out on these estuaries.

Like pigs, they have an extraordinarily acute sense of smell

and that can guide them to food, even beneath the surface of the sand.

Clams!

But how on earth can an animal with massive paws and huge claws

manage to open and extract meat from a tiny shell like this?

The answer is... with surprising dexterity.

Clams may look small in the paws of a grizzly bear,

but they are still worth the effort.

Early autumn. Two months to go before hibernation

and the bear's appetite steps up a gear.

A seasonal change in the bear's physiology allows them to eat continuously

without ever feeling full - a huge advantage during the berry season.

They may eat as many as 200,000 berries a day

and that gives the next big boost to a bear's energy reserves.

But at this time of the year, they will eat whatever they find.

After three months of counting calories, they're back in shape.

So for these grizzly bears in Alaska, the real test is now about to begin.

With luck, they will have put on enough weight to enable them to

survive five to six months of winter.

But what is for sure is that they will only have done so by being extremely unfussy feeders.

The lifestyle of a generalist may seem a good strategy,

but from an evolutionary perspective,

there is always the temptation to specialise.

In India, there is another bear

happy to tackle anything remotely edible.

But that is only for half the year. This bear - the sloth bear -

has started down the road to specialisation.

Inside this mound of clay lies a huge quantity of food

and the sloth bear has just the right equipment to collect it.

It has particularly large claws -

perfect for breaking into these sun-baked termite mounds.

It's worth the effort - one colony may contain a million individuals.

The termites' first line of defence has been broken.

Faced with such a large and destructive predator,

there is little the soldier termites can do to drive the bear away.

The bear hoovers the termites up as they swarm over their smashed mound.

But the greatest prize are the larvae that lie inside the nest.

The bear has other adaptations as well as big claws.

It's lost two front teeth so, by pursing its floppy lips into a tube, it can suck insects into its mouth.

And at the end of its snout, there's a flap that prevents dirt and dust

going up its nose at the same time.

But the sloth bear may be heading for danger -

the same danger that may before long exterminate the giant panda.

For the moment, however, there is no shortage of termites

and the sloth bear has still not become wholly reliant on them.

Just as humans have had an impact on the giant panda and its food,

so they have on the sloth bear.

In India, sloth bears live alongside people.

Conflict between the two is common,

resulting in hundreds of maulings every year.

During the day, bears here must take refuge in areas not used by people.

Sloth bears may not compete with cattle for food,

but land turned to grazing reduces the bears' termite harvest.

Loss of natural habitat

has had a serious impact on wildlife across the globe,

but man-made habitats have provided new opportunities for many omnivores.

The modern city. It seems a sterile world of concrete, steel and glass.

It must surely be one of the most difficult places

for a wild animal to make a living.

Well, it would be...

were it not for the extravagant habits of the people who live here.

The largest cities may contain more than ten million human inhabitants

and, where there are people, there is food - lots of it.

A city this size produces around 10,000 tons of waste a day.

If the residents are not to drown in leftovers,

it all needs to be cleaned up - continuously.

Good hygiene is so important in these crowded conditions

that much time and money is spent trying to sanitise our cities.

But it isn't easy to wipe away the evidence of food, not completely.

To an animal with an acute sense of smell, food stands out.

Everything else is grey by comparison.

We may not notice the scraps left behind, but what's not taken away

can become an opportunity for others.

Under the partial cover of darkness,

a familiar face materialises.

Racoons have found our cities very much to their liking.

Their great climbing skills

enable them to find shelter in roofs and chimney breasts during the day

and to move with ease in all parts of this complex environment - a fact recorded by city security cameras.

DOG BARKS

But to find food, racoons must descend to the ground.

They're bold and intelligent animals

and negotiate roads as confidently as human pedestrians do.

Indeed, city racoons are less likely to be hit by a car

than their country cousins

who get less experience of judging the speeds of vehicles.

In an attempt to thwart garbage raiders,

rubbish collection continues around the clock.

But racoons are quick to take advantage of any opportunities.

If there is food around, they will find it.

The skills that made racoons so successful in their original home

also serve them well here - in the fast lane.

The inquisitiveness they showed when looking for food on the forest floor

now leads them to rich pickings.

The manual dexterity that enabled them to capture crayfish in streams

now leads them to take off the lids of dustbins...

and winkle morsels from jars, boxes and tins.

Racoons are an American success story.

Their population has increased 20 times since the 1930s

and their range has expanded by 30%.

They are now one of the most successful and widespread mammals on the continent.

The biggest opportunists of all have a slightly less subtle approach.

Bears can break into cars as easily as they can open clam shells.

It takes more effort, but the rewards can be huge.

Here in Britain, the streets belong to a different urban prowler -

the red fox.

Unlike racoons, foxes are territorial,

but they're also extremely adaptable.

In one year, a fox can change from being totally rural to totally urban.

So foxes are always on the move.

If I were to explore these city streets for just a few hours,

I'd almost certainly see more foxes

than I would in a whole year of walking in the countryside.

Indeed, cities like this can support ten times as many foxes

as a similar area in the country.

Foxes have one other thing going for them -

at least in Britain - their popularity.

Surveys regularly show that the red fox is among the nation's most favourite mammals.

That's a fact that foxes have been quick to exploit.

Many of us encourage our friendly neighbourhood foxes by putting out food for them.

And the foxes are only too glad to take it.

Indeed, in this city, some 60% of a fox's diet come from free handouts.

And the more food there is, the more foxes there are.

However, there's another kind of urban opportunist

that is much more successful than the red fox,

but it's at the opposite end of the popularity scale.

We don't encourage it in any way and yet it thrives on our leftovers.

If statistics are anything to go by, you are within five metres of one at all times.

In fact, there is probably one directly beneath me as I speak.

Warm water emptying from baths and washing machines

and sluicing into the network of sewers beneath our homes

creates a surprisingly stable and temperate environment.

It's an ideal habitat for one of the most widespread, adaptable mammals on the planet - the brown rat.

It's not just the steady temperature that the rats like,

there's a steady supply of food as well.

Scraps flushed down the sewers allow a rat to spend its entire life here,

though, contrary to popular belief,

there is seldom enough food to support swarms of rats.

The only thing rats need worry about is a sudden rise of water level.

Sewer rats are particularly sensitised to this -

often with good reason.

Her nest is in danger of flooding

but, fortunately, she knows a safer place to take her babies.

They're guided very largely by smell

and follow tried-and-tested routes that they know to be safe.

Moving six youngsters under such conditions seems a hard task,

but rats are resilient creatures -

which makes them well-suited to living in unnatural surroundings.

In spite of their numbers, we seldom see rats out and about,

but we know they're there - eating our food, probably spreading disease,

so we wage war on them with traps and poison.

But what happens when rats live unchecked in a human society?

In this temple in northern India, rats are sacred.

The local people believe that, after death, they return to Earth as rats.

So rats here are fed and protected and, indeed, worshipped.

So this is not just a rat haven, it's a rat heaven

and the rats take full advantage of it.

In the wild, rats are nocturnal. But not here.

These rats don't shun the daylight like city rats. Why should they?

There's nothing to harm them here. And there's plenty of food.

As a result, they swarm in great numbers.

Colonies in the wild which grow to be about 600 strong

normally then break down and divide.

But here, their population has stabilised at around 6,000.

The size of the worldwide population of rats is incalculable.

They inhabit every continent on Earth, including Antarctica.

Could there be a more successful mammal?

Well, yes - us.

The human species.

We are the ultimate demonstration of just how successful a mammal can be

that is prepared to eat pretty well anything.

This is the Kumbh Mela - a spectacular Hindu festival in central India,

attended by millions of people.

It is the largest gathering of people for a common cause

ever seen in the history of the world.

Over two weeks, this temporary city on the banks of the Ganges

will shelter a staggering 100 million people.

Since they are Hindus, most are strictly vegetarian

but, across the world, we seem to be able to thrive whatever the diet -

whether it be one dominated by lentils and rice, or by hamburgers.

We have learned how to create our own food resources

so that our population is no longer limited by the quantity of food that occurs naturally.

That development enabled us first to dominate the Earth and, eventually, to over-run it.

But an essential key to our success

has been the one that we share with rats, racoons, bears and foxes -

an adaptable nature and an ability to seize an opportunity when we see it.

In fact, you might say that it is not the meek that have inherited the Earth...but the opportunists.

We first went to that cave in Texas to film the bats that roost there

but, while we were doing so,

we noticed that skunks were coming in at night to collect the bats that had fallen to the ground.

If ever there was an example of opportunism among animals, that was it, so we filmed the skunks as well.

It was behaviour that had never been recorded before, but predicting animal behaviour isn't easy.

In order to capitalise on the skunks' behaviour,

cameraman Paul Stewart had to work a quarter of a mile underground in truly horrible conditions.

It's amazing. There's something like ten million bats in this cave

as well as the skunks and racoons that we're looking for for the filming.

There's a lot of ammonia from their droppings

and, as well as that, we've been warned about the flesh-eating maggots and even a rattlesnake.

So we need some serious protective gear.

We need this mask, which will protect me from ammonia.

I've got wellington boots to stop me sinking into the guano

and a helmet to stop the ample amounts of urine coming from the bats.

The camera we're using is infrared. It uses light the bats can't see,

and nor can we, so we'll be working in total darkness.

We hope the camera kit will work. What we don't know is whether the behaviour we want will be happening.

It's time for us to get our kit on and go down into the cave and find out.

The behaviour I'm here to film

isn't one that's well known, even scientifically.

If we're lucky, we'll have the first record

of a supreme opportunist braving really tough conditions to get food.

That's one of the reasons I enjoy filming - to produce firsts.

Conditions here may suit the bats, but they challenge any other mammal, however opportunist.

The ammonia concentration is the same as in household cleaning fluid.

The floor of the cave is deep in bat guano,

yet many insects feed on it,

and anything else they can catch.

And the temperature? 45 degrees Celsius.

Well, that was, um...four fairly intense hours in the cave of nothing...really, turning up.

It's really hostile down there. The ammonia was starting to get through the mask, making it hard to breathe.

You start to smell all sorts there.

At the same time, because of the light from the eyepiece, I was a magnet for biting insects.

But then something amazing happens.

The bats, you can hear they're starting to frenzy and to turn.

Nothing can prepare you for what it's like when they're in the cave.

Suddenly, this breeze starts up, then dust appears in the air - all the fur from the bats.

It's like being in a Dyson vortex vacuum cleaner or something. You feel taken up in it.

And then it starts to rain and that's the bats. When they take off,

they lighten the load a little bit and urinate.

I've probably been urinated on by about six million of them. Thank you, bat.

I came out and, just so annoyingly, there was a skunk on the trail,

having seen nothing for that whole period.

So I think it's time for a rest, a drink of water

and then I go back down there. Better luck next time.

That persistence paid off.

Paul became just another opportunist, exploiting the cave.

The first animal we had some success filming were the opossums.

They seem to live down here. They must have a bomb-proof constitution.

We saw very little sign of skunks. Then we had a couple of sightings.

Day by day, you see a little bit more and you can predict

where the skunks will be.

After a while, the priority became not just getting shots of skunks, but getting nice shots of skunks.

That meant you had to be more careful with the lighting.

By about the tenth day, we knew we'd got what we most wanted -

a sequence never filmed or even seen before.

Tonight, we got some skunks...

It's quite a climb out... out of that cave.

Anyway...we got some skunks. It looked...

It looked good. The skunks move along the edge of the wall.

It's kind of sad that the baby bats that have made it through the flesh-eating insects,

they've got to the wall and they've got that tiny chance, then you see this skunk hoovering them.

That's it. The last day of filming.

Not the most pleasant location, but the skunks have been amazing.

It seems that we have a sequence. That's good news.

When filming some species, the dangers are more obvious.

Grizzly bears are bigger, stronger, heavier and faster than you are.

They have huge teeth and huge claws.

In short, if they want to make a meal of you, there's little you can do to stop them.

Yet some people specialise in getting close to grizzly bears,

as you need to do in order to film them. How do they do it?

Filming wildlife, you rely on experts all the time, often heavily.

But even though you're under the guidance of an expert, you don't take your thinking cap off.

That was great. He turned towards camera and just grabbed it. It's a shame he's behind the grass.

Working with the grizzly bears in Alaska

with an expert called Buck Wild, we had three close encounters

where the bears came within six or eight feet.

In each of those situations, Buck Wild stopped the animal by holding his hands up.

But I would say that I never felt comfortable

and, although he did stop the bears, one day the bears won't stop.

I wouldn't want to be in that situation.

One film maker has spent more time than anyone else with bears

and has had close encounters that would terrify the bravest of men -

Canadian, Jeff Turner.

I've always been drawn to bears.

I have a connection, a feeling for them that's always been there.

I've only been charged by a bear once in the last 15 years, and that was early on.

I think I was charged because I didn't have enough experience.

That's all part of getting close to them -

being able to understand when enough is enough.

You have to understand that with an animal like a bear because if they're really not happy, they...

they can quickly...kill you.

The number one rule when you're working with bears

is you don't want to surprise them. You always want them to know that you're there.

Rule number two is, to close the distance, you've got to be unaggressive, unthreatening.

Keep your eyes down. As they get closer, talk to them.

It's about tone of voice. It's how you say it.

It's about putting the bear at ease. You can communicate that easily.

In the past, many scientists regarded animals as machines, driven by base instincts,

and tried to classify their behaviour in simple terms.

For these opportunist mammals, that approach is doomed to fail.

Predicting THEIR behaviour is one of the great challenges in understanding animals.