All language subtitles for The Life of Mammals 8of9 Life in the Trees 720p HDTV x264 AAC MVGroup org_Subtitles01.ENG

Meerkats in the Kalahari Desert.

They spend the night in burrows.

They find all the food they need
on the ground.

They are swift and expert runners.

But oddly enough, they also climb

and they have very good reasons
for doing so.

But first of all, they have to warm
up in the early morning sun.

And once they are warm,
it's time for breakfast.

They find that, for the most part,
underground.

If you have your head in the sand,
you can't see danger approaching.

And since they have many predators,
someone must always stand guard.

Sentries aren't very effective if
they can't see over the tall grass,

so to get a really good view, they
have to climb as high as they can.

They don't have particularly long
claws, or any other special
climbing adaptations.

Nonetheless, they are surprisingly
agile up in the branches.

They'll climb up just about anything
if it gives them extra height.

An ability to climb is important
for a meerkat on sentry duty,

but for some mammals, it's essential.

They spend nearly all their time
up in the branches.

If you do that, you really do need
special adaptations.

So, what kind of body
does a tree dweller need?

Grasping hands, long arms to reach
distant branches, a long tail,
perhaps, to help with balance?

So, nothing like this, then!

These are hyrax
and, in this safari lodge in Kenya,

they have acquired a taste
for sunbathing.

Looking at their general body shape,

you might think they'd be as good
in trees as rabbits or guinea pigs.

But they are surprisingly capable
at climbing around in the branches

and the reason has to do
with their special feet.

Their rubbery soles
don't look very special and you can
only see how effective they are,

when their owners stop lazing about
in the sun and go off to feed.

Hyrax have
an extremely flexible spine.

That helps them to scamper up
tree trunks with surprising speed.

But it's their feet
that help them stay up there.

There are special muscles
in the middle of each foot

which pull up the centre of the sole.

The pads are moist, creating
a slight suction which improves
their grip, though not all that much.

Watching them clamber around
makes me feel I ought to be
standing underneath with a net,

just in case they fall!

And what is the reward
for this high-wire act?

Leaves.

They supply the hyrax
with both food and drink.

Succulent leaves are hard to find
on the ground,

but up in the branches,
hyrax can get all they need
for the day in a couple of hours.

So climbing trees is vitally
important for a hyrax, even if
it does slip every now and then.

Fortunately,
these trees are not very high,

but elsewhere in the world,
there are trees
that are ten times as tall as this,

and there, to be safe, you need
something better than rubbery feet.

Claws should be long.

And so should tails.

Tails may not look like climbing
aids, but they can be of great help
in keeping your balance.

This is tropical America -
and these are coati.

Much of their food can be found
on the ground.

They climb, primarily,
for a different reason...

safety.

At the first sign of danger,
up they go.

These days, we too have got
specialist tree-climbing gear.

You start by catapulting
a fishing line over a bough,
and using that to haul up a rope.

Then, with clip-on hand-holds -
and the help of a counterweight -
you can go up, too.

As in all forests, the trees compete
to capture the sunshine.

Here, in the tropics,
they grow very tall in the process.

And it is up in the canopy, 100
or more feet above the ground, that
the real richness of the forest lies.

A third of the Earth's land
is still covered by trees
of one kind or another.

So, not unexpectedly, mammals
belonging to very different families

have managed to acquire the skills
and physical adaptations needed
to get up into the trees to feed.

This, I suppose, is what most people
would think of as a real forest -

the tropical rainforest.

There's a greater variety of food
up here than there is anywhere else
in the natural world.

The most obvious source of food
up here, of course, are leaves.

There are certainly enough of them.

But leaves aren't really
very good food.

They're rather tough, indigestible
and don't contain much nutriment.

One mammal solves that problem not
by eating more, but by doing less.

The sloth moves as if it's powered
by the wrong sort of batteries

and prevents itself from falling off,
not by muscle-power, but by hanging
from hooks - its claws.

But there's a lot more than leaves
to eat up here, as coatis know.

If you are fast and agile enough,
you can catch birds up here.

But if you are not, well,
some birds make their nests here

and then eggs and chicks
make a good and easy meal.

And then there are brightly-coloured
fruits with fleshy coverings, which
are sufficiently good enough to eat

to persuade animals of all kinds
to swallow them
and so distribute the seeds.

The coatis need little encouragement
to do that.

Fruit makes up most of their diet
and it is quite a good plan
to grab it before it falls

and comes within reach of other
fruit-eaters down on the ground.

If you are going to stay up here for
a long time, you will need to drink.

That - perhaps surprisingly -
is not necessarily a problem.

Sometimes it's even easier to get a
drink up here than it is down below.

These bromeliads - vase plants -
are full of water

and sometimes these tiny ponds
contain insect larvae or even frogs.

So there's protein as well.

Woolly monkeys
regularly drink from them,

so they have no need to go down
to the ground and hardly ever do so.

All in all, the larder in the forest
canopy is far too rich to ignore

and many mammals come up here
and feed up here.

But they have very special
climbing skills and they are
much more at home up here than I am.

These are proper tree-climbing claws.

They belong to the sun bear
of Indonesia.

It is a fruit-eater and spends
more of its time up in the trees
than any other bear.

Bears don't have tails
that might help with their balance.

But balance isn't a problem for the
sun bear because it usually embraces
branches rather than runs along them

and it has very strong forearms.

And if that's the way you climb,
going down is almost as easy
as going up.

The South American tamandua
is an anteater.

Like all anteaters,
it has powerful front legs
with which to rip open ants' nests,

and they're a great help in climbing.

It has a tail and that has become
an extremely valuable climbing aid.

It's prehensile, it can grip.

It is, in effect, a fifth limb,

so the tamandua can use
its front legs in the same way
that its ground-living relatives do.

Its tail is so well-muscled, it can
support the animal's entire weight...

..which is just as well!

But there are only so many ant
and termite nests in any one tree

and, sooner or later, the tamandua
has to go and look elsewhere.

That means it has
to leave the branches
and trundle across the forest floor.

No big mammal can spend
its entire life in a single tree.

They all have to move
to find new sources of food.

Descending one tree,
moving across the ground and
climbing up another is one method.

But there is another,
more energy-efficient way

to cross from one tree
to another up there.

Here in South America, woolly
monkeys do that by using their tails

which are even longer and stronger
than the tamandua's.

A small gap like that
might be crossed with the help
of a prehensile tail,

but no tail is going to help
with a gap that size.

From up there,
they must look like an abyss -

but they are the great challenges
for any tree dweller.

Squirrels deal with the problem
with dazzling ease.

They are such lightweights

that they can race along the thin
twigs at the end of the branches

and they are spectacular jumpers.

Their powerful hind legs
provide the thrust.

Their long tail acts as a rudder.

And their shorter front legs
serve as shock absorbers
to cushion the landing.

Superb sight enables them to judge
distance with great accuracy,

an essential ability when racing
along this three-dimensional highway.

They are at their most acrobatic
during the mating season

when males pursue the females.

One male may begin the chase,
but others quickly join in.

Eventually, one wins.

But as soon as he has claimed his
prize, the chase will start again

and the female may mate with
up to eight different males in a day.

But a gap this size is just too big,

so a grey squirrel, like a tamandua,
often has to come to the ground
to visit all the trees in its range.

A grey squirrel can leap eight feet.

But there is another tree dweller
that can leap much farther than that.

Although it's no bigger than my hand,

it could jump from this tree
to that tree over there,
more than 50 feet away,

an astonishing distance.

To see how it does it,
we'll have to come back at night.

Since they have an acute sense
of smell and love seeds and nuts,

maybe these will tempt one down
from the tree tops.

They are flying squirrels.

How do they fly?

Just watch.

Maybe "gliding squirrel"
would be a more accurate name.

They are, nonetheless, astonishing.

That furry membrane stretching
between wrist and ankle
makes a most efficient aerofoil.

Flying squirrels are not territorial
and half a dozen can be foraging
in the same area of woodland.

Although this squirrel may have
travelled a very long distance

to get to this valuable source
of food,

it's such an expert glider, it has
done so with a minimum of effort.

And in forests like this one,
where food sources
are often very widely dispersed,

the ability to travel fast and far
but with very little effort

is a very valuable ability indeed.

There are few gaps in these forests
that defeat them,

but to cross really long distances,
they do need height.

They steer partly with their tail

and partly
by moving their outstretched legs,

so that they vary the tension
of their gliding membrane.

And you can see that they CAN steer

when one squirrel uses the same
take-off point, but glides away
to land on different trees.

Even so, they are not agile enough
in the air to escape birds of prey,

so during the day, they sleep in
holes and only emerge when it's dark.

Gliding from branch to branch
was a comparatively small step
for tree-living mammals,

but one group of them
made a truly gigantic leap.

Their arms changed into wings.

The shoulders, the elbows,
the wrists remained much the same,

but the hand and the fingers
changed dramatically.

Flying foxes -
fruit bats in Australia.

They and their insect-eating cousins
are the only mammals

that have developed
true, powered flight.

They are so big
that they can't roost in holes.

Instead, they sleep out
in the open in colonies that may be
hundreds of thousands strong.

The thumb on each hand is free
of the wing and has a hooked claw.

Using that -
and the claws on the toes -

fruit bats are surprisingly nimble,
clambering about in the branches.

Wings may have solved the problem
of getting from one tree to another,

but landing is still a challenge.

As a fruit bat approaches its
chosen perch, it goes into a glide.

Then it lowers its toes
and hooks them onto a branch.

This is a textbook example
of how it's supposed to be done.

But some perches are more difficult
to reach than others.

Wings need regular grooming.

They are also very delicate,
but small tears quickly heal.

The wing membrane is among the
fastest growing of mammalian tissues.

They fan their wings to keep cool.

It can be very hot
hanging in the baking sun.

Take-off
requires a special technique.

Two or three wing beats lift
the body to the horizontal, and only
then should the feet be unlatched,

so you don't lose too much height.

It's hard work, particularly
if you are carrying a baby
which is a third of your own weight.

Once in the air, however, fruit bats
are extremely strong flyers.

They can travel great distances -
as much as 30 miles, 50 kilometres -
in a single night,

if that's necessary to find food.

They may have lost a lot of moisture,
hanging around in the midday sun,

so their first call is often
to a nearby lake to get a drink.

They do this in a rather unusual way.

First,
they dip their chests in the water.

Then they return to their roost
and lick the moisture from their fur.

But there ARE hazards.

Crocodiles.

The bats only touch the water
for less than a second

and usually the crocodiles are just
not quick enough to catch them.

But if one miscalculates
and comes down on the water,
it's a different matter.

They are surprisingly good swimmers.
The worst danger comes
when they get to land.

Being unable to drop into space,
as they can from a perch,

they find it difficult to take off.

Now the crocodiles
have the advantage.

But a few individuals
lost to crocodiles

makes little impact
on the bat colony.

This roost alone
contains a staggering five million.

Living together
in these vast numbers
brings several important advantages.

Flying foxes collect fruit
and nectar of many different kinds.

But knowing which species of fruit
tree is in season when is not easy,
and some are very unpredictable.

If a few individual bats return
smelling of a particular fruit,

the news that this food has just
come on the market spreads quickly
through the whole colony.

Each bat knows where trees
of the various species can be found,

so the next night, it will go
to its own favourite patch
to collect the new fruit.

That is why the whole five million
don't follow one another
to the same tree.

Huge wings are good
for long-distance flying, but not
for manoeuvrability in the air.

When the bats return in the dawn,
hunters are awaiting them.

Eagles know exactly
where a bat's blind spots are
and attack from below.

Powerful though eagles are,
fruit bats are big animals
and a hit isn't necessarily a kill.

Raids like these are another reason
why an individual bat finds it
an advantage to roost in a colony.

Since it is surrounded
by tens of thousands of others,

there is a good chance that an eagle
will pounce on someone else.

Most colonies have a resident pair
of eagles that nest nearby.

A breeding pair will take about
half a dozen bats a day, but that
makes little impact on bat numbers.

Skilled though the eagles are
in taking bats on the wing,

their most successful strategy
is to snatch them
as they hang in the branches.

There's another way of getting
around in the treetops.

Instead of having fingers
that are greatly elongated
and form struts for a wing,

they can be very small, muscular and
give you an extremely powerful grip.

And the mammals that did that
are of particular interest to us

because they contain
our earliest ancestors.

Most of them are small and nocturnal,
and the best way to find them
is with a torch like this.

Highly reflective eyes
caught in the torch's beam.

They belong to a slender loris -
a primate, related to the monkeys -

and it lives in southern India.

Using a light may be the best way
of finding a loris,

but it's certainly not the best way
of seeing how they behave naturally.

To do that,
you have to turn off your lights.

Infrared cameras give us the rare
chance of watching a slender loris

without disturbing it.

It's moving so quietly,

that if it wasn't for this monitor,

I wouldn't even know
that it was just over there.

Lorisis have elongated thumbs
and have lost their index fingers,

so their grasp is wide enough
to encircle quite stout branches.

They can hold on so tightly that
it's almost impossible to detach one
from a branch against its will.

It's the talent for gripping -
and a long reach -

that enables them
to deal with that problem
of crossing from one tree to another.

That's what it is after - berries.

There is another here.

Lorisis live in small groups
of four or five.

Something seems
to have caught this one's eye.

Perhaps it's our dim infrared light.

It's frozen, motionless - standard
alarm behaviour from a loris.

It can't move fast, so stands little
chance of out-running a predator.

Instead, it simply stops and hopes
that nobody will notice it.

And now it is off again.
It's scent marking.

That drop of urine
will tell any others that it is here.

It washes its hands in its urine,
to leave a trail
of smelly footprints behind it.

Some people think the urine
gives the animal a better grip.
It's certainly sticky!

Its eyes both face forwards,

giving it the stereoscopic vision
to judge distance accurately.

It hunts not by speed,
but by stealth.

Silence - acoustic camouflage -

enables it
to catch its prey unawares.

Gripping feet -
like prehensile tails -

leave hands free for the pounce.

That was a grasshopper!

And now it's found a stick insect.

This is a mantis. Mantises
defend themselves in two ways -

either by camouflage
or aggressive display, like this.

And neither of them seem much good
against a loris!

Only one creature stands a chance
of removing something
from the grasp of a loris.

And that is another loris!

Africa has got
its own similar creature - only
a much more lively and athletic one.

The lesser bushbaby.

It's probably
the most numerous primate in Africa,

but you seldom see it
because it only comes out at night.

They have a regular pathway
through these trees

which they mark with their urine,

so you can predict they will go
from one tree to the other.

They're related to lorisis
and physically similar -

with grasping hands,

stereo vision and large ears.

But their way of getting around
is completely different.

They hunt not by stealth,

but by speed.

They jump 30 times their body length.

This one is carrying an infant.

And a leap like that
is nothing to a bushbaby!

Before one takes off,
it moves its head from side to side,
working out the best place to land.

That's important,
because these trees are very thorny.

Bushbabies of one species or another
have colonised every type of forest
in Africa,

and millions of years ago,
ancestral bushbabies
even spread beyond the continent.

Somehow - perhaps
on a floating log - they reached
the island of Madagascar.

Here, there were neither predators
nor competitors,

and they diversified into
an extraordinary range of species

which exploit every environment
on the island.

They are the lemurs.

LEMUR CRIES

The most specialised of them
is the golden bamboo lemur.

It was discovered only recently,

and it lives on a part of the bamboo

that would be fatal to most animals.

Bamboo pith is full of cyanide.

The golden lemur
eats 12 times as much as would
normally kill an animal of its size.

Other Madagascan plants
defend themselves in a different way.

Didierea is covered
with ferocious spines,

yet it is the chosen home
and feeding grounds
of another lemur - the sifaka.

Clambering about here

requires some very delicate footwork.

Mother's tail clearly makes
a better handhold for a youngster -

but even at this age, a young sifaka
is able to negotiate the spines.

Collecting didierea
leaves and flowers -

the sifaka's main food -

looks more hazardous
than travelling through its branches.

But when sifakas decide to move,

they can travel very fast indeed.

They use the same method
as bushbabies,

but with such speed and confidence

that they seem
to bounce from trunk to trunk.

Only in slow motion
can you see how accurately they land,

and how instantaneously
they can take off again.

But given the chance,

they assess their jumps with care.

Takeoff starts sideways-on
to the line of flight,

so they have to rotate their bodies
in midair.

Those hind legs, having kicked off,

have to be swung forward to act as
shock absorbers as they make contact.

Their back feet are long and narrow,
with an enormous big toe,

so that they can lock on to a trunk
as soon as they hit it.

Within seconds, they are off again.

And a female can even do all this
while she is carrying a baby.

Down on the ground, the method
doesn't work quite so well.

Extremely long legs
and very short arms

make it impossible
to run on all fours,

so, again, it has to be jumping.

But with no vertical trunk to push
away from, the leaps are shorter.

Back in the trees,
they can travel at speed again.

And they need to,
for they have a savage enemy.

The fossa.

Its speed through the branches
rivals that of the sifakas,

but its technique
is entirely different. It's not
a primate with jumping ancestors,

but a kind of giant mongoose -
and it is still a four-footed runner.

Nonetheless, they are a close match
for one another.

But when it comes to the long jump,

the sifaka wins.

A four-footed runner
can't match that.

But it's caught a scent of something
else - a female who is ready to mate.

She has taken up residence in a tree,
and there she is holding court.

She will attract several males.

There is going
to be strong competition.

An unusually long tail
helps in maintaining balance,

and they manage to negotiate
surprisingly thin branches.

The female decides who to mate with.
She drives off
those she's not interested in.

THEY SNARL

Mating itself is a noisy affair.

It's made the more difficult,

by having to balance on a branch
while it is going on.

THEY GRUNT

THEY CRY AND HISS

Few animals can match
a fossa for speed in the trees,

and few can descend headfirst,
like this.

The fossa can do so,
because it has very flexible ankles

that allow it to twist its feet
to point backwards.

To find the supreme tree-traveller,
we have to go to another continent.

We have to climb into the canopy

of the forests of South-East Asia.

BIRDS SING

This forest is home to the fastest
of all the flightless inhabitants
of the canopy in the world.

It is so swift and so agile,

that it is capable
of catching birds in midair.

Gibbons.

Not monkeys, but small apes.

Their long jump record is about
the same as a sifaka - around 40ft -

but they can move
at even greater speed.

They are such skilled acrobats
and can change direction in mid-flow.

We may be distantly related
to the lesser apes,

but when you watch gibbons like this,

you realise how ill-equipped we are
for a life in the trees.

Our forearms are too short,
our thumbs too big, our shoulders
and hips too inflexible

and our eye-to-hand co-ordination -
compared with gibbons - is poor.

They have one characteristic
which we, and all primates, lack -

that is a ball-and-socket joint
in their wrists.

THAT allows them to perform
these fantastic aerial gymnastics.

Hurtling through the branches
hand over hand

is the gibbons' standard way
of getting around.

Their unique wrist joint

enables them to rotate the body
around the hand and not the shoulder.

That saves a lot of energy!

Moving at this speed
can be hazardous. Branches may break.

Jumps may be misjudged.

Researchers estimate
that most gibbons fracture bones
at least once in their lives.

And fatal falls
are certainly not unknown.

Life in the trees
is a dangerous business.

One serious mistake
is likely to be your last.

Mankind's success started
when its feet hit the ground

and it stood up on its hind legs.

But the coati, hyrax,
tamandua and the gibbon

are proof that there is a
very good living to be had up there.

GIBBONS CRY

Exactly what goes on
high in the canopy of the rainforest,
100-200ft above the ground,

was, for a long time, a mystery.

It was so difficult to get up there
and move around safely.

But now, we've got ways
of doing just that.

And the key to them...is this -

a very, very powerful catapult!

James Aldred is a catapult expert.

The first thing you need to do
is find your tree!

'Having found a suitable tree,
you need to get the rope up into it.

'You stretch out a bit of tarpaulin

'and lay the line out. Fishing line.

'Play it out there,
so it won't snag as it's running,

'connect a fishing weight,
stick it in the catapult and go!

'Usually, you hit the trunk first
time, or get snagged anyhow.

'Sooner or later, you'll get it.

'Having got that lightweight line
over, you pull up the climbing rope.

'Anchor that,
and you're ready to go up there.'

The scene is set to get a human
up into the rainforest canopy.

My climb to the canopy

was only possible
after a great deal of preparation.

James and the team worked
in the forest for ten days
before the crew and I arrived.

'We went with an assistant producer
and climbing colleague,
Phil Hurrell.

'One of the main hazards
in the rainforest was rain!
It rained continually from day one.

'There were storms, winds...
Dislodging dead wood from above!

'The next problem was snakes.
We actually found a hognose viper
in with our kit.

'Once you get up there,'

the last
hazard you encounter is primates.

Howler monkeys are getting rather
boisterous, hooting and hollering.

They are only about this big.
They are quite a small primate.

They are quite intimidating
and territorial and did their best
to get me out the tree.

They succeeded! Embarrassing to
be seen off by a primate this big,

but such is the way of life!

Finding a suitable tree
is very time-consuming.

'Phil and I must have climbed 12-15
trees over those first ten days.'

We're about four days
into our ten-day set-up period,

but we're having real trouble
finding a decent location.

It's got to be a really fantastic
shot - something that really knocks
off anything that's gone before.

'But the next day, I thought
I'd found the perfect tree.'

It's very big, very exposed.

Each branch is the size
of a moderate UK oak tree.

Big. It's a big tree!

Having said that, it is an emergent.
The view is stunning,
but it IS exposed.

It's very exposed -

and not somewhere you want
to dangle David Attenborough!

It took us six or seven days
to even find a tree.

When you get up there, you're
rewarded with a stunning insight

to a world
no-one else has ever seen.

You see things
which no-one else has seen,
or will see. Very privileged.

Those last days were manic. Phil
rigged one tree, I rigged the other.

'By the skin of our teeth!

'Once the crew arrives,
you get the camera person up first.

'In this case it was Justine.'

Nearly there, Justine.

It looks good from here, actually.

I'll film you there.
Suits me!

'So, she ran up there. Got settled.

'Phil was ready to receive David.

'To get David up,
we used a counterbalance system -

'a rope going up over a pulley,
across to another pulley
and back to the ground.

'Someone climbs up one side, with
David attached on the other side.

'They jump off a branch,
they come down as a sack of spuds
and lift David into position.'

'The idea was he could move down
that cable, parallel to a branch.

'He could talk about the things you
could expect to find in the canopy.

The other shot was a reveal to show
David in context. Nerve-racking!

We had 16kg of camera going down
on a cable which was 100m -

180ft up - and you've got, you know,
David Attenborough at the other end.

However many safeties you do -
it WAS bomb-proof -
it does make your heart flutter!

Is it quite solid down here now?

David has just been up and down -
safely - which is a good thing.

It's good. I'm feeling
rather pleased with myself.

In recent years, the abundance
of tropical forest species

and the detail of their
relationships has been revealed.

First-hand observation
has been vital, but simply
seeing the animals in the forest

is a challenge in itself.

A colleague, Lesley Ambrose, has
studied bushbabies for eight years

and she only sees the eyes
in the trees!

Studying the animals in the canopy
remains a major problem.

We really know nothing
about what they get up to.

Although you can only see the eyes
of these animals and you may never
get a close-up view,

fortunately nearly all bushbabies
give a range of very loud calls.

HIGH-PITCHED CRIES

Some of the calls
are like whistles...

Some of them are like screams...

Some of them
sound like cross babies crying -

which is why
they are called bushbabies.

Once we cottoned on to this idea
of the differences in the calls,

we began recording them in earnest.

We now have a huge library
of the sounds
of all these different species.

By recording these sounds, and then
by studying them in the laboratory,

by displaying them on a graph,

you can understand how
they communicate with each other.

This provides an enormously complex
means of communication,

which we're beginning to unravel.

Some of the calls -
particular sounds they communicate
over a long distance -

seem to be species-specific.

That's how we recognised the fact
that animals that may look the same,

were totally different species!

When I started, there were
only six species known to science.

Now, we're approaching 26 species.
There's still a few
we're not sure about

and others that
we just don't know what they are!

All of us students
have discovered at least
one new species of bushbaby,

during their field work.

If anyone wants to study
these animals in the rainforest,

it's actually a good opportunity
to find out new things
that no-one has ever seen before.

It's surely astonishing
that in the 21st century,

we're STILL discovering
new species of mammals.

Not just any old mammals - primates.
The group to which WE belong!

For, although the tropical forest
has been a mammal habitat
for many millions of years,

it's only now, in the 21st century,

that we humans are truly equipped
to reveal its mysteries.

In the next episode
of The Life Of Mammals,

we meet the monkeys -
creatures with colourful appearances

and even more colourful social lives.