The Living Planet

These beautiful flowers belong to one of the most successful,

the most widespread and the commonest of plants.

There are about 10,000 species in this one family,

and they claim over a quarter of all the vegetated land on earth.

They are pollinated by the wind, they need far less water than most trees,

and they can survive both burning and freezing. They are the grasses.

These tough, persistent plants continue to grow even when they're trimmed

day after day by grazing teeth.

They are able to withstand all this rough treatment

because the point from which a grass leaf grows is at its base

close to the ground and is permanently active.

So grass provides a continuous banquet for creatures big and small.

Down among the tangled grass stems live not only creatures that eat grass

but others that feed on the grass-eaters.

Lizards snap up small insects and mantis munch grasshoppers.

Spiders tackle almost any creature that moves

and dung beetles clear up the droppings from above.

Among the most industrious of these tiny labourers are the termites.

On many tropical grasslands, they flourish in such numbers that, one way or another,

they consume more of the grass than big creatures like antelope, cows or kangaroo.

In Brazil's savannahs, there are more termite mounds per acre than anywhere in the world.

And termites are highly nutritious -

so much so that the giant anteater can exist by feeding on them and nothing else whatever.

This creature has very poor eyesight and very poor hearing,

and finds its way around mostly by smell, so, as long as I keep downwind of it,

there's no reason why it should be particularly disturbed by my presence.

You might think that that would make it very vulnerable to enemies.

The fact is, out on the savannahs here, it's got very few enemies.

The only things that might attack it are a jaguar or a puma, or if it was a baby, a savannah fox.

And it has a very good defence against such creatures.

Those huge forelegs, with enormous muscles on them and gigantic claws,

are quite powerful enough to rip the stomach from a puma or a jaguar.

It was always thought that those legs are actually for ripping open termite hills,

and they may be used to some extent for that purpose.

But it seems more likely now that they are primarily defensive weapons,

because when they actually come to feed,

this creature doesn't do so much of a sweep with its front claws

as to use them very, very carefully to open the exit tunnels in the termite hills.

Once it has done that, it pokes its nose into the tunnel entrance

and flicks out its 20-inch-long tongue, coated with sticky mucus,

and picks off the worker termites clinging to the tunnel walls.

After about half a minute, before the soldier termites - which have powerful bites -

can rally to the defence of the opened tunnel, the anteater moves on.

It is a wanderer, always on the move, sleeping at night out in the open,

blanketed against the cold by its huge hairy tail.

Having no permanent den, the female carries her youngster with her, piggyback.

Other termite hunters live on the surface of the mounds themselves.

Beetle larvae lurk in burrows and lure flying ants and other insects to them

by the luminous glow of their heads.

Sometimes the termite mounds are attacked at their very foundations.

This is the biggest insect-eater on earth, the giant armadillo,

a massive animal that weighs over a hundredweight.

There are few more powerful diggers.

It's no finicky eater like the giant anteater,

but rips its way through the ground into the heart of the termite hill.

With its defences breached, the termite colony is very vulnerable.

This mouse, oxymicterus, has a particular fondness for termites

and regularly follows in the wake of the giant armadillo.

But the termites' biggest enemies are even smaller.

Carnivorous ants regularly raid the colonies, carrying off the helpless, pallid termite larvae.

The defenders of the colony, the soldier termites, engage the enemy ants.

These termite warriors have jaws so specialised for fighting

that they can't feed for themselves and have to be tended by the workers.

Each species is armed in its own way.

Some have short nippers, some sharp shears.

Others have blades that strike outwards and others nozzles on their forehead

through which they squirt a sticky poison spray.

Other ants are vegetarians, like the termites,

and use their jaws to demolish the living grass plants, scissoring up the leaves,

sawing through the stems and carrying off the plant piecemeal.

Grass consists largely of cellulose and that is a very difficult substance to digest.

Termites do it with the help of bacteria in their gut.

The grass-cutting ants have another and quite extraordinary method

of making its nutriment digestible.

Laboriously, they haul the pieces of grass back to their nest,

which may be as much as 100 yards away and have several hundred small entrances.

Inside an entrance, a tunnel leads down into a vast labyrinth of corridors

that may extend for 80 or 90 feet in a horizontal direction

and lead to as many as 2,000 interlinked chambers.

Such a nest may contain as many as 20 million ants.

The workers carry their cuttings deeper and deeper into the nest.

And here, 15 feet below the surface of the ground, in special chambers,

they feed the grass to a fungus.

This fungus forms crumbly white lumps and grows nowhere else but in these nests.

Carefully, the ant gardeners clean every fragment of grass.

Meticulously, they remove every spore of any other fungus

that might grow down here if it got the chance. Weeds, as you might say.

The waxy skin that covers the leaf surface is stripped away

and then the pieces are cut up into even smaller fragments.

The gardeners push the prepared morsels of grass into the mass of the fungus.

The fungus digests it, cellulose and all, and grows,

and the ants then feed on the fungus, which, unlike grass, they can digest.

The ants tend their gardens with great care.

Dead pieces of fungus and coarse, unsuitable fragments of leaves

are carefully removed and carried away.

With unflagging energy, porter lines of ants carry the waste down the long corridors

to the lowest chambers of all, 20 feet below ground, that serve as the colony's refuse tips.

These are not only rubbish dumps, but cemeteries,

for here they also bring the bodies of dead workers.

Dawn on the grasslands of Brazil, the campo.

It's still chilly and the dew lies heavily.

But the rising sun will soon dry out the pasturage and rouse the daytime inhabitants.

The grassland birds have no trees from which to sing. Some make do with grass stems.

Others, like the scissor-tailed flycatcher, proclaim their territorial rights by visual display,

flying incessantly and conspicuously above their chosen plots.

The seriama, a catcher of snakes and insects, surveys the prospects from a termite hill.

The tapir has browsed throughout the night, but now, as the sun rises,

it makes its way back to the forest that grows in the moist ground beside the river,

for it prefers that shady obscurity to the hot conspicuousness of the daytime plains.

On the other hand, the savannah deer has slept all night and only grazes when it is light.

It prefers to be able to see its enemies.

The armadillo is no grass-eater. It's looking for insects, roots and birds' eggs,

and even a lizard or a small snake.

As the day warms up, reptiles become active.

The tegu lizard is sufficiently powerful to be able to take on all-comers.

Just what it likes, and no small bird, no matter how aggressive, is able to repel a hungry tegu.

Eggs on the ground are very much at risk from creatures like this.

But where else can you put them? There are few trees on the grassland.

But there are termite hills.

The flicker is a kind of woodpecker and drills into termite hills

just as efficiently as its cousins do into tree trunks.

And when the flicker has finished with its hole, kestrels often take it over.

The male has a lizard.

Softly, he summons the female, who is incubating her eggs in the hole beneath.

The burrowing owls nest in holes in the ground,

taking over ones that have been abandoned by armadillos

or even digging them for themselves.

The male perches on a termite hill on guard, for the chicks are about to emerge.

Danger - a harrier.

Now it's safe once more.

As long as the chicks can't fly, they're in danger from armadillos, tegus and other predators.

So it is very important that they get their flight feathers as quickly as possible,

and already, only a couple of weeks after hatching, they are showing through the down.

Out in the fresh air, there is space to preen and a chance to sunbathe.

Once more there is an alarm... It's the spur-winged plovers.

The plovers are quarrelsome birds.

Even though each pair has established its claims over a patch of grassland,

the birds continually dispute with their neighbours.

Rivals display aggressively, running along the frontier between their territories

and dive-bombing one another.

Their nest is probably as safe as it would be even if they remained sitting on it,

for their eggs are marvellously camouflaged and very difficult to see.

The adult tinamou, on the other hand, is just as well-disguised as the plover's eggs.

Its strategy is to stay put and freeze.

Just as well, for its eggs are very conspicuous, a brilliant shiny purple.

One ground-nester on the open plains, however, fears nothing.

It's big enough and strong enough to take on even an armadillo or a tegu.

The rhea, the South American ostrich.

It's the male that makes the nest and incubates the eggs.

And he is polygamous, with half a dozen or so females, all of whom will lay in his nest.

But with so many contributors, the compiling of a clutch can be a tricky business.

Sometimes several females, each with an egg ready to be laid, will turn up at the same time

and there's some confusion as to who's going to have the first turn.

He doesn't seem to want them to lay in the main clutch.

Perhaps he's worried about them treading on his eggs, so they'll have to sit outside.

The first female goes down.

Once laid, the egg has to be brought in to join the rest of the clutch

if he is to incubate it properly.

Another female settles down to lay.

And another egg joins his collection.

His final clutch may be huge, up to 50 or so.

They've come from many different females and been laid over a period of eight days,

but all hatch together.

The young pipe to one another while they're still inside their shells,

stimulating the eggs that are a bit behind to speed up their development.

The advantage of hatching simultaneously is that the young, soon after they emerge,

can go off and feed together under Father's watchful eye.

The open grassland is full of dangers and there are very few places to hide

from the many enemies that lie in wait for the chicks.

The maned wolf will certainly take one if it gets the chance.

It hunts alone, never forming packs, seldom even seen with its mate.

It maintains contact with others of its kind by an occasional bark

and by leaving its scent on bushes and termite mounds, spraying its urine high up

so that the wind will pick up the smell and broadcast it.

This wolf's tastes are, oddly, strongly vegetarian. Fruit forms a large part of its diet.

But it certainly takes birds if it can, and the tinamou is particularly vulnerable,

for it's almost flightless.

Trees don't grow on the open plains of Argentina and Brazil because, for much of the year,

there is too little rain.

During the dry season, the shallow lakes are reduced to stretches of baked mud.

Capybara, giant semi-aquatic guinea pigs, crowd into the few shrinking pools that remain.

Cayman are compelled to spend much of their time out of water,

and turtles jostle for places along the contracting margins with the capybara.

But during April, the clouds begin to gather and in June they burst.

It's a testing time for many of the grassland creatures.

2,000 miles north of the Brazilian campo, the grasslands of Venezuela, the Ilanos,