Cork - On the Wild Side Natural World

A magnificent 200-year-old cork oak,

able to thrive on the poorest Mediterranean soils.

Thousands of years ago, people learnt to harvest their spongy bark

for a uniquely versatile material - cork.

They also began to graze the land between the trees

and to grow a few other crops.

Forests of these cork oaks survive to this day in a few parts of Europe

and with them an astonishing variety of plant and animal life.

Cork woodland is especially rich in bird life

with more than 100 different species breeding here in southern Portugal.

They include some of Europe's rarest birds,

which still find sanctuary amongst these remarkable trees.

The bark of the cork oaks is stripped away every nine years.

It's sold for many different uses, from floor tiles to fishing floats.

But the greatest revenue comes from the billions of stoppers

we use each year to close our wine and champagne bottles.

It's because of the high value of cork bark

that this ancient landscape, with its rural culture and its wildlife,

have been protected until today.

But its future is by no means certain.

If metal screw-caps and plastic were to completely replace natural cork

to stop our wine bottles, then a drastic change could be on the way,

because landowners would have to replace their oak woodlands

with other, more conventional crops.

So what is it about these forests

that make them so valuable to both people and wildlife?

The Alentejo region of southern Portugal

stretches from Lisbon in the west,

to the hills of the Spanish border in the east.

It's about 10,000 square miles, or the size of Wales,

and it's the world's most important cork-growing area.

These woodlands of evergreen cork oaks and their close relative,

the Holm oak, are known in Portugal as Montados.

Although the Montado is so good for wildlife, it's by no means a wilderness,

but rather a natural ecosystem of woodland and pasture

which has been sympathetically adapted for farming

in this sustainable way for more than 1,000 years.

Typically, the pastures under the trees are grazed,

although where there are patches of better quality soil,

landowners have traditionally grown citrus, vines and olives.

This has created a rich mosaic of habitats,

which is as beneficial for wildlife as it is for the farmers.

Nevertheless, to make a living based mainly on cork,

each family needs well over 1,000 acres,

where the oaks can thrive despite the dry, poorer quality soils.

Francisco Garrett is a farmer whose family have managed

a large area of forest in a traditional way for many generations.

Apart from an intimate knowledge of his own cork oak woodland,

Francisco has a passion for the future survival

of the Portuguese Montado, including its spectacular wildlife.

Well, this is a very pleasant thing,

just wandering in the Montado on a beautiful day,

spring day like this, sun is shining,

and hearing the birds and seeing the birds of prey

that have just come in for nesting.

I don't think there is anything better that one can enjoy

than live in the country here and see all this growing

and I just hope that it can be kept like this.

We have been for four or five generations living on cork

and I hope that future generations can continue to live on it.

Although the ancient Greeks and Romans knew about the value of cork bark,

it only began to be harvested commercially in Portugal about 300 years ago.

It's still done by teams of men using hand axes

and no viable mechanical method has yet been invented

to do the job as effectively.

The important thing is to know the amount of force that you have to input this

so that it doesn't damage the living part of the bark.

These axes are manufactured locally in several towns where they make it

and you have some bigger ones and some smaller ones.

It's a very nice thing and special for Portugal.

The stripping is done in midsummer

when the bark comes away from the living tissue, the cambium, more easily.

The smell of just-peeled cork oak and the colour of it, it's fantastic.

The skills needed for harvesting cork are often handed down from father to son.

You have to be really skilful to go up in the trees

and work with an axe and up in the air.

Very important on this, it is sustainable

because every nine years you peel it and you don't destroy the tree.

The more you peel it, the better the cork is.

What an extraordinary tree!

Cork oaks are the only trees in the world from which you could strip

an entire piece of bark like this without killing it.

Every tree this size yields sufficient bark

to produce 4,000 corks and this harvest provides employment

for at least 60,000 Portuguese workers.

Each tree is daubed with a number to record the year of the harvest.

This will remain visible as the bark thickens from the inside,

reminding owners that these trees can next be harvested in 2016.

During the hottest part of the day,

the cork harvesters are not the only ones to welcome a break.

A pair of booted eagles has nested nearby and the male

has been patiently waiting for the human activity to quieten down

before delivering food to his mate.

If cork and Holm oaks grow side by side, booted eagles will always

choose the cork oak for their nest site in preference to the Holm oak.

Maybe the gnarly bark holds the sticks better.

Who knows?

They're called booted eagles because of their heavily feathered legs,

and both adults build the nest, often lining the shallow cup with oak leaves.

Successful nests are re-used in future years and although two eggs are generally laid,

typically only one chick fledges because siblicide is common.

The attentive male will catch numerous birds and small mammal prey

in between the harvesting activity.

During August the annual cork harvest draws to a close

and activity in the parched Montado

gradually slows down as autumn approaches.

By late October the stripped cork trees are now deep red

as they begin to re-grow their bark.

The oaks now provide another abundant harvest

and the large acorns have their own nutritious value,

particularly for pigs!

One of the most important species that goes together

with the Montado and the cork oak is the Alentejo black pig

and that is used for the... the smoked ham.

The acorns give the ham its unique nutty flavour

and the pigs gorge on them from November until February.

The meat of this pig is very valued and it's one of the yearly revenues

of the Montado because the cork only happens every nine years.

In undisturbed areas of rough grassland,

surface runways reveal a smaller, secretive mammal hunting for acorns.

This is Cabrera's vole, a species unique to Spain and Portugal,

which favours the cork forests.

It will return to its usual diet of grass and sedges

when the acorns are finished.

Even though winter doesn't get very cold in this part of Portugal,

the cork oaks still shut down their growth from November onwards.

The winter months allow Francisco more time

to give his many thousands of cork oaks the attention that they need

to remain healthy and so continue to produce high quality bark and acorns.

These trees, they have been pruned several times, so once you do it

you have to continue doing it because when man interferes in nature,

once he has, he has to continue doing it, to balance the tree,

that it has the same leaf area as the root area

and adequate to the age of the tree.

The more important part of pruning is in the young trees

so that you have a straight bark,

at least two, three metres high, without any branches,

so you can have a nice piece of cork for the stoppers.

By the end of the year, cork bark from the surrounding woodlands

has virtually filled the storage yards.

This natural, sustainable product now provides a good living

for those working in the factories.

Winter also brings visitors from abroad to the Montado.

Up to 60,000 European cranes

migrate each year from Scandinavia to take part in the acorn bonanza.

Their trumpeting calls are one of the most evocative sounds

of the Montado winter.

The cranes don't like to swallow the acorns whole,

so skilfully de-husk them first.

As a winter destination for nearly 30 other species of migrant birds from Northern Europe,

the Portuguese Montado are becoming increasingly significant.

Millions of robins, chaffinches and thrushes from Britain alone

spend each winter in the warmer sanctuary of the cork forests.

However, it's only in the last 20 years that the rich diversity

of plant and animal life has been seriously studied here.

Tiago Marques and Ana Rainho are bat specialists.

Caves and old mine-workings

are traditionally used by Alentejo's bats for winter hibernation.

Ana and Tiago are surveying their populations before the bats disperse to breed.

These are greater mouse-eared bats,

just one of 26 species found in this region of Portugal.

Even here, some, like Mehely's horseshoe bat, are extremely rare,

but today the scientists are concentrating on

a relatively abundant cork woodland specialist.

This species or this bat is called the bent-wing bat

because despite his small body size

he has these large and very narrow wings,

and to keep them forward they just bend the tip of the wing.

You can see it now open, it bends it.

So that's why it's called like that.

Their long wings are perfect for rapid flight between the oak trees in search of insects.

And thanks to the minimal use of pesticides

there's no shortage of them in the Montado,

both for bats and for insect-eating birds,

like the lesser spotted woodpecker.

By early March, birds like hoopoe, warblers and nightingale

have already begun their spring courtship,

based on the promise of plentiful food supplies to feed their young.

Woodchat shrikes and endangered rollers

have returned from Africa to breed.

Petticoat narcissi are the first floral beacons of spring,

triggering a rampage of wild flowers,

an increasingly rare sight in the rest of agricultural Europe.

Mediterranean catchfly forms pink saucers around the cork oak trunks.

The evergreen, umbrella-like canopy provides welcome shade for these light-sensitive flowers.

Unlike so much of Europe, there's hardly any chemical run-off

from the surrounding land, so spring rains

replenish the streams and ponds with beautifully clean water,

which is good news for the pollution-sensitive animals like amphibians.

These are male marsh frogs,

trying to attract females and establish a territory.

In the slower moving rivers and pools throughout Alentejo

stripe-necked terrapins are abundant.

Like all reptiles, terrapins are cold-blooded

and need to absorb heat by basking on suitable rocks.

Throughout early spring barn swallows use the mud

they collect from the margins of the pond

to construct and repair their nests.

Marsh frogs are not the only noisy amphibian here.

Stripeless tree frogs are also common.

They reserve their mating chorus until nightfall.

FROGS CALL

During the night a male Iberian midwife toad

has kept a chain of eggs moist in the pool.

Wrapped around his hind legs, they shackle the toad for six weeks until hatching.

Before dawn, he'll find a damp, cool shelter to prevent the eggs from drying out.

Fire salamanders hunt for invertebrate prey throughout the night.

With its striking yellow and red markings,

this is a rare sub-species found only here.

It will also hide up during the day.

As too will the spadefoot toad.

Using its shovel-like rear feet and corkscrew body movement,

the toad buries itself in the soft soil of the cork forests

before the end of the night.

In Britain, you seldom hear nightingales singing after dawn.

NIGHTINGALE SINGS

But in this very undisturbed area

these normally secretive birds will often continue throughout the day.

The relative peace and quiet

also encourages many of Europe's rarest birds to breed here,

such as the black-shouldered kite.

This male is quartering one of the Montado's

more open, grassy areas for small rodent prey.

It's now mid-March and a female, ready for breeding,

watches the performance with a critical eye.

These beautiful birds can hover over their prey in a similar way to a kestrel.

It's an ability that differentiates them from their common relatives,

the red and the black kite.

The female sees that her prospective partner

is at last returning with a courtship gift.

She will join him on his post for a handover ceremony.

And then fly off with her engagement present

to the chosen nest site in an old olive tree.

She's unlikely to be disturbed here - the farmer who would have harvested the olives is long gone.

So too the cork-oak woodland that once surrounded the abandoned farmstead,

probably cleared during the 1980s

when EU subsidies encouraged a switch to more intensive crops, like maize.

At the same time wine drinking was becoming more and more popular,

with a corresponding increase in demand for cork bark.

The producers of cork stoppers could hardly keep pace

and in some factories standards of quality and cleanliness fell.

As a result, complaints of tainted or "corked'" wine rose

and opened the way for new plastic or metal alternatives,

marketed as cleaner and more modern than cork stoppers like these.

By early 2000, the cork industry had lost almost a quarter of its market to this new competition

and some landowners, fearing the worst, continued to replace their cork oaks with cereal crops.

But on these dry, impoverished soils

many such projects were doomed to failure.

Once felled, cork woodland is very difficult to restore.

A complex ecosystem such as the Montado takes time,

knowledge and patience to recreate, as Francisco knows well.

There's a Portuguese proverb that says...

HE SPEAKS PORTUGUESE

In English this means these vineyards of mine,

olive groves of my parents and Montados of my ancestors

and that shows the time it takes to have a Montado established.

Carefully controlled plantations like this

are how modern farmers try to recreate their cork woodlands,

but there was a simpler way in the past.

One of the good memories I have from my childhood

is that walking in the Montado, with my grandfather,

he would just look for an acorn, he would pick it up

and with the heel of his boot,

just do like this, put it back like this,

and after pick up a piece of... with thorns like this

and just put it on top of the acorn just to protect it.

He would choose a place where there were no cork trees

and hopefully next year we would have a nice sprouting

young cork tree in that place.

Look - here's a beautiful acorn that has germinated.

You see? Hopefully this acorn in 20, 30 years' time

will be giving some cork.

I won't be here to harvest it but I hope my sons, you know,

or my grandsons will be here for it.

Let's hope it's here.

Francisco's long-term view of the Montado

includes a passion for its wildlife,

so he leaves about 10% of his woodland un-grazed.

Natural regeneration encourages a mixed understorey of flowers

and shrubs, including the evergreen arbutus or strawberry tree.

A special thing about the Arbutus unedo, is that its leaves

is the food for a very specific caterpillar of the pasha butterfly.

They only feed on these leaves, so by keeping these we help nature.

By understanding wildlife and sympathetically managing his Montado,

Francisco helps secure the increasingly rare pasha butterfly.

Walking through here, that I do in weekends,

one of the things I've found is a nest of a nightjar.

They are quite frequent here and they are very difficult to find

because they mix with nature so, so well.

Red-necked nightjars are masters of camouflage.

Only a glinting eye reveals her sitting on her nest in the leaf litter.

She will sit out the daylight hours on her clutch of eggs with hardly a movement,

trying to avoid the attention of the many species of snakes found here.

Being good climbers, ladder snakes can also be a threat to tree-nesting birds.

Growing up to a metre in length,

they're one of the largest species in Europe.

Grass snakes are common in the Montado

and when basking in the open need to stay alert to danger themselves,

particularly when it's most likely to come from above.

This is a female short-toed or serpent eagle,

and she's expecting some food from her mate.

It's characteristic for him to arrive with a half-swallowed ladder snake,

which she is then obliged to pull from his throat.

The male provides all the food for both his mate and the chick

during its first two weeks of life.

It's April and the cork oaks are flowering once again.

There can't be many places where the continued survival

of one species of tree helps to feed so many mouths!

This attentive mother is a woodchat shrike,

who with that hooked bill,

can dispatch anything from beetles and grasshoppers

to small lizards and the young of other birds to feed her own brood.

That variety of prey is largely thanks to the patchwork of habitats in the Montado

and it's the mixture of woodland and pasture

which also enables the iconic azure-winged magpie

to raise its offspring in such healthy numbers.

Gaggles of these handsome birds

are often seen diligently searching for insects.

It would be easy to assume that this pair are the nestlings' parents.

However, they're just as likely to be siblings from one of last year's broods,

who, instead of breeding themselves, have forfeited their first year

to help attend to their new relatives.

Minimal use of insecticides and herbicides,

together with "habitat friendly" traditional management,

means that countless insects are always available on the menu.

Another vital part of this management system is water conservation.

Farmers will often channel their precious spring water

into traditional stone troughs

and the surrounding damp vegetation of such places

is favoured by Europe's largest amphibian, the sharp-ribbed salamander.

The temporary supply of water in the troughs coincides perfectly with the salamander's spawning season.

They will often clamber in to lay their eggs amongst the algae on the bottom.

Local farmers have an ancient superstition

that a salamander in a water trough will soon drink it dry!

Of course, this is only a myth.

Or is it?

It's easy to dismiss an old legend - much harder, though,

to replace an ancient system

that gives haven to even the rarest of Alentejo's breeding birds,

such as the black stork.

The more remote areas of cork-producing woodland, near the Spanish border,

provide a vital European sanctuary for these impressive, enigmatic birds.

It's now May and this male, having just returned from Africa,

is looking for a female to pair with.

She's below, checking out the oak trees for a potential nest site,

so he must attract her attention.

He does this by circling overhead

with his long, red legs dangling towards her but the climax occurs

when he throws his head back to utter a special call.

HE WHISTLES

If suitably impressed, the female joins him

in a graceful aerial ballet, which if you are lucky enough to witness it,

is one of the loveliest sights on the Montado.

Black storks are extremely rare and now highly protected in Portugal.

Because they prefer to nest in mature cork oaks,

they're symbolic of the intimate link between conserving wildlife

and a healthy, successful cork industry.

The future of the Montado and its wildlife

is largely determined by economics.

Cork growers must be able to sell their crop

to the factories for a worthwhile price.

Faced with intense competition from alternative closures,

the manufacturers have modernised and cleaned up their production methods,

to rid cork of any charge that it may sometimes spoil a bottle of wine.

Nowadays the sheets of raw cork

are immersed twice in sealed vats of boiling water,

killing off any moulds or bacteria

and making it more flexible to work with.

In today's spotlessly clean, state-of-the-art factories,

the stoppers are individually scanned for imperfections.

They're sterilised, polished and graded,

and samples from every batch are scrupulously checked

in the company's labs for the chemical trichloroanisol or TCA,

which can cause an off-taste in a bottle of wine.

TCA is produced by micro-organisms in the soil, on trees

and even on a brand-new wine bottle, but rarely now in cork factories!

Since 2006, the Portuguese cork industry seem to have conquered TCA contamination.

For the moment, with the cork industry fighting back in this way,

the Montado and its wildlife have gained some respite.

Even very shy animals are able to live successfully here,

particularly in the more remote, thinly populated areas.

This shepherd might walk 20 kilometres in a day

without meeting another soul or seeing any other grazers

except perhaps for some quite special local deer.

These might look like ordinary red deer,

but they're a distinct sub-species, found only in Portugal and Spain.

While they're grazing, the scene looks tranquil, idyllic even.

However, when the deer feel the urge to drink, their behaviour changes dramatically.

Now they're tense and nervous, more reminiscent of African antelope

at a waterhole on the lookout for lions.

A local red fox is obviously no danger to them

but they're still instinctively alert.

Is there a predator still existing in Portugal

which could invoke such extreme caution?

The answer is yes.

The most endangered big cat in the world, the Iberian lynx -

certainly capable of killing a deer calf

or even an injured or weak adult.

Having been persecuted for years, a pair of these mesmerising cats

has recently been spotted in the Alentejo region,

and conservation biologists are desperately hoping that they'll breed successfully.

There's certainly enough prey here for lynx to kill or scavenge,

although any dead animal such as a deer

will soon be spotted by other sharp-eyed scavengers on patrol.

Always the opportunist, a red fox is first to the carcass, but it won't have long to feed at leisure.

A black vulture has already seen the meal.

And a Griffon vulture is also swooping in.

This might be the last chance for the vixen to get at her meal,

although she's been of service to the vultures by opening up the tough skin.

As vultures cruise the skies

they're always on the lookout for feeding activity,

so it's not long before they start arriving in greater numbers.

There's a loose feeding hierarchy around a carcass,

but as more vultures arrive, the situation becomes noisy and chaotic,

perhaps more typical of the African savanna than rural Portugal!

BIRDS SCREECH

After a feeding frenzy lasting several hours,

almost a hundred vultures have stripped the carcase bare.

And many are so satiated that for the moment,

only sleep and digestion seem an option.

It's early June and around some old, abandoned buildings on their land,

Francisco and his wife Teresa

have come to check on the current residents.

The barn swallows have been here since March but there's a much larger bird

that comes to nest in the church almost every year.

HE SPEAKS IN PORTUGUESE

In a small window hole,

barn owl chicks about seven weeks old are close to fledging.

They nest sometimes here and they also do it on the other side.

But this year they want to have a better view of, of the lake.

Barn owls, along with five other owl species, breed very successfully in the Montado.

It's a sure indication of the plentiful rodent prey,

including Cabrera's vole, that can be found here.

A declining population in the countryside does, at least,

have a bonus for the local swallows.

The abandoned priest's house has provided some perfect nest sites.

Each young swallow eats about 150,000 insects before leaving the nest.

Insects are so abundant in the Montado

that a pair of Portuguese swallows regularly rears three broods each season,

rather than the two more typical in Britain.

The spring flowers have long withered.

But throughout May and until mid June, the summer flowers provide a new tapestry of colour.

Stunning though they are,

it's not this astonishing display of wild flowers

which will save the Montado.

It's more to do with visionary farmers, like Francisco,

who are prepared to experiment with new ways of improving the production

and the quality of cork bark for the factories.

The main reason why I plant lupins in the Montado

is because I am of the opinion

that we can't have bare soil in the Montado.

Lupins is a legume, it fixes nitrogen in the soil

and it also covers the soil in winter, avoiding erosion.

And you can graze them when it's dried, with the sheep or cattle.

It's very good for the soil, below the cork oak.

Ground cover like this also helps retain moisture

and keep the shallow tree roots cooler during the height of summer

when temperatures can often reach 40 degrees Centigrade or more.

Lupins are imported flowers and don't attract bees in the same way as native flowers like lavender.

With wild flowers so plentiful,

most cork farmers allow bee-keepers to manage hives on their land.

For this they get a small rent and a share, perhaps,

of the plentiful crop of delicious, aromatic honey.

But the bee-keepers here do have an enemy,

albeit one of the most attractive ones imaginable.

Bee-eaters, who, as their name implies, feed on bees.

The light, sandy soil might not be ideal for growing crops

but exposed banks are perfect for excavating nest burrows.

Throughout Alentejo, colonies of bee-eaters

provide an iridescent spectacle of energy and colour.

Bee-eaters are not the only creatures here

with an appetite for the bees.

The eyed or ocellated lizard catches them too,

although on this occasion, he's got a wasp.

These handsome but declining lizards thrive in the Portuguese Montado.

They're Europe's largest species, growing up to a metre long

and capable of eating small rodents.

However, despite their size,

they're certainly not immune from danger themselves.

Throughout June, a black stork with young to feed

would have no hesitation in trying to grab one.

Hunting over a large area, the diet of black storks is varied,

including other lizards, many amphibians

and even small fish when available.

With a nest full of very hungry four-week-old chicks,

the adult storks will have to maintain a steady supply of food

if the chicks are to fledge in July.

These birds are very sensitive, but if undisturbed,

most black stork pairs successfully rear

three to four chicks every year.

Our black-shouldered kite parents, however,

with their nest in the old olive tree,

have chicks which are already close to flying,

if their vigorous wing exercises are anything to go by.

Although the parents are still catching and bringing in rodents for their young

they'll also encourage the chicks to leave the nest

as soon as possible now.

There's such a lot of clambering about going on

that by the time the mother kite returns again with food,

she could easily assume her chicks have already flown.

At least until one of them drops abruptly in for lunch!

By July, right across this vast, parched, shimmering area of Portugal,

hundreds of plant species have already flowered and set seed.

Thousands of birds and other animals

have successfully reared their young.

It's a success that depends on farmers managing their Montados

in the time-honoured, traditional way,

but also with an eye to the future.

When the cork harvest comes around once more,

it becomes a crucial test of the farmers' skills

and their continuing livelihood, as Francisco knows well.

We live on cork so when we've got to the time of harvesting it

and sending it to the factory, we've been able to raise it.

There were no shortcomings during those nine years

and all the 40 years before it.

And this is an achievement, it's a reward, and what keeps you living.

Most of this high-quality cork will be turned into wine stoppers,

essential for the economy of the Montados.

As a bonus the cork oaks themselves will absorb

millions of tonnes of carbon dioxide from the atmosphere each year.

Billions of high-quality corks

are still used by wine bottlers all over the world.

They're a low-energy, bio-degradable product

that ticks every green credential,

yet are still under threat of replacement

by synthetic plastic stoppers and metal screw-caps.

So might the future of the cork forests and their wildlife

be up to us consumers, and if so, what can we do about it?

One thing that we should do

is when we go to the supermarkets and choose a wine,

I would try and know if the bottle is using a cork stopper

and of real cork because if it is,

I know for sure that this will be contributing for the sustainability

of a vast Mediterranean area where you have a large number of species.

The future of so much wildlife seems dependant on such seemingly trivial choices.

Of course we can make choices and you can make a choice of

preserving a habitat that is unique in the Mediterranean area or not -

choose something that's nature-friendly or not.