In the Wild (1992) s01e06 Episode Script

Barrow Island Part 3: The Cycle of Life

HARRY: The ultimate aim of conservation is balance - balance between the resources man needs and a respect for all other living things.
Here on Barrow Island, we have some of the world's rarest animals - at least two species are thought to be extinct on the mainland.
My job - to ensure that all these animals continue to live a balanced life without destruction by man and his works.
(THEME MUSIC) When Barrow became an oilfield in 1966, it could have been the end for the animals.
This happens in so many parts of the world.
But here, 60km off the north-west coast of Australia, on this desert island, the wildlife thrives.
I've been a conservation adviser for the company since 1964.
At one stage, they asked me to join the staff, but I'd rather work as a consultant because that way, I don't have any conflict between what the company wants and what I have to do as a conservationist.
This island is unique.
It's developed over 6,000 years in total isolation from Aborigines and introduced animals and plants which totally changed the mainland ecology and changed it for all time.
There.
Come on, come on.
Come on.
Come on, come on.
I got ya.
Come on! Now, now, now.
It's alright.
It's alright.
Yes, yes, yes.
Oh, this poor old fella Boy, old and all, he's giving it a good go for us! He's just about at the end of his time.
He's reached, in human standards, about 85, maybe 90.
He's been displaced in his territory.
He's been fighting.
You see the scars.
And, of course, the ticks have got in.
Great, big ticks, full of eggs, ready to drop off.
The absolute mark of a battered old man is his chewed ears.
In case you're wondering (HISSES ANGRILY) if, on Barrow Island, anybody can walk out and catch a kangaroo, it's not that easy! As I say, this poor old fella is on his last legs.
He's blind in one eye.
See that cloud across his eyeball.
So I was able to sneak up on him on the blind side.
By the time he jumped, I was too close.
One of the saddest things about the job here is not interfering in the natural processes of living.
When you see an animal like this that's old and sick and is gonna die, you leave it - you just leave it like it is.
It's the hardest part of the job, I think.
But it has to be, because on Barrow Island, it is an island - there's only limited space.
Each one of these animals needs about 40 acres.
And so a population explosion means that the old, the weak or the very young go to the wall.
Every animal deserves to die with some dignity.
So I think I'll let this fellow back to his spot in the rocks.
There you go.
Go on! Everything in nature has a reason.
There's no accidents.
No matter how strange or peculiar it may appear, it has a valid reason.
All of those tracks are here for a reason.
It's not this water.
(SPITS) That's really brine.
In fact, it's sea water that's evaporated away.
It's even saltier than sea water.
It's Dead Sea water.
It comes in over the bar during storms and fills up and evaporates.
Really brine.
The answer's over there, on the other side.
There's the answer.
A soak.
That's sweet water.
Little bit salt.
Little bit.
But certainly liveable.
And just there, right alongside, two feet away, is the really supersaturated salt.
Now, where's it come from? This whole sand hill sits on a hard ledge.
And the water that's caught in the sand hill slowly trickles down and floats on top of the salt layer.
And the kangaroos particularly - they're the ones who do it mostly - come in and dig away here, expose the freshwater table and just have a tiny little soak.
And all the other animals that drink water know about it - the doves and the bandicoots and the rat-kangaroos - and they all come in and drink here too.
And so this whole area becomes an enormous mass of animals at night drinking while they can.
Now, how does this fit in with animals' ownership of areas, territories? Well, if we make a mud map so that this is the sand hill and here's the waterhole here we've got the soakages coming out along that edge.
Now, normally a euro would own all of that.
Because it's such an important resource to survival, we have two things involved here.
One of them is territory, which belongs to an individual animal, and the other one is range, which is an area over which an animal can move and be tolerated by other animals.
So what we've got here is a whole series of territories that overlap like this.
And their overlapping point is a common range in which all animals will come and tolerate each other.
It's a bit like people have their own house.
If you bump into somebody in the street, you may apologise, but you don't worry there are other people on the street.
But the moment a stranger comes into your house That's your territory.
The street's your range and the house is your territory.
It belongs to you and you object to people coming in unless you want them there.
In the same way here, all animals can come in and drink, but if this animal comes across to this area, then there's a fight to drive him back out.
This is part of the answer to the problem of the euro on Barrow Island.
My early work here indicated the euro was dying out.
In 1964, when I first counted them, I got, I think, about 200 animals.
And then, in 1966 and 1969, I was getting less than 50, and it looked very bad.
At that time, I didn't understand this range/territory situation.
What was happening - I was spotlighting just after a cyclone and the animals were evenly spread all over the island and I was getting very big counts.
And then, later when I was spotlighting, I was spotlighting in the stress times of the year, the very harsh times, and the animals were all congregated on these few places - these common ranges.
And they just didn't happen to be on spotlighting ranges, so I didn't see any animals.
And that's why drawing conclusions on insufficient evidence is very, very dangerous.
Now we know that the population of euros on Barrow Island is quite static.
It fluctuates a little bit.
It's dynamic - it moves up and down to that degree.
But we've got a secondary test.
We pick up skulls of dead animals in caves.
We look at their teeth and that tells us the age the animal dies.
And we know from that there are no premature deaths.
Every animal reaches completely adult age.
That means there's no problems for the euros on Barrow Island, despite the oilfield.
That makes us pretty happy too.
It means that our systems of conservation are working here.
Although the dominant vegetation on Barrow is spinifex, there's over 200 species of other plants which are very important in the ecosystems.
They've got exactly the same problems as the animals.
They need protection against being eaten, protection against their competitors and most of all, protection against the climate - the heat and the wind.
Here's a couple of different plants.
Corchorus and sida.
Although they look fairly different, they both use the same technique - a complete covering of fur, felt-like fur, across the leaves.
This one's leaves are a bit more prickly.
The fur's not so cottony, it's more prickly.
And you'll notice in both plants the young leaves stay closed up, because they're succulent and tender and liable to lose a lot of moisture.
And the corchorus, they stay completely closed up like a clamshell.
This is caustic bush - or sarcostemma is the scientific name.
These things are just the stems.
So that helps to control its water output.
It oozes a sticky white sap which is, as the name suggests, caustic - very burning.
Here's one with real problems.
Right on the edge of the cliff, getting all the salt spray and wind, just growing in a crevice in the rocks.
So, how does it protect itself? First of all, it has very few leaves, and those few it has are covered with a dense mat of fur, like cotton wool.
So if an animal eats it, it just gets a mouthful of cotton wool.
Just to help it even further, its armed with a murderous set of spines.
Just to touch them and they stick in.
When you live on a desert island, things get a bit out of proportion.
But the boys here haven't lost their sense of humour.
By comparison with the spinifex, these 30-foot trees are as big as giants.
So they call this 'the Valley of the Giants'.
About 20,000 years ago, this was an old valley, and all the mud, the stone were washed down and deposited here.
This is, in fact, a fossil valley.
When it rains now, the water penetrates there and all the year round, there's water about 10 feet down.
The long-reaching roots of these eucalypts go down and tap the water - tap the water table.
And so we have a little patch of them.
The way these protect themselves against the elements - their leaves hang down so that the edge is towards the sun and they get minimal amount of light on them and minimal water loss.
And against animals, the leaves are coated in a waxy substance.
If you break it off, it's got a very (SNIFFS) very strong, familiar odour to every Australian - the smell of eucalyptus.
Eucalyptus is readily told from all the other plants by its flowers.
The flowers are absolutely typical of eucalypt.
Little caps or operculums on them.
And as they ripen, these peel off and the flower comes out in its full glory.
They don't look terribly glorious, but on Barrow Island, they support a whole range of life.
Honey-eaters and insects all come for the nectar flow.
and, of course, they, in turn, pollinate the flowers and we come to the seeds.
These seed capsules are quite ripe and they're now ready to play their part in the cycle of life and survival on Barrow Island.
Most of them will be eaten.
Some will survive and continue these eucalypts in the Valley of the Giants.
Every visit I make reveals another tiny piece of this complex ecological pattern, this web of life on Barrow Island.
One mammal of especial interest is the spectacled hare-wallaby.
Once widely spread across the mainland, today it's probably extinct except for this thriving community here on Barrow Island.
Ooh, this is one of the good bits.
A shower and clothing and a drink and an airconditioned laboratory, 'cause that's my way of fighting the conditions on Barrow Island.
Our main study animal is the only animal we catch and really work on, and that's the hare-wallaby.
This fellow, we caught last night.
And he's been 12 hours in a special cage which catches his urine, body water.
He was weighed before he went into the cage and then he'll be weighed again.
The reason we brought this one in - he lost his tag.
He's been tagged before, but he's been fighting and lost his tag.
Now, now.
Steady down.
Now, now, now, now.
It's OK.
These little tags go in the animal's ear like so (HISSES) Alright! (HISSES) (HISSES) Now, in spite of all that fuss, it didn't hurt him at all.
It's a stainless steel tag with a number on.
Now, that stays with him forever.
That's like a wedding ring.
And that's his number.
Just wipe that bit of stuff out of his eye.
That's something that happens to hare-wallabies.
Bit dry.
(HISSES) Now, I need a couple of measurements.
I need the length of his hind foot.
Now, be a good fellow and stay still.
And the length of that bone that goes from your hip to your knee.
With a hopping animal, that's very important, because that is the only bone in the body that stays constant - doesn't change with age.
It's 155.
I also have a couple of swabs.
With that eye being a little bit infected, it's a possibility that it might be a disease of some sort.
There are diseases on Barrow Island.
These are sterile swabs.
We've two in each jar.
So we'll just take a swab along there.
And we'll culture that out and see if there is something.
Just make a note on there that that's the eye before we get into trouble.
There's a good fellow.
Yes, it didn't hurt a bit.
Put the rest of the details on after.
And another swab - another sterile swab - from the mouth.
Open up.
Come on, let's have a look.
That's it.
You help me.
That's right, give me a help.
So that's the other swab.
We've two swabs.
Make a note of that.
Everything has to be recorded.
Eye, mouth.
The only other thing is any comment on the animal.
(HISSES) (GENTLY) Oh, come on! Simmer down! Interesting to note - as soon as I touch the ears, he gets very upset, because the ears are the critical place in hare-wallabies.
As soon as you touch their ears, they think you're threatening them.
They get attacked.
I can scratch his tummy and he doesn't worry at all or his feet or his hands.
As soon as I touch his ears, he's in trouble, because that's their real threat thing.
And you can tell a damaged animal by the amount of chewing he's got on his ears.
You're probably wondering, "Why hare-wallabies particularly?" They're the balance animal on Barrow Island.
They're just big enough and easy enough to see and record to be a good working animal but they're also an extremely good animal for adaptation to the environment.
Already we've found out they don't drink - that is, water - they get their moisture from their food.
They have certain sized territories.
And we know about their shelter needs, how much heat they can take and how much heat kills them.
We know we think we know what killed them in the mainland.
Not the predation by foxes and cats but the destruction of big spinifex, big, clumpy spinifex they lived in.
We know things about their anatomy too.
They've got a kidney that's so designed that they recycle their urine in such a way as to keep the moisture in their body.
This is a fairly common trick.
But no animal that we know does it as effectively as the hare-wallaby.
There's all sorts of other things about them on the pathological side.
Things like their blood type and the way it clots on the slightest cut.
There's no bleeding loss.
It clots immediately and stops.
All of these things are all building up into a total picture of what makes a hare-wallaby tick.
And when you think that we've got 15 mammals on Barrow Island and about 80 species of birds and 40 species of reptiles, and we only know that much about one of them - the hare-wallaby - you see we've got a long way to go.
And that's what lab work's about too.
I'll just put him back in his bag.
(HISSES) (GENTLY) Alright, alright.
(HISSES) If you ever get the chance to handle a hare-wallaby, that's the right way to handle him - by the tail like that.
He's quite happy that way.
(HISSES) He doesn't sound very happy, does he? Never mind.
I'll hold him there for a moment.
Now, the comments on that animal are "No ticks "good condition and "fur undamaged".
In other words, he hasn't been fighting.
He's a male, but he hasn't had territorial fights - he hasn't been fighting for territory.
He's in really good shape.
So he'll now go back to where he belongs, join up with his wife or wives.
This is the sort of thing we've found out.
This fellow This fellow, as the paper says, we got him here.
Now, based on the number of animals I've already taken, he's got to be one of three males.
His territory is about that size, and he overlaps the territory of five females, which are much smaller territories.
So when I say "He'll be released to go back to his wife," I really mean 'wives'.
And what happens, we think, is they move in a cycle and enjoy the favours of a lot of ladies.
But it's not really like people, because these animals only are sexually attractive at certain times, and he's gotta have a lot of wives to find one who's willing, as it were.
The females are permanently pregnant.
That is, once they have a joey, they have another one ready to come but it doesn't develop until the season's right - a cyclone comes or rainfall comes and the grass and spinifex starts to grow - and at that time, the joey then starts to develop.
So even if all the males were wiped out by a catastrophe, there'd still be another wave - another population or another generation of hare-wallabies would come up.
That's just part of the lab work.
There's lots of other parts.
They're pretty boring and uninteresting.
They don't involve handling animals while doing computer analyses and sums and arithmetic which I'm not very keen on anyway, so we'll leave it at that, I think.
So that's really why I'm here.
This delicate fabric of living, of life, plants and animals interwoven in a glorious net.
It's taken centuries for this to happen and we can destroy it so easily.
My job - to keep it so that your kids and mine can see it all in the times to come big animals, little animals, plants, right down to the sea itself.
We need them not just for their own sake, but for the sake of now and tomorrow, for people.
All this has to be here for everybody forever.
But there's no single simple solution to the problems of continued existence.
Any answers are as complicated as life itself.
Only one thing is certain.
If we are to preserve our environment and to save this priceless wildlife, we need much, much more knowledge.

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