0:00:09 > 0:00:13We live in the age of information.
0:00:13 > 0:00:16Events are transmitted to the palms of our hand
0:00:16 > 0:00:1824 hours a day.
0:00:18 > 0:00:21Events which surprise us,
0:00:21 > 0:00:25occasionally even frighten us.
0:00:25 > 0:00:29We're going to bring you some of the most bizarre and mysterious
0:00:29 > 0:00:33natural phenomena on the planet.
0:00:33 > 0:00:38From the Dutch car that got completely cocooned in a silky web,
0:00:38 > 0:00:43- to the day that Sydney turned crimson.- This is unbelievable.
0:00:43 > 0:00:47And from the swarms and plagues sweeping the world,
0:00:47 > 0:00:51to the mystery surrounding 200 whales in Tasmania.
0:00:52 > 0:00:58Using eyewitness accounts, news footage and experts and scientists,
0:00:58 > 0:01:03we are going to try and explain what on Earth is going on.
0:01:25 > 0:01:28Right then, for our first set of weird events,
0:01:28 > 0:01:31we're going to witness first-hand what happens
0:01:31 > 0:01:35when creatures behave in bizarre and surprising ways.
0:01:37 > 0:01:40There's an explosive event which shocked the residents
0:01:40 > 0:01:45of a quiet Hamburg suburb and a parasite that will have you gagging.
0:01:46 > 0:01:50But we start in the city of Rotterdam in Holland.
0:01:50 > 0:01:53When, in 2009...
0:01:53 > 0:01:55this happened.
0:01:55 > 0:01:59It was like something out of a Grimms' fairy tale. Look at it.
0:01:59 > 0:02:03The poor owner of this red Honda had something much worse
0:02:03 > 0:02:05than a parking ticket stuck on his car.
0:02:07 > 0:02:10And it didn't stop there.
0:02:10 > 0:02:14Everything was entangled in this mysterious web.
0:02:16 > 0:02:21A closer inspection revealed millions of the silk-spinning
0:02:21 > 0:02:24offspring of a species of ermine moth.
0:02:29 > 0:02:32So, what were so many caterpillars doing wriggling
0:02:32 > 0:02:34over the surface of this thick web?
0:02:37 > 0:02:42Well, Dr Ray Barnett is a moth expert from Bristol Museum.
0:02:42 > 0:02:47Can he explain this extraordinary event?
0:02:47 > 0:02:49The adult female, flying about at night, like most moths,
0:02:49 > 0:02:51would find the right food plant
0:02:51 > 0:02:55and then would lay a clump of about 50 eggs.
0:02:55 > 0:02:57Tiny little caterpillars hatch out
0:02:57 > 0:03:00and then they will start to move about and find some food.
0:03:00 > 0:03:04And that's when they start to form webs.
0:03:04 > 0:03:08The silk is made from proteins in the caterpillar's saliva.
0:03:08 > 0:03:10It's both strong and sticky.
0:03:12 > 0:03:16Normally, we see caterpillar silk being used to make a cocoon
0:03:16 > 0:03:19for their transformation into an adult moth.
0:03:19 > 0:03:20But in Rotterdam,
0:03:20 > 0:03:24the ermine moth caterpillars had a totally different plan.
0:03:24 > 0:03:27They spin this silk over the food that they're on
0:03:27 > 0:03:29and hide underneath it.
0:03:29 > 0:03:32And that just means that the birds, which are the main visual predators
0:03:32 > 0:03:36of caterpillars, are unable to get at them easily.
0:03:39 > 0:03:42And they're not the only creatures out to get them.
0:03:42 > 0:03:45There's also a particularly resourceful parasitic wasp,
0:03:45 > 0:03:48which lays its eggs on their skin.
0:03:48 > 0:03:51Its larvae then feeds on the caterpillar.
0:03:51 > 0:03:55It's in their interest cos they're nice and juicy and very attractive
0:03:55 > 0:03:58for birds to eat, in particular, to protect themselves in that way.
0:03:59 > 0:04:03The reason they chose this street in Rotterdam
0:04:03 > 0:04:06is because it's lined with plenty of their favourite food.
0:04:06 > 0:04:08The leaves of the Spindle tree.
0:04:08 > 0:04:11But why was the web so enormous,
0:04:11 > 0:04:15completely covering the trees from top to bottom?
0:04:16 > 0:04:21What seems to happen when we get these really big aggregations
0:04:21 > 0:04:25is that you've had several females lay eggs on the same plant.
0:04:25 > 0:04:28And so, they're all joining together and making a, sort of, super web,
0:04:28 > 0:04:32which can cover whole hedgerows if there's enough of them.
0:04:32 > 0:04:35And, of course, as they get bigger they need more food
0:04:35 > 0:04:38and so the web expands and increases.
0:04:38 > 0:04:42Fair enough. But this still doesn't explain why they coated the car.
0:04:42 > 0:04:46As they gradually exhausted the food supply, so, they continued to
0:04:46 > 0:04:50look for more by spinning more web and expanding out and, perhaps,
0:04:50 > 0:04:55leaving the tree that they were feeding on to try and locate more.
0:04:56 > 0:04:59If you imagine yourself as a poor, little, defenceless caterpillar,
0:04:59 > 0:05:01you can't just run across the road because the birds will eat you.
0:05:01 > 0:05:03So, you have to keep your protection with you.
0:05:03 > 0:05:08You have to keep spinning the web and moving underneath that web.
0:05:08 > 0:05:11So, they're moving off the tree, they don't know where they're going,
0:05:11 > 0:05:14but they're looking to try and find some more food plants.
0:05:14 > 0:05:18And, consequently, they've ended up covering all the bits and pieces
0:05:18 > 0:05:22around the tree, which happened to include, in this case, a car.
0:05:22 > 0:05:25So, quite a remarkable incident. But I don't think they were fooled.
0:05:25 > 0:05:27They didn't think this was something to eat.
0:05:27 > 0:05:31They're just on their way to try and find more to eat.
0:05:31 > 0:05:35So, the reason for this incredible car-cooning caterpillar event
0:05:35 > 0:05:39was a bumper year for ermine moth, triggering a desperate race
0:05:39 > 0:05:44for caterpillar food and a very sticky situation for the car owner.
0:05:46 > 0:05:49What an astonishing spectacle!
0:05:49 > 0:05:54It's almost a work of motoring and caterpillar art, I have to say.
0:05:54 > 0:05:57Nevertheless, we are getting more reports of these things
0:05:57 > 0:06:00and the time to look out for them is in May and June.
0:06:00 > 0:06:03Especially, if you have Bird Cherry trees or Spindle trees
0:06:03 > 0:06:06in your garden. If you do, don't park your car underneath them.
0:06:06 > 0:06:11And we stay with unusual appetites for our next weird event,
0:06:11 > 0:06:13which is truly amazing.
0:06:13 > 0:06:16We're crossing the border from Holland to Germany
0:06:16 > 0:06:20to the outskirts of Hamburg, where, in 2005,
0:06:20 > 0:06:25a small pond became the focus of international shock and revulsion.
0:06:25 > 0:06:30About a thousand dead toads were discovered lying around the edges.
0:06:30 > 0:06:34Their bodies appearing to have exploded.
0:06:34 > 0:06:39Eyewitnesses said they swelled up to about three and a half times
0:06:39 > 0:06:44their normal size and then simply burst.
0:06:44 > 0:06:47And they burst with such an explosive force,
0:06:47 > 0:06:52that their entrails were blown over several square metres.
0:06:52 > 0:06:54Nice(!)
0:06:54 > 0:06:58The amphibians affected were European Common toads
0:06:58 > 0:07:00and the carnage took place in April,
0:07:00 > 0:07:02around the time when they were spawning.
0:07:02 > 0:07:05Scientists initially thought that foreign racehorses
0:07:05 > 0:07:08at a nearby track might have brought in a virus or an infection.
0:07:08 > 0:07:11But when they tested the water and the toads,
0:07:11 > 0:07:14they found absolutely nothing.
0:07:14 > 0:07:19The location was dubbed the Pond of Death and then things escalated
0:07:19 > 0:07:23as the deaths spread across the border to a nearby Danish lake.
0:07:23 > 0:07:29What could possibly be causing these gruesome events?
0:07:29 > 0:07:32Eventually, scientists came up with a theory
0:07:32 > 0:07:34that implicated these types of birds
0:07:34 > 0:07:39and placed them at the centre of this mystery.
0:07:39 > 0:07:41You see, corvids, like this raven,
0:07:41 > 0:07:44are amongst the most intelligent of birds.
0:07:44 > 0:07:47If you want to know just how clever they are,
0:07:47 > 0:07:51take a look at these extraordinary Japanese crows.
0:07:51 > 0:07:56You see, they had some tough nuts to crack, walnuts to be precise.
0:07:56 > 0:07:59They realised they needed some help.
0:07:59 > 0:08:01So, they were dropping them
0:08:01 > 0:08:04onto the road and using cars to crack them open.
0:08:04 > 0:08:06Pretty brainy.
0:08:06 > 0:08:10But retrieving them was dangerous.
0:08:10 > 0:08:16So, these avian masterminds took it one stage further.
0:08:18 > 0:08:20Just look at this.
0:08:20 > 0:08:24They started deliberately dropping them onto pedestrian crossings
0:08:24 > 0:08:27so they could collect the contents of the nuts
0:08:27 > 0:08:30when the traffic stopped.
0:08:34 > 0:08:38Come on, that is pretty clever.
0:08:39 > 0:08:41But what have highly intelligent birds
0:08:41 > 0:08:44got to do with exploding toads?
0:08:46 > 0:08:50Well, when scientists examined the corpses of the toads,
0:08:50 > 0:08:52they found a couple of interesting things.
0:08:52 > 0:08:54Firstly, a tiny beak-shaped mark
0:08:54 > 0:08:58just above where the toad's liver should be.
0:08:58 > 0:09:00And then, when they looked inside,
0:09:00 > 0:09:04they found that the liver was missing.
0:09:04 > 0:09:06And what it appears that had happened
0:09:06 > 0:09:09is that the local crows had learned to peck the liver out
0:09:09 > 0:09:13through the body of the toad and thus avoid its toxic skin.
0:09:13 > 0:09:17No-one knows how they learned where the liver was located,
0:09:17 > 0:09:20but we do know that toad's skin is
0:09:20 > 0:09:24so poisonous that many animals can have a fatal reaction to it.
0:09:24 > 0:09:28But the liver is so nutritious, it's worth working out
0:09:28 > 0:09:31how to extract it safely.
0:09:31 > 0:09:35Now, when toads are attacked by predators, their natural response
0:09:35 > 0:09:39is to swell up and make themselves as big as possible.
0:09:39 > 0:09:42So, it looks as if they'd be impossible to swallow.
0:09:42 > 0:09:44But, of course, with the liver missing
0:09:44 > 0:09:49and without a diaphragm, those lungs just swelled and swelled
0:09:49 > 0:09:53and swelled until, in the end, they simply exploded.
0:09:56 > 0:09:58Clever birds, corvids.
0:09:58 > 0:10:02So, the mystery of the exploding toads was finally solved
0:10:02 > 0:10:07by smart detective work and it was the crows' refined taste
0:10:07 > 0:10:09for toad liver that was to blame.
0:10:09 > 0:10:13But if you thought those poor toads had it bad,
0:10:13 > 0:10:18wait until you see what our next weird species gets up to.
0:10:18 > 0:10:22For our final bizarre animal story, we're in the UK,
0:10:22 > 0:10:24in Lewisham, south-east London.
0:10:24 > 0:10:28A couple preparing a fish supper were horrified to find
0:10:28 > 0:10:33this sinister-looking creature staring out of the fish's mouth.
0:10:35 > 0:10:39Fishmonger, Donna Cawley, was also mortified when she found
0:10:39 > 0:10:42one of these creepy-looking creatures in her fish.
0:10:42 > 0:10:45I was absolutely shocked to see it cos I didn't know what it was.
0:10:46 > 0:10:49It's just, it's not normal, really, is it? To go home
0:10:49 > 0:10:51and find that in a fish's mouth.
0:10:51 > 0:10:54They look like maggots to me.
0:10:56 > 0:10:58Not very nice to look at all.
0:10:58 > 0:11:01These animals are turning up in fish's mouths
0:11:01 > 0:11:04all around the world and the reaction is always the same.
0:11:04 > 0:11:06One of repulsion and loathing.
0:11:08 > 0:11:11They look like an ordinary fish tongue.
0:11:12 > 0:11:16It's segmented, looks almost like a beetle.
0:11:16 > 0:11:20But if you look closely, it has little feet that move around
0:11:20 > 0:11:23and the tongue looks like it's walking.
0:11:23 > 0:11:28And the first time that we saw this, we were really freaked out.
0:11:28 > 0:11:31So, what exactly are these things?
0:11:31 > 0:11:35And why are they lurking in the fish's mouths?
0:11:35 > 0:11:39Dr Tammy Horton is a marine biologist who has studied
0:11:39 > 0:11:41these unsavoury members of the isopod family.
0:11:41 > 0:11:45And their habits might make you gag.
0:11:45 > 0:11:49All of these isopods have been called tongue-biters.
0:11:49 > 0:11:52What happens is a larval isopod will infect
0:11:52 > 0:11:56by crawling under the gill cavity and settle on the fish's tongue.
0:11:56 > 0:11:59Now, it has very sharp claws that enable it to grip onto the skin
0:11:59 > 0:12:03of the fish and to grip underneath the tongue and into the flesh.
0:12:03 > 0:12:07It will stay there and grow by blood-feeding on the host.
0:12:07 > 0:12:10So, it just chews away at the skin or part of the tongue
0:12:10 > 0:12:14and starts to feed from the arteries of the fish.
0:12:14 > 0:12:18I've seen parasitised fish with no tongue left.
0:12:18 > 0:12:24So, the isopod itself becomes a replacement tongue for that fish.
0:12:24 > 0:12:28The tongue is completely chewed away and eaten up.
0:12:28 > 0:12:31You can see the seven pairs of legs,
0:12:31 > 0:12:35each is armed with a strong dactyl, which is like a claw.
0:12:35 > 0:12:39And it's these which the isopod uses to cling onto the fish's tongue.
0:12:39 > 0:12:42They do cling onto your finger.
0:12:42 > 0:12:45They grip on and you can hold them upside down
0:12:45 > 0:12:47and they'll hold on with just one claw.
0:12:47 > 0:12:49They're that sharp and that strong.
0:12:49 > 0:12:52Although they cause quite a lot of horror, seeing something like this,
0:12:52 > 0:12:55these are all members of the order Isopoda.
0:12:55 > 0:12:58They're very wide-ranging, they live in seaweed,
0:12:58 > 0:13:02they live on the seashore, they live in the deep oceans,
0:13:02 > 0:13:05in trenches and also in your back garden.
0:13:05 > 0:13:10You see, woodlice are probably the isopods we're most familiar with.
0:13:10 > 0:13:12You can find them all over the world.
0:13:12 > 0:13:15There are around 40 different species in the UK alone.
0:13:15 > 0:13:18And when you look at them, the family resemblance
0:13:18 > 0:13:22with the tongue-eating parasite is pretty obvious.
0:13:22 > 0:13:27But these two also have a big brother.
0:13:27 > 0:13:30The aptly named giant isopod,
0:13:30 > 0:13:34a scavenger found at the bottom of our deepest oceans.
0:13:34 > 0:13:39This animal can walk along the sea floor quite happily and quite fast.
0:13:39 > 0:13:42Like the parasitic isopod, it has strong mouthparts
0:13:42 > 0:13:48which can be used for crushing and tearing at flesh.
0:13:48 > 0:13:52I wouldn't want to put my hands anywhere near this guy's mouth.
0:13:56 > 0:13:59Impressive though this giant relative is,
0:13:59 > 0:14:03it's the habits of the little tongue-biter called Cymothoa
0:14:03 > 0:14:06that provokes the strongest reaction.
0:14:06 > 0:14:09To me, to find one of these parasites inside a fish's mouth
0:14:09 > 0:14:12is a moment of joy and elation because they're quite rare.
0:14:12 > 0:14:16But for someone who is buying a fish in a fishmongers,
0:14:16 > 0:14:19to find one of these is probably the complete opposite reaction.
0:14:19 > 0:14:21It's one of horror and disgust.
0:14:23 > 0:14:25Well, you might think, what a horrible thing,
0:14:25 > 0:14:29but then, equally, you'd have to admit that
0:14:29 > 0:14:33that tongue-biting parasite is a triumph of evolution.
0:14:33 > 0:14:36All of the adaptations it's made to survive inside its host.
0:14:36 > 0:14:40And when you think about it, it's easy to see where sci-fi writers get
0:14:40 > 0:14:44inspiration when they want to come up with their next species of alien.
0:14:48 > 0:14:50Each of these bizarre stories,
0:14:50 > 0:14:56show the extremes creatures will go to just to find their next meal.
0:14:56 > 0:15:00Whether you're cocooning a car in your hunt for leaves,
0:15:00 > 0:15:05detonating toads by pecking out their livers,
0:15:05 > 0:15:10or replacing your host's tongue as you drink its blood,
0:15:10 > 0:15:12We might find them weird or repugnant,
0:15:12 > 0:15:14but for the species concerned,
0:15:14 > 0:15:19it's a perfectly natural solution to a problem. Top marks.
0:15:19 > 0:15:23Now, if the little things in life can have so much impact,
0:15:23 > 0:15:27wait till you see what happens when we move on to the really big stuff.
0:15:27 > 0:15:30Our next couple of weird events are storms.
0:15:30 > 0:15:34And I can guarantee you won't have seen anything like them before.
0:15:34 > 0:15:38Coming up, we'll be finding out what made one of the world's
0:15:38 > 0:15:42most iconic cities look like it was built on another planet.
0:15:42 > 0:15:46But, before that, we travel to Switzerland
0:15:46 > 0:15:48to the small town of Versoix.
0:15:48 > 0:15:53This pretty Swiss quayside on Lake Geneva is popular with tourists
0:15:53 > 0:15:57and, in the summer, it's an idyllic spot.
0:16:00 > 0:16:03But on January 26th 2005,
0:16:03 > 0:16:06the locals woke up to a surprise.
0:16:06 > 0:16:10You see, overnight, their quayside had been transformed into a strange,
0:16:10 > 0:16:14eerie and beautiful natural ice sculpture.
0:16:17 > 0:16:20One local resident recorded what has to be
0:16:20 > 0:16:24one of the most extraordinary dog walks they've ever taken.
0:16:27 > 0:16:30Everything was coated in a thick glaze of ice,
0:16:30 > 0:16:33up to ten centimetres deep.
0:16:38 > 0:16:41Boat owners, well, they were left with a sinking feeling
0:16:41 > 0:16:46as the weight of the ice had started to capsize their yachts.
0:16:46 > 0:16:50And some car owners, anxious to retrieve their vehicles,
0:16:50 > 0:16:53bravely tried to hack or melt them free.
0:16:56 > 0:17:01So, what on Earth had happened to create this astonishing scene?
0:17:02 > 0:17:04Well, the answer was actually simple.
0:17:04 > 0:17:08You see, during the night, temperatures had reached minus ten,
0:17:08 > 0:17:10not unusual in itself.
0:17:10 > 0:17:13But, this combined with winds gusting across the lake
0:17:13 > 0:17:16at 60 miles an hour, had produced something extraordinary.
0:17:16 > 0:17:19The whipped-up waves and spray, hitting the quayside
0:17:19 > 0:17:23on the south-western shore, simply froze on the spot.
0:17:23 > 0:17:28And the results were nothing short of wondrous.
0:17:29 > 0:17:32It was a good week before the ice thawed
0:17:32 > 0:17:36and freed the entombed trees, benches and cars.
0:17:41 > 0:17:45This was a true one-off event for the residents of Versoix.
0:17:45 > 0:17:48A little bit of magic in the middle of winter,
0:17:48 > 0:17:51something none of them would ever forget.
0:17:53 > 0:17:58Incredible images. Haunting, like a vision from a Grimms' fairy tale.
0:17:58 > 0:18:02But if those images chilled you, our second weird weather event
0:18:02 > 0:18:04will have you gasping.
0:18:04 > 0:18:06We're heading, now, to Australia,
0:18:06 > 0:18:10to its largest and most famous city - Sydney.
0:18:10 > 0:18:13On 23rd September 2009,
0:18:13 > 0:18:17what happened to Sydney amazed the world
0:18:17 > 0:18:20because it, literally, changed colour overnight.
0:18:25 > 0:18:28That morning, everything was drenched in red.
0:18:28 > 0:18:30It was almost like the colour of blood.
0:18:30 > 0:18:33And I could see that it was throughout the city.
0:18:33 > 0:18:35From his high-rise apartment,
0:18:35 > 0:18:38Jonathan Berry had a ringside seat on these incredible events.
0:18:38 > 0:18:42It was completely even. It was almost as if
0:18:42 > 0:18:45I was on Mars.
0:18:45 > 0:18:49It was very still, there was no wind and I couldn't taste it
0:18:49 > 0:18:52and I couldn't touch it and I couldn't smell it. There was nothing.
0:18:52 > 0:18:54Ten past six in the morning
0:18:54 > 0:18:59and it's September 23rd 2009.
0:18:59 > 0:19:02Sydney-siders grabbed their cameras and phones
0:19:02 > 0:19:04and recorded the surreal scenes.
0:19:04 > 0:19:07This is unbelievable.
0:19:08 > 0:19:10Absolutely amazing.
0:19:11 > 0:19:146:30 in the morning. Look at this.
0:19:19 > 0:19:23I woke up and I was, like, what is going on?
0:19:23 > 0:19:25This is like the Apocalypse
0:19:25 > 0:19:28or it's like Armageddon has actually hit Earth, you know.
0:19:28 > 0:19:31It was just out of this world, it really was.
0:19:31 > 0:19:36Nate Johnston documented a bizarre commute to work.
0:19:36 > 0:19:38This is seven o'clock in the morning.
0:19:40 > 0:19:43It was really eerie.
0:19:43 > 0:19:46I catch the same ride, you know all the scenery and not being able
0:19:46 > 0:19:50to see what's in front of you, yeah, it was almost a bit freaky.
0:19:50 > 0:19:527:20.
0:19:55 > 0:19:58The fact that the visibility was reduced to about 15,
0:19:58 > 0:20:0020 metres in front of you.
0:20:00 > 0:20:02I couldn't even see the Harbour Bridge
0:20:02 > 0:20:06until we were practically under it. It was really weird.
0:20:06 > 0:20:08What had happened?
0:20:08 > 0:20:12How did Sydney become like the surface of Mars overnight?
0:20:16 > 0:20:20Well, the answer lay 2,500 kilometres away,
0:20:20 > 0:20:23deep in the heart of Australia's outback.
0:20:26 > 0:20:30Dust. Iron rich and deep red.
0:20:30 > 0:20:34This is what had caused Sydney's extraordinary transformation.
0:20:35 > 0:20:39Here, dust storms are just part of life,
0:20:39 > 0:20:43but this event was, really, on a totally different scale.
0:20:43 > 0:20:46Hardened Aussie, John White, has experienced
0:20:46 > 0:20:48most of what the outback had to throw at him.
0:20:48 > 0:20:53The dust storms that I normally come across are fairly short-lived
0:20:53 > 0:20:55and you can see them coming.
0:20:55 > 0:20:59There's normally a beautiful, blue sky and then you can see
0:20:59 > 0:21:01the dust storm coming towards you.
0:21:01 > 0:21:05It comes through, maybe a half hour or so, it's there.
0:21:05 > 0:21:07And then, sometimes, you get a bit of rain and then it clears up.
0:21:07 > 0:21:12While crossing a track, he had an accident at just the wrong time.
0:21:14 > 0:21:18Shortly after, a storm, unlike anything he'd ever seen before,
0:21:18 > 0:21:21overwhelmed his stricken vehicle.
0:21:23 > 0:21:25The wind was absolutely atrocious.
0:21:25 > 0:21:29The airborne sand, you couldn't stand up in it.
0:21:29 > 0:21:32It was coming into your skin, even with my big beard,
0:21:32 > 0:21:35you could feel it on your skin.
0:21:35 > 0:21:37It was absolutely horrendous.
0:21:38 > 0:21:41Atmospheric scientist, Craig Strong,
0:21:41 > 0:21:45is an avid connoisseur of dust storms.
0:21:45 > 0:21:48I reckon a good dust storm is one you can taste.
0:21:48 > 0:21:51You know, so, you can taste it in your mouth,
0:21:51 > 0:21:52you can roll it in your teeth.
0:21:52 > 0:21:56And you can say, yeah that's about ten microns in size.
0:21:56 > 0:21:58You know, that's a good dust storm for me.
0:21:58 > 0:22:00Craig predicted its arrival.
0:22:00 > 0:22:03He'd been watching events conspire over the weeks
0:22:03 > 0:22:06and months leading to the storm.
0:22:06 > 0:22:08We had floods in January, bringing sediment
0:22:08 > 0:22:11into the inland parts of Australia.
0:22:13 > 0:22:18We had droughts in the arid and the semi-arid areas of Australia,
0:22:18 > 0:22:21putting the vegetation cover under stress.
0:22:23 > 0:22:27And then, we had a really intense cold front move through,
0:22:27 > 0:22:30which created very strong winds.
0:22:32 > 0:22:33All the conditions were right
0:22:33 > 0:22:35to produce an incredibly large dust storm.
0:22:35 > 0:22:4016 million tonnes of frenzied dust
0:22:40 > 0:22:43was now being whipped into the air.
0:22:43 > 0:22:44At the height of the storm,
0:22:44 > 0:22:49visibility where I was, round the track, was less than a metre.
0:22:49 > 0:22:52And if I had have walked over the sand dune,
0:22:52 > 0:22:55I can just about guarantee I would never have found my way back
0:22:55 > 0:22:56to the truck.
0:23:01 > 0:23:04At source area, the wind speeds were up around about,
0:23:04 > 0:23:08they varied from 70 to 90 kilometres per hour.
0:23:10 > 0:23:12It feels like sandpaper.
0:23:12 > 0:23:15I had my beard pulled up over my nose
0:23:15 > 0:23:19and eyes and just trying to protect my face when I was out in it.
0:23:19 > 0:23:23Yeah. It was unbelievable.
0:23:23 > 0:23:27This was the mother of all dust storms.
0:23:27 > 0:23:31600 miles long and 300 miles wide.
0:23:31 > 0:23:36A monstrous cloud the size of Spain rolling across Australia.
0:23:36 > 0:23:39As it travelled across the country,
0:23:39 > 0:23:44stunned Australians recorded the incredible spectacle.
0:23:44 > 0:23:45'Absolutely amazing.'
0:23:50 > 0:23:55- 'It's not moving.- I can't believe it's just coming across.
0:23:55 > 0:23:57- 'Yeah, I'm recording it.- OK.'
0:24:01 > 0:24:02- 'Holy- BLEEP.'
0:24:09 > 0:24:12'It's going to get really dark soon, isn't it?'
0:24:13 > 0:24:16What was amazing about the amount of dust we were seeing
0:24:16 > 0:24:19was just how dense the dust was, you know.
0:24:19 > 0:24:24The visibilities were roughly about one kilometre.
0:24:24 > 0:24:28Now, to put that into context, you would have to go
0:24:28 > 0:24:30to the source areas, normally,
0:24:30 > 0:24:32to get that sort of level of dust concentration.
0:24:33 > 0:24:37'It just got blacker.
0:24:37 > 0:24:40'Oh, my gosh. I think we better go inside.
0:24:41 > 0:24:43- 'Yeah.- Oh, that is horrible.'
0:24:43 > 0:24:47When it reached Sydney, less than 24 hours later,
0:24:47 > 0:24:50the intensity of the storm stunned everybody.
0:24:50 > 0:24:55From country to city, people woke up this morning to an eerie, red haze,
0:24:55 > 0:24:57the likes of which many had never seen before.
0:24:57 > 0:24:59It was all due to a dust storm.
0:24:59 > 0:25:04Everything is red. So, if you look around the streets, it's just red.
0:25:04 > 0:25:07I mean, this isn't some sort of camera error.
0:25:07 > 0:25:09I mean, that's what everything looks like.
0:25:09 > 0:25:11Do you know the thing?
0:25:11 > 0:25:15Radio stations keep playing music that's related to dust.
0:25:15 > 0:25:17So, we have Dusty Springfield
0:25:17 > 0:25:21and Slim Dusty all blaring over the radio this morning.
0:25:21 > 0:25:27MUSIC: "I Just Don't Know What To Do With Myself" by Dusty Springfield
0:25:27 > 0:25:30Dust storms are not unusual in Australia.
0:25:30 > 0:25:34But this was by far the biggest since records had begun.
0:25:34 > 0:25:40It had also travelled the furthest and caused the most disruption.
0:25:40 > 0:25:42It was phenomenal, you know.
0:25:42 > 0:25:46Being able to witness such a phenomenon, it's...
0:25:46 > 0:25:50I don't think I will in my lifetime again, to be honest.
0:25:53 > 0:25:55I've never seen anything like this at all.
0:25:55 > 0:25:58I know that there are dust storms in South Australia and Western Australia
0:25:58 > 0:26:02and in the centre, but that's a long, long way away from Sydney.
0:26:05 > 0:26:09Being here when the dust storm rolled through was really...
0:26:09 > 0:26:13it was quite a privilege, you know, it was really quite exciting.
0:26:15 > 0:26:18We now realise that we're actually sitting on the edge
0:26:18 > 0:26:21of a very large desert and we can, as city dwellers,
0:26:21 > 0:26:24be impacted by these very large dust storms.
0:26:30 > 0:26:33To realise that I was out in the start of that...
0:26:35 > 0:26:41..it was amazing to think that, where I was, that storm went that far.
0:26:41 > 0:26:43Yeah, it was absolutely phenomenal.
0:26:46 > 0:26:50So, that dust had travelled 1,500 miles from Sydney.
0:26:50 > 0:26:53But, you know what, our nearest desert, the Sahara,
0:26:53 > 0:26:56is the same distance away.
0:26:56 > 0:27:00Once in a while, an easterly wind will blow a sand storm out
0:27:00 > 0:27:03into the Atlantic, where a westerly wind will pick it up
0:27:03 > 0:27:06and blow the dust to the UK.
0:27:06 > 0:27:09So, although we don't get storms of that magnitude,
0:27:09 > 0:27:14even here in the UK, the Sahara Desert makes itself felt.
0:27:14 > 0:27:18And we can see it. Dust all over our cars.
0:27:20 > 0:27:24Now, one-off, weird weather episodes like these are awe-inspiring.
0:27:24 > 0:27:30But a 2011 report on climate change predicts that there's going to be
0:27:30 > 0:27:35an increase in what they're calling "unprecedented extreme weather".
0:27:35 > 0:27:39So, as atmospheric conditions become more erratic, amazing events,
0:27:39 > 0:27:44like those in Versoix and Sydney, may well become more frequent.
0:27:48 > 0:27:52Now, the next weird events we're going to bring you
0:27:52 > 0:27:56have unusual weather as their root cause with results that are,
0:27:56 > 0:27:59for many, the stuff of nightmares.
0:27:59 > 0:28:02It's plagues and swarms.
0:28:02 > 0:28:05From the beetle invasion on a remote Colorado mountain
0:28:05 > 0:28:10to a plague truly the size of Wales, creating havoc in its wake.
0:28:12 > 0:28:16We're back in Australia with an animal hated by humans
0:28:16 > 0:28:17the world over.
0:28:20 > 0:28:24It's 1993 on a farm in southern Australia
0:28:24 > 0:28:28and a desperate farmer is battling a mouse plague
0:28:28 > 0:28:30of biblical proportions.
0:28:30 > 0:28:33Oh, they're in my boots. Oh!
0:28:33 > 0:28:35She's determined to save the pigs
0:28:35 > 0:28:40she knows are besieged in the shed by hundreds of thousands of mice.
0:28:40 > 0:28:41Oh, yuck. Oh.
0:28:43 > 0:28:45Mice which are so desperate for food,
0:28:45 > 0:28:49they're literally trying to eat her pigs alive.
0:28:57 > 0:29:00That was 18 years ago
0:29:00 > 0:29:04and set a world record for the worst mouse plague ever recorded.
0:29:04 > 0:29:09But, unfortunately, for farmers all across southern Australia,
0:29:09 > 0:29:112011 is looking like it's going to be
0:29:11 > 0:29:15another terrible year for mice.
0:29:15 > 0:29:19New crops have been devoured across South Australia, Victoria
0:29:19 > 0:29:23and Western Australia in the worst mouse plague in almost two decades.
0:29:23 > 0:29:26Ian Cass from Loxton, South Australia...
0:29:27 > 0:29:30..is on the front line of this latest plague.
0:29:32 > 0:29:35He keeps 650 sheep on his farm.
0:29:35 > 0:29:38Feeding that many animals keeps him busy enough.
0:29:40 > 0:29:44The problem for Ian is that he's also, inadvertently,
0:29:44 > 0:29:48feeding millions of tiny mouths.
0:29:52 > 0:29:54Oh!
0:29:54 > 0:29:55We've tried poisoning them.
0:29:55 > 0:29:58We've tried all sorts to try and cut their numbers.
0:29:58 > 0:30:01Over here, quick. Look in here.
0:30:05 > 0:30:07Death by numbers in here.
0:30:10 > 0:30:14Nothing works. We can't beat them. We've killed millions.
0:30:14 > 0:30:18But we can't beat them. They're are a nightmare.
0:30:18 > 0:30:19Oh, yuck.
0:30:21 > 0:30:22And here are the stats.
0:30:22 > 0:30:26A mouse eats up to a third of its body weight every day.
0:30:26 > 0:30:27That's about eight grammes.
0:30:27 > 0:30:30Not a lot, you might think, but when you multiply that
0:30:30 > 0:30:33by the estimated half a million plus mice
0:30:33 > 0:30:36which are living on Ian's farm, they could consume
0:30:36 > 0:30:41one and a half metric tonnes of grain every 24 hours.
0:30:43 > 0:30:46In this part of South Australia, they've been used to mouse plagues,
0:30:46 > 0:30:47every six years or so.
0:30:47 > 0:30:50But, recently, it's been more like every four.
0:30:50 > 0:30:55Not surprisingly, they seem to tie in with years
0:30:55 > 0:30:57when there's a bumper harvest.
0:30:57 > 0:31:01But this is not the whole story. Greg Mutsy is a pest expert.
0:31:01 > 0:31:04He's been studying Australia's mouse plagues
0:31:04 > 0:31:06and is shocked at recent events.
0:31:06 > 0:31:07It's been very severe
0:31:07 > 0:31:11and the population densities in the paddocks have been terrifically high.
0:31:11 > 0:31:14Perhaps, a thousand mice per hectare across vast areas.
0:31:14 > 0:31:18There would be fewer than ten per hectare when things are normal.
0:31:18 > 0:31:21Now, there's more than 100 times that number.
0:31:21 > 0:31:25Mice have a fairly well-defined seasonal breeding pattern.
0:31:25 > 0:31:30They start breeding when the crops mature in September, October.
0:31:30 > 0:31:32They breed until the crops are harvested.
0:31:32 > 0:31:36Then, they feed on whatever grain is spilled at harvest.
0:31:36 > 0:31:38At that time, they run out of food, they stop breeding.
0:31:38 > 0:31:40They usually have a population crash.
0:31:40 > 0:31:43Greg thinks that part of the problem is that changes
0:31:43 > 0:31:45in the way farmers grow and manage their crops now mean
0:31:45 > 0:31:48there's more food left in the fields
0:31:48 > 0:31:51during, what should be, the lean times.
0:31:51 > 0:31:56So, why was 2011 such a bumper year for the mice?
0:31:56 > 0:31:58This last season, we had a fantastic season.
0:31:58 > 0:32:01We had above-average rainfall and exceptional, exceptional crops.
0:32:01 > 0:32:04It was really good.
0:32:04 > 0:32:08There was plenty to eat and this, combined with a mild winter,
0:32:08 > 0:32:11meant perfect conditions to kick-start a plague.
0:32:14 > 0:32:15They can breed at six weeks of age
0:32:15 > 0:32:19and pump out a litter of about six every three weeks.
0:32:19 > 0:32:22And, usually, very few of them survive.
0:32:22 > 0:32:26But, during these mouse plagues, because of the abundance of food
0:32:26 > 0:32:28and the fact that they outnumber the predators so vastly,
0:32:28 > 0:32:31you get much higher juvenile survival.
0:32:31 > 0:32:35And the rate of increase in the populations is dramatically higher.
0:32:35 > 0:32:37- Oh.- BLEEP.
0:32:37 > 0:32:40Now, mouse plagues are strange enough in themselves,
0:32:40 > 0:32:44but there is something particularly weird about them.
0:32:44 > 0:32:47The strange things about house mice is that, although they've got
0:32:47 > 0:32:51almost a global distribution now, the only places where they cause
0:32:51 > 0:32:56these massive mouse plagues appear to be in Australia and in Western China.
0:32:57 > 0:32:59So, let's get this straight.
0:32:59 > 0:33:02There are house mice all over the world.
0:33:02 > 0:33:04But what's extraordinary is that they're only plaguing
0:33:04 > 0:33:06in two countries.
0:33:06 > 0:33:09Why? Why would this be happening?
0:33:13 > 0:33:15The reasons are still a mystery,
0:33:15 > 0:33:18but, in Australia, it could be partly due to the fact
0:33:18 > 0:33:21that house mice are an invasive species,
0:33:21 > 0:33:26introduced by European settlers in the late 1700's.
0:33:29 > 0:33:34Back home, they're a key component of a long-established ecosystem.
0:33:34 > 0:33:39And they provide food for some of our most iconic hunters.
0:33:43 > 0:33:47But, here in Australia, they have few natural predators
0:33:47 > 0:33:50and little direct competition from the local wildlife.
0:33:50 > 0:33:54So, when conditions are right, nothing can stop them.
0:33:54 > 0:33:57Except, perhaps, man.
0:33:57 > 0:34:01Mouse plagues have become a part of the landscape in Australia
0:34:01 > 0:34:04and have been for a long, long time.
0:34:04 > 0:34:07Well, there was a massive mouse plague in 1917.
0:34:07 > 0:34:09Three and a half tonnes of mice
0:34:09 > 0:34:13that were captured in one night around a single grain stack
0:34:13 > 0:34:17in Western Victoria during that period.
0:34:18 > 0:34:21These days, there isn't the manpower to kill them by hand
0:34:21 > 0:34:24and Ian has to resort to poison.
0:34:24 > 0:34:27Now, I'm never keen on killing animals but here, I have to admit,
0:34:27 > 0:34:29there really isn't much choice.
0:34:29 > 0:34:32I estimate, and it's only my estimation,
0:34:32 > 0:34:36that we'd have to have killed well over a million out here already.
0:34:36 > 0:34:39You're, sort of, starting to see
0:34:39 > 0:34:42bodies starting to appear on the ground.
0:34:46 > 0:34:49But there are some unpleasant side-effects.
0:34:50 > 0:34:54How do you describe the smell of a million dead mice? It stinks.
0:34:56 > 0:35:02The events of 2011 have equalled Australia's worst-ever mouse plague.
0:35:02 > 0:35:05They're munching their way through
0:35:05 > 0:35:08an estimated billion dollars of grain.
0:35:08 > 0:35:11Horrific times, there, for those Australian farmers,
0:35:11 > 0:35:15but I have to tell you, things are very different in the UK
0:35:15 > 0:35:17when it comes to house mice like these.
0:35:17 > 0:35:21You see, they've been so relentlessly persecuted by man
0:35:21 > 0:35:24that they're no longer very common.
0:35:24 > 0:35:27So, if you have a mouse in the house these days,
0:35:27 > 0:35:28it's far more likely to be a wood mouse
0:35:28 > 0:35:31that's come in from the garden.
0:35:31 > 0:35:33You can tell them apart easily.
0:35:33 > 0:35:37Wood mice have much larger eyes, larger ears, a longer tail
0:35:37 > 0:35:40and they're perfectly white on their underside.
0:35:40 > 0:35:45So, whilst they are plaguing in Australia, in UK homes,
0:35:45 > 0:35:48house mice are in short supply.
0:35:50 > 0:35:53For our next weird animal event, we feature a little creature
0:35:53 > 0:35:57with an altogether more endearing public image.
0:36:00 > 0:36:02The colourful, little ladybird.
0:36:05 > 0:36:10Loved by gardeners because of their enormous appetite for aphids.
0:36:11 > 0:36:16Their popularity is reflected in their collective name -
0:36:16 > 0:36:19a loveliness of ladybirds!
0:36:21 > 0:36:24But, in America in 2009,
0:36:24 > 0:36:28visitors to the mountains of Colorado were confronted with this.
0:36:28 > 0:36:32We came upon a tree that looks like it has red bark.
0:36:32 > 0:36:36Only thing is, that ain't red bark.
0:36:36 > 0:36:37It's certainly not.
0:36:37 > 0:36:42And not so much a loveliness, more of a smothering scarlet-ness.
0:36:42 > 0:36:45Tens of millions of these little, crimson beetles were crawling
0:36:45 > 0:36:48all over the trees and plants.
0:36:48 > 0:36:50Visitors and residents, alike, were confused
0:36:50 > 0:36:54by the sheer scale of the ladybird invasion.
0:36:54 > 0:36:56Oh, my God, they are everywhere.
0:36:56 > 0:37:00They're going to start attacking us. This is unbelievable.
0:37:00 > 0:37:04You can see them all over here, covering the trees, the rocks.
0:37:04 > 0:37:07Looks like somebody's just taken a bucket of tomato juice
0:37:07 > 0:37:09and splashed everything.
0:37:09 > 0:37:13From the mountains of California to the Rockies of Colorado,
0:37:13 > 0:37:16it's normal to see ladybirds gathering together in August
0:37:16 > 0:37:18to mate and then to hibernate.
0:37:21 > 0:37:25But this gathering was on an unprecedented scale.
0:37:25 > 0:37:26So, what was going on?
0:37:28 > 0:37:32Well, it turns out that 2009 was a red-letter year
0:37:32 > 0:37:36for these colourful, little members of the beetle family.
0:37:38 > 0:37:41A wet spring followed by a soggy summer,
0:37:41 > 0:37:43meant a bumper year for aphids.
0:37:43 > 0:37:47These tiny insects reproduce at an alarming rate.
0:37:47 > 0:37:53And more of this ladybird food means more ladybirds, lots more ladybirds.
0:37:53 > 0:37:59By 2009, in August, ladybird numbers had reached astonishing levels.
0:37:59 > 0:38:03The resulting massive mating and hibernation gatherings
0:38:03 > 0:38:06were truly a unique and wonderful spectacle.
0:38:08 > 0:38:11But the next weird gathering of insects is not so benign.
0:38:11 > 0:38:15In fact, it's one of the most destructive forces
0:38:15 > 0:38:17in the invertebrate world.
0:38:17 > 0:38:19We're back in Australia,
0:38:19 > 0:38:23where, in 2010, the country was hit by a plague,
0:38:23 > 0:38:27which was both uncontrollable and unstoppable.
0:38:27 > 0:38:30Swarms of locusts are sweeping across rural areas
0:38:30 > 0:38:32in the Australian state of New South Wales.
0:38:32 > 0:38:38Up to one billion locusts in a swarm, moving over an area
0:38:38 > 0:38:43twice the size of the UK, were sweeping across
0:38:43 > 0:38:46parts of southern Australia and creating mayhem.
0:38:48 > 0:38:51Ow, ow, ow, ow.
0:38:54 > 0:38:58My friends and I, just, we saw this big, well, it was kind of
0:38:58 > 0:39:01a brown cloud and we thought, like, it was going to rain or something.
0:39:01 > 0:39:03But we stepped outside and, like,
0:39:03 > 0:39:06we stuck our hands in it and there were just locusts.
0:39:06 > 0:39:10At Irymple Primary School near the outback town of Mildura,
0:39:10 > 0:39:15the kids were enjoying their playtime when the swarm hit.
0:39:15 > 0:39:18There were millions.
0:39:18 > 0:39:20100 million.
0:39:20 > 0:39:21Billions.
0:39:21 > 0:39:23Probably trillions.
0:39:25 > 0:39:26Like, lots of them.
0:39:27 > 0:39:29It just felt disgusting.
0:39:29 > 0:39:33Mostly all the girls were just, "Aaaah."
0:39:33 > 0:39:37But it wasn't just the kids whose playtime was being disrupted
0:39:37 > 0:39:39by the millions of winged visitors.
0:39:39 > 0:39:42Local sporting clubs are at their wits' end too
0:39:42 > 0:39:46as the interlopers crowd their bowling greens and fairways.
0:39:46 > 0:39:48From tennis courts to golfing greens,
0:39:48 > 0:39:51anywhere with a bit of grass was fair game.
0:39:51 > 0:39:53In Mildura,
0:39:53 > 0:39:58the local football team were forced to take on two different opponents.
0:40:00 > 0:40:03But, whilst the locusts were causing chaos in the town,
0:40:03 > 0:40:06it was altogether more serious out among the farms.
0:40:06 > 0:40:09Here, the locusts were not just an inconvenience,
0:40:09 > 0:40:13they were a devastating force.
0:40:13 > 0:40:17Professor Simpson is one of the world's leading experts on locusts
0:40:17 > 0:40:20and knows all about their destructive power.
0:40:20 > 0:40:24They eat, each day, about their own body weight in food.
0:40:24 > 0:40:29And when you multiply that single locust by hundreds of millions
0:40:29 > 0:40:33or billions, you can get the sort of devastation that we see.
0:40:34 > 0:40:36But what's really weird about locusts is
0:40:36 > 0:40:41that they all start life as a harmless, little grasshopper,
0:40:41 > 0:40:45one who shuns company and prefers a solitary life.
0:40:46 > 0:40:49It's true. They prefer to be on their own.
0:40:52 > 0:40:54So, what could possibly change them
0:40:54 > 0:40:59from shy singleton into a veracious, gregarious plague insect?
0:41:02 > 0:41:05When conditions favour a large build-up in population,
0:41:05 > 0:41:10for example, after rain, and then they get brought together by food
0:41:10 > 0:41:16and their environment, they flip from being shy, solitary animals
0:41:16 > 0:41:20into being actively aggregating, potentially swarm-forming creatures.
0:41:20 > 0:41:23And we wanted to know why do they do that and how do they do that.
0:41:23 > 0:41:25That's the key to being a locust,
0:41:25 > 0:41:27rather than being a normal grasshopper.
0:41:27 > 0:41:31The prof had a theory that it was something to do with being
0:41:31 > 0:41:33in close contact with other locusts.
0:41:33 > 0:41:37And so, they set about testing this theory in a rather unusual way.
0:41:37 > 0:41:40So, we sat for many, many hours in hot rooms,
0:41:40 > 0:41:43tickling locusts on different body parts with a paint brush.
0:41:43 > 0:41:47And then, measuring their behavioural change as a result of that.
0:41:47 > 0:41:53And we found that touch alone can cause a locust to switch,
0:41:53 > 0:41:55very quickly, into the swarming form.
0:41:55 > 0:41:58They found that the touching releases a hormone
0:41:58 > 0:42:02similar to serotonin, which we associate with pleasure.
0:42:02 > 0:42:07And it's this which triggers the change from grasshopper to locust.
0:42:08 > 0:42:12But our locust are just wingless hoppers at the moment.
0:42:14 > 0:42:19And they move across the country as a kind of marching, hopping army.
0:42:25 > 0:42:29After five weeks, their wings are finally ready.
0:42:34 > 0:42:37So, now, the locusts can take to the air
0:42:37 > 0:42:40and are capable of covering vast distances.
0:42:43 > 0:42:48And, for the farmers, this is the start of the real nightmare.
0:42:48 > 0:42:52These airborne swarms have become unstoppable eating
0:42:52 > 0:42:53and breeding machines.
0:42:53 > 0:42:56And, frankly, nowhere is safe.
0:42:56 > 0:43:00On the outskirts of Mildura, farmer Terry Bavidas
0:43:00 > 0:43:04had everything to lose as the swarm approached his farm.
0:43:08 > 0:43:10We'd had a very good start to the season.
0:43:10 > 0:43:13My hay was about six inches high.
0:43:14 > 0:43:18I came home about ten o'clock one morning for a cup of coffee.
0:43:18 > 0:43:23And I walked outside and there was just this humongous plague
0:43:23 > 0:43:28of locusts just outside and I didn't know where they'd come from.
0:43:28 > 0:43:32And I knew straight away my crop was going to be decimated.
0:43:32 > 0:43:38There was about five or six locusts hanging off each strand of hay.
0:43:38 > 0:43:43By four o'clock that afternoon, they had decimated about 12 acres.
0:43:43 > 0:43:45It's just not funny at all.
0:43:45 > 0:43:49But Terry wasn't going to get mad, he was going to get even.
0:43:49 > 0:43:53A friend of mine had found an exhaust fan out of a paint shop
0:43:53 > 0:43:57and I've got it rotating at 290 kilometres an hour.
0:43:57 > 0:44:01I had to pinch the kids' go-kart motor to do it.
0:44:01 > 0:44:04Terry had created the Locust Muncher.
0:44:06 > 0:44:09And it was payback time.
0:44:09 > 0:44:12I was getting rids of hundreds, hundreds per second.
0:44:12 > 0:44:13I couldn't tell you how many.
0:44:15 > 0:44:18A friend of mine, Mickey, called me the Nutty Professor.
0:44:18 > 0:44:21Every single person that went past laughed their head off.
0:44:21 > 0:44:23So, hey, it works.
0:44:23 > 0:44:27Terry's Mad Max solution might have helped to save some of his crops,
0:44:27 > 0:44:31but the plague continued, moving relentlessly across the country,
0:44:31 > 0:44:36gobbling up field after field of precious crops.
0:44:37 > 0:44:39Meanwhile, back at Sydney University,
0:44:39 > 0:44:41Professor Simpson had made a remarkable
0:44:41 > 0:44:46discovery about what was driving their insatiable appetite.
0:44:46 > 0:44:50The locusts were actually craving protein.
0:44:50 > 0:44:53And the nearest source of protein,
0:44:53 > 0:44:55within a locust swarm,
0:44:55 > 0:44:58is the locust in front of you.
0:44:58 > 0:45:05So, cannibalism drives mass migration in these swarms.
0:45:06 > 0:45:09They're on a forced march, if you like,
0:45:09 > 0:45:11to avoid being someone else's lunch,
0:45:11 > 0:45:14but chasing the lunch in front of them.
0:45:14 > 0:45:17The cannibalistic tendencies of these insects did little
0:45:17 > 0:45:20to endear them to the residents of Mildura,
0:45:20 > 0:45:24who were capturing their locust encounters on camera.
0:45:24 > 0:45:28- Driving and it's hard to tell the road from the locusts.- Yeah.
0:45:31 > 0:45:35My mum hated that because she'd have to get a car wash,
0:45:35 > 0:45:38like, once a week cos of those locusts.
0:45:38 > 0:45:39The dogs liked them.
0:45:39 > 0:45:44Cos when they splattered on the car they just licked them off.
0:45:44 > 0:45:50Australia's 2010 locust plague lasted 12 long months.
0:45:50 > 0:45:53It covered 190 thousand square miles.
0:45:53 > 0:45:56And, apart from the inconvenience,
0:45:56 > 0:46:01it was estimated that it cost farmers two billion dollars.
0:46:03 > 0:46:07It's not surprising those locusts cover such vast distances.
0:46:07 > 0:46:12What more motivation would you need than your nearest neighbour arriving
0:46:12 > 0:46:14and then turning cannibal to eat you?
0:46:14 > 0:46:16We'd all move on, wouldn't we?
0:46:16 > 0:46:21The trigger for all of these plagues was an abundance of food.
0:46:21 > 0:46:24The mice benefited from a record harvest.
0:46:24 > 0:46:26For the ladybirds, it was a wet spring
0:46:26 > 0:46:29that meant huge amounts of aphids.
0:46:29 > 0:46:34And the locust benefited from a bumper start to the growing season.
0:46:34 > 0:46:39When these tiny creatures mass together, they become greater
0:46:39 > 0:46:42than the sum of their parts, often with dramatic results.
0:46:43 > 0:46:47For our final weird events, we're heading down to the beach,
0:46:47 > 0:46:51where we'll be seeing what happens when sea creatures end up
0:46:51 > 0:46:54in the wrong place at the wrong time.
0:46:54 > 0:46:57From the crabs that were found in their tens of thousands
0:46:57 > 0:46:59on a UK beach,
0:46:59 > 0:47:03to the baffling event involving 200 whales in Tasmania.
0:47:05 > 0:47:08But we start in the UK,
0:47:08 > 0:47:12where, in 2010, visitors to a West Country beach were greeted
0:47:12 > 0:47:15with a scene of total devastation.
0:47:17 > 0:47:22Starfish were lying dead in their thousands,
0:47:22 > 0:47:24for no apparent reason.
0:47:26 > 0:47:30These familiar sea creatures are not actually fish at all.
0:47:30 > 0:47:34They're echinoderms, related to sea urchins.
0:47:34 > 0:47:38So, they're unable to survive for long out of the water.
0:47:41 > 0:47:47But what on Earth caused this many to wash up, dead, on a single beach?
0:47:47 > 0:47:51The answer lay in an unfortunate combination of events.
0:47:51 > 0:47:54You see, the starfish had just been mating.
0:47:54 > 0:47:58Each female produces up to 65 million eggs in a season
0:47:58 > 0:48:01and they prefer to do this in shallow water.
0:48:03 > 0:48:06The starfish were weakened after breeding
0:48:06 > 0:48:10and a nasty Atlantic storm simply washed them up onto the beach.
0:48:10 > 0:48:12Battered and exhausted,
0:48:12 > 0:48:15they were unable to make their way back into the sea.
0:48:15 > 0:48:18So, they dried out and died.
0:48:18 > 0:48:22The sad result was, actually, totally natural.
0:48:22 > 0:48:25But, nevertheless, was upsetting for everyone who witnessed it.
0:48:28 > 0:48:33Staying in the UK, just ten months later, on January 4th in 2011,
0:48:33 > 0:48:38Thanet in Kent played host to another grisly scene.
0:48:38 > 0:48:42This time, the bodies of 25,000 velvet swimming crabs
0:48:42 > 0:48:44literally carpeted beach.
0:48:46 > 0:48:51Now, there are over 5,000 different species of crab in the world.
0:48:52 > 0:48:55They all use gills to breathe.
0:48:55 > 0:48:58But some can live on land as well as in the sea.
0:49:00 > 0:49:04But velvet swimmers are strictly underwater species.
0:49:04 > 0:49:08And being on the beach is a death sentence.
0:49:08 > 0:49:12So, why on Earth did thousands end up like fish out of water,
0:49:12 > 0:49:15lying dead all over the beach?
0:49:15 > 0:49:18Well, unlike the poor, old starfish,
0:49:18 > 0:49:22the answer lay not below the water, but above it.
0:49:23 > 0:49:27Britain was in the grip of an unusually cold winter
0:49:27 > 0:49:30and the weather was having a chilling effect on the ocean too.
0:49:30 > 0:49:34The crabs simply couldn't cope with the severe cold
0:49:34 > 0:49:36and died of hypothermia.
0:49:36 > 0:49:41Admittedly, not a pleasant end for them, but it was a lifeline
0:49:41 > 0:49:45for the seabirds who were also suffering in the cold temperatures.
0:49:45 > 0:49:49Fortunately, for both the starfish and the velvet swimming crabs,
0:49:49 > 0:49:51numbers recovered very quickly
0:49:51 > 0:49:55and there were no long-lasting effects on their species.
0:49:57 > 0:49:59For our final weird event,
0:49:59 > 0:50:03we're heading into uncharted waters with some much-loved creatures
0:50:03 > 0:50:06whose lives hold so much fascination for us,
0:50:06 > 0:50:09but also many mysteries too.
0:50:14 > 0:50:17Whales are found in every ocean on the planet.
0:50:17 > 0:50:21The size of their brains rivals that of primates.
0:50:21 > 0:50:24These are complex creatures, which have evolved to navigate
0:50:24 > 0:50:27our seas and make epic migrations.
0:50:29 > 0:50:33So, why on Earth would such an animal do this?
0:50:37 > 0:50:41'The Northern bottlenose whale remains some distance up river.
0:50:41 > 0:50:45'The time for rescue teams to move in is getting ever closer.'
0:50:45 > 0:50:49January 19th 2006 and all eyes were on London
0:50:49 > 0:50:53as a Northern bottlenose whale turned up in the Thames.
0:50:53 > 0:50:54Rescuers battling to save
0:50:54 > 0:50:56the whale stranded in the Thames
0:50:56 > 0:50:59say the next few hours will be critical to its survival.
0:50:59 > 0:51:02This creature would normally be found in the depths
0:51:02 > 0:51:04of the North Atlantic.
0:51:04 > 0:51:08So, what was it doing in the middle of our capital city?
0:51:08 > 0:51:11It's likely that this young adult had simply got lost
0:51:11 > 0:51:13and was trying to reach Atlantic waters.
0:51:13 > 0:51:17But heading west up the Thames wasn't going to get it anywhere.
0:51:17 > 0:51:21Rescuers eventually stepped in and winched the distressed
0:51:21 > 0:51:24and exhausted whale onto a barge.
0:51:24 > 0:51:27We're now moving it out into the centre of the Thames.
0:51:27 > 0:51:28CROWD CHEERS
0:51:28 > 0:51:31The crowd, obviously, is going crazy because it's been a long,
0:51:31 > 0:51:32long ordeal here for the poor creature.
0:51:32 > 0:51:35But, despite their best efforts,
0:51:35 > 0:51:39on the journey back down the Thames, the whale sadly died.
0:51:43 > 0:51:46Now, an individual animal making a mistake is one thing,
0:51:46 > 0:51:48but we are now heading to the Southern Ocean
0:51:48 > 0:51:52and to the island of Tasmania where, in 2009,
0:51:52 > 0:51:57a whole group of whales stranded on a quite horrifying scale.
0:51:57 > 0:52:00Rescuers are, tonight, trying to save the survivors
0:52:00 > 0:52:03from another mass whale stranding in Tasmania.
0:52:05 > 0:52:06It was March 1st
0:52:06 > 0:52:10and almost 200 whales were piled up along the Tasmanian beach.
0:52:10 > 0:52:15These scenes on King Island were horrible.
0:52:15 > 0:52:18Many already lay dead in what was
0:52:18 > 0:52:22one of the largest mass strandings of whales ever recorded.
0:52:22 > 0:52:25Volunteers flooded to the beach
0:52:25 > 0:52:30to try whatever they could to keep the remaining animals alive.
0:52:37 > 0:52:40So, what could possibly cause such creatures to commit,
0:52:40 > 0:52:43what amounts to, mass suicide on the beach?
0:52:46 > 0:52:51What we can say with some certainty is that there are 85 species
0:52:51 > 0:52:55of Cetacean in the world, yet only ten of these regularly strand
0:52:55 > 0:52:59in any numbers. This starts to tell scientists something about
0:52:59 > 0:53:01why these events might happen.
0:53:01 > 0:53:04In the UK, whale rescue is coordinated
0:53:04 > 0:53:09by the British Divers Marine Life Rescue and run by Stephen Marsh.
0:53:09 > 0:53:12One whale species that seems predisposed to stranding,
0:53:12 > 0:53:15to mass stranding, is the pilot whale.
0:53:15 > 0:53:18Pilot whales are called pilot whales because they follow their leader.
0:53:18 > 0:53:21What happens is that they will follow one animal
0:53:21 > 0:53:22wherever that animal goes.
0:53:22 > 0:53:25If that animal has problems and goes up onto a beach,
0:53:25 > 0:53:28the rest of the animals will try to go with it as well.
0:53:30 > 0:53:34The fact that these are highly social animals helps explain
0:53:34 > 0:53:38the large numbers, but it doesn't answer what on Earth causes them
0:53:38 > 0:53:41to go on, what amounts to, a death wish.
0:53:41 > 0:53:44That's where, frankly, it gets complicated.
0:53:44 > 0:53:50There are many theories, but none that could explain every incident.
0:53:52 > 0:53:55But one clue could come from the fact that unites
0:53:55 > 0:53:57all of the species that mass strand.
0:53:57 > 0:54:00They all use echolocation.
0:54:01 > 0:54:05In Tasmania, at the Australian Antarctic Division,
0:54:05 > 0:54:08Nick Gales is a marine mammal specialist,
0:54:08 > 0:54:10who studies whales in the southern waters.
0:54:10 > 0:54:12Effectively, if you like, you could have a group of animals
0:54:12 > 0:54:14that are quite used to living offshore.
0:54:14 > 0:54:17So, they're very, very skilled at living
0:54:17 > 0:54:19beyond the continental shelf of the various continents.
0:54:19 > 0:54:21They feed out there.
0:54:21 > 0:54:23Occasionally, their prey will come in very shallow
0:54:23 > 0:54:25and that brings them into the coast.
0:54:25 > 0:54:27You get storms and it stirs up the water.
0:54:27 > 0:54:29And while it looks very obvious to us,
0:54:29 > 0:54:32standing on the beach, that there's a big beach there,
0:54:32 > 0:54:35if you were to put yourself 50 metres offshore with a face mask on,
0:54:35 > 0:54:36swimming around,
0:54:36 > 0:54:39and not look above the water and get a clear picture,
0:54:39 > 0:54:41it's very easy to get disorientated.
0:54:41 > 0:54:44And, even though these whales have fantastic underwater sonar,
0:54:44 > 0:54:47when it's very rough and there's a lot of sand in the water,
0:54:47 > 0:54:49they're, effectively, semi-blinded.
0:54:49 > 0:54:53Also, with these whales relying on echolocation to navigate,
0:54:53 > 0:54:55the inevitable question is,
0:54:55 > 0:54:59does human activity in our seas have a role to play
0:54:59 > 0:55:01in causing them to come ashore?
0:55:03 > 0:55:05Man has a habit of putting barriers in front of
0:55:05 > 0:55:09a lot of sea creatures and one of those is acoustic pollution.
0:55:09 > 0:55:13This can be caused by military activity, where they're out there
0:55:13 > 0:55:17hunting submarines or using sonar at the same level
0:55:17 > 0:55:20that whales and dolphins are going to be communicating at.
0:55:20 > 0:55:24For them, it must be like sticking your head inside a loudspeaker.
0:55:24 > 0:55:25We're muffling the sound
0:55:25 > 0:55:28and we are creating something that's really going to frighten them.
0:55:28 > 0:55:32But how much blame can be pinned on human activity is debatable,
0:55:32 > 0:55:36because mass strandings have been reported for centuries,
0:55:36 > 0:55:39long before we pumped noise into our oceans.
0:55:41 > 0:55:44Whilst we don't understand all of the reasons they come ashore,
0:55:44 > 0:55:47once they're here, it's a race against time
0:55:47 > 0:55:49to get them back into the water.
0:55:52 > 0:55:56Amongst the volunteers who help rescue whales in Tasmania
0:55:56 > 0:55:58is Kris Carlyon.
0:56:00 > 0:56:03There is a lot of death and that's quite hard to deal with.
0:56:03 > 0:56:07But that one animal that you get back in the water
0:56:07 > 0:56:12and released and successfully watch it swim away, it's pretty special.
0:56:12 > 0:56:16But is returning them to the ocean actually the right thing to do?
0:56:16 > 0:56:20Can they really survive after all of the trauma they've suffered?
0:56:20 > 0:56:26Marine biologist, Rosemary Gales, heads the Tasmanian rescue team.
0:56:26 > 0:56:30And she's done some pioneering work which gives the rescuers hope.
0:56:30 > 0:56:33Over a year ago, we deployed some satellite transmitters
0:56:33 > 0:56:38on some pilot whales that we released up in the northwest of Tasmania.
0:56:38 > 0:56:40And we put five out and then, over the next month, we followed
0:56:40 > 0:56:45those animals via satellite and also followed it up with an aerial survey.
0:56:45 > 0:56:48So, we flew on them. Obviously, with the satellite links
0:56:48 > 0:56:49we knew exactly where they were.
0:56:49 > 0:56:51And it's one of the most exciting things ever
0:56:51 > 0:56:54to have seen them all free-swimming in Bass Strait.
0:56:54 > 0:56:57To actually know that they are OK and they did behave
0:56:57 > 0:57:00like free-swimming whales was... It just vindicated all our efforts.
0:57:00 > 0:57:03It's a fantastic result.
0:57:03 > 0:57:07This groundbreaking study is fantastic news.
0:57:07 > 0:57:10Scientists believe that if a whale can survive the first fortnight
0:57:10 > 0:57:15after a stranding, then the chances of long-term survival are very good.
0:57:15 > 0:57:19And with satellite tags deployed, we can start to learn more
0:57:19 > 0:57:24about the movements and behaviour of these giants, out in the oceans.
0:57:24 > 0:57:28And, perhaps, finally start to unravel some more of the mysteries
0:57:28 > 0:57:30surrounding their lives.
0:57:33 > 0:57:38Whether it's rough seas throwing up weakened starfish onto a beach,
0:57:38 > 0:57:42sub-zero temperatures giving crabs a fatal case of hypothermia,
0:57:42 > 0:57:46or the tragic stranding of 200 pilot whales,
0:57:46 > 0:57:50when things go wrong in the sea, our beaches are often the places
0:57:50 > 0:57:55where we get to unravel the mysteries and pick up the pieces.
0:57:56 > 0:58:00What all of these stories prove is that nature's weirdest events
0:58:00 > 0:58:02still have the power to shock us,
0:58:02 > 0:58:07to stop us in our tracks and have us stare in awe.
0:58:07 > 0:58:10And whilst many of these phenomena are explained,
0:58:10 > 0:58:13many remain a mystery.
0:58:13 > 0:58:16And there is one thing for certain and that is
0:58:16 > 0:58:22that nature still has plenty of surprises just waiting to happen.
0:58:22 > 0:58:25Next time on Nature's Weirdest Events...
0:58:25 > 0:58:29Incredible holes open in the Earth's crust.
0:58:29 > 0:58:31There's a frightening mystery in Arkansas...
0:58:31 > 0:58:37What makes that happen? For them just to drop out of the sky like that.
0:58:37 > 0:58:40..and a massive surge of sea foam
0:58:40 > 0:58:44gives beachgoers a day they'll never forget.
0:58:52 > 0:58:56Subtitles by Red Bee Media Ltd