TEDIndia 2009
Charles Anderson: Dragonflies that fly across oceans
Charles Anderson opdager guldsmede der krydser oceaner
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Mens han boede og arbejdede som marinebiolog på Maldiverne, lagde Charles Anderson mærke til en pludselig eksplosion af guldsmede på bestemte årstider. Han forklarer hvordan han omhyggeligt sporede vejen for en almindelig, lille guldsmed, kaldet globe skimmer, kun for at opdage at den havde den længst trækkende rejse af noget insekt i verden.
Charles Anderson - Marine biologist
Charles Anderson studies marine life in the Maldives, a nation of coral atolls in the Indian ocean. Full bio
Charles Anderson studies marine life in the Maldives, a nation of coral atolls in the Indian ocean. Full bio
Double-click the English transcript below to play the video.
00:15
Actually, I come from Britain,
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Faktisk, kommer jeg fra England,
00:18
but I've been living in Maldives for 26 years now.
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men jeg har boet på Maldiverne i 26 år nu.
00:21
So, that's home really.
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Så, det er virkelig et hjem for mig.
00:23
The Maldives, as I'm sure you're aware, are a chain of islands
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Maldiverne, som jeg er sikker på I er klar over, er en række af øer
00:25
off the southwest coast of India here.
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ud for Indiens sydvestkyst her.
00:27
Capital, Malé, where I live.
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Hovedstaden, Malé, hvor jeg bor.
00:29
Actually, sitting here today in Mysore,
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Faktisk, sidder vi her i dag i Mysore,
00:32
we're closer to Malé than we are to Delhi, for example.
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og er tættere på Malé end vi er på Delhi, for eksempel.
00:36
If you're in IT, India, obviously, is the place to be at the moment.
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Hvis man er indenfor IT, er Indien, selvsagt stedet at være i øjeblikket.
00:39
But if you're a marine biologist, Maldives is not such a bad place to be.
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Men hvis man er marinebiolog, er Maldiverne slet ikke så dårlig et sted at være.
00:42
And it has been my home these years.
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Og det har været mit hjem disse år.
00:44
For those of you who've been there, fantastic coral reefs,
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For jer der har været der, fantastiske koralrev,
00:46
fantastic diving, fantastic snorkeling.
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fantastisk dykning, fantastisk at snorkle.
00:48
I spend as much of my time as possible
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Jeg brugt så meget af min tid som muligt
00:50
investigating the marine life.
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på at undersøge livet i havet.
00:52
I study fish,
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Jeg studerer fisk,
00:54
also the bigger things, whales and dolphins.
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også de større ting, hvaler og delfiner.
00:57
This is a blue whale. We have blue whales
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Dette er en blåhval. Vi har blåhvaler
00:59
in the waters around here, off Maldives,
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i vandene her omkring, ved Maldiverne,
01:02
around the waters of India. You can see them off Kerala.
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rundt om vandene i Indien. Man kan se dem fra Kerala.
01:04
And, in fact, we're very lucky in this region.
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Og, faktisk, er vi meget heldige i denne region.
01:06
One of the best places in the world to see blue whales
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Et af de bedste steder i verden at se disse blåhvaler
01:08
is here in this region.
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er her i denne region.
01:10
In Sri Lanka, if you go down to the south coast of Sri Lanka,
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I Sri Lanka, hvis man tager ned på sydkysten i Sri Lanka,
01:13
during the northeast monsoon season,
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i den nordøstlige monsunsæson,
01:15
you can see blue whales very, very easily.
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kan man se blåhvalerne meget, meget nemt.
01:17
It's probably the best place in the world to see them.
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Det er nok det bedste sted i verden at se dem.
01:19
Now, when I talk about the northeast monsoon season,
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Men, da jeg talte om den nordøstlige monsunsæson,
01:22
I'm sure many of you here know exactly what I mean,
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er jeg sikker på at mange af jer ved præcis hvad jeg mener,
01:24
but perhaps some of you are not quite so sure.
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men måske er nogle af jer ikke helt så sikre.
01:27
I need to explain a little bit about monsoons.
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Jeg bliver nød til at forklare et par ting om monsunen.
01:29
Now, monsoon, the root of the word "monsoon"
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Monsun, roden af ordet "monsoon"
01:31
comes from the word "season."
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kommer fra ordet "sæson".
01:33
So, it's just a season. And there are two seasons in most of South Asia.
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Så, det er bare en sæson. Og der er to sæsoner i det meste af syd Asien.
01:38
And in the summer India heats up, gets very hot.
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Og om sommeren ophedes Indien, bliver meget varmt.
01:40
Hot air rises, and air is drawn in off the sea to replace it.
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Varm luft stiger, og luft bliver trukket ind fra havet for at erstatte den.
01:45
And the way it works is, it comes from the southwest.
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Og måden det virker på er, det kommer fra sydvest.
01:47
It comes off the ocean here and is drawn up towards India.
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Det kommer fra havet her og bliver trukket op mod Indien.
01:50
So it comes from the southwest. It's a southwest monsoon.
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Så det kommer fra sydvest. Det er en sydvestlig monsun.
01:53
Picks up moisture as it crosses the ocean.
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Samler fugt op i takt med at det krydser havet.
01:55
That's what brings the monsoon rain.
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Det er det der medbringer monsunregnen.
01:57
And then in the winter things cool down.
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Og om vinteren bliver alt koldere.
01:59
High pressure builds over India.
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Der bygges et højt lufttryk op over Indien.
02:01
And the whole system goes into reverse.
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Og hele systemet sættes i bakgear.
02:04
So, the wind is now coming from the northeast
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Så, vinden kommer nu fra nordøst
02:06
out of India, across the Indian Ocean,
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ud af Indien, krydser det Indiske Ocean,
02:08
this way towards Africa.
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denne vej mod Afrika.
02:11
Keep that in mind.
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Husk på det.
02:13
Now, I'm a marine biologist, but I'm actually
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Nu er jeg marinebiolog, men jeg er faktisk
02:15
a bit of an old fashioned naturalist, I suppose.
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noget af en gammeldags naturalist, tror jeg.
02:17
I'm interested in all sorts of things, almost everything that moves,
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Jeg er interesseret i alle mulige ting, næsten alt der bevæger sig,
02:19
including dragonflies. And I'm actually
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inklusiv guldsmede. Og jeg vil faktisk
02:21
going to talk, this afternoon, about dragonflies.
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tale om, denne eftermiddag, om guldsmede.
02:23
This is a very beautiful species, it's called the Oriental Scarlet.
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Dette er en meget smuk art, den hedder Oriental Scarlet.
02:26
And one thing you need to know about dragonflies,
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Og en ting man skal vide om guldsmede,
02:28
one important thing,
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en vigtig ting,
02:30
is that they lay their eggs in fresh water.
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er at de lægger deres æg i ferskvand.
02:32
They need fresh water to breed.
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De har brug for ferskvand for at formere sig.
02:34
They lay the eggs into fresh water.
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De ligger deres æg i ferskvand.
02:36
Little larvae hatch out in fresh water.
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Små larver udklækkes i ferskvand.
02:38
They feed on other little things. They feed on mosquito larvae.
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De spiser andre små ting. De spiser myggelarver.
02:41
So, they're very important.
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Så, de er meget vigtige.
02:43
They control mosquito larvae, among other things.
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De kontrollerer myggelarver, blandet andet.
02:45
And they grow and grow by stages. And they climb out
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Og de vokser og vokser i trin. Og de klatrer ud
02:48
of the water, burst out, as the adult which we see.
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af vandet, springer ud, som den voksne vi ser.
02:50
And typically, there is a lot of variation,
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Og typisk, er der stor variation,
02:52
but if you have a dragonfly with, say, a one year life cycle,
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men hvis man har en guldsmed med, eksempelvis, en etårig livscyklus,
02:55
which is quite typical, the larva, living in the fresh water,
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hvilket er temmelig typisk, larven, levende i det ferske vand,
02:58
lives for 10 or 11 months.
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lever i 10 eller 11 måneder.
03:01
And then the adult, which comes after, lives for one or two months.
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Og så den voksne, der kommer derefter, lever i en eller to måneder.
03:04
So it's essentially a freshwater animal.
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Så det er dybest set et ferskvandsdyr.
03:06
It really does need fresh water.
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Det har virkelig brug for ferskvand.
03:09
Now, the particular species of dragonfly
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Men, den bestemte art guldsmed
03:11
I want to talk about is this one,
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jeg vil tale om er denne,
03:13
because most dragonflies, like the one we've just seen,
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fordi de fleste guldsmede, ligesom den vi lige har set,
03:16
when the adult is there for its brief one or two months of life,
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når den voksne er der i sit korte et eller to måneders liv,
03:18
it doesn't go very far. It can't travel very far.
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flyver den ikke særlig langt. Den kan ikke rejse særlig langt.
03:21
A few kilometers, maybe, is quite typical.
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Et par kilometer, måske, er temmelig typisk.
03:23
They are very good fliers, but they don't go too far.
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De er rigtig gode flyvere, men de kommer ikke langt.
03:26
But this guy is an exception.
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Men denne fyr er en undtagelse.
03:28
And this is called the Globe Skimmer,
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Og denne kaldes Globe Skimmer,
03:30
or Wandering Glider.
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eller Wandering Glider.
03:32
And, as the name might suggest, it is found pretty much around the world.
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Og, ligesom navnet foreslår, kan den findes mere eller mindre i hele verden.
03:35
It lives throughout the tropics, the Americas,
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Den lever i troperne, Nord-, Syd- og Centralamerika,
03:37
Africa, Asia, Australia, into the Pacific.
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Afrika, Asien, Australien, ind i stillehavet.
03:40
And it wanders far and wide. We know that much about it.
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Og de rejser langt og bredt. Så meget ved vi om den.
03:43
But it really hasn't been studied very much.
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Men den er i virkeligheden ikke blevet studeret særlig meget.
03:45
It's a rather mediocre looking dragonfly.
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Den ser temmelig gennemsnitlig ud for en guldsmed.
03:49
If you're going to study dragonflies, you want to study those really bright beautiful ones,
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Hvis man vil studere guldsmede, vil man studere de virkelig lysende, smukke nogen,
03:52
like that red one. Or the really rare ones, the endemic endangered ones.
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ligesom den røde. Eller de virkelig sjældne, endemiske truede nogle.
03:55
This is, it seems a bit dull you know.
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Dette er, den ser lidt kedelig ud.
03:58
It's sort of dull-colored. And it's fairly common.
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Den har en kedelig farve. Den er temmelig udbredt.
04:01
And it occurs everywhere -- you know, why bother?
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Og den er overalt -- I ved, hvorfor gøre sig den umage?
04:04
But if you take that attitude, you're actually missing something rather special.
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Men hvis man har den attitude, misser man noget temmelig specielt.
04:07
Because this dragonfly has a rather amazing story to tell.
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Fordi denne guldsmed har en temmelig utrolig historie at fortælle.
04:10
And I feel very privileged to have stumbled across it
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Og jeg føler mig meget priviligeret over at have fundet den
04:13
living in the Maldives.
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ved at leve i Maldiverne.
04:15
When I first went to the Maldives,
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Da jeg først tog til Maldiverne,
04:17
dead keen on diving, spent as much of my time
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fastsat på at dykke, bruge så meget som muligt af min tid
04:20
as I could in and under the water.
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som jeg kunne i og under vandet.
04:22
Didn't notice any dragonflies; maybe they were there, maybe they weren't.
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Jeg lagde ikke mærke til nogen guldsmede; måske var de der, måske var de der ikke.
04:24
Didn't notice them.
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Lagde ikke mærke til dem.
04:26
But after some time, after some months, one day
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Men efter noget tid, efter nogle måneder, en dag
04:28
as I was going out and about,
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da jeg gik rundt omkring,
04:30
suddenly I noticed hundreds of dragonflies, hundreds of dragonflies.
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lagde jeg pludselig mærke til hundredvis af guldsmede, hundredvis af guldsmede.
04:34
Something like this, these are all this species Globe Skimmer.
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Noget i denne stil, disse er alle denne art Globe Skimmer.
04:37
I didn't know at the time, but I know now,
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Jeg vidste ikke på det tidspunkt, men jeg ved det nu,
04:39
they're Globe Skimmers, hundreds of them.
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de er Globe Skimmers, hundredvis af dem.
04:41
And they were there for some time. And then they were gone.
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Og de var der i noget tid. Og så var de væk.
04:43
And I didn't think anything more of it until
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Og jeg tænkte ikke mere over det indtil
04:45
the following year, when it happened again,
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de efterfølgende år, da det skete igen,
04:47
and then the year after that, and then the year after that.
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og så året derefter, og så året efter det.
04:50
And I was a bit slow, I didn't really take too much notice.
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Og jeg var lidt langsom, jeg lagde i virkeligheden ikke så meget mærke til det.
04:53
But I asked some Maldivian friends and colleagues, and yes they come every year.
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Men jeg spurgte nogle maldiviske venner og kolleger, og ja de kommer hvert år.
04:55
And I asked people about them and yes,
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Og jeg spurgte mennesker om dem og ja,
04:57
they knew, but they didn't know anything,
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de vidste det, men de vidste ikke noget,
04:59
where they came from, or anything.
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hvor de kom fra, eller noget.
05:01
And again I didn't think too much of it.
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Og igen, jeg tænkte ikke for meget over det.
05:04
But slowly it began to dawn on me that something
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Men langsomt begyndte det at trænge ind for mig, at noget
05:06
rather special was happening.
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temmelig specielt skete.
05:08
Because dragonflies need fresh water to breed.
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Fordi guldsmede har brug for ferskvand for at formere sig.
05:11
And the Maldives, and I'm sure some of you have been there --
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Og Maldiverne, og jeg er sikker på at nogle af jer har været der --
05:14
so here is home.
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der er hjemmet.
05:16
So, Maldives, beautiful place.
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Så, Maldiverne, smukt sted.
05:18
(Laughter)
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(Latter)
05:20
It's built entirely of coral reefs.
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Det er bygget udelukkende af koralrev.
05:22
And on top of the coral reefs are sand banks.
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Og oven på koralrevene er sandbanker.
05:24
Average height, about that much above sea level.
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Gennemsnits højde, cirka så meget over havniveau.
05:27
So, global warming, sea level rise, it's a real serious issue.
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Så, global opvarmning, stigende vandstand, det er et virkelig alvorligt emne.
05:30
But I'm not going to talk about that.
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Men det vil jeg ikke tale om.
05:32
Another important point of these sand banks
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Et andet vigtigt punkt af disse sandbanker
05:34
is that when it rains,
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er at når det regner,
05:36
the rainwater soaks down into the soil. So, it's gone.
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forsvinder regnvandet ned i jorden. Så, det er væk.
05:38
So, it stays under the soil.
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Så, det bliver under jorden.
05:40
The trees can put their roots into it.
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Træerne kan sætte deres rødder i det.
05:42
Humans can dig holes and make a well.
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Mennesker kan grave et hul og lave en brønd.
05:44
But dragonflies -- a bit tricky.
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Men guldsmede -- en smule indviklet.
05:47
There is no surface fresh water.
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Der er ikke noget ferskvand på overfladen..
05:49
There are no ponds, streams, rivers, lakes,
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Der er ikke nogen dam, vandløb, floder, søer,
05:51
nothing like that.
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ikke noget af den art.
05:53
So, why is it that every year
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Så, hvordan kan det være at der hvert år
05:55
millions of dragonflies, millions,
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er millioner af guldsmede, millioner,
05:57
millions of dragonflies turn up?
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millioner af guldsmede der dukker op?
05:59
I got a little bit curious. In fact I'll stop here,
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Jeg blev en smule nysgerrig. Faktisk vil jeg stoppe her,
06:01
because I want to ask, and there is a lot of people who,
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fordi jeg vil spørge om, og der er mange mennesker der,
06:04
from India of course, people who grew up spending your childhood here.
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fra Indien selvfølgelig, mennesker der voksede op og tilbragte deres barndom her.
06:07
Those of you who are Indian or spent your childhood here,
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De af jer der er indere eller tilbragte jeres barndom der,
06:11
let me have a show of hands, who of you --
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ræk hånden i vejret, hvem af jer --
06:13
not yet, not yet!
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ikke endnu, ikke endnu!
06:15
You're too keen. You're too keen. No. Hang on. Hang on.
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I er for ivrige. I er for ivrige. Nej. Vent. Vent.
06:17
Wait for the go. I'll say go.
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Vent på tegnet. Jeg siger go.
06:21
Those of you who grew up in India,
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De af jer der voksede op i Indien,
06:24
do you remember in your childhood, dragonflies,
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kan I huske jeres barndom, guldsmede,
06:26
swarms of dragonflies? Maybe at school,
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guldsmedesværme? Måske i skole,
06:28
maybe tying little bits of string onto them?
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måske binde små stykker snor i dem?
06:30
Maybe pulling bits off? I'm not asking about that.
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Måske trække stykker af? Det spørger jeg ikke om.
06:32
You've only got to say, do you remember seeing lots of dragonflies.
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I skal kun sige, kan I huske at se massevis af guldsmede.
06:36
Any hands? Any hands? Yes. Thank you. Thank you.
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Nogen hænder? Nogen hænder? Ja. Tak. Tak.
06:39
It's a widespread phenomenon
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Det er et udstrakt fænomen
06:41
throughout South Asia, including the Maldives.
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gennem Sydasien, inklusiv Maldiverne.
06:45
And I got a bit curious about it.
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Og jeg blev en smule nysgerrig omkring det.
06:47
In the Maldives -- now, in India there is plenty of water,
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I Maldiverne -- nu er der i Indien rigeligt med vand,
06:49
so, dragonflies, yeah, of course. Why not?
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så, guldsmede, ja, selvfølgelig. Hvorfor ikke?
06:51
But in Maldives, no fresh water. So, what on Earth is going on?
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Men i Maldiverne, ikke noget ferskvand. Så hvad søren sker der?
06:54
And the first thing I did was started recording
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Og det første jeg gjorde var, at jeg begyndte at optage
06:57
when they turned up in the Maldives.
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når de viste sig på Maldiverne.
06:59
And there is the answer, 21st of October.
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Og der er svaret, den 21 oktober.
07:01
Not every year, that's the average date.
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Ikke hvert år, det er en gennemsnitlig dato.
07:03
So, I've been writing it down for 15 years now.
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Så, jeg har skrevet det ned i 15 år nu.
07:05
You'd think they're coming from India. It's the closest place.
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Man skulle tro at de kommer fra Indien. Det er det tætteste på.
07:07
But in October, remember, we're still in southwest monsoon,
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Men i oktober, husker I, vi er stadigvæk i den sydvestlige monsun,
07:10
Maldives is still in the southwest monsoon.
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Maldiverne er stadig i den sydvestlige monsun.
07:12
But wind is, invariably, every time, is from the west.
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Men vinden kommer, konstant, hver gang, fra vest.
07:15
It's going towards India, not from India.
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Den kommer mod Indien, ikke fra Indien.
07:17
So, are these things, how are these things getting here?
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Så, er disse ting, hvordan kommer disse ting her?
07:19
Are they coming from India against the wind?
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Kommer de mod vinden fra Indien?
07:21
Seemed a bit unlikely.
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Det synes lidt usandsynligt.
07:23
So, next thing I did is I got on the phone.
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Så, det næste jeg gjorde var at jeg samlede telefonen op.
07:25
Maldives is a long archipelago.
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Maldiverne er en lang øgruppe.
07:27
It stretches about 500 miles, of course it's India here.
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Det strækker sig cirka 750 kilometer, selvfølgelig er det Indien her.
07:29
I got on the phone and emailed to friends and colleagues.
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Jeg samlede telefonen op og jeg mailede til venner og kolleger.
07:31
When do you see the dragonflies appear?
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Hvornår ser I guldsmedende dukke op?
07:34
And pretty soon, a picture started emerging.
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Og kort derefter, begyndte der at vise sig et billede.
07:36
In Bangalore, a colleague there sent me
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I Bangalore, en kollega derfra sendte mig
07:38
information for three years, average,
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information for tre år, gennemsnit,
07:40
24th of September, so late September.
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24. september, så i slutningen af september.
07:42
Down in Trivandrum, a bit later.
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Nede i Trivandrum, lidt senere.
07:44
Far north of Maldives, a bit later.
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Langt nord for Maldiverne, lidt senere.
07:46
Then Malé, then further south.
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Så Malé, så længere sydpå.
07:48
And then the southernmost Maldives.
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Og så det sydligste af Maldiverne.
07:50
It's pretty obvious, they're coming from India.
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Det er temmelig åbenlyst, at de kommer fra Indien.
07:53
But they are coming 400 miles across the ocean, against the wind.
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Men de krydser 600 kilometer hav, imod vinden.
07:56
How on Earth are they doing that?
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Hvordan i alverden gør de det?
07:58
I didn't know.
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Jeg vidste det ikke.
08:00
The next thing I did was I started counting dragonflies.
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Det næste var at jeg begyndte at tælle guldsmede.
08:02
I wanted to know about their seasonality,
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Jeg ville vide om deres sæsonmæssige variationer,
08:04
what time of year, this is when they first arrive,
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hvilken årstid, dette er da de først dukkede op,
08:06
but how long are they around for? Does that give any clues?
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men hvor lang tid er de der? Giver det nogen spor?
08:08
So, I started a very rigorous scientific process.
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Så, jeg begyndte en meget skrap videnskabelig process.
08:11
I had a rigorous scientific transect.
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Jeg fik en skrap videnskabelig deling på tværs.
08:13
I got on my bicycle,
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Jeg stod på min cykel,
08:15
and I cycled around the island of Malé.
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og jeg cyklede rundt på øen Malé.
08:17
It's about five kilometers around,
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Det er cirka fem kilometer rundt,
08:19
counting the dragonflies as I go,
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talte guldsmedene på min vej,
08:21
trying not to bump into people as I'm looking in the trees.
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prøvede på ikke at støde ind i folk i takt med at jeg kigger i træerne.
08:24
And they're here for a very short time,
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Og de er der i meget kort tid.
08:28
October, November, December. That's it.
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Oktober, november, december. Det er alt.
08:30
And then they tail off, there's a few, but that's it.
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Og så flyver de afsted, der er et par, men det er alt.
08:32
October, November, December. That is not the northeast monsoon season.
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Oktober, november, december. Det er ikke den nordøstlige monsun sæson.
08:34
That's not the southwest season.
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Det er ikke den sydvestlige sæson.
08:36
That's the inter-monsoon,
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Det er inter-monsunen,
08:38
the time when the monsoon changes.
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tidspunktet hvor monsunen ændrer sig.
08:40
Now, what I said was, you get the southwest monsoon going one way,
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Det jeg sagde var, at man får den sydvestlige monsun der går en vej,
08:43
and then it changes and you get the northeast monsoon going the other way.
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og så ændrer den sig og man får den nordøstlige monsun der gør den anden vej.
08:47
And that sort of gives the impression you've got one air mass
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Og det giver på en måde et indtryk af at man har en luftmasse
08:49
going up and down, up and down. It doesn't work like that.
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der går op og ned, op og ned. Det fungerer ikke på den måde.
08:51
What happens, actually, is there is two air masses.
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Det der sker er, faktisk, at der er to luftmasser.
08:53
And there is a front between them, and the front moves.
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Og der er en front mellem dem, og fronten flytter sig.
08:56
So, if you've got India here,
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Så, hvis man har Indien her,
08:58
when the front is up above India you're into the southwest monsoon.
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når fronten er oppe over Indien er man inde i den sydvestlige monsun.
09:00
Then the front moves into the northeast monsoon.
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Så flytter fronten sig ind i den nordøstlige monsun.
09:04
And that front in the middle is not vertical,
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Og den front i midten er ikke vertikal,
09:06
it's at an angle.
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den er i en vinkel.
09:08
So, as it comes over towards Malé
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Så, i takt med at den kommer ind mod Malé
09:10
I'm standing in Malé underneath the front.
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står jeg i Malé under fronten.
09:13
I can be in the southwest monsoon.
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Jeg kan være i den sydvestlige monsun.
09:15
But the wind above is from the northeast monsoon.
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Men vinden ovenover er fra den nordøstlige monsun.
09:17
So, the dragonflies are actually coming from India on the northeast monsoon,
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Så, guldsmedende kommer faktisk fra Indien med den nordøstlige monsun.
09:20
but at an altitude at 1,000 to 2,000 meters up in the air. Incredible.
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men i en højde på 1.000 til 2.000 meter oppe i luften. Imponerende.
09:26
These little insects, it's the same ones we see out here [in India],
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Disse små insekter, det er de samme vi ser herude [i Indien],
09:29
two inches long, five centimeters long,
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to inch lange, fem centimeter lange,
09:31
flying in their millions, 400 miles across the ocean,
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flyvende i millionvis, krydser 600 kilometer hav,
09:35
at 2,000 meters up. Quite incredible.
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2.000 meter oppe i luften. Temmelig imponerende.
09:39
So, I was quite pleased with myself. I thought wow, I've tracked this one,
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Så, jeg var temmelig selvtilfreds. Jeg tænkte wow, jeg har fulgt denne,
09:42
I know how they come here. Then I scratched my head a bit,
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nu ved jeg hvordan de kommer her. Så kløede jeg mig lidt i hovedet,
09:44
and that's okay,
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og det er okay,
09:46
I know how they come here, but why do they come here?
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jeg ved hvordan de kommer her, men hvorfor kommer de her?
09:49
What are millions of dragonflies doing, flying out over the ocean every year
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Hvad laver millioner af guldsmede, ved at flyve over oceanet hvert år
09:54
to their apparent doom?
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til det der tilsyneladende er deres undergang?
09:56
It doesn't make sense. There is nothing for them in Maldives.
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Det giver ingen mening. Der er ikke noget for dem at komme efter i Maldiverne.
09:58
What on Earth are they doing?
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Hvad i alverden laver de?
10:00
Well, to cut a long story short,
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Jamen, for at gøre en lang historie kort,
10:03
they're actually flying right across the ocean.
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flyver de faktisk tværs over oceanet.
10:06
They're making it all the way across to East Africa.
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De klarer den hele vejen over Østafrika.
10:09
I know that because I have friends who work on fisheries' research vessels
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Det ved jeg fordi jeg har venner der arbejder på fiskeri forskningsfartøjer
10:12
who have sent to me reports from boats out in the ocean.
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der har sendt rapporter til mig fra både ude i oceanet.
10:14
I know because we have reports from Seychelles,
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Jeg ved det fordi vi har rapporter fra Seychellerne,
10:16
which fit in as well, down here.
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der også passer ind, hernede.
10:18
And I know because
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Og jeg ved det fordi
10:21
when you look at the rainfall,
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når man ser på regnmængden,
10:23
these particular insects, these Globe Skimmers
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formerer disse bestemte insekter, disse Globe Skimmers
10:25
breed in temporary rain water pools.
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sig i midlertidige regnvands pytter.
10:29
Okay, they lay their eggs where the seasonal rains are,
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Okay, de lægger deres æg hvor den sæsonbestemte regntid er,
10:31
the monsoon rains.
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monsunregnen.
10:33
The larvae have to develop very quickly.
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Larverne skal udvikle sig meget hurtigt.
10:36
They only take six weeks. Instead of 11 months, they're six weeks.
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Det tager kun seks uger. I stedet for 11 måneder, de tager seks uger.
10:38
They're up, and they're off.
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De er oppe, og de er afsted.
10:40
Now, here we have, in case you can't read at the back,
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Her har vi, for det tilfælde at jer omme bagved ikke kan læse det,
10:42
the top is rainfall for India.
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i toppen er regnmængden for Indien.
10:44
And we're starting in June. So this is the monsoon rain.
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Og vi starter i juni. Så dette er monsunregnen.
10:47
By September, October, it's drying out.
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Til september, oktober, tørrer den ud.
10:49
Nothing for these dragonflies. There is no more seasonal rain.
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Ikke noget til disse guldsmede. Der er ikke mere sæsonpræget regn.
10:51
They've got to go hunting for seasonal rain.
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De skal ud og jage efter sæsonpræget regn.
10:54
And they fly south. As the monsoon withdraws to the south
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Og de flyver sydpå. Som monsunen trækker sig tilbage til syden
10:57
they come down through Karnataka, into Kerala.
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kommer de ned gennem Karnataka, ind i Kerala.
11:00
And then they run out of land.
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Og så løber de tør for land.
11:02
But they are incredibly good fliers. This particular species,
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Men de er fantastisk gode flyvere. Denne bestemte art,
11:04
it can fly for thousands of kilometers.
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den kan flyve i tusindvis af kilometer.
11:06
And it just keeps going. And the wind, the northeast wind
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Og den fortsætter bare. Og vinden, den nordøstlige vind,
11:08
swooshes it around and carries it off across the ocean to Africa,
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suser den rundt og bærer den afsted tværs over oceanet til Afrika,
11:12
where it's raining.
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hvor det regner.
11:15
And they are breeding in the rains of Africa.
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Og de formerer sig i Afrikas regn.
11:17
Now, this is southeast Africa. It makes it look like there are sort of
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Nu er dette det sydøstlige Afrika. Det får det til at se ud som om der på en måde er
11:19
two breeding periods here. It's slightly more complicated than that.
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to formerings perioder her. Det er lidt mere kompliceret end det.
11:23
What's happening is they are breeding in the monsoon rains here.
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Det der sker er at de formerer sig i monsun regnen.
11:26
And the dragonflies you can see today
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Og de guldsmede man kan se i dag
11:29
outside here, on the campus,
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herude, på campus,
11:31
are the young of this generation.
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er ungerne af denne generation.
11:34
They hatched out in India.
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De udklækkede i Indien.
11:36
They're looking for somewhere to breed. If it rains here they'll breed.
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De leder efter et sted at formere sig. Hvis det regner her, formerer de sig.
11:39
But most of them are going to carry on. And next stop,
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Men de fleste af dem fortsætter. Og det næste stop,
11:41
perhaps only four or five days away is going to be East Africa.
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måske kun i fire eller fem dage væk er det østlige Afrika.
11:44
The wind will swoosh them out across here.
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Vinden suser dem ud forbi her.
11:46
If they pass the Maldives they might go and have a look,
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Hvis de passerer Maldiverne stopper de måske fordi og kigger,
11:49
nothing there, they'll carry on.
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der er ikke noget, så de drager videre.
11:51
Here, here, Kenya, East Africa,
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Her, her, Kenya, det Østlige Afrika,
11:56
they've actually just come out of a long drought.
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de er faktisk lige kommet ud af en lang tørke.
11:58
Just last week the rains broke. The short rains broke
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Sidste uge startede regnen. Den korte regn begyndte
12:01
and it's raining there now.
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og det regner der nu.
12:03
And the dragonflies are there. I have reports from my various contacts.
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Og guldsmedene er der. Jeg har indberetninger fra mine forskellige kontakter.
12:06
The dragonflies are here now. They're breeding there.
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Guldsmedende er her nu. De formerer sig her.
12:08
When those guys, they'll lay their eggs now.
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Da de fyre, de lægger deres æg nu.
12:11
They'll hatch out in six weeks. By that time
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De udklækkes om seks uger. Til den tid
12:13
the seasonal rains have moved on. It's not there, it's down here.
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er den sæsonpræget regn flyttet videre. Det er ikke der, det er dernede.
12:15
They'll fly down here. And the clever thing is
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De flyver derned. Og den smarte ting er
12:17
the wind is always converging to where the rain is.
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at vinden altid konvergerer sig hvor regnen er.
12:20
The rain occurs, these are summer rains.
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Regnen kommer, dette er somre med regn.
12:22
This is a summer monsoon.
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Dette er sommermonsunen.
12:24
The sun is overhead there. Summer rains in southern Africa.
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Solen står højt der. Sommer regnen i det sydlige Afrika.
12:27
The sun is overhead, maximum heating,
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Solen står højt, maksimal opvarmning,
12:29
maximum evaporation, maximum clouds,
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maksimal fordampning, maksimale skyer,
12:31
maximum rainfall,
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maksimal regnmængde,
12:33
maximum opportunities for reproduction.
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maksimale muligheder for reproduktion.
12:35
Not only that, because you have this convection,
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Ikke nok med det, fordi man har denne konvektion,
12:39
you have this rising of the air
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man har denne stigende luft
12:41
where it's hot, air is drawn in.
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hvor det er varmt, bliver luften trukket ind.
12:43
There's a convergence. So, wherever the rain is falling,
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Der er en konvergens. Så, hvornår regnen end falder,
12:46
the air is drawn towards it to replace the air that's rising.
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bliver luften trukket ind for at udskifte den luft der stiger.
12:49
So, the little fellow that hatches out here,
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Så, den lille fyr der udklækkes her,
12:52
he gets up into the air, he is automatically carried
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han kommer op i luften, han bliver automatisk båret
12:54
to where the rain is falling.
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derhen hvor regnen falder.
12:56
Lay their eggs, next generation, they come up,
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Lægger dens æg, næste generation, de kommer op,
12:59
automatically carried to where the rain is falling.
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bliver automatisk båret derhen hvor regnen falder.
13:01
It's now back there. They come out, it's time to come back.
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Nu er det her. De kommer ud, det er på tide at komme tilbage.
13:04
So, in four generations, one, two, three,
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Så, i fire generationer, en, to, tre.
13:06
four and then back.
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fire og så tilbage.
13:08
A complete circuit of the Indian Ocean.
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Et komplet kredsløb i det Indiske Ocean.
13:11
This is a circuit of about 16,000 kilometers.
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Dette er et kredsløb på cirka 16.000 kilometer.
13:16
16,000 kilometers, four generations, mind you,
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16.000 kilometer, fire generationer, at I ved det,
13:20
for a two inch long insect. It's quite incredible.
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for et insekt på 5 cm. Det er temmelig utroligt.
13:22
Those of you from North America
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Dem af jer der kommer fra Nordamerika
13:24
will be familiar with the Monarch butterfly.
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vil være bekendte med Monark sommerfuglen.
13:27
Which, up until now has had the longest known insect migration.
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Hvilket, indtil nu har haft den længst kendte insektvandring.
13:30
It's only half the length of this one.
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Det er kun halvt så langt som denne.
13:32
And this crossing here, of the ocean,
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Og denne overgang, af oceanet,
13:34
is the only truly regular transoceanic crossing
325
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er den eneste virkelige transoceaniske overgang
13:39
of any insect.
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af noget insekt.
13:41
A quite incredible feat.
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En temmelig utrolig bedrift.
13:43
And I only stumbled on this because I was living in Malé,
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Og jeg faldt kun over dette fordi jeg boede i Malé,
13:45
in Maldives for long enough
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på Maldiverne længe nok
13:47
for it to percolate into my brain
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til at det løb gennem min hjerne
13:49
that something rather special was going on.
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så der skete noget temmelig specielt.
13:53
But dragonflies are not the only creatures that make the crossing.
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Men guldsmede er ikke kun væsner der laver den passage.
13:55
There is more to the story.
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Der er mere til den historie.
13:57
I'm also interested in birds. And I'm familiar
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Jeg er også interesseret i fugle. Og jeg er bekendt
13:59
with this fellow. This is a rather special bird.
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med denne fyr. Dette er en temmelig speciel fugl.
14:01
It's a falcon. It's called the eastern red-footed falcon, obviously.
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Det er en falk. Den kaldes den østlige aftenfalk, selvfølgelig.
14:04
But it's also called the Amur Falcon.
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Men den kaldes også amurfalken.
14:06
And it's called the Amur Falcon
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Og den kaldes amurfalken
14:08
because it breeds in Amurland.
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fordi den formerer sig i Amurland.
14:11
Which is an area along the Amur River, which is up here.
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Hvilket er et område langs Amur floden, som ligger heroppe.
14:13
It's the border, much of it is the border
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Det er grænsen, meget af det er grænsen
14:15
between China and Russia, up here in the far east.
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mellem Kina og Rusland, heroppe i det fjerne østen.
14:18
So, Siberia, Manchuria.
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Så, Siberien, Manchuriet.
14:20
And that's where it breeds.
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Og det er der den formerer sig.
14:22
And if you're a falcon it's quite a nice place to be in the summer.
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Og hvis man er en falk er det et temmelig fint sted at være om sommeren.
14:24
But it's a pretty miserable place to be in the winter.
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Men det er et temmelig usselt sted at være om vinteren.
14:26
It's, well, you can imagine.
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Det er, jamen, I kan forestille jer det.
14:28
So, as any sensible bird would do,
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Så, som enhver fornuftig fugl ville gøre,
14:32
he moves south. They move south. The whole population moves south.
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flytter den sydpå. De flytter sydpå. Hele bestanden flytter sydpå.
14:35
But then the being sensible stopped.
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Men så holder den op med at være fornuftig.
14:37
So, now they don't stop here, or even down here.
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Så, nu stopper de ikke her, eller selv hernede.
14:39
No, they turn across here.
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Nej, de vender rundt her.
14:41
They have a little refueling stop in northeastern India.
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Det har et lille stop for at tanke op i det nordøstlige Indien.
14:45
They come to the latitude of about Mumbai or Goa.
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De kommer til den samme breddegrad som Mumbai eller Goa.
14:48
And then they strike out across the ocean, down to Kenya.
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Og så flyver de ud over oceanet, ned til Kenya.
14:50
And down here, and they winter down here [in southern Africa].
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Og her ned, og de overvintrer hernede [i det sydlige Afrika].
14:53
Incredible. This is the most extraordinary migration
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Utroligt. Dette er den mest usædvanlige vandring
14:56
of any bird of prey. A quite incredible migration.
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af nogen jagtfugl. En temmelig utrolig vandring.
14:59
And they are not the only one that makes the crossing.
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Og de er ikke de eneste der laver den passage.
15:01
They have the most incredible journey, but several make the crossing from India
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De har den mest utroligt rejse, men adskillige laver den passagen fra Indien
15:04
to Africa. Includes this one, the hobby.
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til Afrika. Inklusiv denne, lærkefalken.
15:06
This fellow is a very nice bird, this is the Pied cuckoo.
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Denne fyr er en meget fin fugl, dette er en broget gøg.
15:08
Those of you from northern India will be familiar with this.
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De af jer der kommer fra det nordlige Indien vil være bekendte med den.
15:10
It comes with the monsoons.
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Den kommer med monsunen.
15:12
This time of year they cross back to Africa.
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På denne årstid laver de trækket tilbage til Afrika.
15:15
And this guy, the roller, a rather beautiful bird.
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Og denne fyr, ellekragen, en temmelig smuk fugl.
15:17
It's known as the Eurasian Roller. In India it occurs in the northwest,
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Den er kendt som den Eurasiske ellekrage. I Indien findes den i den nordvestlige del,
15:20
so it's known as the Kashmir Roller.
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så den er kendt som Kashmir ellekragen.
15:23
And these birds, what I've done is I've complied all the records,
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Og disse fugle, det jeg har gjort er at jeg har indsamlet alle journalerne,
15:25
all the available records of these birds,
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alle de tilgængelige optegnelser om disse fugle,
15:27
put them together, and found out they migrate at exactly the same time
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satte dem sammen, og fandt ud af at de trækker på præcis det samme tidspunkt
15:29
as the dragonflies.
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som guldsmedene.
15:31
They make use of exactly the same winds.
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De bruger præcis de samme vinde.
15:33
They travel at exactly the same time with the same winds
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De rejser på præcis det samme tidspunkt med de samme vinde
15:35
to make the crossing. I know they travel at the same altitude.
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til at lave passagen. Jeg ved de rejser på i den samme højde.
15:38
It's known about the Amur Falcon. This guy, unfortunately,
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Det er kendt om Amurfalken. Denne fyr, uheldigvis,
15:40
one of these met an unfortunate end.
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en af disse mødte deres endeligt.
15:42
He was flying off the coast of Goa,
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Han fløj ud for Goas kyst,
15:45
21 years ago, 1988. October, 1988.
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for 21 år siden, 1988. Oktober, 1988.
15:48
An Indian Navy jet was flying off Goa,
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En indisk jetfly fløj ud for Goa,
15:50
bang! In the middle of the night. Fortunately, a two engine jet
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bang! Midt om natten. Heldigvis, et tomotors jetfly
15:53
got back to base, and they pulled the remains of one of these [Eurasian Rollers] out.
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kom tilbage til basen, og de trak resterne af en af disse [Eurasisk ellekrage] ud.
15:56
Flying at night over the Indian Ocean 2,424 meters.
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Fløj om natten over det Indiske Ocean i 2.424 meters højde.
16:00
Same height as the dragonflies go.
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Samme højde som guldsmedene flyver i.
16:02
So, they are using the same winds.
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Så, de bruger de samme vinde.
16:04
And the other thing, the other important factor
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Og den anden ting, den anden vigtige faktor
16:06
for all these birds, all medium sized fellows,
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for alle disse fugle, alle fyrene i medium størrelse,
16:09
and this includes the next slide as well, which is a bee-eater.
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og dette inkluderer også den næste slide, som er en biæder.
16:12
Bee-eaters eat bees. This one has a nice blue cheek.
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Biædere spiser bier. Denne har en fin blå kind.
16:14
It's a Blue-cheeked Bee-eater.
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Det er en blåkindet biæder.
16:17
And every one of these birds that makes the crossing
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Og hver eneste af disse fugle der laver passagen
16:19
from India to East Africa
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fra Indien til Østafrika
16:21
eats insects, large insects,
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spiser insekter, store insekter,
16:24
the size of dragonflies. Thank you very much.
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på størrelse med guldsmede. Mange tak.
16:27
(Applause)
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(Bifald)
ABOUT THE SPEAKER
Charles Anderson - Marine biologistCharles Anderson studies marine life in the Maldives, a nation of coral atolls in the Indian ocean.
Why you should listen
Since 1983, Charles Anderson has lived and worked in the Maldives, a group of more than 1,000 coral islands that is the world's lowest-lying country. Marine life here is rich and fascinating, and Anderson has been instrumental in identifying it and promoting its preservation. This year, the Maldives became the first nation to ban shark fishing, after recognizing that the decline in live sharks was impacting the lucrative tourist trade.
Anderson has discovered several new species of fish, and was awarded the President of Maldives Award for Service to Fisheries in 1995, the only non-Maldivian ever to receive this honor. He and his wife, Susan, run several whale-watching trips each year where tourists take part in a national survey of cetaceans (whales and dolphins). recently, Anderson has identified the world's longest insect migration: the 18,000 km flight of tiny Pantala flavescens dragonflies back and forth across the Indian Ocean. He has found that the migration begins in India and proceeds via the Maldives (a mystifying stopover, because freshwater is scarce on these low-lying atolls) and the Seychelles -- and then all the way to East Africa.
Charles Anderson | Speaker | TED.com