Ocean-Crossing Dragonflies Discovered 95
grrlscientist writes "While living and working as a marine biologist in Maldives, Charles Anderson noticed sudden explosions of dragonflies at certain times of year. He explains how he carefully tracked the path of a plain, little dragonfly called the Globe Skimmer, Pantala flavescens, only to discover that it had the longest migratory journey of any insect in the world."
Maldives (Score:3, Insightful)
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He used a boat?
Impressive... (Score:5, Insightful)
It would be interesting to know what percentage of them survive.
Re:Impressive... (Score:5, Funny)
...or ability to harness solar energy ;)
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Re:Impressive... (Score:5, Informative)
TFA has a video that explains quite a bit about the species and one of the interesting things about it is that the dragonfly cruses at an altitude of 1-2 km over the surface. They migrate in order to catch the rainy season of East Africa and India. The winds at this altitude move toward the rainy areas due to meteorological effects so they do make use of air currents.
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Maybe the dragonfly can feed on other insects along the way. Also I wondered if it is light enough to sit on the water using surface tension.
Re:Impressive... (Score:5, Informative)
When you are small and light it is not actually required that you expel energy to float, the turbulence in the air can keep you going to a very long time for example water can stay in a cloud long enough to become softball sized hail and a glider can stay in the air all day, the energy is technically wind energy derived from solar and it is not coming from the object flying.
Re:Impressive... (Score:4, Interesting)
True but at least in the case of the sailplane (or albatross) you need control authority to steer out of sink and into lift which does take energy. In the case of an insect I can't see it having sufficiently low drag to take advantage of lift. To do that you need to be able to put your nose down and fly out of sink sometimes.
Re:Impressive... (Score:5, Insightful)
Well... they are insects, so their strategy is usually based in numbers. Maybe only 1 in 5 dragonflies (warning, numbers made up) get to end the travel safely; that would be unacceptable for men or other animals that take years to mature but for insects could be reasonable.
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"Bug bomb malfunction, Thodin."
Too obscure? ...even for /. ?
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In the case of an insect I can't see it having sufficiently low drag to take advantage of lift.
I don't follow you here. What makes you think a dragonfly has too much drag to be able to gain enough speed to generate lift? Between the lift and the air currents, I can see how it could conserve quite a lot of energy if it knows how to ride the currents.
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In the case of an insect I can't see it having sufficiently low drag to take advantage of lift.
I don't follow you here. What makes you think a dragonfly has too much drag to be able to gain enough speed to generate lift? Between the lift and the air currents, I can see how it could conserve quite a lot of energy if it knows how to ride the currents.
I mean if it finds itself in a body of sink (air going down) it won't be able to fly out into air which is rising (lift) while an albatross would be able to do that because it can fly faster.
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Is that sustained speed or burst speed? I heard (way back in my youth in Biology class or... somewhere) that they reach these speeds in short bursts or when changing direction.
Re:Impressive... (Score:4, Informative)
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I seem to remember dragonflies semi-regularly keep one pair of their wings stationary during flight. Perhaps they also sometimes fly with both not-flapping? Certainly there's an airfoil.
Generally they are highly agile, capable of incredible feats for such simple nervous system - for example, during pursuit of their pray, they supposedly follow a "camouflaging" flightpath; first one which makes them stationary in relation to the scenery, from the point of view of the pray! Afterwards, when closer, they becom
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Now here is a science story makes me say "wow".
Chasing the rain seasons... wonder if they make use of the same seasonal trade wind that kept the ancient maritime trade going around the Indian Ocean?
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Their flight speed is up to 5 m / s.
Would that be laden or unladen?
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Re:Impressive... (Score:4, Informative)
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I believe you made a typo. That should be closer to 7.5 days. Assuming maximum speed and no diversions from the direct path.
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Then again the maximum speed is almost certainly measured without any wind.
Or rather, it's an airspeed, which is measured relative to the surrounding air, and is thus unaffected by wind speed. Your speed relative to the ground can be greatly affected by wind, but your airspeed tends to be the same regardless of the wind.
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Uh, that would be about 1.5 days—there are 86,400 seconds in a day. That's assuming that they maintain their maximum flight speed the whole time, of course.
Is that for an American or an East-African Globe Skimmer? ...just wanted to know...
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My toy helis can only fly for about 6-8 minutes, and they need me around to control them.
Whereas here we have something that can autonomously fly 400 miles over the ocean from place to place, and probably flying for days. Something that can navigate, find+catch food, reproduce etc.
Our tech is still very behind in so many ways.
Re:Impressive... (Score:5, Funny)
400 miles is about 640,000 meters
640k should be enough for anyone.
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Just wondering - how many dragonflies it would take to carry a one pound coconut?
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It depends on how many dragonflies it takes to feed those birds who tag along.
Re:Impressive... (Score:5, Funny)
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Man, you are really *working hard* for that +5 Funny aren't you?
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Experiment [xkcd.com]
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There isn't all that much mass, either.
> They must have commendably efficient ways of staying in the air,
I'm sure the ratio of surface area to mass has something to do with it.
What I want to know is, when we say "Ocean-crossing" here, does he just mean they're flying from India to the Maldives (about 500 miles offshore)? Because the word "crossing" normally implies "from one side to the other", which, when it comes to oceans, would ge
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What I want to know is, when we say "Ocean-crossing" here, does he just mean they're flying from India to the Maldives (about 500 miles offshore)? Because the word "crossing" normally implies "from one side to the other", which, when it comes to oceans, would generally be a rather greater distance (multiple thousands of miles).
TFA (extremely interesting video) shows that the dragonflies migrate from India to South East Africa (via the Maldives and Seychelles). In four generations, they chase the rains across the Indian Ocean and back. About 16000km.
And several species of birds follow them, including the Amur Falcon [wikipedia.org], which annually migrates from Siberia to Southern Africa.
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What I want to know is, when we say "Ocean-crossing" here...
But we didn't say "ocean-crossing dragonflies" here, we said "ocean crossing dragonflies".
How do you get an ocean to cross a dragonfly? And how do you get the dragonfly to hold still while it does it?
It's like that movie about eight freaks with legs [imdb.com].
(Hint: tags aren't working for everyone.)
TED (Score:4, Informative)
http://www.ted.com/talks/charles_anderson_discovers_dragonflies_that_cross_oceans.html [ted.com]
Name (Score:5, Insightful)
Re:Name (Score:5, Funny)
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"Ralph"
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... before HIS discovery...
As in the discovery that it flew so far.
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Yeah, sounds like Captain Obvious better start turning things up a notch.
He apparently has some serious competition living in Maldives.
Re:Name (Score:5, Informative)
According to the wikipedia:
Pantala flavescens, the Globe Skimmer or Wandering Glider, is a wide-ranging dragonfly of the family Libellulidae. This species and Pantala hymenaea, the "Spot-winged Glider", are the only members of the genus Pantala from the subfamily Pantalinae. It was first described by Fabricius in 1798.[1] It is considered to be the most widespread dragonfly on the planet.
The English common names "Wandering Glider" and "Globe Skimmer" refer to its migratory behaviour.[3] The German name Wanderlibelle mean "migrant dragonfly". In Hong Kong, its name translates as Typhoon Dragonfly as it arrives with or shortly before the seasonal rain.
http://en.wikipedia.org/wiki/Globe_Skimmer [wikipedia.org]
It seems to me that it has been known that it just seems to "show up" at specific times of the year and does migrate, but nobody knew just how far it really did migrate.
Wow! Only one question comes to mind (Score:3, Funny)
How many would it take to carry a coconut?
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How many dragonflies to get the coconut away from the octopus?
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One thing is certain: there's no stopping them. The dragonflies will soon be here. And I, for one, welcome our new insect overlords.
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That depends Is it african or indian?
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Does it blend?
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Idiocracy, here we come.
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No, really, please label the link as a link to a video. It's a PITA for me to watch videos, so I usually don't. But I guess if all you want to do is get page views, by all means, continue misleading users.
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...It's a PITA for me to watch videos...
Leave the toys put away when watching p0rn! That will help.
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...It's a PITA for me to watch videos...
Leave the toys put away when watching p0rn! That will help.
I didn't hear him complaining. ;)
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20 minutes tops without viagra.
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Any longer than 4 hours and you're supposed to see a doctor.
He will be a secret dragonfly (Score:1)
Well listen, someday
You'll hear a rush of wings
So distant, a sound of secret things
There, look there, up in that rusty sky
Yonder, sweeps the dragonfly
So awesome, he blocks the setting sun
He'll come to collect the souls of everyone
Come dragon, come
In from the sun
He floats with an eerie grace
A giant blue green sentinal
From some distant time and space
And because he'll come, he'll have no regrets
Surely he'll come to lay this birth to rest
I know one day you'll see him
But please don't ask me why
He will be a secre
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If we're going to do dragonfly songs, how about this one [youtube.com] from DDR.
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I read that to the tune of "The Ballad of Jed Clampett". Amazingly it fits!
They've always been ocean crossing... (Score:5, Funny)
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How bout them locust? (Score:3, Interesting)
Anyhow, here's a linky to a National Geographic article (it also suggests the original American populations of locusts were immigrants from across the ocean).
http://news.nationalgeographic.com/news/2005/12/1228_051228_locusts.html
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Ok, be fair, it's all about CGI locusts destroying CGI office buildings while people run around screaming and has lots of kewel explosions and flame
Slashdot slowing down? (Score:1)
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"Months ago"? That's pretty quick for Slashdot, actually.
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Hey, you disagreeing does NOT make this a troll.
This is a fact. Come with me, let’s meet a doctor. Let’s test this out. I bet you $100 this is how it”s working.
You being in denial and repressing it (also trough moderation) does not change that.
Even doctors themselves complain about other doctors acting like that. While doing it themselves.
Man, some moderators are intolerant stupid close-minded asses...
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No, you are a grammar nazi. Just not a spelling nazi.
Coconuts (Score:1)
Flying Debugger? (Score:1)
the letters in TFA are hilarious (Score:2)