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Dave W.
Info Junkie
USA
26022 Posts |
 Posted - 03/17/2005 : 20:19:37
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What, if any, are the current best hypotheses for the evolutionary reason(s) (selection pressures, etc.) that these geese flock the way they do (the classic V, that is).
Gimme a couple of sentences summarizing, and then support them, please.
I ask because a flock flew over my house today, but it was just half a V. A diagonal line of perhaps 100 geese, with a few gaps in it.
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- Dave W. (Private Msg, EMail)
Evidently, I rock!
Why not question something for a change?
Visit Dave's Psoriasis Info, too. |
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filthy
SFN Die Hard
USA
14408 Posts |
Posted - 03/17/2005 : 20:34:00 [Permalink]
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quote:
Originally posted by Dave W.
What, if any, are the current best hypotheses for the evolutionary reason(s) (selection pressures, etc.) that these geese flock the way they do (the classic V, that is).
Gimme a couple of sentences summarizing, and then support them, please.
I ask because a flock flew over my house today, but it was just half a V. A diagonal line of perhaps 100 geese, with a few gaps in it.
Not something I've studied, but I read some years back that the "V" formation of migrating ducks and geese, and pelicans no less, has something to do with air current resistance, the leader breaking the wind (snicker) for the rest. And, according to the article, the birds swap leaders as they go, making flying easier for all.
How this behavior, like many, evolved is hard to say, and I can't think of a guess to hazard.
Agree; this is much better than the sewage pit I've been in lately.
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"What luck for rulers that men do not think." -- Adolf Hitler (1889 - 1945)
"If only we could impeach on the basis of criminal stupidity, 90% of the Rethuglicans and half of the Democrats would be thrown out of office." ~~ P.Z. Myres
"The default position of human nature is to punch the other guy in the face and take his stuff." ~~ Dude
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Dave W.
Info Junkie
USA
26022 Posts |
Posted - 03/17/2005 : 20:41:06 [Permalink]
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| Perhaps surprisingly, I was unaware that any other species (much less genus) flew in such a formation. Ducks? Yeah, I've seen 'em flying that way... in a cartoon, and I figured the artists were simply screwed up. But, pelicans? Wow, I really am clueless about this stuff. |
- Dave W. (Private Msg, EMail)
Evidently, I rock!
Why not question something for a change?
Visit Dave's Psoriasis Info, too. |
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H. Humbert
SFN Die Hard
USA
4574 Posts |
Posted - 03/17/2005 : 20:43:29 [Permalink]
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Yeah, what filthy said. Has to do with minimizing drag.
It isn't coincidence that the "V" formation is the basic shape of a "flying wing" airplane design.
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"A man is his own easiest dupe, for what he wishes to be true he generally believes to be true." --Demosthenes
"The first principle is that you must not fool yourself - and you are the easiest person to fool." --Richard P. Feynman
"Face facts with dignity." --found inside a fortune cookie |
| Edited by - H. Humbert on 03/17/2005 20:45:12 |
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Dave W.
Info Junkie
USA
26022 Posts |
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H. Humbert
SFN Die Hard
USA
4574 Posts |
Posted - 03/17/2005 : 21:11:56 [Permalink]
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Ok, links. Well, I found this. (It is a creationist link, so ignore the part that says their flight pattern proves god). Apparently there is more than one theory, or perhaps better to say there might be more than one reason. One is the position of the birds' eyes make it impossible to see directly in front of them or directly behind, turing a "follow the leading" formation into a case of the blind leading the blind.
Another theory says they fly in a "V" because it is easier than flying in an "S."
And here's a paper titled Energy Savings in Formation Flight of Pink Footed Geese if you're looking for something a bit more technical.
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"A man is his own easiest dupe, for what he wishes to be true he generally believes to be true." --Demosthenes
"The first principle is that you must not fool yourself - and you are the easiest person to fool." --Richard P. Feynman
"Face facts with dignity." --found inside a fortune cookie |
| Edited by - H. Humbert on 03/17/2005 21:53:48 |
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Dave W.
Info Junkie
USA
26022 Posts |
Posted - 03/17/2005 : 21:37:28 [Permalink]
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Okay, so perhaps the better question is this: why do any birds fly in formation at all? Seems to me that most migratory birds don't bother with regimentation. And ideas like "boids" seem to do pretty well towards explaining general flocking behaviour.
A related question: do any fish swim in rigid formation?
By the way, while I was watching the half-V today, the last 20 or so birds started overtaking the front end of the formation, with perhaps ten birds in the middle perhaps struggling to make sense out of the speed differences. At one point in time, the whole thing looked a bit like a flying S, on its side and stretched out on the ends. |
- Dave W. (Private Msg, EMail)
Evidently, I rock!
Why not question something for a change?
Visit Dave's Psoriasis Info, too. |
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Dr. Mabuse
Septic Fiend
Sweden
9688 Posts |
Posted - 03/17/2005 : 23:25:09 [Permalink]
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quote:
Originally posted by filthy
Not something I've studied, but I read some years back that the "V" formation of migrating ducks and geese, and pelicans no less,
I think I've seen cranes (Lat. Grus grus) do that too. |
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Dude
SFN Die Hard
USA
6891 Posts |
Posted - 03/18/2005 : 01:01:25 [Permalink]
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quote:
A related question: do any fish swim in rigid formation?
Not sure... but schooling fish can appear to have only one brain, as the entire school moves in reaction to stuff (like scuba diving dudes) seemingly like one organism. I'm pretty sure it is just rapid reactions, but it is neat to see.
Can't think of any fish that swim in anything like a V or whatnot though.
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Ignorance is preferable to error; and he is less remote from the truth who believes nothing, than he who believes what is wrong.
-- Thomas Jefferson
"god :: the last refuge of a man with no answers and no argument." - G. Carlin
Hope, n.
The handmaiden of desperation; the opiate of despair; the illegible signpost on the road to perdition. ~~ da filth |
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dv82matt
SFN Regular
760 Posts |
Posted - 03/18/2005 : 02:31:23 [Permalink]
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This may be what you're looking for.
quote:
Scientists have given a clear demonstration of why birds fly in a "V" formation.
It is something the animals do because it reduces energy expenditure, helping large birds to migrate in groups.
http://news.bbc.co.uk/1/hi/sci/tech/1608251.stm |
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filthy
SFN Die Hard
USA
14408 Posts |
Posted - 03/18/2005 : 04:50:38 [Permalink]
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It is interesting to note that, with a few exceptions, only short-winged waterfowl use the "V" formation. These flap their wings constantly, at a comparable cost in energy. Typically, their breast muscles are quite large when compared those of other species.
Pelicans, being gliders of sorts and wide-winged, fall out of this group, but the "V" still profits them in that, at only a few feet above the waves, they travel a little faster with less work for their wings. They're fun to watch. Typically, the lead bird will give it's wings a couple of slow flaps, and it will pass through the group like falling dominos.
I have never seen any other seabird use the "V". Puffins might, but I don't know from puffins, and I'm currently getting crazy researching something else.
With smaller birds such as songbirds, I'd think that the formation would have to be very tight to gain any benefit. And those that travel in flocks, such as grackles, blackbirds, and starlings, go in such tremendous numbers that the "V" would be endless. The last in line might be hard-pressed hard to get a roosting place within the safety of the flock (they sometimes are anyway, but why organize it?).
That does not happen with waterfowl, as the skeins are typically of a small number of birds, although skeins might follow each other in great number.
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"What luck for rulers that men do not think." -- Adolf Hitler (1889 - 1945)
"If only we could impeach on the basis of criminal stupidity, 90% of the Rethuglicans and half of the Democrats would be thrown out of office." ~~ P.Z. Myres
"The default position of human nature is to punch the other guy in the face and take his stuff." ~~ Dude
Brother Boot Knife of Warm Humanitarianism,
and Crypto-Communist!
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filthy
SFN Die Hard
USA
14408 Posts |
Posted - 03/18/2005 : 08:00:03 [Permalink]
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quote:
Originally posted by Dude
quote:
A related question: do any fish swim in rigid formation?
Not sure... but schooling fish can appear to have only one brain, as the entire school moves in reaction to stuff (like scuba diving dudes) seemingly like one organism. I'm pretty sure it is just rapid reactions, but it is neat to see.
Can't think of any fish that swim in anything like a V or whatnot though.
On a related note, many times I've seen flocking birds, notably red wing blackbirds, behave in the same way as a school of fish, executing mass aerial manovers as if choriographed. Doves and pigeons as well.
The only example in fish that I can think of off hand, and it's not all that good, is the loose formations pilot fish form around the head of their host sharks. And then there's only the vaguest of set patterns which will break up as soon as the shark stops crusing and makes a sudden move.
I don't know if this is on topic or not, but naked mole rats have a definite formation when digging new tunnels. One or two work at the face and the rest line up behind to pass the dirt back.
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"What luck for rulers that men do not think." -- Adolf Hitler (1889 - 1945)
"If only we could impeach on the basis of criminal stupidity, 90% of the Rethuglicans and half of the Democrats would be thrown out of office." ~~ P.Z. Myres
"The default position of human nature is to punch the other guy in the face and take his stuff." ~~ Dude
Brother Boot Knife of Warm Humanitarianism,
and Crypto-Communist!
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Gorgo
SFN Die Hard
USA
5310 Posts |
Posted - 03/18/2005 : 08:30:47 [Permalink]
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Naked Mole Rats? Wow. Got pictures?
Know why one side of the V is longer than the other? |
I know the rent is in arrears
The dog has not been fed in years
It's even worse than it appears
But it's alright-
Jerry Garcia
Robert Hunter
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filthy
SFN Die Hard
USA
14408 Posts |
Posted - 03/18/2005 : 09:59:21 [Permalink]
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quote:
Originally posted by Gorgo
Naked Mole Rats? Wow. Got pictures?
Know why one side of the V is longer than the other?
On this page, about 2/3 of the way down, I've written a brief essay on them. Pics are provided in the links. Look for the essay titled Heterocephalus glaber.
As for uneven Vs, birds are not known for evening things out. In fact, as far as I know, only we do that and often badly.
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"What luck for rulers that men do not think." -- Adolf Hitler (1889 - 1945)
"If only we could impeach on the basis of criminal stupidity, 90% of the Rethuglicans and half of the Democrats would be thrown out of office." ~~ P.Z. Myres
"The default position of human nature is to punch the other guy in the face and take his stuff." ~~ Dude
Brother Boot Knife of Warm Humanitarianism,
and Crypto-Communist!
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Gorgo
SFN Die Hard
USA
5310 Posts |
Posted - 03/18/2005 : 10:09:41 [Permalink]
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Yeah. It's longer because there are more birds on one side than the other.
Thanks. Now, that's some good lookin' eusocial mammals.
Thanks, Filthy. That was actually interesting.
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I know the rent is in arrears
The dog has not been fed in years
It's even worse than it appears
But it's alright-
Jerry Garcia
Robert Hunter
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furshur
SFN Regular
USA
1536 Posts |
Posted - 03/18/2005 : 11:32:48 [Permalink]
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My grandfather told me geese follow the lead goose because he is the one with the map.
Now that I am older I know this to be false because only the Ganders would use a map or ask for directions...
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If I knew then what I know now then I would know more now than I know. |
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