Challenge Questions

Hi Edignan, I'm right behind you on this one.
Well actually, behind and a bit to one side so that I can ride on your vortices.
Del
_{(I wish that guy at the back would stop honking...if he wants to overtake, he should just go for it)}

Popular bumper sticker out my way

I'm not tailgating, I'm drafting

I don't know if you've ever watch myth busters, but they had a great episode about drafting.

Gotta come up with something not in Wiki

Well done to you, edignan, for grabbing it !

I have it on good authority that Pelican fly in 'Squadrons' (!), for the reasons you give.

Here is more, with some nice diagrams (it's somewhere in there - follow the link at the bottom).

The question then would be why some birds do NOT, either flock or fly together - like the albatross who flys solo around and around the world

_{or why of all the things to be an "expert" on it had to be this miserable bastard}

Being gregarious (flocking) in itself is not enough, migration is where energy saving come in. Albatross are more like lone sharks who cruise about all the time. I guess that being a big bird helps, in as much as more energy can be saved. Small birds can't mess around in formation, it would be too easy for predators.

So, the v-flyers have to be migratory, gregarious, non-predators, and big. Beyond goose, I'm a bit stuck ! Pigeons clearly aren't big/bright enough ! ! Maybe there is an aquatic equivalent. We could maybe go for dolphins/ducklings as a comparisons ?

_{(forget the pigeons - I never said it ! )}

Re Albatross, these guys use a different technique combining ground effect as they ride the updraft in front of waves which are moving so they can surf these moving slopes.

They also have very long slender wings which a) have a very high lift capability designed for gliding (in this case slope soaring) with minimal effort (maximum glide ratio), and b) with this geometry the vortex off the wing tip is quite low and also would add little proportionaly to the following wing. Apart from that there is not that much room on the wave to form a formation and it would change continually.

Apart from that, yes it may just not be in their genes to work that way.

Maybe the Albatross don't flap/glide the right way to benefit from formation ? Could be that there aren't enough of them to fly together, or they simply don't want/need to. It's not like they're in a race.

I believe pelicans and some relatively small ducks do this too. These are probably more reliable references in this case than Wickedpaedera

GA Ed

What you said is absolutely correct but we usually only observe the birds from ground level, if you were to observe the birds from the altitude at which they are flying you would also see that each bird in the "V" is also slightley higher than the one in front in order to take advantage of the vortices.

DITTO and GA

"However, it does not work quite the same way as drafting in racing. Birds fly in a flock for better lifting force, whereas the race cars stay close for less total aerodynamic drag force."

If it did, would the announcers refer to the practice as flocking?

Yup! staying to one side and slightly below helps the birds in trail to work less by harnessing the wing tip vorticies of the bird in front.

I was standing along side an FAA examiner when a flock of geese flew by. He quipped: "Isn't it amazing how they can do that?!"

I responded with:

"Yes it is and please notice that there are no regulations or en route controllers telling them what to do!"

The scowl he gave me would have atopped a clock!

L.J.

Your answer sounds good, but why a "V"? Why not to one side or the other?

Hi edignan, What a great aerodynamic flying ! GA from me too ! Let me add a couple of more observations on "V" formation flight of geese migrating to warmer place- why they do it this way? 1. By flying in a "V" formation, the flock increases the efficiency by almost 71 % compared to just one bird flying alone. 2. Sharing the same direction & working as a TEAM, they get to the destination quicker & easier. 3. When a goose leaves the formation, he feels the resistance of the air & the difficulties of flying alone. then he quickly comes back to the formation to take advantage of the flock's power in front of him. 4. When the leader goose gets tired, he goes to the end of the "V" formation, while another goose takes the lead. 5. The geese flying on a "V", they quack to encourage to the ones in the front. In that way they keep the same speed. 6. When a goose gets sick, injured or gets tired, he leaves the formation. Other geese leaves the formation too & they virtually escort to help out & protect him. They remain with him till he is OK to join the "V"---- Moral of the story : Let's be like GEESE. Rangasamy

Dear Mr. RANGASWAMY,

There is a power point-presentation on th subject what you have put the message here and I have to search in which DVD I have stored and to-morrow I will send this to this Liink.

Thanks,

DHAYANANDHDAN.S

CR4 MEMBER,

INDIA

Wish I could remember the entire piece, sage advice in response to a question about the proclivity of Man to search for answers... "What does a bird know of the air through which it flies, or the fish of the water through which it swims..."

Sorry, though, I cannot credit this correctly. I CAN'T FIND THE BOOK! Hope someone (or some cat) is familiar with it, and can share the entire piece, and credit appropriately.

It sounds like the birds know quite a bit about the air through which they fly! Not too sure about them fish.

My wife and I Have known this for 25 years. We fly GA aircraft up to 12,600 lbs. when following a heavy [C5A, C130, 7xx series boeing or MD80] standard procedure is to follow at least 3 minutes behind and 50 feet above the heavy to avoid the downward side of the vortices because the vorticies swirl from bottom of wing tip to top of wingtip on both sides aof the aircraft. Getting trapped in a vortex could damage a light aircraft structure or slam one into the ground if at low altitude. You'll also find that military formation flying technique also takes advantage of the wingtip vortex updraft by placing trailing aircraft slightly outside and above the wingtip of the leading aircraft. We learned all this from observing biologic air traffic [BIRDS].

Some birds that fly in 'V' formation do so to catch the air current from the other birds ahead of them to help them to continue flying in formation i.e. teamwork.

Thank you,

Denice M., CQA/ ASQ

Your all WRONG!

It's cause the one in front has the GPS! and the rest just love reading over his shoulders for a peek!

He's probably looking at foul (fowl for those who don't get the pun) pictures online.

You are also wrong!

It is because every one wants to see good way ahead. If they fly one behind other, they can not see the way ahead!

I've always wondered if the bird at the point of the V was the one determining where the flock was going of if there was communication between birds. Then I saw a swarm of starlings and now I'm really confused. How does a swarm of starlings decide where it is going? Surely there is no one bird directing the motion nor could there be that much communication between birds.

http://www.youtube.com/watch?gl=CA&hl=en&v=XH-groCeKbE

Cool video - maybe it's the same with fish shoals ? The response appears fast, but a humans sense of speed is different to other creatures. It could be that a slight change of direction by birds on the edge (reaction to predator, wind/water) has a ripple effect on the rest. ET might view a bunch of commuters walking through a city as equally intriguing - it often feels like a free-for-all, but major collisions are rare. Something like a Mexican wave ? Even a Korean one, move with the crowd or you get s***

Kris,

While I don't know about birds, fish are equipped with a mechanosensory "organ" known as a "lateral line", typically running down each side of the fish, from behind the gill slit back to caudal fin.

It enables a fish to sense nearby vibrations and changes in water pressure, thereby allowing a group of fish to move almost in unison.

When a fish is swimming alone, the lateral line can help it defend itself, by aiding it in sensing approaching movement/danger.

Anyone who has tried to catch a small marine tropical fish (e.g., damsels, blue devils, dominoes, etc.) in a fairly large home aquarium can attest to the fact that the little fish seems to have a sixth sense with respect to the approaching net, and can move like lightning...

===================================================================

Just my $0.02...

Thanks, JMAM, it's a very worthwhile 2 cents !

The lead bird (at the forward point of the 'V' formation) is working the hardest by being the first to 'break through' the air, which is offering resistance to its flight. the lead bird leaves a trail of air turbulence that helps lift along the V-shaped direction, and it is a bit easier for the other birds to fly in the wake of the lead bird. The birds also share the work by rotating the lead like sports people do in long distant events, sharing the workload makes the task easier.

There are no toilets up there so of course you are not gonna fly right behind the guys in front :)

Geese cannot pooh in flight.

I beg to differ. I am quite sure most other birds are able to (I have a poo bombed car to prove it). Can you tell us why Geese are incapable of moving bowels during flight?

I am no Ornathologist..... In general, bird which fly with their legs back (geese, ducks.. most water fowl cannot pooh in flight. Others (mostly land birds) fly with legs forward, sparrows, robins, jays, pigeons... etc. can pooh in flight. Birds don't have a bowel such as mammals do. they have no sphinctor (sp).

Ha, Ha. Sounds believable to me! But I am not about to hangout at the lake with an umbrella to prove you wrong. LOL . Perhaps the term "Loose as a Goose" comes into play somewhere here.

bird which fly with their legs back.....

They probably can, but the required splaying of legs would cause them to crash.

Oh, come on, surely you knew the very first entry would be right didn't you? Everyone knows that.

elibrary.unm.edu/sora/Auk/v093n03/p0554-p0559.pdf

I live under a long-distance migration path. I've noticed that with larger "V"s the lines are not strictly straight. Is it possible that by narrowing the angle of the "V" the geese further back are able to benefit from some aggregate of the efforts of the geese in front?

The physics of aerodynamics and turbulence apart, the birds by flying in V formation avoid colliding against each other by remaining in visual contact.

You got it...and that the others have succumbed to the big thou shalt not: the resort to anthropomorphic answers to explain observed animal behavior.

The first instance was with the mention of drafting, air flow and things of that nature: an appeal to reason is if bird were endowed with such information and could make a conscious decision....but this falls away on recognition, solely, that Vee flying birds do not have the brain capacity, either, for drawing such conclusions or for translating the information into a coordinated (or individual) plan of action.

The nature of any formation flying among birds, resorting to first principles, can best begin to be explained by the well observed and understood, innate/inborn imprinting behavior. Couple that with the fact of a blind visual zone directly in front of each trailing bird...then any aerodynamic effect can easily be seen as secondary, if not irrelevant.

But, about the aerodynamic effect...

Could it not also be surmised that it is just that thing (the drafting effect) which a Vee formation, and its participants are actually "seeking" to avoid? We can observe that migrating geese (for example) neither glide nor soar during cruise flight, but continue flapping ceaselessly. A reasonable inference...that each bird, from lead to rear-wards, by flying (not directly behind but) into "clear air ahead," avoids any "advantage" (anthropomorphic or birdwise) pursuing its forward progress...and also forward progress that does not overtake the lead bird(s) and formation ahead. (If formation migratories were seen to alternately flap and glide, it might be supposed that the purpose of such gliding was to slow...in order to resume formation synchronicity with the flock ahead; but this we do not see.

So if, apart from innate behavioral tendencies, aero flow and turbulence plays any role, it must be such that it prevents members of Vee flying bird gaggles from flying (veering) inward toward a single-line trailing path (even if we as humans might see that as an easier path for intelligent followers).

TexEx

I haven't discounted the theory of aerodynamics put forward by friends. Birds may not be able to interpret the theory of turbulence but they can adapt to the conditions created when flying in formation. And they will react instinctively to the pattern set by their ancestors.

I haven't read all this, but it looks impressive !

sounds reasonable.

People! Please get jobs! (don't tell me you already have, that will change my opinion about the real cause of this recession...).

Visualize flying for hours looking at your buddies back end you would move out a little for a different view.

I would say for drag purposes as well as visual reasons.

It is very simple..... Geese have only learned up to the letter "V"..... Soon we will all see them flying in a "W" formation!

Actually I have already seen it!

I believe.....

The lead bird creates a wake which provides less drag on all the birds following in the vee formation. In bicycle racing, a similar formation works so well that the lead cyclist must be rotated out frequently, but the group can proceed notably quicker than when a random formation is used.

Regards to all-this was too easy!

Easy - but the comparison with cyclists is without doubt false. The cyclists (and other vehicles) derive their traction from the ground, so they can actually apply a net forward force to the air - and so pull the air along with them. The birds derive all their forces from the air, so at constant speed the net forward force on the air is zero.

The benefit can perhaps best be understood by comparing the flock of geese with a large wing. At a fixed air-speed, the lift available from a well-designed wing grows significantly faster than the dimensions of the wing. By flying together the geese are simulating a compound wing structure, so the overall efficiency of lift-creation improves. That means that all the geese except the leader have to work less hard to stay aloft - so the effect is the same as for the bicyclists. There may also be a contribution to reducing forward drag-per-bird (as for a larger aircraft), but SFIK that has not been demonstrated; however, if true it might explain the tendency for the tail of the 'V' to be sharper than the front - and also suggest some additional benefit from the compound V that is sometimes observed with very large flocks.

Have you ever seen goose droppings?? I'd fly a little to the side too!!

Ha Ha, Geese are perhaps smarter than we think!

When the arrow based forward formation is made ,after take off,the lead bird's wings create an outward air thrust leaving reduced air pressure/partial vacuum to its left and right side wings.The succeeding flyer birds on both sides take advantage of this reduced air pressure zone created so that they exert relatively easierforward filght thrust energy facilitated by preceeder.Likewise the diverging 'A' [assume inversed 'V']and continued flock formation helps to reduce forward thrust energy of subsequent flocks.The flight lift energy could be individually to be managed based on weight of each bird at it's risk.Synergized energy is best demonstrated by birds in nature.This formation can also expected to offer a forward collective thrust in the atmosphere by way of reducing external spacial air pressure[forward outward air thrusr]so that entire flock face reduced air friction/pressure.Nature -man's ever green teacher.