CLOSE
Getty Images
Getty Images

Why Do Flocks of Geese Fly in a “V” Shape?

Getty Images
Getty Images


In large swaths of the U.S. this time of year, it seems you can’t get more than a few feet without tripping over a Canada Goose; they come down here from the Great White North for the winter months (or, in some places, hang out year-round). When they’re not lounging about in field and stream, you might see them flying overhead, usually in a large "V" formation, with one bird in the lead and the others trailing behind it in two diverging lines.

Why do they fly in a “V”? Not just because a “Q” would be too hard. Scientists have found that the “V” formation serves two functions that make group travel easier.

Give Me A Lift

One reason—first proposed by aerospace engineers Peter Lissaman and Carl Shollenberger in 1970—is that the shape of the formation makes the birds more energetically efficient flyers than they would be flying alone. As a goose flies, air rushes around its wings, creating circular, rotating patterns of air at the ends of the wings called wingtip vortices. The vortices push air downward and upward in different spots (you can see a pretty clear illustration of this here), and if another goose is flying in one of the spots where the air is getting pushed up, it gets some free lift (the air force that directly opposes the goose’s weight) from the efforts of the first goose.

If geese fly in a group and arrange themselves correctly, then every one behind the leader gets a little extra lift and doesn’t have to flap as much to maintain altitude and forward momentum. The less they flap, the more energy they conserve, and the farther they can fly.

For a long time, scientists only had mathematical models, photos and distant observations of live geese to support this idea. The aerodynamics made sense, and observed birds were almost always in positioned in the formation to gain some advantage, but no one was able to directly measure the energetic benefit, if any, to free-flying birds.

Then, in 2001, French scientists had a unique opportunity to do just that when they crossed paths with a film company that had trained great white pelicans to fly in formation behind motorboats and ultralight planes for movie scenes. Researchers from the Centre d'Etudes Biologiques de Chizé, led by ecologist Henri Weimerskirch, fitted the birds with heart rate monitors and then filmed them in flight. Their data showed that the heart rates of pelicans flying in “V” formation were 11.4–14.5 percent lower than that of any one bird flying alone, and that the birds in formation could afford to flap less and glide more, for energy savings of 11.4–14.0 percent.

Given this, why don’t all birds fly in the “V”? It seems the advantages of the formation only apply to larger birds, like geese and pelicans, and aren’t as pronounced for smaller, lighter birds. But other formations may have their benefits, too. While the “cluster” formations that pigeons fly in, for example, actually cost them energy versus flying alone, they might allow large groups to fly close together and maneuver and turn without mid-air collisions.

An Eye On You

Researchers have noticed something funny with some bird flocks: While the birds usually fly in positions that give them some energy benefit, not every bird is always in the expected optimal position, and therefore they get lower energy savings. Some birds just aren’t making the most of the “V,” which got people thinking that there might be another reason for the formation.

That reason might be that the formation allows the birds to maintain visual contact with each other and to communicate, making it easier to keep the group together and navigate. Taking the angles of the formation and what they know about geese’s field of vision and “blind spots” into account, researchers from the University of Rhode Island hypothesize that a “V” angle of 29 degrees or more would allow every bird in the group to see every other bird. There don't appear to be any studies that directly test this idea.

Just like with the energy conservation idea, though, the birds don’t always take up the optimal spot for clear visual contact. Most fly, instead, in positions that give them some benefit in terms of both energy and flock contact, or in one or the other. Those close-but-no-cigar situations beg the question of whether there's another "V" advantage we're not seeing, or if it's just really hard for birds to find and maintain the best spot in the formation.

nextArticle.image_alt|e
Cameron Spencer, Getty Images
arrow
Big Questions
How Do Aerial Skiers Perfect Their Jumps?
Cameron Spencer, Getty Images
Cameron Spencer, Getty Images

If you've ever watched an aerial skier in action, you know that some of the maneuvers these athletes pull off are downright jaw-dropping—and you've probably seen more than a few of these skiers land on their rear ends at some point. The jumps are incredible, but they're also so technical that one seemingly insignificant motion can drop a skier on his or her tail.

Given that the skiers can fly up to 60 feet in the air and come down on a 37-degree grade, it seems like just going out and trying a new trick would be a good way to break your neck. That's why you'll need one unexpected piece of equipment if you want to start training for aerials: a towel.

Instead of perfecting their flips and twists over the snow, aerial skiers try out their new maneuvers on ramps that launch them over huge swimming pools. The U.S. national team has facilities in Park City, Utah and Lake Placid, New York that include specially designed pools to help competitors perfect their next big moves. The pools have highly aerated patches of bubbles in their centers that decrease the surface tension to make the water a bit softer for the skiers' landings.

If you're an aspiring aerial skier, expect to get fairly wet. New skiers have to make a minimum of 200 successful jumps into water before they even get their first crack at the snow, and these jumps have to get a thumbs up from coaches in order for the skier to move on.

This sort of meticulous preparation doesn't end once you hit the big-time, either. American Ashley Caldwell, one of the most decorated athletes in the sport, is competing in her third Olympics in Pyeongchang, but failed to advance past the qualifiers on February 15, as she wasn't able to land either one of the two triple-flipping jumps she attempted. Still, it's this very sort of risk-taking that has brought her to the top of her game, and caused friction with more than one of her past coaches.

"Why win with less when you can win with more?" Caldwell said of her competition mentality. “I don’t want to go out there and show the world my easiest trick. I want to show the world my best trick, me putting everything on the line to be the best.”

You can check out some of Team USA's moves in the video below:

Have you got a Big Question you'd like us to answer? If so, let us know by emailing us at bigquestions@mentalfloss.com.

nextArticle.image_alt|e
iStock
arrow
Big Questions
Is There Really Such Thing As 'Muscle Memory'?
iStock
iStock

Is there really such a thing as 'muscle memory'? For example, in the sense of your fingers remembering where the keys of the keyboard are?

C Stuart Hardwick:

Yes and no. There is no literal memory in the muscles, but the thing people call “muscle memory” exists, though the name is a misnomer.

A better name might be “subconscious memory,” as the information is stored in the brain, but is most readily accessible—or only accessible—by non-conscious means.

What “non-conscious” refers to here is the brain’s enormous capacity to train up what might almost be called “subroutines,” that exist outside our conscious experience. I like the term for this that at least one researcher in the field uses: “zombie agency.”

Zombie agents are non-conscious, or sub-conscious (in the literal, not the Freudian sense) that can do essentially everything you can do except make value judgments. So, for example, you don’t consciously know how to control your muscles in order to walk —in all likelihood, you wouldn’t know where to begin—but your zombie agents do, and they’ll take you wherever you want to go, dodging curbs and puppies, and “waking you” when appropriate to decide which babies to stop and kiss.

Zombie agents can be rather startling things. When you suddenly become aware that you’ve driven halfway across town in the direction of the office instead of going to the shoe store Saturday morning, you have zombie agents to thank. You “wake” as if from slumber, and with the frightening realization that you’ve been flying down the highway at prodigious speed while your mind was on other things. You feel as if you’ve been asleep, and in a way you have—but a very funny kind of sleep in which it is only the uppermost layer of abstract reason that is disassociated from the rest of conscious experience. Your zombie agents have been driving to work, responding to traffic, adjusting the radio, noting the check engine light, all the things you think of as “you, driving the car,” except the big one: deciding where to go. That part was on automatic pilot (which is another good way to think of this).

This is at the advanced end of the spectrum. Typing your friend’s phone number using “muscle memory” is at the other, but it’s the same phenomenon.

We didn’t evolve to remember phone numbers, so we aren’t very good at it. In fact, we are so bad at it, we invent all sorts of mnemonic devices (memory aids) to help us [in] relating numbers to words or spacial memory, either of which are closer to the hunting and gathering we are evolved for. The illusion of “muscle memory” arises because we are supremely well adapted to manual manipulation and tool-making. We don’t need to invent a memory aid to help us remember what we do with our hands, we only have to practice.

So the conscious mind says “dial Tabby’s number,” and our fingers—or more correctly, the zombie agent which learned that task—do it. Similarly, after sufficient training, we can do the same thing with tasks like “play a major fifth,” "drive to work,” or “pull an Airbus A380 up for a go-around.”

It feels like muscle memory because the conscious mind—the part you experience as being you—is acting like a coach driver, steering the efforts of a team of zombie agents, all harnesses to collective action. But it isn’t muscle memory, it's just memory—though it may be stored (or at least some of it) in the deeper, motor cortex parts of the brain.

This post originally appeared on Quora. Click here to view.

SECTIONS

arrow
LIVE SMARTER
More from mental floss studios