Skip to main content

How birds of a feather flock together

[ad_1]


Scientists have long wondered how and why fish swim in shoals and birds fly in flocks—what’s in it for the individuals? New research from New York University helps shed some light on what benefits they derive from their formations.



Unlike, say, a peloton of cyclists that are travelling on land by pushing their tires against the ground, fish and birds are moving in a medium that’s all around them, not just below them—and they’re both doing it, basically, with similar mechanisms: what NYU Ph.D. candidate Joel Newbolt, the study’s lead author, refers to as “flapping.”



Previous work has demonstrated that “in these groups like schools and flocks, you can do things like reduce the amount of energy it takes to move through the water or through the air,” Newbolt says. These ways of traveling lead schools of fish and flocks of birds to move in characteristic shapes. The geometry may differ from species to species—a flock of starlings moves differently than a V of Canada geese—but both are deriving benefit from their flock.


In previous models of this behavior, scientists assumed that each fish or bird was flapping exactly the same way, like a group of machines. But the reality is more complicated: even though every goose in the world is different from every other goose, still somehow all groups of Canada geese fly in similar configurations.



Ironically, the researchers behind this latest study actually used machines to model flapping in a controlled setting. They positioned two hydrofoils, a lifting surface designed to cut through liquid efficiently, in a tank of water. They lined the foils up one behind the other, and “flapped” both of them in a manner that parallels the general movement of a fish’s swimming tail or a bird’s flapping wings. What they found was that the lead hydrofoil created a wake behind it that “affects the position of the follower,” according to a supplementary video published by the researchers. That wake “can even keep the follower from colliding with, or separating from, the leader.”



The experiment “shows that these configurations are very robust,” says Lehigh University’s Keith Moored, who was not involved with the current research. His lab also studies flapping. The research lends more weight to the idea that the shape of schools of fish or flocks of birds is mediated by the air or water surrounding them, he says, which exercises force on wings or fins.



But the real surprise finding was that the relationship between the hydrofoils—and the influence of the wake—remained the same regardless of variations in how they flapped. “I was actually very surprised by that finding,” says Lehigh. “It’s a completely new idea.” The thing that kept them similar was the force exerted by the water itself. In the experiments, the wake left by the lead hydrofoil dictated the relationship that the back hydrofoil maintained. It pushed the back hydrofoil away or pulled it closer.



Understanding how individual fish and birds manage to move in groups so successfully can also offer insights to the designers of alternative energy technologies like wind and water power, the team hopes. “Depending on the river speed and their spacing, you can get more efficiency in the following ones,” Newbolt says.



But even the animals remain mysterious at this point. “There’s really so much to be understood about these movements in groups,” says Newbolt.




[ad_2]

Written By Kat Eschner

Comments

Post a Comment

Popular posts from this blog

Ice technicians are the secret stars of the Winter Olympics

[ad_1] The emphasis of this year's two-week-long Winter Olympic Games has been placed squarely on the Olympians themselves. After all, the stated purpose of the international competition is to bring together the world’s greatest athletes in a nail-biting competition across fifteen different winter sports. But before the curlers, skiers, and skaters even arrived in Pyeongchang, South Korea, the Olympians of the ice technician world were already a few weeks deep in a competition of their own. Mark Callan of the World Curling Federation and Markus Aschauer of the International Bobsleigh and Skeleton Federation both say they’re hoping to make the best ice the Winter Olympics have ever seen. To transform the barren concrete jungle of existing tracks and arenas into an ice- and snow-covered wonderland is an enormous undertaking. And it takes a keen understanding of the physics and chemistry that keeps frozen precipitation pristine. Curling Callan has been making and maintaining ic...
Post a Comment
Read more

How to avoid the mid-movie bathroom break

[ad_1] Long movies and the urge to pee have been linked since the early days of cinema. Sixty-three years before Avengers: Endgame and its three-hour runtime, moviegoers settled in for nearly four hours of The Ten Commandments . “There will be an intermission,” director Cecil B. DeMille announced during the movie’s introduction. And audiences’ bladders were relieved. On average, movies aren’t getting longer, but they also don’t come with a predetermined bathroom break. That means when nature calls, you’ve got to either sit in growing discomfort or gamble on the best time to run to the restroom. But it doesn’t have to be this way, and for most people, setting your body to “do not disturb” is fairly simple. Go before the show The first piece of advice is also the easiest: pee before the movie starts. Generally, healthy adults urinate every 3-4 hours, so the longer a movie runs, the more urgent it becomes to reset your internal p...
Post a Comment
Read more

Charted: Here's how much your food waste hurts the environment

[ad_1] Our species is pretty good at wasting food. Some we discard at the farm for being undersized or oddly shaped. Others we allow to decay in their shipping containers, thrown away before they even reach shelves. We leave even more foodstuffs wasting away in grocery stores, often by letting it sit there until it reaches its sell-by date. As consumers, we don’t have much control over most of the process that brings our food to the grocery store, but we do have control over how much food we personally waste. Let's face it: We’ve all found liquified lettuce in our veggie drawers. Don't fret. It's arguably impossible to consume 100 percent of the food we buy. But a healthy reminder of the effect food waste has on the environment might help us all to be more conscious of the amount of food we eat—and don't eat. Consumer food waste varies extensively depending on the area. In South and Southeast Asia, the Food and Agriculture Organization (FAO) estimates that only around ...
Post a Comment
Read more