Murmurations : is the term used to describe birds flocking and swarming in the sky. Very often, it will take just one bird to change the direction of the swarm. While I have written about swarms before, physicist Andrea Cavagna who studies Bose-Einstein condensates has compared the swarming physics to that of a superfluid; atoms which fall into place in a Bose-Einstein condensate. Sounds far-fetched? read on to know more...

Movement : Cavagna was hardly the first scientist to be intrigued by these acrobatics—known, in a rare instance of technical language coinciding with poetry, as “murmurations.” Other animals that travel in groups showing the same uncanny ability to move in apparent unison away from a predator or toward a food source. One 20th-century ornithologist seriously proposed that they coordinated their movements by telepathy. That possibility hasn’t found much support in biology. The other explanation is that a signal to change direction originates with one or a few individuals, probably on the periphery (the ones most likely to see a threat), and travels as a wave front across the flock, like a ripple spreading across a pond from a dropped pebble. It is just an artifact of human vision that we can’t see it happen in real time. But high-speed cameras can capture it, and computers can model the behavior.

Swarm faster than individuals : Prince­ton biologist Iain Couzin and MIT oceanographer Nicholas Makris have shown that in the presence of a predator, or a potential food source, or an opportunity to spawn, a wave of movement crosses a school of fish five to ten times faster than any one of them can swim—“incredibly well orchestrated,” says Couzin, “like a ballet.” The fish they’ve studied exhibit a threshold response, changing course only when a sufficiently large fraction of their visible neighbors have.

Wave Phenomena : As for starlings, Cavagna and his collaborators have shown recently that each keeps track of the six or seven closest starlings, adjusting its flight to stay in synchrony. In a new paper, they show how a signal originating with a single individual can cross a hundred-yard-wide flock in a fraction of a second, with virtually no distortion or diminution. The equations that describe this are those that govern waves—rather than, say, the diffusion of a gas or liquid. In the broadest sense, the same laws that photons obey are in play when a flock of starlings encounters a peregrine falcon.

Article Link: http://www.smithsonianmag.com/science-nature/how-just-one-bird-can-urge-entire-flock-change-directions-180952426/?no-ist

Related paper: http://www.sciencedirect.com/science/article/pii/S0003347213000432

Swarming behavior: http://people.esam.northwestern.edu/~cristian/research_body.html

Must watch video link: amazing starlings murmuration (full HD) -www.keepturningleft.co.uk

Main pic source : http://www.rspb.org.uk/discoverandenjoynature/discoverandlearn/birdguide/name/s/starling/roosting.aspx

Gif and video source: http://americablog.com/2014/01/stunning-flock-starlings-video.html

Time lapse of bird flight patterns : http://www.visualnews.com/2014/01/27/bird-flights-mapped-into-time-lapse-sky-performances/

#scienceeveryday #sciencesunday #swarm