tags: birds, flock behavior, denmark, wildlife, wow, streaming video
This astonishing video from Denmark documents a flock of 300,000 birds in flight. I've seen flocks of as many as a million (or more) shorebirds in flight, but despite that, the sight never ceases to amaze me. For example, how do birds fly at such high speeds in such close quarters, changing directions seemingly at random, without crashing into each other?
What is the largest flock of birds you've ever seen? What species were in this flock? Do mixed-species flocks move differently than same-species flocks?
Life Science
Brain & Behavior
Comments
Some Italians looked at flying flocks in Rome. Their conclusion was that the birds were each following about 6 neighbours, and that was good enough to avoid collisions and also create these wonderful patterns.
Posted by: Bob O'H | November 14, 2009 1:42 PM
During the winter we often have enormous murders of crows on campus. They populate the tall (28m or above) trees, making the sidewalks an unhealthy proposition.
But it's wonderful to watch them fly; they're not rule-following flocks like these starlings. They seem intelligent, autonomous, almost democratic in a noisy way.
Posted by: george.w | November 14, 2009 2:34 PM
following six neighbors? what do they do when the six they are following shoot off into six different directions?
Posted by: "GrrlScientist" | November 14, 2009 3:31 PM
Cool. If they're following their six nearest neighbors, it sounds like what we're seeing is crystallography in motion. I love that thought & the ways bioscience & geoscience are continually intersecting. They could also be considered as a granular system.
I doubt I've ever seen more than a few hundred birds in a fock. I've seen thousands of geese settled on a marsh, but they probably represented dozens of flocks.
Posted by: argillic | November 14, 2009 4:20 PM
Flocking seems to be an example of emergent behavior, behavior that is not a property of any individual bird, but rather emerges as a property of the group itself... there is no leader, nor any no overall control but instead the flock's movements are determined by the moment-by-moment decisions of individual birds following simple rules in response to interactions with their neighbors in the flock.
This phenomenon was researched by Wayne Potts who used a frame-by-frame analysis of high-speed film of sandpiper flocks as well as through computer modeling by Craig Reynolds through an artificial life program called boids, who noted that the fundamental "laws" of flocking are: (1) separation, steer to avoid crowding local flockmates; (2) alignment, steer towards the average heading of local flockmates; and (3) cohesion, steer to move toward the average position of local flockmates.
Potts, Wayne K. 1984. "The chorus-line hypothesis of coordination in avian flocks." Nature, 24: 344-345.
Reynolds, Craig 2001. "Boids: bacground and update." http://www.red3d.com/cwr/boids/
Posted by: David | November 14, 2009 4:24 PM
Wouldn't want to be standing beneath that....
At any rate, that is the biggest swarm I have ever seen. I am glad that some still exist.
As for the questions regarding bird swarming behavior, I suggest you check out:
http://bingweb.binghamton.edu/~sayama/SwarmChemistry/
Posted by: scienceguy288 | November 14, 2009 9:14 PM
@David: This is most definitely emergent behavior. Emergent behavior is such that results from nonlinear interactions between autonamous agents in a complex system. That is, it is neither completely random nor completely structured. As a bioengineer, this is actually the focus of my research (not necessarily with bird flock dynamics).
Personally, I think the best way to explain this is through Cellular Automata: imagine a 100 by 100 grid. Each space on this grid contains a bird. The birds begin with at a certain state (direction, speed of flight etc.) As time progresses, the bird at any given space changes his behavior based on the behavior of the birds around them. This often creates emergent behavior as the birds are constantly changing states, but often is a somewhat predictable manner.
Posted by: scienceguy288 | November 14, 2009 9:19 PM
This is certainly the largest flock I have ever seen. What I have noticed is the similarity to schools of fish.
Posted by: Canadian Curmudgeon | November 16, 2009 11:44 AM