How do birds flock? Research reveals previously unknown aerodynamic phenomenon
nyu.edu
nyu.edu
"Occasionally one of the curlew's wings would bite into the harder, spiraling air of a vortex left by the the wingtips of a migrating shorebird ahead of him, for even the passage of another bird left a trail in the air that the curlew's delicately sensitized wings could detect. Usually this alteration in the air pattern was the curlew 's first warning that he was overtaking a flock of birds ahead. When he found one of these vortexes, the curlew took advantage of it and followed it with one wing riding the updraft edge of the horizontal column of spiraling air. In this way he found a degree of lift readymade for him and his own wings could work a little easier.
But no other shorebird except the golden plover flew as fast as the curlew did, and each time he slowly overtook the bird producing the vortex ahead. First he would hear the faint twitter of a flock's flight notes, the vortex would grow stronger, then the birds would appear as blurred figures against the grey sky in front. The curlew would fly with them for a time, but his greater speed would gradually drive him ahead. Then once more he would be flying alone."
Karmen vortex shedding is the way I’ve heard it described and birds being highly sensitive to changes in pressure essentially ride the vortex sheds from the birds in front. Once the paper is tracked down I’m eager to see if there is something truly new!
Fish do something even more incredible where they line the vortex sheds up where the add constructively to their velocity. Trout seemingly being so optimized that they can flow up stream even when dead!
https://fyfluiddynamics.com/2018/07/when-i-was-a-child-my-fa...
How can they say they too many birds cause the later positions to be unstable if this is their model? Don't they just run out of circumference and so they can't really model so many birds because the paddles start to overlap?
I suppose the math models the higher number of birds but they didn't 3d print that math and put it in a fish tank.
It wouldn't take PhD's or studies to figure it out - it's a bit like noticing that it's more effort to run than walk.
Cyclists try do draft when possible. When there is no wind, or the wind is from ahead, it's simply: ride behind the rider in front of you. But when the wind comes from the side, it's best to position yourself somewhat to the side of the rider ahead. In my experience (but I have to admit I my experience is quite limited) it's actually surprisingly difficult to find the best position in that case.