How do flocks of birds turn in unison?

Question

Hundreds of birds in a flock will turn at the same moment in the same direction. How do they do that? Can't be sight - to many would run into each other. Schools of fish do it too.

Answer 1

I just asked the same question after reading a BBC news article... http://news.bbc.co.uk/1/hi/scotland/sout...

Tens of *thousands* can do it at the same time without crashing into each other.

Apparently it's not known how. Maybe they pick up the wind vibrations from the wing beats of the birds next-to and above them, or maybe they do actually have some kind of telepathy..

Here's my question in case it gets any further answers..

http://answers.yahoo.com/question/index;...