the L, on 02 January 2013 - 11:22 AM, said:
What? Can you elaborate more?
i saw it in one of those "will the world end in 2012?" documentaries, basically birds are conditioned to take flight straight away when the alarm call is made, even if they're asleep, what happened in this case was something started the part of the flock, who rose up making the alarm cry rousing the rest of the flock but in such a way as to be uncoordinated, it was dark (I bet they were day flying birds), it was cold, there were probably fireworks to boot, all that threw off their innate collision avoidance abilities and part of the flock died.
Does it happen a lot? No, as it takes a nasty confluence of events to produce mass death like that, but it's neither a mystery or a sign.