I sometimes think they have some signals we are not aware of.
In a split second Ibis and Snowy Egret came out of nowhere and dropped down into a small school of fish.
It went from maybe 2 – 3 birds to dozens.
I have learned over time when this happens the best shots are when I focus on a single bird among all the others. Grabbing images of masses of birds always seems good in my head, not so much when I view the results.
Above I was shooting the White Ibis, the two Egrets watching intently were a bonus. That’s why I try my best not to randomly shoot into crowds.
Of course theory and real life don’t always match LOL. If you have a hundred wild animals zooming all around all bets are off.