Questions about Birds on the Beach

There's a place where two beaches meet, a point that sticks out a little with rocks and some sand. Yesterday this point was full of terns, all facing the same direction.

Waiting out a storm? Waiting for news of where the fishing is good? Just resting?



Today, same place, it was the pied shags' turn to enjoy the point.

The terns were flying above. Do shags scare the terns away, I wonder?