A flock of mostly Black Skimmers with a few terns, gulls and Oyster Catchers mixed in were occupying a sand bar at the edge of the ocean near where the Kiawah River runs into the Atlantic.
As I’ve seen before some signal is received by the birds and they all take off and relocate at once.
This was just past low tide and their real estate was shrinking quickly with the incoming tide. They settled down on the next available spot, dislocating a few pipers.
The terns were more inclined to stay put, not minding the surf lapping at their legs.
Beachwalker Park, Kiawah, SC 9/24/2019