A couple of years ago, we stayed in one of the manufactured homes on the edge of Westport Marina. From a small porch on the backside, we could watch the birds flying above Grays Harbor. While watching the brown pelicans, I noted that the gulls were also flying nearby. When a pelican dove for fish the gulls would follow in hopes of getting a snack. Upon closer observation, it became apparent that the gulls were anticipating when a pelican was about to make a dive, and one or more gulls would fly right behind the pelican before the dive. After a while I could predict with high accuracy - gull on the tail, dive imminent.