The big flocks of Scaup shown here in the far distance on the North Basin give a small taste of the the numbers that migratory waterbirds can assemble. Scaup can cover the water almost from coast to coast, as shown in this video from 2017.
So far, no other migratory waterbird has appeared here in quantities approaching the Scaup. The Bufflehead came in a distant second some weeks ago, but most have moved on now. Let’s see, as the season moves on, if any other species is still thriving vigorously enough to dominate the surface in the way that the Scaup are demonstrating.