From Bob Dyer:
The most numerous duck at Shollenberger now is the Greater Scaup. They traditionally show up later than most other migratory ducks. As you can see, the male (colorful) and the female (brown) almost look like they were different species. They mostly hang out in a large flock in the middle of the central pond. By the way, Scaup is pronounced “scop” . Some try to slip in an “l” in the pronunciation, but it isn’t there.