The Ruddy Ducks have come and gone this winter. The first ones, just a quartet, arrived in early November. A few more arrived at the end of that month. Then I didn’t see any organized gatherings of them — just scattered individuals — until early February. Now, in early March, a raft of approximately 75 Ruddies appeared in the North Basin. A handful of Clark’s Grebes and a few local Coots blended in with them.