I’ve now spotted, oops, observed the Spotted Sandpiper in three locations: on the south edge of the North Basin, on the west edge opposite the hotel, and on the west edge more northerly, in the park proper. In each case, the bird had no pronounced spots on its white breast. That’s how they get in the non-breeding season. The birds’ nonstop dipping or teetering body motion left no doubt, however, about their identity.
Spotted sandpipers, as I’ve noted here before, have unusual gender roles. During breeding season, females accumulate seven times more testosterone than they have normally. They claim and aggressively defend territories against other females. They may mate with a number of different males of their choosing. They can store male sperm for a month and lay eggs long after mating. Males generally tend the nest and the young. Details on the Cornell and Audubon websites.