Along with the thousand-strong flock of Scaup that the big winds blew in came this much smaller band of Surf Scoters. Small, but more numerous than in recent years, and very good to see again. Surf Scoters were once almost as plentiful in the bay as Scaup, but the big Cosco Busan oil spill of 2007 wiped out thousands of them, and they’ve struggled to recover. This flock consisted mostly of females, which is potentially good news for population growth.
The Cornell bird lab website gives these “Cool Facts” about Surf Scoters:
Surf Scoters are “molt migrants,” meaning that after nesting, adults fly to an area where they can molt their flight feathers. They briefly become flightless before continuing to their wintering range, and molting areas provide some protection from weather and predators. These spots include sheltered waters from southeastern Alaska to Washington’s Puget Sound, and Quebec and New Brunswick.
Surf Scoters breed on freshwater lakes, where the male defends a moving area around the female. The female with a brood is not territorial.
On crowded lakes, young Surf Scoters often switch from one brood to another. Because the mother provides no parental care other than guarding the chicks, evolutionary selection against such mix-ups may not be very strong.
Some Surf Scoters (mainly immatures) skip the summer trip north to breeding grounds, and hang around bays and estuaries southward to Baja California or New Jersey.
The oldest recorded Surf Scoter was a male, and at least 11 years, 7 months old when he was found in Maryland in 2015. He had been banded in the Newfoundland/Labrador area in 2004.https://www.allaboutbirds.org/guide/Surf_Scoter/overview