This Red-necked Phalarope was foraging in small circles, as described by the Audubon guide.
Audubon: “Phalaropes reverse the usual sex roles in birds: Females are larger and more colorful than males; females take the lead in courtship, and males are left to incubate the eggs and care for the young. Red-necked Phalaropes nest around arctic tundra pools and winter at sea. During migration they pause on shallow ponds in the west, where they spin in circles, picking at the water’s surface. However, most apparently migrate offshore, especially in the east. Despite their small size and delicate shape, they seem perfectly at home on the open ocean.”