When eiders finish nesting their families form large flocks and move along the coast to find mollusks and crustaceans to eat. The birds stay so close together on the water that an eider flock is called a raft.
A reliable place to find them at Acadia is just off Otter Point at high tide. The rafts float above submerged rocks where the mussels and crabs are lurking. Eiders must be very strong swimmers because they seem to prefer diving through crashing waves to pluck a meal from the rocks 50 feet underwater.
In the fall the males change out of their beautiful black and white breeding plumage and become brown with white accents. With the females and juveniles already brown-colored, and the males changing to “definitive basic plumage,” the rafts are composed of mostly brown birds.
Believe me, this can be confusing when you’ve heard there are eiders at Otter Point and you can’t find any that look like this!
(photo by Kaido Kärner from Shutterstock)