The Grand Convention of Down East Common Eiders is an event held annually from January into March near the Blue Hills reversing falls. The accommodations are good there: the fast-moving waters not only don’t freeze, they expose crabs and mollusks for easy picking.
Eight years ago, more than 400 eider conventioneers were celebrating at this time in January. Their numbers have been declining here each year since then. Yesterday, as you see, there were fewer than 50 eiders dancing a thin conga line here, the males in formal black and white, the females bronzed.
Perhaps there will be latecomers flying in after being distracted by our relatively warm winter (until recently). However, common eiders (Somateria mollissima) reportedly have been in steady decline throughout their entire Atlantic coast range. The causes of the decline are not fully known, but research indicates that warming waters may be part of the problem.
Atlantic blue mussels, the birds’ favorite food, are declining severely due to the warmer waters. More bald eagles are staying north in the warming winters where they are significant eider predators. In addition, eiders, our largest native duck, are favorite targets during winter duck-hunting season. (Images taken in Blue Hill, Maine, on January 8, 2022, [swimming] and February 17, 2016 [in flight].)