It's an exciting moment for Mittelhauser on Isle au Haut when he spots a bird banded elsewhere. A yellow band with black letters comes from Labrador-Newfoundland. You really get a sense of how small the total eastern population is when you see the exchange of banding information with Canada. As soon as we started banding here, they began seeing our bands in Canada. Banding has not only proved the site tenacity of these ducks, it has also established the bond between couples.
Harlequins pair on wintering grounds, then fly north together.
They build their nest close to a running stream, on a small midstream island, on high ground safe from flooding, or sometimes in a tree cavity. They feed in the rough current, diving and even walking like dippers on the stream bottom, competing with fish for the larvae of blackflies, stone flies, and other freshwater insects. Once incubation begins, the male drops out. He flies to a familiar molting site and schmoozes with other males until his fresh plumage is in place. Then it's off to the south again, where he meets his mate on their designated wintering grounds.