Our little group walked single file along the shoreline in the slanting, early afternoon sunlight. Pebbles hissed and rattled as they were washed by the waves sweeping up the cobblestone beach. The call notes of yellow-rumped warblers twinkled down from the spruce trees in the nearby forest, contributing their own sound to this serene symphony.

At one point, someone in our group spoke up.

“I see a harlie there.”

The speaker was Judy Markowsky, Maine Audubon member and director of the Fields Pond Nature Center in Holden. She was referring not to the motorcycle, but to a curious little water bird called the harlequin duck.

These birds are agile swimmers that prefer rough, white-water rivers to forage in and breed near during summer. Come winter, they trade rushing freshwater for churning surf, gathering in flocks to feed until they can once again return to their breeding grounds in spring.

It was these ducks we had come to Isle au Haut to see. Specifically, we were there to assist biologist Glen Mittelhauser in his study of the birds.

Mittelhauser has been studying harlequins off the rocky coast of Isle au Haut for 14 years. He started banding them six years ago, obtaining valuable information on population changes and dynamics. Every year he recruits volunteers to help him spot banded birds, decipher the letters and numbers on the leg bands, and make a count of the birds seen.

Band reading may sound easy – and it is, once you get the hang of it – but I found it to be challenging the second I squinted into a spotting scope to read a leg band.

First and foremost, there was the wind. Our first real day of band reading was a day of intermittent rain, choppy surf, and strong, gusty winds. These gusts had the ability, however so slightly (and sometimes not so slightly!), of making the scopes tremble and vibrate. This destroyed visual acuity, turning the characters on the band into indecipherable squiggles.

Of course, the birds didn’t know to cooperate, so we had to wait until they “hauled out” onto ledges so we could see the bands. Even then the bands were not always readily visible, often becoming hidden by seaweed or by the angle of the bird’s stance. This was were multiple volunteers came in handy; several people spread out over a small area equaled many more opportunities to decipher a band once the birds changed position. This made the overall effort successful. Out of almost 80 birds, Mittelhauser was able to record 18 bands – and not all of the birds were banded.

Although I was frustrated by not being able to decipher a band, being out there on that wild coast and being able to observe the birds more than compensated for it. The male harlies were gorgeous in their slate blue and russet plumage, which was marked with bold white stripes, dots, and dashes. In fact, this theatrical coloring gave them their name, harlequin, which derives from a traditional Italian character of comedy and pantomime. This masked actor would dress in an outrageous multicolored costume and do “histrionics,” (theatrical performances) for an audience.

The duck’s Latin name also reflects this: Histrionicus histrionicus. As if its unusual appearance weren’t enough, the bird emits very unduck-like sounds. Their vocalizations are more similar to squeaks than quacks, which earned them an odd nickname: sea mice.

Next week, I’ll tell you more about the trip and provide a more in-depth look at the harlequin duck.

Chris Corio, a volunteer at Fields Pond Nature Center in Holden, can be reached at fieldspond@juno.com