A Harlequin Duck’s Long Cross-Country Migration

January 6 was one of the most frigid birding days I can remember along the beaches of Long Island. I visited Shinnecock Inlet, where the outgoing tide sucked miniature ice floes into the ocean and wind chill temperatures dipped below -10°F.

The region was nearing the end of a prolonged cold snap that locked up most of the Island’s beaches and bays in a thick layer of ice. For the first time in many years, portions of the South Shore bays were completely frozen from the mainland to the barrier beach which forced congregations of waterfowl into the free-flowing ocean and inlets.

There wasn’t an overwhelming amount of birds in the inlet on this day but an immature male Harlequin Duck caught my attention. Harlequin Ducks have been declining throughout the years and are becoming scarce on Eastern Long Island, even at traditional locations such as Shinnecock Inlet.

Despite the blustery conditions, I was able to capture a series of photos of the young male Harlequin from atop the jetty before eventually retreating to my vehicle for warmth. Later that evening, while processing photos, it became apparent that the bird was sporting a blue band on its left leg with white characters “CI.”

How fortunate to have captured a legible leg band in the photos, especially given the conditions.

There was only one opportunity when the bird rolled to its right while preening, briefly exposing its left leg and, ultimately, the band. What makes this resight particularly remarkable is the fact that “CI” was banded along Upper McDonald Creek at Glacier National Park in Montana this past summer on August 29, 2017.

There are several researchers in North America, both East and West Coast, who band Harlequins within their respective, isolated breeding territories. Since 2011, the Glacier Program has banded a total of 210 Harlequin Ducks at Upper McDonald Creek: 47 females, 51 males, and 112 chicks.

Harlequin Ducks have historically been divided into two separate and distinct ranges; the Pacific Coast and the Atlantic Coast. Early nomenclature once delineated two subspecies; H. h. histrionicus (Atlantic) and H. h. pacificus (Pacific) but this distinction is no longer recognized.

Based on past and current research, it has always been understood that western breeding populations winter along the Pacific Coast and eastern populations along the Atlantic, as one would expect.

According to the research, the January 6, 2018 Shinnecock resight constitutes the first-ever documented record of a “Pacific coast” Harlequin Duck migrating to the Atlantic coast.

There is a previous record of a juvenile, first-fall Harlequin Duck, also with Montana origins, taken by a duck hunter on Lake Erie, Erie, Pennsylvania in the fall of 2015. Other than the Lake Erie record, there is no existing evidence that West Coast breeding populations make the long journey east across the continent to winter along the Atlantic coast.

This new evidence raises many questions and will keep the research teams scratching their heads for some time. Hopefully continued related studies will shed more light on the complex life history of this declining species.

Editor’s Note: While spotting or “resighting” banded birds may seem like incredible luck, anyone with a pair of binoculars can record band numbers. A wide array of species making their annual migrations through North America are wearing leg bands that observers can record and report. Your recordings can be a tremendous help to researchers, and may even document new migration habits (as is the case with this post). Check out ornithologist Joe Smith’s great guide to finding banded birds through binoculars.