Toughest of Birds, Dressed Up as a Clown
The harlequin duck (Histrionicus histrionicus) is a cult bird. I came to this conclusion very early in life. I grew up birding in Northern California in the '60s and '70s when breeding harlequins had been gone so long there they didn't even qualify as an ornithological memory. These birds had been reasonably widespread in fast-flowing, rocky Sierra streams until the early 1900s. By the time I was on the birding scene, breeding harlequins had been gone for decades'the last pair was sighted along Yosemite's Merced River in 1950. To add to the bird's mystique, in recent years a few pairs and freshly hatched young appear from time to time in Sierra streams, giving mountain visitors a sliver of hope for a sighting of the elusive species.
No one knows for sure why they declined in the Golden State. Some think that the birds fell victim to fishermen who believe they damage trout fisheries by eating fish eggs and fry. For the record, the real threat that harlequins' pose to trout fisheries is probably low, because of their low density and a diet dominated by insect larvae; fish eggs and fry taken much less frequently. But any species that needs safe nesting sites along the wildest of rivers is going to have a hard time in modern-day California. For now, adding harlequins to a year list in California requires expeditions to wild and often remote coastal locations, where they show up at scattered sites along the rockiest and most wave-battered sections of coastline. To what ends people go for a harlequin experience!
When I was younger, the most reliable spot in Central California was Tomales Point at the extreme north end of the Point Reyes Peninsula, a spot aggressively protected by a rancher whose dislike of birdwatchers was legendary. The most ambitious of listers and Christmas Count organizers chartered small craft to approach the point's dangerous waters by sea. My father, brother, and I ended up taking annual expeditions to the breakwater at Crescent City, about as far north as you can get in the state, where a small group of harlequins could reliably be found every winter. Then the jetty was destroyed by a tsunami. Who knows how this hardy duck handled that!
Harlequin ducks achieve cult status because they are uncommon, associated with the wildest of trout streams and the most achingly lonely and beautiful stretches of rocky oceanic coastlines, and they seem to be disappearing before our eyes. The species currently breeds in two disjunct regions of North America: the mountainous regions of the Northwest and Northern Rockies and the rocky and hilly areas of eastern Canada. In the former region, the breeding populations in individual states of the Northwest U.S. range from the tens to the very low hundreds. In the eastern region, there may be about a 1,000 birds, where historically numbers might have been as high as 15,000. Harlequin duck populations can also be found in Iceland, about 6,000, Greenland,and eastern Siberia.
For a bird that completely lacks any bright cereal-box colors, the harlequin duck is amazingly attractive. Its dark, blue-gray plumage is decorated with elegantly placed white crescents and stripes with black outlines, and its flanks are rusty-orange. The name 'harlequin' is based on the so-named clown-like characters who performed in classic Italian comic theater wearing costumes fashioned of patches of multi-colored fabric. These characters' performances were considered histrionic, hence the duck's scientific name, Histrionicus histrionicus.
The males' striking black-and white-markings may seem clown-like, but they actually allow harlequins to blend into the cresting white-caps of river currents and the breaking waves and eddies of rocky shores. Females are drab, with white facial spots: They resemble diminutive, small-billed scoters.
Harlequin ducks are one of only three species of ducks worldwide that breed in fast-moving mountain streams; the others are New Zealand's mountain duck (Hymenolaimus malacharhynos) and South America's torrent duck (Merganetta armata). Because of the physical demands of foraging for aquatic invertebrates living at very low densities, in water moving up to 15 kilometers an hour (just over nine miles an hour), the mountain stream niche is apparently a tough one for ducks.
Harlequin ducks prefer shallow portions of streams in areas with gravel bars for hauling out; they forage underwater, allowing the current to push down and forward along the length of their body. Torrent-feeding, or fast-stream, ducks, in general, have powerful legs placed far back along their narrow bodies, and long-tails to guide the current down their backs. Powerful kicks propel them underwater as they steer through the currents with partially open wings.
All three fast-stream ducks share adaptations to a limited food supply. They nest at low densities, produce small clutches of four to six eggs, and have a long, 27-29 day incubation period followed by a short, 40-50 day fledgling period. What's more, males leave the nesting area in early summer, earlier than many other kinds of ducks, and travel downriver to coastal areas. With no males around, re-nesting is not an option if the nest fails, but there is more food available for ducklings. Their small clutch size coupled with lack of renesting make it particularly difficult for them to recover from population crashes, such as occurred when the Exxon Valdez spill spread oil in their preferred coastal foraging zone.
Harlequins are seen along the coast, bobbing in the surf in small groups'sometimes with scoters and other sea ducks'as they dive and feed on mollusks, crustaceans, and other invertebrates living among the boulders hidden by the surging water. At the end of the breeding season, the flocks often consist of pairs that reunite when females join the mates that left them months earlier. Harlequins are far more vocal than many sea ducks, communicating with flock mates with a peculiar squeaking noise (You can hear them near the end of the above video). In addition to naturally rocky coastlines, breakwaters are often a good place to see them, and the proliferation of sea walls explains there apparent southward spread in the winter in recent years.
As with many cult birds, the opportunity to watch these remarkable birds in their starkly beautiful habitats requires careful planning. Some particularly good places to see them include the coast of Maine in the winter, the rivers of Glacier National Park in summer, and breakwaters along the coast of Washington and Oregon in winter. I highly recommend taking one of these pilgrimages and becoming a fan of the harlequin duck.