Identification of Wilson’s Phalarope

Phalaropes are such unusual shorebirds – with their swimming and spinning habits, and with females much more colorful than males – that in the past they were often thought of as a family in their own right. More recent studies have firmly established their place among the sandpipers family. But from the birder’s point of view, they are still unique.

Two of these species, the Red-necked Phalarope and the Red-necked Phalarope, nest in the High Arctic tundra and winter at sea. The third species, Wilson’s Phalarope, nests in the marshes of the interior of North America and winters on the lakes of South America. It is the most distinctive member of a single group.

Wilson’s Phalarope breeding range is primarily west of the Mississippi, from the northern Great Plains to the western edge of the Great Basin. Much of this region is arid country where marshes can vary depending on local rainfall, and phalaropes seem prone to changing their breeding sites from year to year. Perhaps as a result, there are numerous records of the species appearing and nesting far to the east of the main range. During the warmer months, it can be seen almost anywhere in North America.

Wilson’s Phalarope ‘fall’ migration begins remarkably early. Females may finish laying eggs for their mates and leave the breeding territory before mid-June. Adult males, having completed or failed their chick-rearing duties, may be on the move in early July; soon after, the newly hatched juveniles begin to roam. In late summer, tens of thousands of individuals congregate on saline lakes in the western United States and Canada – for example, at Great Salt Lake, Utah, and Mono Lake, California – before to make an early fall flight, seemingly non-stop, to western South America. .

The Wilson is generally not difficult to distinguish from the other two phalaropes. It is somewhat larger with a more elongated body shape and a generally noticeably longer beak. It also shows distinct differences in the color pattern in each plumage. Well-marked breeding birds are so different that they rule out any possibility of confusion. Those in pale gray winter plumage are more similar, but differences in head pattern are diagnostic. In flight, whatever the season, they separate easily: Wilson’s has a whitish rump and tail and no wing stripe, while the other two show prominent white wing stripes and a dark center on the tail.

Much more so than the other two phalaropes, however, Wilson’s Phalaropes could be confused with other species of sandpipers. This is partly because he tends to do more walking and wading than the other two. Often he draws attention to himself with active behavior, rushing to the apartments. In winter plumage, gray with yellowish legs, it might suggest something like a Lesser Yellowlegs. The juvenile, more brownish overall, could be reminiscent of a juvenile Stilt Sandpiper. In any case, careful attention to the shape of the bird should make its identity clear.

Wilson’s Phalarope, breeding adult male. June at Box Elder Co., Utah. Photo by Brian E. Small

As one would expect from adult phalaropes in breeding plumage, the pattern of Wilson’s adult male resembles a muted version of the bright colors of the female. Typically the overall effect is darker, as on this bird, but some males in late spring and summer are much paler. The details of the facial pattern, along with the absence of strong pale stripes on the back and the cinnamon wash on the front of the neck, should help rule out the other two phalarope species. Note the black legs of this bird, typical of the breeding season. In adults in winter, the legs vary from greenish to dull yellow, while juveniles have bright yellow legs at first, fading to pale yellow.

Wilson’s Phalarope, juvenile. August in Deschutes County, Oregon. Photo by Brian E. Small

Juvenile Wilson’s Phalaropes, with their strong shades of brown, can be confused with other species of sandpipers, especially when walking on mud flats or wading rather than swimming. In full juvenile plumage, all large wing and upperpart feathers have dark centers and sharply contrasting buff edges. Only a few sandpipers have similar patterns, and none of these match the shape of this bird. With its bright yellow legs, the Phalarope might suggest a short-legged version of the Lesser Yellowlegs, but the latter species has fine spots along the edges of the upperpart feathers, not broad buff edges. Shortly after the independence of these young phalaropes, the scapulars and then the coverts begin to be replaced by plain gray feathers.

Wilson’s Phalarope, first winter immature. September in Ventura Co., California. Photo by Brian E. Small

In full winter plumage, Wilson’s Phalaropes are plain and pale overall, patterned gray and white. The other two species of Phalarope can be plain gray on the back (Red Phalarope) or gray striped with white (Red-neck Phalarope), but they always have a blackish patch behind the eye and a white forehead. In the Wilson’s Phalarope in winter, the band behind the eye is pale gray and the gray of the crown often extends over the forehead. Wilson generally has a significantly longer beak than the other two, but this varies. The individual in this photo is a young bird that has not fully moulted into full winter plumage, still showing dark-centred, buff-edged feathers on the tertials, greater coverts and rear scapulars.

Wilson’s Phalarope, male. May in Cochise County, Arizona. Photo by Brian E. Small

Female Wilson’s Phalaropes during breeding season, with their crisp patterns and rich colors, look similar for the most part, but there is a surprising amount of variation among the males. Some simply look like darker, duller versions of the females, as seen in a photo on the previous page, but others are much paler, like the one in this photo. Although the frosty appearance of this individual may suggest that it is still partly in winter plumage, a closer examination shows that some of its pale gray feathers are relatively fresh. These dull individuals may be second-year males. To identify the species, note the overall elongated shape and the distribution of darker gray and pale cinnamon on the neck.