Solitary Sandpiper

(Tringa solitaria) (SOSA)

Photographic Identification Guide

Solitary Sandpiper Tringa solitaria (SOSA) is a tree nester that breeds in subarctic and low arctic mixed forests of Canada and Alaska. It winters in extreme south-central United States, Central America, the Caribbean islands and central to northern South America.

In this guide, we cover the features, in order of importance, to look for on these birds. When discussing plumages, we use the terms winter, spring, and summer to refer to northern hemisphere seasons. Because some of these birds spend parts of the year in the northern and southern hemispheres, the correct technical terms for the plumage stages—basic and alternate—help avoid the confusion of seasonal terminology.

visual gallery

species account

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Fig. 9. Comparison of Solitary Sandpiper and Lesser Yellowlegs. Note browner plumage and bolder eye ring of Solitary Sandpiper. Arlington Reservoir, Arlington, MA. 22 0ctober 2023.
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Fig. 8. Comparison of Spotted Sandpiper and Solitary Sandpiper. Juveniles. SPSA at Hornsby Bend, Austin, TX; 23 December 2014. SOSA at Arlington Reservoir, Arlington, MA; 16 September 2019.
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Fig. 7. Solitary Sandpiper. Juvenile. Note pale brown legs. Keene, NY. 10 September 2018.
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Fig. 6. Solitary Sandpiper. Juvenile. Note barred tail peeking just past the primaries. Arlington Reservoir, Arlington, MA. 8 October 2021.
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Fig. 5. Solitary Sandpiper. Summer adult (alternate) plumage worn and frayed on margins. Note scattered white spotting on mantle. Cape May, NJ. 24 September 2013.
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Fig. 4. Solitary Sandpiper. Dark underwings are striking in flight. Arlington Reservoir, Arlington, MA. 13 May 2020.
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Fig. 3. Solitary Sandpiper. Spring (alternate) plumage. Note speckled brownish plumage and two-toned bill. Arlington Reservoir, Arlington, MA. 6 May 2022.
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Fig. 2. Solitary Sandpiper. Spring (alternate) plumage. Note crisp streaking on neck and throat. Arlington Reservoir, Arlington, MA. 14 April 2018.
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Fig. 1. Solitary Sandpiper. Winter (basic) plumage. Note pale legs and bold eye ring. Livingston, LA. 12 December 2023.

The photos in this species account are arranged in this order:

Basic: winter plumage, roughly December to March.

Solitary Sandpiper begins its molt to winter (basic) plumage in the fall; full basic plumage is usually attained by mid-December; see Fig. 1.

Alternate: first spring and summer after hatch year or adult breeding plumage, March to July.

Beginning in spring, winter (basic) feathers on Solitary Sandpiper are gradually replaced by alternate feathers; see Fig. 2, Fig. 3.

Juvenile: young birds, recently hatched, July to late November.

Juvenile feathers are acquired on the breeding grounds immediately after the natal down is shed and before the young begin their southbound migration; see Fig. 6, Fig. 7.

Size and weight

Females average slightly larger than males and have longer bills.

Body length:

7.5–9.25 in. (19–23 cm)

Wingspan:

22–23.5 in. (55–59 cm)

Bill length:

1.1–1.3 in. (27–32 mm)

Weight:

1.1–2.3 oz. (31¬–65 g)

Calls

In migration, Solitary Sandpiper emits a high pitched kikiki call as it flushes and rises rapidly in the air, then cruises about looking for a safe place to land. On the breeding grounds, both sexes sing high-pitched songs during the nesting cycle.

Calls in Nome, AK, 2017:

Calls in Nabor Carillo, Mexico, 2016:

Plumage and other characteristics

Solitary Sandpiper is one of the few shorebirds with nearly identical spring and summer (alternate), winter (basic) and juvenile plumages.

In all plumages, a bold, pale eye ring is characteristic of the bird; see Fig. 3, Fig. 5.

In all plumages, the back (mantle) is brownish gray with pale spotting. The underparts are white. Neck and upper breast are streaked gray; see Fig. 2, Fig. 7.

When the birds are on the ground, a dark patch at the bend of the wing is conspicuous in most plumages; see Fig. 3, Fig. 6.

The legs are pale grayish green to yellowish brown; see Fig. 2, Fig. 5, Fig. 6.

The bill is straight, medium length and usually two-toned, with a greenish gray base and dark tip; see Fig. 1

Note the dark underwings in flight. The upper wings are unmarked gray; see Fig. 4, Fig. 7.

The tail is dark at center, barred on the edges; see Fig. 4. The barred tail edges often peek out from underneath the folded wing tips; see Fig. 3, Fig. 6.

Winter (basic) plumage is brown on the back (mantle) with small white spots on the feather margins. The white spots give the appearance of pale zigzag margins to the mantle feathers; see Fig. 1.

Beginning in late March, winter (basic) feathers are replaced by spring (alternate) feathers. The back (mantle) is grayer with larger white spots and the neck and upper breast have crisp gray streaking; see Fig. 2, Fig. 3.

Spring (alternate) and summer (alternate) are the same plumage; however, as seasons advance, feather margins become worn and the plumage looks different. Beginning in July, Solitary Sandpiper’s alternate plumage begins showing signs of severe wear and the back spotting becomes sparse and uneven; see Fig. 5. Most birds do not acquire winter (basic) plumage until they are close to or at their wintering areas.

Juvenile back (mantle) plumage, though similar to adult (alternate) plumage, is browner with smaller pale or buffy spots; see Fig. 6.

The neck and upper breast on juveniles is marked with diffuse pale brown stripes; see Fig. 7.

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Breeding range, migration, wintering range, habitat

Solitary Sandpiper (SOSA) is one of the few shorebird species that nests in trees, using old nests of medium-sized passerines such as jays.

Nesting habitat consists of muskeg bogs with scattered spruce or other coniferous forests in subarctic and low arctic regions of Canada and Alaska.

In spring and fall, Solitary Sandpiper migrates in a broad front, primarily through the eastern two-thirds of North America.

Winter range for Solitary Sandpiper covers the southernmost United States, the Caribbean islands, most of Central America and northern South America.

During the nonbreeding season, the majority of Solitary Sandpipers are seen in inland ponds or flooded fields, sometimes in wet rice fields. Sightings on ocean shores are uncommon.

Most food throughout the year consists of adult or larval insects, small crustaceans and mollusks, and sometimes frogs.

Similar species

SOSA compared to SPSA

During migration seasons, Solitary Sandpiper (SOSA) and Spotted Sandpiper (SPSA) are sometimes found in similar habitats. These are mostly nonflocking birds that turn up singly at streambanks, riverbanks or wetlands. Both walk with a teeter, the Spotted far more so than the Solitary. Both emit high-pitched double or triple whistles when flushed.

Note the following:

Solitary Sandpiper is slimmer, longer-necked and longer-legged. Spotted Sandpiper looks dumpier with more compact dimensions.
Spotted Sandpiper flies with short flicks of stiff wings between landing spots. Solitary, when flushed, quickly rises high and flies in a swooping swallow-like fashion with angled wings.
In breeding (alternate) plumage, Spotted Sandpiper has distinctive dark spots on gleaming white underparts. Solitary Sandpiper’s underparts are always white up to the breast.
In breeding (alternate) plumage, Spotted has pinkish-orange at the base of the bill. The color fades to a darker orange or brownish at other seasons. Solitary’s bill is usually grayish brown or greenish brown at the base throughout the year.
In all plumages, Solitary back (mantle) is brownish with distinctive pale or white spots. Spotted mantle is usually a solid brown; in the juvenile, the wing coverts are barred; see Fig. 8.
Solitary Sandpiper has a bold eye ring and a pale line extending forward from the eye to the bill with a dark line below it. Spotted also has an eye ring, though not as bold, and the pale and dark lines from the bill extend backward to behind the eye.
In flight, Solitary tail is dark at the center and barred on the edges. Spotted tail is mostly brown with a pale zigzag margin.
In flight, Solitary has brown wings above with no pattern and dark gray-brown wings below with some barring. Spotted in flight has a thin white wing line above and mostly pale underwings.

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SOSA compared to LEYE

At first glance, Solitary Sandpiper (SOSA) seems like a miniature version of Lesser Yellowlegs (LEYE). For a comparison image, see Fig. 9.

Note the following:

Solitary Sandpiper back (mantle) is browner and darker than Lesser Yellowlegs.
Though both birds have conspicuous eye rings, Solitary Sandpiper eye ring is much bolder.
In breeding (alternate) plumage, Lesser Yellowlegs is barred on the belly and flanks. Solitary Sandpiper is hardly ever marked on the belly or lower breast.
Solitary Sandpiper legs are greenish or yellowish brown; Lesser Yellowlegs legs are bright yellow.
In flight, the center of Solitary Sandpiper tail is dark with heavy barring on the edges. Lesser Yellowlegs tail is whitish with light barring toward the tip.
In flight, seen from above, Solitary Sandpiper and Lesser Yellowlegs wings are all gray. Seen from below, Solitary Sandpiper wings are dark and Lesser Yellowlegs wings are pale and lightly barred.

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SOSA compared to GRSA

Solitary Sandpiper (SOSA) is the nearctic sister species to the palearctic Green Sandpiper (GRSA). The two species are extremely similar. The easiest identification feature is that Green Sandpiper has a white rump and gray-barred tip of the tail (best seen in flight) and Solitary has a dark-centered tail with barred edges.