Least Sandpiper

The Least Sandpiper holds the distinction of being the smallest shorebird on the planet, barely larger than a sparrow. Despite its diminutive size, it is a long-distance migrant and a familiar sight at wetland edges across much of North America.

Breeding plumage is warm brown, heavily mottled with darker feather centers on the back, giving a scaly appearance. Nonbreeding birds are duller grayish brown. The bill is thin, short, and slightly drooped, and the legs — the most reliable identification feature — are a distinctive yellowish-green rather than the black legs of most other small sandpipers.

Key field marks

• Yellowish-green (not black) legs — the single best field mark
• Very small size, smaller than other "peep" sandpipers
• Warm brown, scaly-looking upperparts in breeding plumage
• Thin, short, slightly drooped dark bill
• Often feeds on drier ground and grassy edges more than open mud

Similar species

• Semipalmated Sandpiper and Western Sandpiper: both have black legs and are slightly larger and grayer overall.
• Pectoral Sandpiper: notably larger with a sharply demarcated streaked breast band.
• Leg color is the most reliable way to separate the Least Sandpiper from its similarly sized relatives, especially in muddy conditions where legs may appear darker than they are.

Habitat

Least Sandpipers favor the muddy, often grassy edges of freshwater and brackish wetlands, wet meadows, and the drier margins of mudflats, more so than the open tidal flats preferred by some other small sandpipers.

Range and migration

They breed across the subarctic and boreal wetlands, bogs, and tundra edges of Canada and Alaska. They winter from the southern United States through Central America, the Caribbean, and into South America, migrating through nearly all of North America along the way.

Behavior

Least Sandpipers often forage in loose, small groups, walking with a slightly crouched posture as they pick rapidly at the mud surface, distinguishing their feeding style somewhat from the more probing action of larger sandpipers.

Voice

The flight call is a thin, high, rolling "kreeet" or "breep," often given as the birds flush in tight, twisting flocks.

Feeding

They feed on small insects and other tiny invertebrates picked from mud, often in slightly drier or more vegetated spots than other peeps.

Nesting and breeding

Pairs nest on the ground in a shallow, well-hidden scrape amid sedges or moss in northern bogs and wet tundra; the female typically lays four eggs, and both parents share incubation duties.