Western Sandpiper

Overview

The Western Sandpiper is one of the smallest common North American shorebirds, part of the group known informally as "peeps" for their diminutive size and similar plumages. In breeding plumage it shows rufous tones on the crown, ear coverts, and scapulars against otherwise gray-brown upperparts, while non-breeding birds appear plainer gray above and white below. Its relatively long, slightly drooped bill tip is a helpful feature for separating it from other small peeps.

It breeds on Alaskan tundra and migrates in huge numbers along both coasts of North America, often forming dense mixed flocks with other small sandpipers.

Feather Identification

• Breeding upperparts: Rufous tones on the crown and scapular feathers contrast with grayer wing coverts, giving a two-toned back pattern.
• Non-breeding upperparts: Plain gray-brown, lacking the rufous highlights, similar to other small peeps but often slightly paler.
• Bill: Relatively long for its size with a noticeable downward droop at the tip, longer and more curved than the Semipalmated Sandpiper's bill.
• Legs: Black, matching most other small Calidris sandpipers.
• Compared to similar species: The longer, more drooped bill and rufous scapular patches in breeding plumage separate it from the shorter, straighter-billed Semipalmated Sandpiper.

Plumage Notes

Breeding adults show rufous coloring on the crown and scapulars against grayer wing coverts; non-breeding birds are plain gray-brown above and white below, losing the rufous tones entirely. Sexes look similar, though females may show slightly less rufous coloring than males. Juveniles show bright rufous-fringed scapulars creating a distinctive two-toned back pattern, more vivid than in adult non-breeding plumage.

Habitat & Range

Western Sandpipers breed on coastal tundra in western Alaska, migrating along both the Pacific and Atlantic coasts of North America, as well as through the interior, to winter along coastlines from the southern United States through Central and northern South America. They favor mudflats, sandy beaches, and coastal marshes during migration and winter.

Behavior & Field Notes

This species forages by probing rapidly in soft mud and shallow water for small invertebrates, often alongside other small sandpipers in large mixed flocks. Its call is a thin, high-pitched "jeet" or "cheet," useful for distinguishing it from similar species by ear. Nesting occurs on the ground on Arctic tundra, typically well concealed among low vegetation near water.