Sanderling

The Sanderling is one of the most familiar shorebirds to anyone who has walked a sandy beach, instantly recognizable by its habit of scurrying along the swash zone in tight little groups, always just ahead of the incoming waves.

In nonbreeding plumage it is the palest of all sandpipers — pale gray above and clean white below, with a black bill, black legs, and a black shoulder patch. Breeding adults become mottled rufous and black on the head, neck, and upper back, though this bright plumage is less often seen away from the Arctic.

Unusually among sandpipers, the Sanderling lacks a hind toe, an adaptation thought to aid its distinctive fast running gait on sand.

Key field marks

• Palest of the small sandpipers in nonbreeding plumage: pale gray above, white below
• Black bill and black legs
• Lack of a hind toe (visible in close photographs, unlike other small sandpipers)
• Rufous-and-black mottled plumage on head and upperparts in breeding season
• Bold black wingstripe visible in flight
• Characteristic wave-chasing feeding behavior on open sandy beaches

Similar species

• Dunlin (nonbreeding): browner and grayer, with a longer, drooped bill, and does not chase waves in the same tight, mechanical fashion.
• Western Sandpiper / Semipalmated Sandpiper: smaller, browner overall, longer or shorter bills respectively, typically on mudflats rather than open sandy surf beaches.

Habitat

Sanderlings are strongly associated with open, sandy ocean beaches, where they feed in the wave-wash zone, though they also use mudflats and lakeshores during migration.

Range and migration

They breed on high Arctic tundra in a circumpolar distribution, including the northernmost parts of North America, Greenland, and Siberia. After breeding, they undertake long migrations to winter on sandy beaches across nearly every continent, making the Sanderling one of the most widely distributed shorebirds in the world.

Behavior

Sanderlings feed by running rapidly back and forth with the rhythm of the waves, probing the wet sand exposed as each wave recedes and retreating just ahead of the next one — a highly energetic, almost comical feeding style.

Voice

Calls include a short, sharp "kip" or "twick," often given in flight or when flushed from a feeding flock.

Feeding

They feed primarily on small invertebrates exposed by wave action, including mole crabs (sand crabs), amphipods, and marine worms, probing rapidly with their short bills.

Nesting and breeding

Pairs nest on the ground on open Arctic tundra, often in gravelly or sparsely vegetated areas; the female may lay two clutches with different mates in a single season, an unusual breeding strategy among shorebirds.