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The Ivory Bill·Birds·Shorebirds

Sanderlings, Calidris alba

Sanderling foraging in sand among rocks

Sanderlings are shorebirds that breed in high Arctic tundra habitats in regions including Greenland, Canada, and Siberia from June to early August.

Sanderlings are commonly found in dry, rocky tundra with sparse vegetation, such as mosses and lichens, where insects like flies, beetles, and spiders are abundant during the short Arctic summer.

They forage in intertidal zones, particularly on sandy beaches and mudflats, for small crustaceans, marine worms, mollusks, and amphipods. They may also feed on fish fry and algae.

Sanderlings exhibit a distinctive foraging behavior, known as “wave chasing,” where they run rapidly along the shoreline, following retreating waves to capture prey. Their quick movements and keen eyesight enable them to efficiently exploit the intertidal zone.

Courtship involves aerial displays where males perform slow, exaggerated flight patterns with distinctive calls. On the ground, males display by puffing up their chests, fanning their tails, and calling persistently to attract a mate.

Nest building is done by the female, who scrapes a shallow depression in the ground, often lined with lichens, moss, and small stones. Nests are typically located in open, elevated areas to avoid flooding.

Egg laying occurs from late June to early July, with the female usually laying four eggs. Both parents share incubation duties, which last about 24 to 31 days. Upon hatching, the chicks are precocial and leave the nest shortly after drying. Initial diets for chicks consist of small insects and other invertebrates, which they forage for with some guidance from the parents.

Chicks learn to forage by following their parents and imitating their foraging techniques. They face vulnerabilities such as predation by Arctic foxes, skuas, and jaegers, as well as the harsh Arctic weather. Parental care involves leading chicks to food-rich areas and protecting them from predators.

Chick fledging occurs about 17 to 21 days after hatching, with continued guidance from adults as the chicks refine their foraging skills. Their diet gradually broadens to include a wider variety of insects and invertebrates as they grow.

Sanderlings undertake long migratory journeys, leaving their breeding grounds in late August to early September. They follow specific flyways, traveling along the coasts of North America, Europe, and Asia to reach wintering regions in South America, Africa, and Australasia.

Wintering habitats include sandy beaches, estuaries, and tidal flats, where they forage for small crustaceans, marine worms, mollusks, and other intertidal invertebrates. Their diet in winter is diverse, reflecting the variety of food available in these coastal habitats.

Sanderlings typically leave their wintering grounds in late April to early May, returning north to their breeding areas as the Arctic ice melts and the tundra becomes accessible again, providing abundant insect prey for the breeding season.