Sanderling, Calidris alba

Sanderling, Calidris alba. Photograph taken with the rocky shoreline of the greater Bahía de los Ángeles area, Baja California, January 2019. Photograph courtesy of George Flicker, Bahía de los Ángeles. Identification courtesy of Mary & George Flicker, Bahía de los Ángeles.

The Sanderling, Calidris alba, is a member of the Scolopacidae Family of Sandpipers and Allies, that has ninety-seven members placed in fifteen genera, and one of twenty-four global species of the Calidris Genus. They are known in Mexico as playero blanco and playero gordo.

The Sanderling is small and plump in stature. The sexes are similar in appearance. They have a white head, pale gray underparts, and white underparts with a distinctive dark shoulder patch. In flight they show a bold, broad, white wing-stripe bordered by black. Their bill is long, black, straight, heavy and stout, their iris is dark brown to black and their legs and feet are black. They have three toes and lack a hind toe, a hallux, distinguishing the Sanderling from other sandpipers.

During the winter and while migrating the Sanderling is found predominantly on sandy beaches with hard-packed sand and within salt lagoons in close proximity to beach wrack and on occasion within estuaries and rocky coasts. Their feeding style is unique running ahead of incoming waves and chasing after receding ones, probing the sand for subsurface invertebrates. They consume aquatic and terrestrial invertebrates including small crustaceans and bivalve mollusks, limited amounts of small polychaete worms, insects, and talitrid amphipods. They are complete long-distance migrants breeding in the high-artic tundra in remote areas far beyond human habitation and development and wintering in both tropical temperate and south temperate sites. Their migration varies from 3,000 km to greater than 10,000 km. They have life spans of up to thirteen years.

The Sanderling is similar in appearance to several other sandpipers but has a whiter face, a short black straight bill than the others.

The Sanderling can be found on all Mexican beaches along the Atlantic Coast (throughout the Gulf of Mexico, where they are rare, and in the Caribbean on the east coast of the Yucatán Peninsula) and the Pacific Coast.

From a conservation perspective the Sanderling is currently considered to be of Least Concern with stable, widely distributed populations. Their populations are in significant decline in certain areas which is attributed to human pedestrian and vehicle traffic disturbance of their beach habitat significant affecting their foraging areas and roosting sites. This includes their wetland staging areas which provide adequate food to complete their migrations.