Shoreline Sanderling

Shoreline sanderling. A sanderling pauses briefly on the shoreline to look at the camera. Lincolnshire, UK.

Whilst photographing grey seals over the winter months I always spend some time on the mud flats and shoreline photographing waders. By lying completely still and flat on the sand the birds eventually get used to me and hunt for grubs just a few metres away. 

Sanderlings: The Tireless Wanderers of the Shoreline

Among the rhythmic ebb and flow of coastal tides, sanderlings (Calidris alba) scurry across sandy beaches, their tiny legs a blur of motion as they chase waves for a fleeting feast. These small, charismatic shorebirds are a hallmark of sandy coastlines worldwide, captivating birdwatchers and beachgoers alike with their tireless activity and unique charm.

What Makes Sanderlings Unique?

Sanderlings are small, stocky sandpipers, easily recognised by their pale plumage and endearing habit of darting back and forth with retreating waves. While their behaviour is captivating, it’s their life story—marked by extraordinary migration and survival in extreme environments—that makes them truly remarkable.

Fascinating Facts About Sanderlings

1. Epic Migratory Journeys
   Sanderlings are long-distance migrators, traveling up to 10,000 km annually. Breeding in the Arctic tundra during the brief summer, they embark on remarkable journeys to wintering grounds along coastlines in every continent except Antarctica. Their migration routes span the globe, from Alaska to South Africa and Siberia to South America.
2. Masters of the Intertidal Zone
   These birds are specialists in the dynamic intertidal zone, feeding on small invertebrates like crustaceans, mollusks, and marine worms. They use their sensitive bills to probe the wet sand or snatch prey from the water’s edge, timing their foraging with the movement of waves.
3. Seasonal Makeovers
   Sanderlings undergo dramatic changes in plumage throughout the year. During the breeding season, they sport mottled rusty-brown feathers, which blend seamlessly with the Arctic tundra. In winter, they transition to a clean, pale grey and white appearance that mirrors the sandy beaches they inhabit.
4. Tidal Travellers
   Sanderlings are highly mobile, constantly moving to follow the tide. Their scurrying behaviour isn’t just for show—it’s a strategic way to access food left behind by retreating waves while avoiding the risks of deeper water or predators.
5. A Global Citizen
   Few birds have such a widespread distribution as sanderlings. From the shores of Scotland to the beaches of Australia, they can be found almost anywhere with a sandy coastline, making them one of the most cosmopolitan shorebird species.
6. Arctic Survivors
   Breeding in the Arctic presents unique challenges, including freezing temperatures and a short breeding window. Sanderlings adapt by nesting on bare ground or mossy areas, laying eggs that are well-camouflaged against predators. Once hatched, chicks are precocial, quickly learning to forage and fend for themselves.

Conservation Challenges

While sanderlings are not currently endangered, they face numerous threats that could jeopardise their populations:

• Habitat Loss: Coastal development, beach erosion, and pollution reduce the availability of their crucial feeding and resting habitats.
• Disturbance: Human activities, such as recreational beach use, can disrupt their foraging and roosting behaviours, leading to energy loss during migration.
• Climate Change: Rising sea levels and shifts in Arctic ecosystems threaten their breeding and wintering habitats.
• Declining Prey Availability: Pollution and overfishing can reduce the abundance of the invertebrates they rely on for food.

Efforts to conserve sanderlings include protecting critical coastal habitats, regulating beach activities, and supporting international agreements like the African-Eurasian Migratory Waterbird Agreement (AEWA) to ensure safe migration routes.

Why Sanderlings Matter

Beyond their charm, sanderlings play an essential role in the ecosystem. By preying on small invertebrates, they help maintain the balance of intertidal zones. Their presence is also an indicator of healthy coastal habitats, making them a focal point for conservation efforts.

How You Can Help

• Respect the Shoreline: Avoid disturbing foraging or resting birds by keeping a respectful distance.
• Support Habitat Protection: Advocate for the conservation of wetlands, estuaries, and beaches.
• Contribute to Citizen Science: Participate in bird counts and monitoring programs to aid researchers in tracking sanderling populations.