Sanderling (Calidris alba)
|Size||Length: 18 - 21 cm (2) (3)|
Wingspan: 35 - 45 cm (2) (4)
|Weight||33 - 110 g (2)|
The sanderling is classified as Least Concern (LC) on the IUCN Red List (1).
One of the most widespread of all shorebirds (4) (5) (6), the sanderling is a small, highly active wader, typically seen racing after waves on sandy beaches as it hunts for small food items along the waterline (2) (3) (5) (6) (7). It is quite a plump species, with a short, stout, black beak and black legs (2) (3) (4) (6), and is unique amongst sandpipers in that it lacks a hind toe, as an adaptation for running fast on sand (3) (4) (6). At all times of year the sanderling can be recognised by its pure white underparts and broad white wingbar, bordered with black, which is visible in flight. During the breeding season, the head, upperparts and breast are reddish-brown to buff, mottled with black and white, while non-breeding birds are largely white, with pale grey upperparts and a distinctive dark shoulder patch (2) (3) (5) (6) (7).
Although the male and female sanderling are similar in appearance, females are usually slightly larger and paler than the males, with less reddish-brown colouration (2) (3) (6). Juveniles resemble the non-breeding adult, but are more darkly marked with black and white on the back, and have a buffy breast and head, streaked with black (2) (3) (5) (6) (7). The calls of this species include a short, soft twick or wick wick, and the male gives a frog-like call in flight over the breeding grounds (3) (5) (7).
The sanderling is an extremely widespread species, occurring on nearly all temperate and tropical sandy beaches throughout the world, and found on every continent except Antarctica (3) (4) (5) (6). It breeds throughout the Arctic, with the highest numbers nesting in the Canadian Arctic, Greenland and Siberia. In the Americas, the sanderling winters along the coast from Canada to Argentina, while elsewhere it winters on coasts from Western and Southern Europe to Africa, and from South Asia to Australasia, as well as on some Pacific islands (2) (3) (4) (8) (9).
The sanderling breeds on barren, stony Arctic tundra, usually on well-drained ridge tops, gentle slopes or level plains with sparse vegetation that includes willows, sedges, heathers and saxifrage (Saxifraga species). Although it may occur on inland lakes, ponds and streams during migration, this species more usually occupies coastal habitats during winter, including open, sandy beaches and the sandy outer reaches of estuaries, as well as rocky or muddy shores, and occasionally mudflats (2) (3) (7) (9).
The sanderling usually feeds in small flocks, typically foraging close to the water’s edge, where it captures small prey items exposed by the waves. It may also probe with the beak in wet sand and mud (2) (3) (4) (6), with sensors in the beak enabling it to detect prey up to two centimetres away (8). During the breeding season, prey usually consists of insects, as well as some spiders and crustaceans, initially supplemented by a little plant material when the birds first arrive at the breeding grounds. At other times of year, molluscs, crustaceans, worms and insects are taken, in addition to occasional fish, jellyfish and carrion (2) (3) (8) (9).
The sanderling is a widespread species and not currently considered at risk of extinction (9). However, some populations are believed to be in decline, with threats to the species including habitat loss and degradation, pollution, altered river flows, and disturbance from human recreational use of beaches (particularly from free-running dogs), to which the sanderling is quite sensitive (2) (3) (8) (9) (10). The species is also susceptible to outbreaks of avian influenza, and its breeding habitat and prey may potentially be impacted by global climate change (3) (9).
The sanderling is listed on Appendix II of the Convention on Migratory Species (CMS) (11), and is also protected under the African-Eurasian Waterbird Agreement (AEWA), which calls upon parties to undertake conservation actions for bird species that depend on wetland habitats for at least part of their annual cycle (12). The sanderling’s migration patterns and population dynamics are being studied as part of the Sanderling Project of the International Wader Study Group (6), and the species is also likely to benefit from various wetland conservation initiatives across its range (3). Other recommended conservation actions for this small waterbird include regulating human activity on beaches to minimise disturbance (10) and undertaking further research into the species’ biology, ecology and specific habitat requirements (3).
To find out more about the sanderling and its conservation see:
Birds of North America Online:
International Wader Study Group - Sanderling Project:
For more information on the conservation of wetland birds see:
African-Eurasian Waterbird Agreement:
For more information on this and other bird species please see:
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- Avian influenza: also known as “bird flu”, a contagious disease caused by any strain of influenza virus that is carried by and primarily affects birds.
- Carrion: the flesh of a dead animal.
- Crustaceans: diverse group of arthropods (a phylum of animals with jointed limbs and a hard chitinous exoskeleton) characterised by the possession of two pairs of antennae, one pair of mandibles (parts of the mouthparts used for handling and processing food) and two pairs of maxillae (appendages used in eating, which are located behind the mandibles). Includes crabs, lobsters, shrimps, slaters, woodlice and barnacles.
- Incubate: to keep eggs warm so that development is possible.
- Molluscs: a diverse group of invertebrates, mainly marine, that have one or all of the following; a horny, toothed ribbon in the mouth (the radula), a shell covering the upper surface of the body, and a mantle or mantle cavity with a type of gill. Includes snails, slugs, shellfish, octopuses and squid.
- Tundra: treeless, grassy plains characteristic of arctic and sub-arctic regions. They are very cold and have little rainfall.
IUCN Red List (June, 2010)
- del Hoyo, J., Elliott, A. and Sargatal, J. (1996) Handbook of the Birds of the World. Volume 3: Hoatzin to Auks. Lynx Edicions, Barcelona.
Macwhirter, B., Austin-Smith Jr, P. and Kroodsma, D. (2002) Sanderling (Calidris alba). In: Poole, A. (Ed.) The Birds of North America Online. Cornell Lab of Ornithology, Ithaca. Available at:
- O’Brien, M., Crossley, R. and Karlson, K. (2006) The Shorebird Guide. Houghton Mifflin Company, New York.
The Cornell Lab of Ornithology - All About Birds: Sanderling (June, 2010)
International Wader Study Group: Sanderling Project (June, 2010)
- Peterson, R.T., Mountfort, G. and Hollom, P.A.D. (1993) Collins Field Guide: Birds of Britain and Europe. HarperCollins Publishers, London.
- Nellis, D.W. (2001) Common Coastal Birds of Florida and the Caribbean. Pineapple Press, Florida.
BirdLife International (June, 2010)
- Thomas, K., Kvitek, R.G. and Bretz, C. (2003) Effects of human activity on the foraging behavior of sanderlings Calidris alba. Biological Conservation, 109: 67-71.
Convention on the Conservation of Migratory Species of Wild Animals (June, 2010)
Agreement on the Conservation of African-Eurasian Migratory Waterbirds (June, 2010)