All About Sandpipers, Familiar Shorebirds
Sandpiper Migration, Breeding, Diet, and Conservation Status
Oct 15, 2009
Along the coastlines of the world and in wetlands, particularly in the northern hemisphere, sandpipers are common shorebirds: brown or grayish birds with pale breasts. They wade in shallow water or walk along sand and mud flats, probing in the ground with their long beaks, or turning over rocks and seaweed in search of food.
Sandpipers belong to the taxonomic family Scolopacidae and include, among others, curlews, dowitchers, dunlins, godwits, redshanks, sanderlings, sandpipers, and turnstones. The sandpiper family is the largest family of wading birds. They are found on every continent except Antarctica, and throughout most of the temperate northern hemisphere they are seen almost anywhere, even far inland.
Sandpiper Migration
For most birdwatchers, the time to see many species of sandpiper is during the winter because the birds migrate far north in summer to breed. In doing so, they take advantage of the abundant food in subarctic and arctic regions during the warmest months; however, food becomes unavailable during the cold months of the year and the birds return south to forage on beaches and in wetlands. Some species both migrate and overwinter in large flocks.
Godwits are particularly known for their long migrations between locations in the southern hemisphere and the far north. For example, Red Knots (Calidris canutus) that breed in northern Canada spend the winter in southern South America, traveling up to 30,000 kilometres (more than 18,000 miles) twice each year. Bar-tailed Godwits (Limosa lapponica) make similarly long migrations from New Zealand to Alaska, sometimes flying for 10,000 kilometres without stopping to rest or feed.
Like other birds, sandpipers probably use coastlines, the sun and stars, and the Earth’s magnetic field to find their way. Scientists suspect the birds also hitch a ride on prevailing winds to save energy.
Sandpiper Breeding
Birds of the sandpiper family are known for their impressive courtship displays before breeding, both in flight and on the ground. Display flights involve hovering, wing fluttering, glides, and rapid ascents, as well as song. On the ground, the birds display their wings by lifting them.
The Ruff (Philomachus pugnax) a common sandpiper of Europe and Asia and rare visitor to North America, has the most impressive courtship display. Males fluff up collars of feathers, making themselves look like they are wearing elaborate headdresses. They display in areas known as leks, often working in pairs composed of a dark ruffed male and a white ruffed male to attract females. The darker individual is the dominant bird in these pairs, and gets the most mates.
Sandpiper nests are built on tussocks of grass in wetlands or on the ground in grassy drier areas. Eggs are incubated for 18 to 30 days and the young are already quite independent when they hatch. They fledge by seven weeks of age. The roles of male and female adult birds with respect to care of the nest and young differ between species.
Sandpiper Diet
During the non-breeding season, while sandpipers are engaged in their characteristic probing of the earth, their diet is mostly invertebrates—aquatic worms, snails and other mollusks, crabs and other crustaceans. During the breeding season, they feed mostly on insects, which are plentiful in the north during the brief summer. They eat some plant material at all times of the year.
The beaks of these birds are designed to find and catch prey. Some have very long curved bills for probing deeply into the ground, and these bills have sensitive tips to identify prey when they find it. Others species have shorter bills for picking up food on the surface. The turnstones have sturdier bills for overturning stones and pushing seaweed aside.
Sandpipers are thought to have evolved more than thirty-five million years ago and most species are doing well. A major threat to their continued success, however, is the human destruction of migration stopovers and wintering grounds. A number of species are listed as endangered or critically endangered.
Sources
Firefly Encyclopedia of Birds. Perrins, Christopher ed. Buffalo: Firefly Books, 2003
Sea & Coastal Birds of North America Leslie, Scott. Toronto: Key Porter, 2008.
Smithsonian Field Guide to the Birds of North America Floyd, Ted. New York: HarperCollins; 2008.
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