Western Sandpiper
Western Sandpiper
Calidris mauri
At a Glance
A close relative of the Semipalmated Sandpiper. Western Sandpipers nest mostly in Alaska and migrate mostly along the Pacific Coast, but many reach the Atlantic Coast in fall and remain through the winter. Of the various dull gray sandpipers to be found commonly on coastal beaches in winter, Western is the smallest.
All bird guide text and rangemaps adapted from Lives of North American Birds by Kenn Kaufman© 1996, used by permission of Houghton Mifflin Harcourt Publishing Company. All rights reserved.
Category
Sandpiper-like Birds, Sandpipers
IUCN Status
Least Concern
Habitat
Coasts and Shorelines, Freshwater Wetlands, Lakes, Ponds, and Rivers, Saltwater Wetlands, Tundra and Boreal Habitats
Region
Alaska and The North, California, Eastern Canada, Florida, Great Lakes, Mid Atlantic, New England, Northwest, Plains, Rocky Mountains, Southeast, Southwest, Texas, Western Canada
Behavior
Direct Flight, Rapid Wingbeats, Running
Population
3.500.000
Range & Identification
Migration & Range Maps
From breeding grounds in Alaska and eastern Siberia, migrates southeast to wintering areas on both coasts of North and South America. Apparently migrates in series of short to moderate flights, without long overwater flights of some shorebirds.
Description
6 1/2" (17 cm). Bill usually longer than on Semipalmated Sandpiper, drooped at tip (but some overlap in bill shape). Spring adult has rusty marks above, black spots on sides. Fall juvenile like Semi but usually has rusty stripe on scapulars, whiter eyebrow. Winter adults gray above, pale below; see Dunlin and Sanderling. Not as brown as Least Sandpiper; has dark legs.
Size
About the size of a Robin, About the size of a Sparrow
Color
Black, Brown, Gray, Red, White
Wing Shape
Pointed, Tapered
Tail Shape
Rounded, Short, Square-tipped, Wedge-shaped
Songs and Calls
A soft cheep or kreep, higher and thinner than that of Semipalmated.
Call Pattern
Falling, Flat, Rising, Undulating
Call Type
Buzz, Chirp/Chip, Trill
Habitat
Shores, beaches, mudflats; in summer, dry tundra. Migrants and wintering birds are typically on open shorelines, mudflats, sandy beaches, tidal estuaries. In winter mostly along coast, few remaining inland then. Breeds on tundra slopes, choosing dry sites with low shrub layer and with marshes nearby for feeding.
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Behavior
Eggs
4, sometimes 3, perhaps rarely 5. Whitish to brown, with darker brown spots. Incubation is by both parents, about 21 days. At first, female incubates from late afternoon to mid-morning, male only during mid-day, but male's proportion increases later. Female sometimes departs before eggs hatch.
Young
Downy young leave nest a few hours after hatching. Sometimes both parents care for the chicks, but often the female deserts them after a few days, leaving the male to care for the young. Young feed themselves. Age at first flight about 17-21 days.
Feeding Behavior
Forages by walking in shallow water or on mud and probing in mud with bill; also feeds by searching visually and picking up items from surface of shore.
Diet
Includes insects, crustaceans, mollusks, marine worms. On breeding grounds, eats mostly flies and beetles, also other insects, spiders, small crustaceans. Diet in migration and winter varies. On coast eats many amphipods and other crustaceans, small mollusks, marine worms, insects. Inland migrants eat mostly insects, some seeds.
Nesting
Male sings while performing display flight over breeding territory. On ground, unmated male approaches female in hunched posture, tail raised over back; repeatedly gives trilled call. Nest site is on ground, usually under low shrub or grass clump. Nest is shallow depression with sparse lining of sedges, leaves, lichens. Male makes several nest scrapes, female chooses one.
Climate Vulnerability
Conservation Status
Still abundant, but vulnerable because high percentage of population may stop during migration at a few key points, such as Copper River Delta in Alaska. Declining numbers of migrants have been documented in some areas.
Climate Threats Facing the Western Sandpiper
Choose a temperature scenario below to see which threats will affect this species as warming increases. The same climate change-driven threats that put birds at risk will affect other wildlife and people, too.