Courtesy Kenn Kaufman
The Buff-breasted Sandpiper breeds in the high Arctic of Canada and Alaska, including some crucial areas in the Arctic National Wildlife Refuge. During migration, this sandpiper stops for food and rest in North and South America. The short grasslands of Brazil, Argentina, Paraguay, and Uruguay provide wintering grounds. The Buff-breasted Sandpiper is no longer observed in large numbers, except in a few staging areas.
A legend for the range map to the right can be found here
During migration, Buff-breasted Sandpipers use the edges of ponds or lakes, along with a variety of short grass habitats such as mowed fields, golf courses, and airports. Breeding takes place on the Arctic tundra close to water. Buff-breasted Sandpipers winter on the South American pampas, or prairies, where livestock have grazed heavily, and where seasonal flooding keeps the ground moist.
The Buff-breasted Sandpiper feeds mostly on insects by standing motionless as it scans the ground and then dashing after prey to pick it from the surface. The bird's food habits have been poorly studied, but they are known to eat flies, midges, crane flies, and beetles, as well as spiders and seeds from water plants.
Unlike any other shorebird in the Western Hemisphere, Buff-breasted Sandpiper males gather in loose groups called leks, where they perform breeding displays. Males vigorously and sometimes violently defend breeding territories.
Buff-breasted Sandpipers do not form pairs. After mating, the female makes a depression in thick moss and lines it with lichens, leaves, and grasses. Females almost always lay four eggs, with dense markings over a light background; they incubate the eggs for about 24 days. Hatchlings are "precocial," or well developed; they can run, feed themselves, and hide from predators.
A long distant migrant, the Buff-breasted Sandpiper requires migratory stopover sites for rest and refueling. Routes change with the availability of food and appropriate staging areas. Significant numbers of birds may not reach the breeding grounds. Male Buff-breasted Sandpipers start to leave the seasonally flooded prairies of southern South America in February and begin the return flight as early as mid-June. Females depart both grounds later than males. All Buff-breasted Sandpipers appear to cross the Gulf of Mexico. Juvenile Buff-breasted Sandpipers depart the breeding grounds much later than adults and tend to migrate farther east, along the Atlantic Coast.