Least Sandpiper Life History

Habitat

Habitat MarshesLeast Sandpipers breed in tundra and boreal forests across the extreme northern regions of North America. They nest in coastal wetlands, bogs, sedge meadows, and tussock heaths. At the southern reaches of their breeding range, in Nova Scotia and British Columbia, they also nest in sand dunes. During migration they stop on coastal mudflats, rocky shorelines, and inland habitats including wet meadows, flooded fields, and muddy edges of lakes, ponds, and ditches. They winter from the southern United States through the northern half of South America in lagoons, mangrove forests, wet ditches, swamps, wet fields, mudflats, saltmarshes, tidal sloughs, and the edges of lakes, ponds, and rivers.Back to top

Food

Food Aquatic invertebratesLeast Sandpipers eat mostly insects and other invertebrates. They forage on moist mud toward the edges of broad mudflats, sparse cobble beaches, or openings in marsh vegetation. During the breeding season they also forage in drier upland areas such as tundra. They eat small invertebrates such as amphipods, isopods, gastropods, horseshoe crab eggs, water fleas, midges and flies, beetles, and dragonflies. They peck at prey on the surface and probe damp mud for buried prey, using the surface tension of the water to transport the item quickly from their bill tips to their mouths. Females have longer bills than males and feed on larger items buried deeper in the mud. They supplement their diet of invertebrates with seeds of marsh grasses, including smartweed and panic grass.Back to top

Nesting

Nest Placement

Nest GroundLeast Sandpipers nest in tufts of short marsh grass on damp ground. In very wet areas they use slightly drier mossy hummocks. The male establishes the nesting area and makes several scrapes in the ground, and the female chooses one for nesting.

Nest Description

The male starts the nest by pressing his body into the vegetation on the ground and making a scrape. The female finishes smoothing out the hollow and adds a sparse lining of dead vegetation, creating a nest cup about 2 inches across and 1.5-2 inches deep.

Nesting Facts
Clutch Size:3-4 eggs
Number of Broods:1 brood
Egg Length:1.1-1.2 in (2.8-3 cm)
Egg Width:0.8-0.9 in (2.1-2.2 cm)
Incubation Period:19-23 days
Nestling Period:1 day
Egg Description:Pale yellowish-brown, with brown spots or blotches.
Condition at Hatching:Active and covered with down.
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Behavior

Behavior ProbingLeast Sandpipers flock with other shorebirds during fall migration and winter, including Western Sandpipers, Semipalmated Sandpipers, Sanderlings, and Dunlin. They roost in marsh vegetation near feeding areas, usually scattered in small groups. Early in the breeding season, males display for females by calling noisily and making a fast circular flight with bursts of wingbeats and glides, ending with a diving descent to the ground. Males defend their display areas against other males by fighting: they may land on each other’s backs, spar with their feet, and chase each other. Once paired up for the breeding season, they become less aggressive toward other males. Males and females share incubation, with females incubating in the evening and males taking a longer shift that lasts the rest of the day. The pair is monogamous and stays together until the female abandons the brood. The chicks feed themselves, but the male often stays with them until they fledge, keeping predators at bay. Nest predators include Common Ravens, crows, gulls, Sandhill Cranes, jaegers, Short-eared Owls, arctic foxes, and red foxes. Back to top

Conservation

Conservation Low ConcernLeast Sandpipers are widespread and numerous. A 2012 study estimates a continental population of 700,000 birds. Populations appear stable, but may have experienced declines over the last few decades. Least Sandpiper rates a 10 out of 20 on the Continental Concern Score and is not on the 2016 State of North America's Birds Watch List. Through the early twentieth century Least Sandpipers were among the many small sandpipers shot by commercial hunters on the Atlantic coast, but their numbers recovered after the Migratory Bird Treaty Act in 1918. Today, one of their biggest conservation concerns is wetland degradation and destruction. Populations in western and central Canada are thought to be stable, but those in eastern North America are declining. Between 1974 and 1991, the fall migration count in eastern Canada fell by 3 percent per year. The Maritime Provinces population dropped by 15.8 percent annually from 1974–1998. Because their breeding range is broad and remote, it’s likely the declines are happening at other points in their life cycle, such as from losses of wetland habitat on their migration routes and wintering grounds. Since Least Sandpipers are widespread and hard to distinguish from other small sandpipers during surveys, they have not been targeted for specific management by groups such as the Western Hemisphere Shorebird Reserve Network, but they will likely benefit from general protection of shorebird habitat.Back to top

Credits

Andres, B. A., P. A. Smith, R. I. G. Morrison, C. L. Gratto-Trevor, S. C. Brown and C. A. Friis. 2012a. Population estimates of North American shorebirds, 2012. Wader Study Group Bulletin no. 119 (3):178-194.

Lutmerding, J. A. and A. S. Love. Longevity records of North American birds. Version 2015.2. Patuxent Wildlife Research Center, Bird Banding Laboratory 2015.

Nebel, Silke and John M. Cooper. 2008. Least Sandpiper (Calidris minutilla), version 2.0. In The Birds of North America (P. G. Rodewald, editor). Cornell Lab of Ornithology, Ithaca, New York, USA.

Sibley, D. A. (2014). The Sibley guide to birds, second edition. Alfred A. Knopf, New York, USA.

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