Least Sandpipers, Calidris minutilla
Least Sandpipers are small shorebirds that breed in the northern parts of North America, including Alaska and northern Canada, and also northeastern Siberia. During the non-breeding season, they migrate to the southern United States, Central America, the Caribbean, and northern South America.
Least Sandpipers forage in mudflats along coastlines and estuaries, sandy and rocky shorelines, freshwater and saltwater marshes, shallow tidal pools and ponds for insects, crustaceans, mollusks, and worms. They have specialized bills that allow them to probe into mud, sand, and shallow water to capture their prey. Their foraging techniques include rapid pecking, probing, and picking at the substrate.
Least Sandpiper courtship displays involve aerial flights, calling, and other behaviors to establish pair bonds and defend territories. They nest in areas with moist tundra, often near ponds, lakes, or wetlands.
Their nests are shallow depressions lined with grasses, moss, and leaves. They often locate their nests in grassy areas, low vegetation, or even on patches of bare ground.
Females typically lay a clutch of 3 to 4 olive-brown eggs with dark markings which provide camouflage. After laying the eggs, the female incubates them. Chicks usually hatch in about 21 to 22 days.
During the incubation period, the nesting female is vulnerable to Arctic foxes, gulls, skuas, and other predatory birds. The parents may exhibit distraction displays or vocalizations to divert a potential predator’s attention.
Once the eggs hatch, the precocial chicks are born with their eyes open, a covering of downy feathers, and the ability to move around. They quickly leave the nest, becoming active and mobile.
The parents play a crucial role in the chicks’ survival by providing them with food. The parents feed the chicks small invertebrates such as insects, larvae, and crustaceans. They search for these foods in the same wetland and shoreline habitats where they forage for themselves.
Young Least Sandpipers learn to forage by observing and imitating their parents. They follow the adults as they search for food, watching how the adults probe the mud and shallow water for prey.
The parents guide the chicks in their foraging behaviors, leading them to suitable feeding areas and demonstrating the techniques for probing and picking at prey. The chicks gradually refine their skills through trial and error, guided by their parents’ actions.
The fledging period for Least Sandpipers is relatively short, usually around 18 to 21 days after hatching. During this time, the chicks continue to grow, strengthen their flight muscles, and hone their foraging skills.
Once the chicks have developed the necessary strength and coordination, they are capable of independent flight. They begin to explore their surroundings more extensively and start to feed themselves more effectively. The young sandpipers continue to receive some level of care and protection from their parents.
Least Sandpipers are migratory birds. As the colder season approaches, they embark on a remarkable journey to more temperate regions, seeking suitable wintering habitats. Their migration is quite extensive, taking them to a variety of locations across the Americas.
They migrate along several flyways, with populations from different breeding regions using distinct routes.
Birds breeding in the northeastern parts of North America, such as eastern Canada, migrate along the Atlantic coast, heading south to their wintering grounds. Birds from the interior parts of North America, including the Great Lakes region, follow the Mississippi River corridor on their migration journey.
Populations breeding in the central and western parts of North America take the Central Flyway, which leads them through the central United States. Birds from the westernmost breeding areas, including Alaska, follow the Pacific coast down to their wintering habitats.
During the winter, Least Sandpipers seek refuge in a variety of wetland and coastal habitats, mainly in more southerly latitudes. Some Least Sandpipers winter in the southern United States, particularly along the Gulf Coast, Atlantic Coast, and the shores of the Great Lakes.
The sandpipers also migrate to countries in Central America, including Belize, Guatemala, Honduras, Costa Rica, and Panama. Coastal wetlands, estuaries, and mudflats are their favored wintering habitats in these regions.
Some Least Sandpipers can be found wintering on various Caribbean islands, including those in the Greater Antilles and the Lesser Antilles. Still more sandpipers extend their wintering range into northern South America, with countries like Venezuela, Colombia, and Guyana providing suitable habitats along coastal areas and riverbanks.
During the winter months, Least Sandpipers focus on foraging for food in similar wetland and shoreline habitats as they do during the breeding season. These habitats provide them with the necessary food resources to sustain them through the winter until they return to their breeding grounds for the next reproductive season.