The spotted sandpiper (Actitis macularia) is one of the most widespread breeding shorebirds in the United States. I always think of the ocean when I think of a shorebird. However, the spotted sandpiper can be found anywhere near water with a “shore” – streams, lakes, rivers, and, of course, along the seacoast – even in arid and forested areas if there is water available. Spotted sandpipers breed in the northern states and Canada and winter in the southern states, Central America and northern South America.
With its rounded breast and short yellow legs, a spotted sandpiper looks as though it has a pot belly and is leaning forward. These medium-sized birds constantly meander with a bobbing motion while foraging. Although generally seen singly, spotted sandpipers will form small flocks during migration.
The breeding sandpiper is very distinctive looking with dark spots on a white breast, orangish bill and brown back. During the winter, or in nonbreeding birds, the breast is white with no spots. In flight sandpipers show a white stripe along their wings.
Spotted sandpipers eat small invertebrates such as midges, mayflies, grasshoppers and beetles, worms, snails, small crustaceans and small fish. Very versatile in how it feeds, the spotted sandpiper probes in the mud with its bill, picks insects off of vegetation, grabs at airborne prey and lunges at terrestrial prey on the ground.
Spotted sandpipers display a different breeding biology than most other birds. The female arrives first and establishes and defends a territory. She does the courting. Once a mate is selected both parents will build the nest. The male then incubates the eggs and cares for the young. He is the primary parent although the female will occasionally help raise the young. Spotted sandpiper females often practice polyandry (breeding with more than one male. She will sometimes mate with up to four males, each of which will raise a clutch of eggs. And because a female spotted sandpiper can store sperm for up to a month, the eggs that the female lays in a particular nest are not necessarily those of the male that will incubate the eggs and raise the chicks. Interesting!
These sandpipers were photographed along the shore of Medicine Lake in California. Breeding, nonbreeding and young fledgling sandpipers were all wandering about in the early morning sunlight.