About Calidris pusilla (Linnaeus, 1766)
Calidris pusilla, described by Linnaeus in 1766, is a small sandpiper. It measures 15–18 centimetres (6–7 inches) in length, weighs 18–51.5 grams (0.63–1.82 ounces), and has a wingspan ranging from 35 to 37 centimetres (13.8 to 14.6 inches). Adult individuals have black legs and a short, stout, straight dark bill. Their upper body is dark grey-brown, and their underparts are white; the head and neck have a light grey-brown tint. This species can be hard to tell apart from other similar tiny shorebirds, especially the western sandpiper; this group of small shorebirds is collectively known as "peeps" or "stints". A 1984 work by Jonsson and Grant focused on the identification of stints and peeps in British Birds 77(7):293-315. This species' breeding habitat is southern tundra near water in Canada and Alaska. They nest on the ground: the male creates several shallow scrapes, the female selects one and lines it with grass and other materials. The female lays 4 eggs, and the male helps with incubation. A few days after hatching, the female leaves the young in the male's care, and the young feed themselves. These birds forage on mudflats, picking up food by both sight and touch with their bill. Their diet mainly consists of aquatic insects and their larvae, spiders, snails, worms, and crustaceans. Semipalmated sandpipers depend heavily on horseshoe crab eggs during spring migration. During egg laying, females also eat small mammal bones as an additional source of calcium.
