The white-rumped sandpiper (Calidris fuscicollis) is a small migratory shorebird that breeds in the northern tundra of Canada and Alaska. This bird can be difficult to distinguish from other similar tiny shorebirds; these are known collectively as "peeps" or "stints". In flight, it is more easily picked out by its namesake white rump.

Description

thumb|left|in winter plumage

The white-rumped sandpiper is a relatively small bird measuring only , with a wingspan of . The top of its body is a dull grey-brown colour and it has a white eye stripe. Its beak is of medium length, thin and dark, and its legs are very dark. This bird is often mistaken with many similar-looking sandpipers that live in its range or along its migration path.) and a rare vagrant to Australia.

The birds migrate with both nonstop and short-distance multiple-stop flights. During their migration from north to south, they fly over the Atlantic Ocean, gradually moving along the northeastern coast of South America before heading inland towards the islands. This travel generally takes about one month. On their migration from south to north, the white-rumped sandpiper follows a similar path, but does it much more quickly. This migration is done in a fast series of long flights without stopping. One nonstop flight can be as long as . annelids and both adult and larval insects. They are mainly reported to eat aquatic invertebrates. Although it was previously thought they only consumed invertebrates, it has been shown that seeds and moss The specific epithet combines Latin fuscus meaning "dusky" or "brown" with Modern Latin -collis meaning "-necked" or "-throated". Vieillot based his account on the "Del Pestorijo Pardo" from Paraguay that had been described in 1805 by the Spanish naturalist Félix de Azara. The white-rumped sandpiper is now placed with 23 other species in the genus Calidris that was introduced in 1804 by the German naturalist Blasius Merrem. The species is monotypic, with no subspecies recognised. A 2022 molecular phylogenetic study by David Černý and Rossy Natale found that the white-rumped sandpiper was sister to the least sandpiper (Calidris minutilla).

The white-rumped sandpiper is placed in the order Charadriiformes along with gulls, alcids, plovers and oystercatchers. Its family, Scolopacidae, encompasses all sandpipers, and as a stint it is classified in the genus Calidris.

  • North American Peeps: A Different Look at an Old Problem (identification article covering this species and other small calidrids) at surfbirds.com