The white-rumped sandpiper (Calidris fuscicollis) is a small shorebird that breeds in the northern tundra of Canada and Alaska.

Therefore, the majority of sightings occur during the spring or fall in temperate regions and are generally in small numbers around water.

[4] The genus name is from Ancient Greek kalidris or skalidris, a term used by Aristotle for some grey-coloured waterside birds.

[2] The plumage is much less distinct during the winter; however, during all seasons males and females remain similar in their appearance.

In adult basic plumage, the upperparts are a dark grey and at the centers there are black feathers.

[2] More specifically, they live in the marshy, heavily vegetated, hummocky arctic tundra of Alaska and Canada during the breeding season.

During the winter months they inhabit a variety of freshwater and saltwater habitats such as lagoons, estuaries and marshes.

They are considered one of the most extreme long-distance migrants in the world,[10] traversing the entire continent of North America in the span of one month.

After breeding in northern Canada and Alaska, it flies over the Atlantic Ocean to spend the majority of its non-breeding period in South America, particularly along the Patagonian coast in both Chile and Argentina.

For example, the effects of a large storm lead to a higher presence of the white-rumped sandpiper on the King George Islands.

[11] The warming of the climate has led to changes in the number of individuals and the length of their stay in the South Shetland Islands.

[11] White-rumped sandpipers are now observed more frequently in this area as a result of both long and short term climate variations.

[12] Their diet consists primarily of small invertebrates including: molluscs, crustaceans, polychaetes,[13] annelids and both adult and larval insects.

Although it was previously thought they only consumed invertebrates, it has been shown that seeds and moss[13] also make up a portion of the white-rumped sandpiper diet.

This discovery lead to the idea that they might be opportunistic feeders depending on time, season and habitat.

[4] While on mudflats, the white-rumped sandpiper forages by probing in shallow waters and in mud but can also pick up some items from the surface.

The nest is lined with pieces of lichen, leaves and moss which can occur naturally or can be added by the female.

Males defend the breeding territory by gliding and fluttering above it while making oinking and rattling sounds.

When on the ground, the male stretches its wing out to the side and raises its tail into the air to display the white patch on its rump.

The chase ends when the male does a wing raising display, which is common in many sandpiper species.