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Calidris

Genus of birds

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Calidris is a genus of Arctic-breeding, strongly migratory wading birds in the family Scolopacidae. These birds form huge mixed flocks on coasts and estuaries in winter. They are small to medium-sized sandpipers, long-winged and relatively short-billed; some are difficult to identify because of the similarity between species, and various breeding, non-breeding, juvenile, and moulting plumages. With a few exceptions, they have a fairly stereotypical colour pattern, being brownish above and lighter, usually white or buffy coloured, on much of the underside. They often have a lighter supercilium above brownish cheeks. The species are variously known in English as sandpipers or (particularly the smaller species) stints; some have their own unique names, with dunlin (a mediaeval name meaning "[small] brown bird"), knot (imitative of its call), ruff (named after its male display plumage), and sanderling and surfbird (named after their habitat and behaviour). In North America, the smaller species are often known colloquially as peeps.

Their bills are flexible, able to exhibit rhynchokinesis, and have sensitive tips which contain numerous corpuscles of Herbst. This enables the birds to locate buried prey items, which they typically seek with restless running and probing. Migratory shorebirds are shown to have declined in reproductive traits because of temporal changes of their breeding seasons.

01Taxonomy

The genus Calidris was introduced in 1804 by the German naturalist Blasius Merrem with the red knot as the type species. The genus name is from Ancient Greek kalidris or skalidris, a term used by Aristotle for an unidentified grey-coloured waterside bird.

Many of the species have been treated under other generic names at various times in the past, but these treatments leave Calidris polyphyletic; synonyms are in brackets in the list below.

The genus contain 24 species:

The following species-level cladogram is based on a molecular phylogenetic study by David Černý and Rossy Natale that was published in 2022. Some of the nodes are only weakly supported by the sequence data.

Calidris

Red knot, Calidris canutus

Great knot, Calidris tenuirostris

Surfbird, Calidris virgata

Ruff, Calidris pugnax

Sharp-tailed sandpiper, Calidris acuminata

Broad-billed sandpiper, Calidris falcinellus

Curlew sandpiper, Calidris ferruginea

Stilt sandpiper, Calidris himantopus

Spoon-billed sandpiper, Calidris pygmaea

Red-necked stint, Calidris ruficollis

Long-toed stint, Calidris subminuta

Temminck's stint, Calidris temminckii

Buff-breasted sandpiper, Calidris subruficollis

Sanderling, Calidris alba

Dunlin, Calidris alpina

Purple sandpiper, Calidris maritima

Rock sandpiper, Calidris ptilocnemis

Baird's sandpiper, Calidris bairdii

Little stint, Calidris minuta

White-rumped sandpiper, Calidris fuscicollis

Least sandpiper, Calidris minutilla

Pectoral sandpiper, Calidris melanotos

Western sandpiper, Calidris mauri

Semipalmated sandpiper, Calidris pusilla

Little Stint at Jamnagar, India
Little Stint at Jamnagar, India
Temminck's stint at Jamnagar, India
Temminck's stint at Jamnagar, India

02Hybrids

Several hybrids have been discovered between different species in the genus. See Hybridisation in shorebirds for further details.

Long-toed stint (Calidris subminuta) in Kerala
Long-toed stint (Calidris subminuta) in Kerala
Watch videos about CalidrisExplainers and documentaries on YouTube (opens in a new tab)

Sources and credits

This article is adapted from the Wikipedia article Calidris, written by its contributors and licensed under CC BY-SA 4.0. Fathomly has changed the layout, removed citation markers, navigation and maintenance notices, and adjusted punctuation. This adapted version is shared under the same license. For references, see the original article.

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