The rock sandpiper (''Calidris ptilocnemis'') is a small

shorebird 245px, A flock of Red_knot.html" ;"title="Dunlins and Red knot">Dunlins and Red knots Waders or shorebirds are birds of the order Charadriiformes commonly found wikt:wade#Etymology 1, wading along shorelines and mudflats in order to foraging, ...

in the sandpiper family

Scolopacidae Sandpipers are a large family, Scolopacidae, of waders. They include many species called sandpipers, as well as those called by names such as curlew and snipe. The majority of these species eat small invertebrates picked out of the mud or soil. ...

. This is a hardy sandpiper that breeds in the arctic and subarctic regions of Alaska and the Chukotka and

Kamchatka Peninsula The Kamchatka Peninsula (russian: полуостров Камчатка, Poluostrov Kamchatka, ) is a peninsula in the Russian Far East, with an area of about . The Pacific Ocean and the Sea of Okhotsk make up the peninsula's eastern and we ...

s. It is closely related to the purple sandpiper that breeds in arctic regions of northeast Canada and the northwest

Palearctic The Palearctic or Palaearctic is the largest of the eight biogeographic realms of the Earth. It stretches across all of Eurasia north of the foothills of the Himalayas, and North Africa. The realm consists of several bioregions: the Euro-Si ...

Taxonomy

The rock sandpiper was formally described in 1873 by the American ornithologist

Elliott Coues Elliott Ladd Coues (; September 9, 1842 – December 25, 1899) was an American army surgeon, historian, ornithologist, and author. He led surveys of the Arizona Territory, and later as secretary of the United States Geological and Geograph ...

and given the

binomial name In taxonomy, binomial nomenclature ("two-term naming system"), also called nomenclature ("two-name naming system") or binary nomenclature, is a formal system of naming species of living things by giving each a name composed of two parts, bot ...

''Tringa ptilocnemis''. It was formerly placed in the

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial n ...

''Erolia'', but is now placed with 23 other sandpipers in the genus ''

Calidris ''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 the typical " sandpipers", small to medium-sized, long-winge ...

'' that was introduced in 1804 by the German naturalist

Blasius Merrem Blasius Merrem (4 February 1761 – 23 February 1824) was a German naturalist, zoologist, ornithologist, mathematician, and herpetologist. In 1804, he became the professor of political economy and botany at the University of Marburg. Early ...

. The genus name is from

Ancient Greek Ancient Greek includes the forms of the Greek language used in ancient Greece and the ancient world from around 1500 BC to 300 BC. It is often roughly divided into the following periods: Mycenaean Greek (), Dark Ages (), the Archaic p ...

''kalidris'' or ''skalidris'', a term used by

Aristotle Aristotle (; grc-gre, Ἀριστοτέλης ''Aristotélēs'', ; 384–322 BC) was a Greek philosopher and polymath during the Classical Greece, Classical period in Ancient Greece. Taught by Plato, he was the founder of the Peripatet ...

for some grey-coloured waterside birds. The specific epithet ''ptilocnemis'' combines the

''ptilon'' meaning "feather" with ''knēmē'' meaning "leg". Within the genus ''Calidris'' the rock sandpiper is closely related to the sanderling (''Calidris alba'') and

dunlin The dunlin (''Calidris alpina'') is a small wader, formerly sometimes separated with the other "stints" in the genus ''Erolia''. The English name is a dialect form of "dunling", first recorded in 1531–1532. It derives from ''dun'', "dull brown ...

(''Calidris alpina'') and is

sister A sister is a woman or a girl who shares one or more parents with another individual; a female sibling. The male counterpart is a brother. Although the term typically refers to a familial relationship, it is sometimes used endearingly to refer to ...

to the purple sandpiper (''Calidris maritima''). Four subspecies are recognised: *''C. p. tschuktschorum'', (

Portenko Leonid Aleksandrovich Portenko (11 October 1896 – 26 May 1972) was a Soviet ornithologist of Ukrainian origin who carried out extensive zoogeographic studies on the birds of the northern and north-eastern Palaearctic realm. He was born in Smila, ...

, 1937) – breeds on the

Chukchi Peninsula The Chukchi Peninsula (also Chukotka Peninsula or Chukotski Peninsula; russian: Чуко́тский полуо́стров, ''Chukotskiy poluostrov'', short form russian: Чуко́тка, ''Chukotka''), at about 66° N 172° W, is the eastern ...

and in western

Alaska Alaska ( ; russian: Аляска, Alyaska; ale, Alax̂sxax̂; ; ems, Alas'kaaq; Yup'ik: ''Alaskaq''; tli, Anáaski) is a state located in the Western United States on the northwest extremity of North America. A semi-exclave of the U.S ...

*''C. p. ptilocnemis'', ( Coues, 1873) – breeds on the

Pribilof Islands The Pribilof Islands (formerly the Northern Fur Seal Islands; ale, Amiq, russian: Острова Прибылова, Ostrova Pribylova) are a group of four volcanic islands off the coast of mainland Alaska, in the Bering Sea, about north of ...

and on

Hall In architecture, a hall is a relatively large space enclosed by a roof and walls. In the Iron Age and early Middle Ages in northern Europe, a mead hall was where a lord and his retainers ate and also slept. Later in the Middle Ages, the gr ...

and

St. Matthew Island St. Matthew Island (russian: Остров Святого Матвея) is an uninhabited, remote island in the Bering Sea in Alaska, west-northwest of Nunivak Island. The entire island's natural scenery and wildlife is protected as it is part of ...

s *''C. p. couesi'', ( Ridgeway, 1880) – breeds on the

Aleutian Islands The Aleutian Islands ( ; ; ale, Unangam Tanangin, "land of the Aleuts"; possibly from the Chukchi ''aliat'', or "island")—also called the Aleut Islands, Aleutic Islands, or, before 1867, the Catherine Archipelago—are a chain of 14 main, ...

and on the

Alaskan Peninsula The Alaska Peninsula (also called Aleut Peninsula or Aleutian Peninsula, ale, Alasxix̂; Sugpiaq: ''Aluuwiq'', ''Al'uwiq'') is a peninsula extending about to the southwest from the mainland of Alaska and ending in the Aleutian Islands. The ...

*''C. p. quarta'', (

Hartert Ernst Johann Otto Hartert (29 October 1859 – 11 November 1933) was a widely published German ornithologist. Life and career Hartert was born in Hamburg, Germany on 29 October 1859. In July 1891, he married the illustrator Claudia Bernadine E ...

, 1920) – breeds on the south of the

and in the Kuril and

Commander Islands The Commander Islands, Komandorski Islands, or Komandorskie Islands (russian: Командо́рские острова́, ''Komandorskiye ostrova'') are a series of treeless, sparsely populated Russian islands in the Bering Sea located about e ...

Description

Adults have short yellow legs and a medium thin dark bill. The body is dark on top with a slight purplish gloss and mainly white underneath. The breast is smeared with grey and the rump is black. The

subspecies of this bird shows a bold black belly patch.

Distribution and habitat

Birds migrate south to rocky ice-free

Pacific The Pacific Ocean is the largest and deepest of Earth's five oceanic divisions. It extends from the Arctic Ocean in the north to the Southern Ocean (or, depending on definition, to Antarctica) in the south, and is bounded by the continen ...

coasts in winter. The subspecies leap frog each other for winter, with more northerly breeders passing south of more southerly breeders. It can form rather large wintering flocks. Rock Sandpipers which spend the non-breeding season in the Pacific Basin, Alaska, have to endure harsh conditions where they rely on high prey quality, especially of their primary prey - the bivalve '' Macoma balthica''.

Behaviour and ecology

Breeding

Their breeding habitat is the northern tundra on

Arctic The Arctic ( or ) is a polar region located at the northernmost part of Earth. The Arctic consists of the Arctic Ocean, adjacent seas, and parts of Canada ( Yukon, Northwest Territories, Nunavut), Danish Realm ( Greenland), Finland, Iceland ...

coast The coast, also known as the coastline or seashore, is defined as the area where land meets the ocean, or as a line that forms the boundary between the land and the coastline. The Earth has around of coastline. Coasts are important zones in n ...

and the Aleutian and Pribilof Islands. The birds also breed in

Kamchatka The Kamchatka Peninsula (russian: полуостров Камчатка, Poluostrov Kamchatka, ) is a peninsula in the Russian Far East, with an area of about . The Pacific Ocean and the Sea of Okhotsk make up the peninsula's eastern and west ...

and the

Kuril Islands The Kuril Islands or Kurile Islands (; rus, Кури́льские острова́, r=Kuril'skiye ostrova, p=kʊˈrʲilʲskʲɪjə ɐstrɐˈva; Japanese: or ) are a volcanic archipelago currently administered as part of Sakhalin Oblast in the ...

. The breeding pair is usually

monogamous Monogamy ( ) is a form of dyadic relationship in which an individual has only one partner during their lifetime. Alternately, only one partner at any one time ( serial monogamy) — as compared to the various forms of non-monogamy (e.g., polyg ...

, with pair bonds usually lasting several years. They nest on the ground either elevated on rocks or in lower damp location. The male makes several scrapes; the female chooses one and lays 4 eggs. Both male and female take the responsibility for incubation.

Diet

These birds forage on rocky coasts. They mainly eat

insects Insects (from Latin ') are pancrustacean hexapod invertebrates of the class Insecta. They are the largest group within the arthropod phylum. Insects have a chitinous exoskeleton, a three-part body (head, thorax and abdomen), three pairs ...

mollusks Mollusca is the second-largest phylum of invertebrate animals after the Arthropoda, the members of which are known as molluscs or mollusks (). Around 85,000 extant species of molluscs are recognized. The number of fossil species is esti ...

, marine worms, also some plant material. It often feeds up to its breast in water, and often swims. It roosts on rocks near its feeding grounds just above the high tide spray.

References

* "National Geographic" ''Field Guide to the Birds of North'' ''America'' * ''Handbook of the Birds of the World Vol 3'', Josep del Hoyo editor, * "National Audubon Society" ''The Sibley Guide to Birds'', by David Allen Sibley, {{Taxonbar, from=Q737788 Calidris Erolia Native birds of Alaska Sandpipers Birds described in 1873 Taxa named by Elliott Coues