__NOTOC__ The great knot (''Calidris tenuirostris'') is a small

wader 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, ...

. It is the largest

species A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of Taxonomy (biology), ...

of 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. Migratory shorebirds are shown to have decline in reproductive traits ...

''. They are a

migratory bird Bird migration is a seasonal movement of birds between breeding and wintering grounds that occurs twice a year. It is typically from north to south or from south to north. Migration is inherently risky, due to predation and mortality. Th ...

which breeds in

Siberia Siberia ( ; , ) is an extensive geographical region comprising all of North Asia, from the Ural Mountains in the west to the Pacific Ocean in the east. It has formed a part of the sovereign territory of Russia and its predecessor states ...

, Russia, and flies to southern Asia and Australia in the northern winter.

Etymology

The genus name is from

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

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

Aristotle Aristotle (; 384–322 BC) was an Ancient Greek philosophy, Ancient Greek philosopher and polymath. His writings cover a broad range of subjects spanning the natural sciences, philosophy, linguistics, economics, politics, psychology, a ...

for some grey-coloured waterside birds. The specific '' tenuirostris '' is from

Latin Latin ( or ) is a classical language belonging to the Italic languages, Italic branch of the Indo-European languages. Latin was originally spoken by the Latins (Italic tribe), Latins in Latium (now known as Lazio), the lower Tiber area aroun ...

''tenuis'' "slender" and ''rostrum'' "bill".

Distribution

Their breeding habitat is

tundra In physical geography, a tundra () is a type of biome where tree growth is hindered by frigid temperatures and short growing seasons. There are three regions and associated types of tundra: #Arctic, Arctic, Alpine tundra, Alpine, and #Antarctic ...

in northeast

, Russia. They nest on the ground laying about four eggs in a ground scrape. They are strongly migratory wintering on coasts in southern Asia through to Australia. This species forms enormous flocks in winter. The species is also recorded in low numbers in western

Alaska Alaska ( ) is a non-contiguous U.S. state on the northwest extremity of North America. Part of the Western United States region, it is one of the two non-contiguous U.S. states, alongside Hawaii. Alaska is also considered to be the north ...

, United States, most years, and has occurred as a

vagrant Vagrancy is the condition of wandering homelessness without regular employment or income. Vagrants usually live in poverty and support themselves by travelling while engaging in begging, scavenging, or petty theft. In Western countries, ...

British Columbia British Columbia is the westernmost Provinces and territories of Canada, province of Canada. Situated in the Pacific Northwest between the Pacific Ocean and the Rocky Mountains, the province has a diverse geography, with rugged landscapes that ...

, Canada, and in

Oregon Oregon ( , ) is a U.S. state, state in the Pacific Northwest region of the United States. It is a part of the Western U.S., with the Columbia River delineating much of Oregon's northern boundary with Washington (state), Washington, while t ...

West Virginia West Virginia is a mountainous U.S. state, state in the Southern United States, Southern and Mid-Atlantic (United States), Mid-Atlantic regions of the United States.The United States Census Bureau, Census Bureau and the Association of American ...

, and

Maine Maine ( ) is a U.S. state, state in the New England region of the United States, and the northeasternmost state in the Contiguous United States. It borders New Hampshire to the west, the Gulf of Maine to the southeast, and the Provinces and ...

, in the U.S.

Taxonomy and description

''Calidris tenuirostris'', commonly known as the great knot, is the largest species of the

genus Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...

''Calidris'' (sandpiper), in the family

Scolopacidae Scolopacidae is a large family of shorebirds, or waders, which mainly includes many species known as sandpipers, but also others such as woodcocks, curlews and snipes. Most of these species eat small invertebrates picked out of the mud or soil ...

. Its sister species, the

red knot The red knot or just knot (''Calidris canutus'') is a medium-sized shorebird which breeds in tundra and the Arctic Cordillera in the far north of Canada, Europe, and Russia. It is a large member of the ''Calidris'' sandpipers, second only to the ...

, is the next largest. Adult great knots can measure , with a wingspan of , and weighing . This species has short dark legs and a medium-length thin dark bill. Breeding adults have mottled greyish upper parts with some

rufous Rufous () is a color that may be described as reddish-brown or brownish- red, as of rust or oxidised iron. The first recorded use of ''rufous'' as a color name in English was in 1782. However, the color is also recorded earlier in 1527 as a d ...

feathering. The face, throat and breast are heavily spotted black, and there are also some streaks on the rear belly. In winter the plumage becomes uniformly pale grey above. It is distinguished from the red knot by its breeding plumage, in which the latter has a distinctive red face, throat and breast. In other plumages, the great knot can be identified by its larger size, longer bill, deeper chest, and the more streaked upper parts.

Behaviour

These birds forage on

mudflat Mudflats or mud flats, also known as tidal flats or, in Ireland, slob or slobs, are coastal wetlands that form in intertidal areas where sediments have been deposited by tides or rivers. A global analysis published in 2019 suggested that tidal ...

s and beaches, probing or picking up food by sight. They mainly eat

mollusc Mollusca is a phylum of protostome, protostomic invertebrate animals, whose members are known as molluscs or mollusks (). Around 76,000 extant taxon, extant species of molluscs are recognized, making it the second-largest animal phylum ...

s and insects.

Conservation status

The great knot is one of the species to which the

Agreement on the Conservation of African-Eurasian Migratory Waterbirds The Agreement on the Conservation of African-Eurasian Migratory Waterbirds, or African-Eurasian Waterbird Agreement (AEWA), is an independent international treaty developed under the auspices of the United Nations Environment Programme's Convent ...

(

AEWA The Agreement on the Conservation of African-Eurasian Migratory Waterbirds, or African-Eurasian Waterbird Agreement (AEWA), is an independent international treaty developed under the auspices of the United Nations Environment Programme's Convent ...

) applies.

Australia

Since 5 May 2016 and , the great knot is listed as

critically endangered An IUCN Red List critically endangered (CR or sometimes CE) species is one that has been categorized by the International Union for Conservation of Nature as facing an extremely high risk of extinction in the wild. As of December 2023, of t ...

in Australia under the federal ''

Environment Protection and Biodiversity Conservation Act 1999 The ''Environment Protection and Biodiversity Conservation Act 1999'' (Cth) is an Act of the Parliament of Australia that provides a framework for protection of the Australian environment, including its biodiversity and its natural and cult ...

'' (EPBC Act), with the next assessment due on 30 October 2023. Text may have been copied from this source, which is available under
Attribution 3.0 Australia (CC BY 3.0 AU)
licence. A study published in ''

Biological Conservation Conservation biology is the study of the conservation of nature and of Earth's biodiversity with the aim of protecting species, their habitats, and ecosystems from excessive rates of extinction and the erosion of biotic interactions. It is an i ...

'' in March 2023 listed 23 species which the authors considered to no longer meet the criteria as threatened species under the EPBC Act, including the great knot. The reason for the assessment was "Populations now stable or declining at a rate less than threshold". Under state and territory legislation, the species is listed as vulnerable in

New South Wales New South Wales (commonly abbreviated as NSW) is a States and territories of Australia, state on the Eastern states of Australia, east coast of :Australia. It borders Queensland to the north, Victoria (state), Victoria to the south, and South ...

and the

Northern Territory The Northern Territory (abbreviated as NT; known formally as the Northern Territory of Australia and informally as the Territory) is an states and territories of Australia, Australian internal territory in the central and central-northern regi ...

;

endangered An endangered species is a species that is very likely to become extinct in the near future, either worldwide or in a particular political jurisdiction. Endangered species may be at risk due to factors such as habitat loss, poaching, inv ...

South Australia South Australia (commonly abbreviated as SA) is a States and territories of Australia, state in the southern central part of Australia. With a total land area of , it is the fourth-largest of Australia's states and territories by area, which in ...

; and

Queensland Queensland ( , commonly abbreviated as Qld) is a States and territories of Australia, state in northeastern Australia, and is the second-largest and third-most populous state in Australia. It is bordered by the Northern Territory, South Austr ...

Victoria Victoria most commonly refers to: * Queen Victoria (1819–1901), Queen of the United Kingdom and Empress of India * Victoria (state), a state of Australia * Victoria, British Columbia, Canada, a provincial capital * Victoria, Seychelles, the capi ...

, and

Western Australia Western Australia (WA) is the westernmost state of Australia. It is bounded by the Indian Ocean to the north and west, the Southern Ocean to the south, the Northern Territory to the north-east, and South Australia to the south-east. Western Aust ...

References

External links

* *
Great knot
– Photos on Oiseaux.net {{Taxonbar, from=Q18876

great knot __NOTOC__ The great knot (''Calidris tenuirostris'') is a small wader. It is the largest species of the genus ''Calidris''. They are a migratory bird which breeds in Siberia, Russia, and flies to southern Asia and Australia in the northern winte ...

Wading birds Birds of North Asia

Articles containing video clips Taxa named by Thomas Horsfield