| Great knot | |
|---|---|
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| Breeding plumage, Primorsky Krai, Russia | |
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| Winter plumage, Thailand | |
Scientific classification | |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Aves |
| Order: | Charadriiformes |
| Family: | Scolopacidae |
| Genus: | Calidris |
| Species: | C. tenuirostris |
| Binomial name | |
| Calidris tenuirostris (Horsfield, 1821) | |
Thegreat knot (Calidris tenuirostris) is a smallwader. It is one of the largestspecies in the genusCalidris. It is amigratory bird which breeds in easternSiberia, Russia, and flies to southern Asia and Australia in the northern winter.
Within the genusCalidris the great knot is most closely related to thesurfbird (Calidris virgata).[3]
The genus name is fromAncient Greekkalidris orskalidris, a term used byAristotle for some grey-coloured waterside birds. The specific tenuirostris is fromLatintenuis "slender" androstrum "bill".[4]
Their breeding habitat istundra in northeastSiberia, Russia. They nest on the ground laying about four eggs in a ground scrape. They are stronglymigratory wintering on coasts in southern Asia through to Australia. This species forms enormous flocks in winter.
The species is also recorded in summer in low numbers in westernAlaska, United States in most years, and in winter in small numbers west toPakistan,Oman, and theUnited Arab Emirates.[5] It has occurred as avagrant inGreat Britain,Morocco,[5]New Zealand,British Columbia in Canada, and in the lower 48 states of the USA inOregon,West Virginia, andMaine.
Calidris tenuirostris, commonly known as the great knot, is one of the largest species of thegenusCalidris, in the familyScolopacidae. TheruffC. pugnax, with its marked sexual dimorphism in size, can have larger males, but its females are much smaller. Its sister species, thesurfbirdC. virgata andred knotC. canutus, are the next largest. Adult great knots can measure 26 to 30 cm (10 to 12 in), with a wingspan of 56 to 66 cm (22 to 26 in), and weighing 115 to 261 g (4.1 to 9.2 oz).[6][7][8]
This species has short dark legs and a medium-length thin dark bill. Breeding adults have mottled greyish upper parts, with a distinct band ofrufous feathering on the scapular feathers. 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.
These birds forage onmudflats and beaches, probing or picking up food by sight. They mainly eatmolluscs and insects.
The great knot is one of the species to which theAgreement on the Conservation of African-Eurasian Migratory Waterbirds (AEWA) applies.
Since 5 May 2016 and as of August 2023[update], the great knot is listed ascritically endangered in Australia under the federalEnvironment Protection and Biodiversity Conservation Act 1999 (EPBC Act), with the next assessment due on 30 October 2023.[2] A study published inBiological Conservation 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".[9][10]
Understate and territory legislation, the species is as of August 2023[update] listed asvulnerable inNew South Wales and theNorthern Territory;endangered inSouth Australia; andcritically endangered inQueensland,Victoria, andWestern Australia.[2]
Text may have been copied from this source, which is available under aAttribution 3.0 Australia (CC BY 3.0 AU) licence.
