Great knot

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

Taxonomy

Within the genus Calidris the great knot is most closely related to the surfbird (Calidris virgata).<ref>Template:Cite journal</ref>

The genus name is from Ancient Greek kalidris or skalidris, a term used by Aristotle for some grey-coloured waterside birds. The specific tenuirostris is from Latin tenuis "slender" and rostrum "bill".<ref name=job>Template:Cite book</ref>

Distribution

Their breeding habitat is tundra in northeast Siberia, 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 summer in low numbers in western Alaska, United States in most years, and in winter in small numbers west to Pakistan, Oman, and the United Arab Emirates.<ref name="Lewington">Template:Cite book</ref> It has occurred as a vagrant in Great Britain, Morocco,<ref name="Lewington"/> New Zealand, British Columbia in Canada, and in the lower 48 states of the USA in Oregon, West Virginia, and Maine.

Taxonomy and description

Great knots at Lee Point, Darwin, Northern Territory, Australia

File:Great Knot1.ogg

Manly Marina, SE Queensland, Australia

Calidris tenuirostris, commonly known as the great knot, is one of the largest species of the genus Calidris, in the family Scolopacidae. The ruff C. pugnax, with its marked sexual dimorphism in size, can have larger males, but its females are much smaller. Its sister species, the surfbird C. virgata and red knot C. canutus, are the next largest. Adult great knots can measure Template:Convert, with a wingspan of Template:Convert, and weighing Template:Convert.<ref>Jeyarajasingam, A. (2012). A field guide to the birds of Peninsular Malaysia and Singapore. Oxford University Press.Template:Page needed</ref><ref>Van Gils, J., P. Wiersma, G. M. Kirwan, and C. J. Sharpe (2020). "Great Knot (Calidris tenuirostris), version 1.0". In Birds of the World (J. del Hoyo, A. Elliott, J. Sargatal, D. A. Christie, and E. de Juana, Editors). Cornell Lab of Ornithology, Ithaca, NY, USA.</ref><ref>Template:Cite bookTemplate:Page needed</ref>

This species has short dark legs and a medium-length thin dark bill. Breeding adults have mottled greyish upper parts, with a distinct band of rufous 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.

Behaviour

These birds forage on mudflats and beaches, probing or picking up food by sight. They mainly eat molluscs and insects.

Conservation status

The great knot is one of the species to which the Agreement on the Conservation of African-Eurasian Migratory Waterbirds (AEWA) applies.

Australia

Since 5 May 2016 and Template:As of, the great knot is listed as critically endangered in Australia under the federal Environment Protection and Biodiversity Conservation Act 1999 (EPBC Act), with the next assessment due on 30 October 2023.<ref name=sprat>Template:Cite web File:CC-BY icon.svg Text may have been copied from this source, which is available under a Attribution 3.0 Australia (CC BY 3.0 AU) licence.</ref> A study published in Biological 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".<ref name=woinarski2023>Template:Cite journal</ref><ref>Template:Cite web</ref>

Under state and territory legislation, the species is Template:As of listed as vulnerable in New South Wales and the Northern Territory; endangered in South Australia; and critically endangered in Queensland, Victoria, and Western Australia.<ref name=sprat/>

External links

• Great knot – Photos on Oiseaux.net