Knot

Calidris canutus

Introduction

This medium-sized grey wader winters on our larger estuaries before returning to its Arctic breeding grounds.

Although the Knot's winter plumage is uniformly pale grey, birds start gaining brick-red feathering in the spring as they depart for their breeding grounds. Early in the winter, juvenile birds can be identified by a 'scalloped' appearance – each feather has a black line near its edge.

Ringing data show that our wintering Knot come mostly from Iceland, Greenland and the Canadian Arctic. WeBS counts show that The Wash hosts the vast majority of this population, with mid-winter peak counts having increased to in the region of 200,000 birds. Watching their swirling flocks is a true wildlife spectacle.

Key Stats

Common

138.1g

4-4

BTO Records

210k records

Publications

Population and distribution stats for:

No data

No current data

No current data

1% increase 1996/97–2021/22

Population Size

265k

Distribution Change

25.9% expansion

Identification

Curated resources to aid in the identification of Knot

ID Videos

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This section features BTO training videos headlining this species, or featuring it as a potential confusion species.

Knot and Dunlin

Ruff

Songs and Calls

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Listen to example recordings of the main vocalisations of Knot, provided by xeno-canto contributors.

Call:

Flight call:

Status and Trends

Population size, trends and patterns of distribution based on BTO and partnership surveys and atlasses with data collected by BTO volunteers.

Conservation Status

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This species can be found on the following statutory and conservation listings and schedules.

UK Birds of Conservation Concern

Amber listed

Species of European Conservation Concern

Least Concern

IUCN Red List of Threatened Species (global)

Near Threatened

Schedule 1 Licence required (to disturb)*

Birds Directive Annex 1

Listed on the Annexes of*

WBD(II*), Bern(III), Bonn(II), AEWA

* A guide only. Check details with the original legislation, especially those marked with an asterisk. See About Birdfacts for more information.

Population Size

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UK (winter)

265 thousand (2012-17)

Source

BOU Category

Source

First Record*

Recorded in Medieval times

* First documented occurrence. Most species undoubtedly occurred before this. See About Birdfacts for more information.

Population Change

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UK winter population

1% (1996/97–2021/22)

Two races of Knot (out of six worldwide) use the UK's estuaries in winter. The canutus race, that breed in Siberia, are seen here on autumn passage, while the islandica race, that breed in Greenland and Canada, winter here; the UK hosts 80% of the entire islandica population in winter so our estuaries are critically important to this population Austin et al. 2023]. [WeBS data suggest that the long-term trend for Knot in the UK has been more-or-less stable since the early 1990s.

Distribution

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Over 65% of Knots originating from Greenland and Canadian Arctic breeding grounds winter around the coasts of Britain & Ireland, favouring muddy and sandy shores, especially estuaries. They are generally absent from northern and western Scotland and from other stretches of rocky coastline.

Occupied 10-km squares in UK

These figures come from Bird Atlas 2007 and indicate how widespread a species is.

No. occupied in winter

513

% occupied in winter

17%

Bird Atlas distribution maps show where bird species breed or winter in Britain and Ireland. For breeding maps, larger dots indicate higher certainty the species bred in that area.

Click the map to enlarge,
or view it on Bird Atlas Mapstore.

Click the map to enlarge,
or view it on Bird Atlas Mapstore.

To view and download up-to-date distribution information aggregated from across BTO and partnership surveys and schemes, see our data holdings on the NBN Atlas.

European Distribution Map

European Breeding Bird Atlas 2

Distribution Change

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The number of occupied 10-km squares has increased in Britain by 27% and in Ireland by 58% since the 1981–84 Winter Atlas, matching a population increase detected by the Wetland Bird Survey and Irish Wetland Bird Survey.

Change in occupied 10-km squares in the UK

These figures come from Bird Atlas 2007-11 and indicate by how much occupied areas have expanded or contracted over recent decades.

% change in range in winter (1981–84 to 2007–11)

25.9 %

Bird Atlas distribution change maps show how bird distributions have changed through time. Coloured upward-pointing triangles show places apparently colonised over the period; grey downward-pointing triangles show places apparently vacated. Shading show places occupied.

Click the map to enlarge,
or view it on Bird Atlas Mapstore.

Seasonality

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Knots are mostly winter visitors, but with a pronounced passage in autumn as birds arrive from tundra breeding habitats.

Weekly pattern of occurrence

The graph shows when the species is present in the UK, with taller bars indicating a higher likelihood of encountering the species in appropriate regions and habitats.

Phenology graph — Weekly occurrence patterns (shaded cells and reporting rates (vertical bars) based on BirdTrack data. Reporting rates give the likelihood of encountering the species each week.

Movement

Information about Knot movements and migration based on online bird portals (e.g. BirdTrack), Ringing schemes and tracking studies.

Britain & Ireland movement

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View a summary of recoveries in the Online Ringing Report

Foreign locations of birds ringed or recovered in Britain & Ireland

Dots show the foreign destinations of birds ringed in Britain & Ireland, and the origins of birds ringed overseas that were subsequently recaptured, resighted or found dead in Britain & Ireland. Dot colours indicate the time of year that the species was present at the location.

Winter (Nov-Feb)
Spring (Mar-Apr)
Summer (May-Jul)
Autumn (Aug-Oct)

Foreign locations of birds ringed or recovered in Britain & Ireland

European movements

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EuroBirdPortal uses birdwatcher's records, such as those logged in BirdTrack to map the flows of birds as they arrive and depart Europe. See maps for this species here.

The Eurasian-African Migration Atlas shows movements of individual birds ringed or recovered in Europe. See maps for this species here.

Biology

Lifecycle and body size information for Knot, including statistics on nesting, eggs and lifespan based on BTO ringing and nest recording data.

Productivity and Nesting

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Nesting timing

Typical (exceptional) number of broods

Source

Egg measurements

Typical length x width

43x30 mm

Mass (% shell)

19.3g (5%)

Source

Clutch Size

Typical number

4-4 eggs

Observed minimum and maximum

3-4 eggs

Source

Incubation

Incubation by

Male + Female

Typical duration

22-21 days

Source

Fledging

Type of chick

Precocial, downy

Typical duration

20-18 days

Source

Survival and Longevity

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Survival is shown as the proportion of birds surviving from one year to the next and is derived from bird ringing data. It can also be used to estimate how long birds typically live.

View number ringed each year in the Online Ringing Report.

lifespan

Typical life expectancy of bird reaching breeding age

8 years with breeding typically at 2 years

Source

Maximum age from a ringed bird

27 years, 3 months, 29 days (set in 2006)

Source

Survival of adults

All adults

0.841±0.066

Source

Biometrics

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Wing length and body weights are from live birds (source).

Wing length

Average ±1 std deviation; range and sample size in brackets.

Juvenile

164.7±3.9 mm

(158-171 mm, N=1589)

All adults

169.4±6.2 mm

(159-179 mm, N=3618)

Body weight

Average ±1 std deviation; range and sample size in brackets.

Juvenile

164.7±3.9 mm

(158-171 mm, N=1589)

All adults

169.4±6.2 mm

(159-179 mm, N=3618)

Ring Size

Classification, names and codes

Taxonomy, names and species codes for Knot

Classification and Codes

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Order: Charadriiformes
Family: Scolopacidae
Scientific name: Calidris canutus
Authority: Linnaeus, 1758

BTO 2-letter code: KN
BTO 5-letter code: KNOT.
Euring code number: 4960

Alternate species names

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Catalan: territ gros
Czech: jespák rezavý
Danish: Islandsk Ryle
Dutch: Kanoet
Estonian: suurrüdi e. suurrisla
Finnish: isosirri
French: Bécasseau maubèche
Gaelic: Luatharan-gainmhich

German: Knutt
Hungarian: sarki partfutó
Icelandic: Rauðbrystingur
Irish: Cnota
Italian: Piovanello maggiore
Latvian: lielais šnibitis
Lithuanian: islandinis begikas
Norwegian: Polarsnipe

Polish: biegus rdzawy
Portuguese: maçarico-de-papo-vermelho / seixoeira
Slovak: pobrežník hrdzavý
Slovenian: veliki prodnik
Spanish: Correlimos gordo
Swedish: kustsnäppa
Welsh: Pibydd yr Aber

English folkname(s): Silver Plover

Research

Interpretation and scientific publications about Knot from BTO scientists.

Causes of Change and Solutions

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Causes of change

The population trend for Knot is stable, therefore there are no causes of change to note.

Publications (2)

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Consequences of population change for local abundance and site occupancy of wintering waterbirds

Protected sites for birds are typically designated based on the site’s importance for the species that use it. For example, sites may be selected as Special Protection Areas (under the European Union Directive on the Conservation of Wild Birds) if they support more than 1% of a given national or international population of a species or an assemblage of over 20,000 waterbirds or seabirds. However, through the impacts of changing climates, habitat loss and invasive species, the way species use sites may change. As populations increase, abundance at existing sites may go up or new sites may be colonized. Similarly, as populations decrease, abundance at occupied sites may go down, or some sites may be abandoned. Determining how bird populations are spread across protected sites, and how changes in populations may affect this, is essential to making sure that they remain protected in the future.

20.09.17

Papers

Using stable isotope ratios to unravel shorebird migration and population mixing: a case study with the Red Knot Calidris canutus

01.01.06

Papers

More Evidence

More evidence from Conservation Evidence.com

Partners

Birdfacts is based on data collected by volunteers participating in surveys that are organised and funded by BTO, RSPB, Esmée Fairbairn Foundation, JNCC and other partners.

BTO

Esmée Fairbairn Foundation

JNCC

RSPB

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