Red Knot Bird Facts (Calidris canutus)

Visual Identification

Appearance

The Red Knot is a medium-sized shorebird with a distinctive plumage that changes dramatically between seasons.

In breeding plumage, it displays a striking rusty-red face, breast, and underparts, contrasting with its grey back and wings. Breeding females are similar to males, although their plumage is less vibrant, with less red colouring.

During non-breeding seasons, Red Knots transform to a plain grey above and white below. During this time, males and females are alike. They have a straight black bill and short, dark legs. Juveniles resemble non-breeding adults but with scaly patterning on their backs.

Size

Length

23cm to 26cm

Wingspan

45cm to 54cm

Weight

100g to 200g

Colours

Males and females have similar plumage

Primary Colour

Red Grey

Secondary Colour

White

Beak Colour

Black

Leg Colour

Black

Habitat and Distribution

Habitats

Woodland

The Red Knot is not typically found in Woodland habitats.

Garden

The Red Knot is not typically found in Garden habitats.

Wetland

The Red Knot can be found in Wetland habitats.

Coastal

The Red Knot can be found in Coastal habitats.

Urban

The Red Knot is not typically found in Urban habitats.

Farmland

The Red Knot is not typically found in Farmland habitats.

Grassland

The Red Knot is not typically found in Grassland habitats.

Desert

The Red Knot is not typically found in Desert habitats.

Tundra

The Red Knot can be found in Tundra habitats.

Rainforest

The Red Knot is not typically found in Rainforest habitats.

Mountain

The Red Knot is not typically found in Mountain habitats.

Savanna

The Red Knot is not typically found in Savanna habitats.

Distribution

Red Knots breed in the high Arctic tundra and winter on coastal areas across the globe. They can be found on every continent except Antarctica during different parts of their annual cycle.

In North America, they are common along both coasts during migration. Key stopover sites include Delaware Bay in the USA and the Bay of Fundy in Canada.

They also frequent coastal areas in the UK, Australia, and New Zealand during non-breeding seasons.

Elevation Range

Sea level to 300 meters

Climate zones

Arctic, Temperate, Tropical

Distribution Map

This map gives you a rough idea of where you might spot a Red Knot. The coloured areas show countries where these birds have been seen.

A few things to keep in mind:

Birds might not be everywhere in the coloured areas, for example, they may be present around the coast of that country
Where birds live can change with seasons and available food
This map is quite simple - it doesn't show exact locations

We're working on making our maps even better! Soon, we hope to show you:

More detailed maps for bigger countries, including state and region
How birds move around during different seasons

Resident

Breeding

Non-breeding

Passage

Vagrant

Distribution by Region

Species that can be found in the area throughout the year

Algeria Angola Anguilla Antigua and Barbuda Argentina Aruba Austria Bangladesh Barbados Benin Bermuda Bolivia Brazil Brunei Cameroon Cayman Islands Colombia Congo Côte D'Ivoire Cuba Curaçao Czech Republic Denmark Dominica Dominican Republic Ecuador Egypt El Salvador Faroe Islands France French Guiana Gabon Gambia Germany Ghana Greece Grenada Guatemala Guinea Guinea-Bissau Guyana Haiti Honduras Hong Kong Hungary Iceland India Iran Israel Japan Latvia Liberia Libya Malaysia Martinique Mauritania Mexico Montserrat Morocco Myanmar Namibia Netherlands Nigeria Pakistan Panama Papua New Guinea Paraguay Peru Philippines Puerto Rico Russia Saint Barthelemy Saint Kitts and Nevis Saint Lucia Saint Vincent and the Grenadines Senegal Seychelles Sierra Leone Singapore Slovakia South Africa South Georgia and the South Sandwich Islands Spain Sri Lanka Suriname Switzerland Taiwan Tanzania Thailand The Bahamas The United Kingdom Togo Trinidad and Tobago Tunisia Turkey Turks and Caicos Venezuela Vietnam Western Sahara

Species that are present in the area during their breeding season

Greenland Svalbard and Jan Mayen Islands United States of America

Species that are present in the area outside their breeding season

Australia Belgium Belize British Virgin Islands Bulgaria Chile Costa Rica Equatorial Guinea Estonia Ireland Italy Macedonia New Zealand Portugal Uruguay US Virgin Islands

Species that pass through the area during migration

Canada China Finland Indonesia North Korea Norway Poland Saint Pierre and Miquelon South Korea Sweden Ukraine United States of America

Species that appear infrequently (rare) and unpredictably outside their normal range

Albania Azerbaijan Belarus Botswana Cape Verde Croatia Cyprus East Timor (Timor-Leste) Falkland Islands Fiji Georgia Gibraltar Guadeloupe Iraq Jamaica Jordan Kazakhstan Kenya Kuwait Lebanon Luxembourg Mali Malta Mongolia Montenegro Mozambique Nepal Oman Romania Saudi Arabia Serbia Slovenia Somalia Sudan United Arab Emirates Yemen Zambia

Behaviour and Ecology

Bird Attributes

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Bird Attributes Explained

Our bird attributes system rates various aspects of a bird's capabilities on a scale of 0-100, based on data from field observations, scientific studies, and expert knowledge.

Attribute Categories:

Agility: Manoeuvrability, speed, and grace in flight or movement.
Strength: Physical power, often correlating with size and hunting abilities.
Adaptability: Ability to thrive in various environments or changing conditions.
Aggressiveness: Territorial behaviour and assertiveness, particularly during breeding seasons.
Endurance: Stamina, often seen in migration patterns or foraging behaviours.

Understanding the Ratings:

0-20: Very Low
21-40: Low
41-60: Average
61-80: High
81-100: Very High

Remember, these attributes are relative to other bird species and don't necessarily indicate superiority.

Hover over the icon next to each attribute for more information.

Tap the icon next to each attribute for more information.

Agility 85

Agility

Reflects the bird's manoeuvrability, speed, and grace in flight or movement.

The Red Knot demonstrates remarkable agility, particularly during its long-distance migrations and in its ability to navigate diverse coastal environments. Its swift flight and nimble foraging behaviour in shallow waters showcase its high level of agility.

Strength 70

Strength

Indicates the bird's physical power, often correlating with size and hunting abilities.

Whilst not exceptionally strong for its size, the Red Knot possesses sufficient strength to undertake gruelling long-distance migrations, sometimes doubling its body weight beforehand. Its ability to probe into sand and mud for food also indicates a decent level of strength.

Adaptability 95

Adaptability

Represents the bird's ability to thrive in various environments or changing conditions.

Red Knots exhibit extraordinary adaptability, thriving in environments ranging from Arctic tundra to tropical coastlines. Their ability to alter their plumage seasonally and adjust their diet based on location demonstrates remarkable adaptive capabilities.

Aggressiveness 30

Aggressiveness

Measures the bird's territorial behaviour and assertiveness, particularly during breeding seasons.

Red Knots are generally non-aggressive birds, often seen feeding in large, peaceful flocks. They do not typically engage in territorial disputes outside of the breeding season, and even then, aggression is limited to aerial displays rather than physical confrontations.

Endurance 98

Endurance

Reflects the bird's stamina, often seen in migration patterns or foraging behaviours.

The Red Knot's endurance is truly exceptional. Its ability to fly up to 30,000 km (around 18,600 miles) annually, with some individuals covering distances equivalent to the Earth's circumference in their lifetime, places it among the most enduring of bird species.

Diet

Red Knots primarily feed on small invertebrates, including molluscs, crustaceans, marine worms and spiders.

During migration, they rely heavily on horseshoe crab eggs in some regions, with Delaware Bay being a significant stopover point on northward migrations each spring.

Early arrivals to breeding grounds may eat shoots and plant matter if the landscape is not fully thawed for insect life to be widely available.

Their bills are specially adapted to probe for prey in sand and mud, often feeding in large groups during low tide.

Behaviour

Red Knots are known for their impressive long-distance migrations, flying up to 30,000 km (around 18,600 miles) annually. They often gather in large flocks, probing the sand or mud with their bills to find food.

During the breeding season, males perform aerial displays, flying in wide circles while calling to attract females.

Vocalisation

Red Knots are usually silent when foraging alone, but they have a distinctive call, often described as a soft, low 'knut-knut' or 'tut-tut'.

During the breeding season, males produce a more melodious song, a series of fluty whistles that sound like 'tu-li-li-li', often given during display flights over their territories.

Nesting & Breeding

Red Knots breed in the Arctic tundra during the brief summer. Males arrive first and establish territories, performing aerial displays to attract females.

Nests are simple scrapes on the ground, often lined with leaves and lichen. Females typically lay 4 olive-green eggs with brown spots. Both parents share incubation duties.

The incubation period lasts about 22 days, and chicks are precocial, able to leave the nest and feed themselves shortly after hatching. They fledge after about 18-20 days.

Conservation and Status

Global Conservation Status

Near Threatened ^[1]

Red Knots face significant conservation challenges due to habitat loss and climate change. Overharvesting of horseshoe crabs, a key food source during migration, has impacted some populations.

Conservation efforts focus on protecting critical stopover sites and regulating horseshoe crab harvests.

Population Data

Global Population Estimate

891,000 - 979,000 individuals ^[2]

Global Population Trend

^[3]

Trend data may be uncertain or fluctuating

Additional Information

Quick Facts

Other names:

Knot, Lesser Knot

Family:

Scolopacidae

Average Lifespan

8 to 10 years

Max Lifespan

27 years ^[4]

Predators

Red Knots face predation from various species, including Arctic foxes, jaegers, and large gulls on their breeding grounds. During migration and winter, falcons and other raptors pose threats.

Did You Know?

Red Knots can double their body weight before long migratory flights.
Some Red Knots fly the equivalent of the Earth's circumference in their lifetime.
Their scientific name, Calidris canutus, is linked to King Canute of England, who allegedly tried to command the tides.

FAQs

Why are red knots so important?

Red knots are fascinating to researchers who are able to gain valuable insights into their lengthy migration patterns due to banding programs which are used to understand trends in population decline and changes to habitats worldwide.

Due to the vast numbers that descend upon Delaware Bay each year to feed on the eggs of horseshoe crabs, the species is directly linked to bringing in a significant amount of money to the local economy, with ecotourism in this region raising around $36 million annually.

Why are red knots called moon birds?

Moonbird is the nickname given to an individual red knot, tagged as B95, which is the oldest known individual of its species and the subject of books and documentaries.

The nickname ‘moon bird’ originates from the fact that during this bird’s lifetime, its long-distance migrations have exceeded the length of the journey from Earth to the Moon.

References

1
website: BirdLife International. 2018. Calidris canutus. The IUCN Red List of Threatened Species 2018: e.T22693363A132285482.
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2 3
report, 2018: Wetlands International
4
website, 2012: Robinson and Clark, The Online Ringing Report: Bird ringing in Britain & Ireland in 2011
View source