Illustration © David Allen Sibley.
Learn more about these drawings.
Text © Kenn Kaufman, adapted from
Lives of North American Birds
Photo: Doug Wechsler/Vireo
Red Knot
Calidris canutus
| Conservation status | Once far more numerous in North America, but huge numbers were shot on migration in late 1800s. Some populations have declined sharply since the 1960s. The subspecies that migrates from southern Argentina to the Canadian Arctic in spring relies on stopover habitat along Delaware Bay, where the knots fatten up on the superabundant eggs of horseshoe crabs before they continue north to the Arctic. Overharvesting of horseshoe crabs along the central Atlantic Coast has led to a sharp reduction in this food source for migratory shorebirds, and Red Knots seem to have been hit hard by this. |
|---|---|
| Family | Sandpipers |
| Habitat | Tidal flats, shores; tundra (summer). In migration and winter on coastal mudflats and tidal zones, sometimes on open sandy beaches of the sort favored by Sanderlings. Nests on Arctic tundra, usually on rather high and barren areas inland from coast, but typically near a pond or stream. |
Photo Gallery
Feeding Behavior
On tidal flats, forages mostly by probing in mud with bill, finding food by touch. On dry sand and on tundra breeding grounds, forages mostly by sight, picking items from surface.
Eggs
3-4. Pale olive-green, with small brown spots. Incubation is by both sexes (although male may do more), 21-22 days. Young: Downy young leave nest soon after hatching. Both parents tend young at first, but female leaves before young are old enough to fly. Young feed themselves. Young are able to fly at about 18-20 days after hatching, become independent about that time.
Young
Downy young leave nest soon after hatching. Both parents tend young at first, but female leaves before young are old enough to fly. Young feed themselves. Young are able to fly at about 18-20 days after hatching, become independent about that time.
Diet
Includes mollusks, insects, green vegetation, seeds. In migration and winter, feeds on small invertebrates that live in mud of intertidal zone, especially small mollusks, also marine worms, crustaceans. On breeding grounds, feeds mostly on insects, especially flies. Also eats much plant material, especially early in breeding season (when insects may be scarce), including shoots, buds, leaves, and seeds.
Nesting
Early in breeding season, male flies in high circles above territory, hovering on rapidly quivered wings and then gliding, while giving mellow whistled calls. Female may fly around territory with male. On ground, male displays with wings held high. Nest site is on ground on open tundra, usually near water. Nest is a shallow scrape lined with leaves, lichen, moss.
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- All Seasons - Common
- All Seasons - Uncommon
- Breeding - Common
- Breeding - Uncommon
- Winter - Common
- Winter - Uncommon
- Migration - Common
- Migration - Uncommon
Songs and Calls
A soft quer-wer; also a soft knut.How climate change could affect this bird's range
In the broadest and most detailed study of its kind, Audubon scientists have used hundreds of thousands of citizen-science observations and sophisticated climate models to predict how birds in the U.S. and Canada will react to climate change.
Read more: climate.audubon.org
Each map is a visual guide to where a particular bird species may find the climate conditions it needs to survive in the future. We call this the bird’s “climatic range.”
The colors indicate the season in which the bird may find suitable conditions— blue for winter, yellow for summer (breeding), and green for where they overlap (indicating their presence year-round).
The darker the shaded area, the more likely it is the bird species will find suitable climate conditions to survive there.
The outline of the approximate current range for each season remains fixed in each frame, allowing you to compare how the range will expand, contract, or shift in the future.
The first frame of the animation shows where the bird can find a suitable climate today (based on data from 2000). The next three frames predict where this bird’s suitable climate may shift in the future—one frame each for 2020, 2050, and 2080.
You can play or pause the animation with the orange button in the lower left, or select an individual frame to study by clicking on its year.
Red Knot In the News More News
Press Room
Audubon Honors Public Officials with Conservation Hero Awards
Former Bush and Obama Deputy Interior Secretaries Among 2018 Republican and Democratic Honorees
Birding
Inside Birding's Most Dramatic 24 Hours
Every May hundreds of birders crisscross New Jersey in the frenzied, exhausting, demoralizing, jubilant event that is the World Series of Birding. This year, 'Audubon' reporters embedded with three of the teams.
Conservation
Inside the Biomedical Revolution to Save Horseshoe Crabs and the Shorebirds That Need Them
It took a dedicated birder to convince pharma giant Eli Lilly to use a synthetic compound instead of horseshoe crab blood in a mandatory medical test. Now, he hopes the rest of industry will follow.
Red Knot Across Audubon
Coastal Stewardship: Atlantic & Pacific
Protecting shorebirds in habitats especially vulnerable to development and climate threats
Central Flyway Migration Corridor
Protecting the Central Flyway’s diverse marsh and wetland habitats for migrating species
