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Guide to North American Birds

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Breeding adult. Photo: Brian Kushner/Flickr

Priority Bird

Red Knot

Calidris canutus

This chunky shorebird has a rather anonymous look in winter plumage, but is unmistakable in spring, when it wears robin-red on its chest. It nests in the far north, mostly well above the Arctic Circle (the first known nest was discovered during Admiral Peary's expedition to the North Pole in 1909); its winter range includes shorelines around the world, south to Australia and southern South America. Where it is common, the Red Knot may roost in very densely packed flocks, standing shoulder to shoulder on the sand.

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.

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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.

Illustration © David Allen Sibley.
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Text © Kenn Kaufman, adapted from
Lives of North American Birds

Migration

A few winter on southern coasts of the United States, but many go to southern South America for the winter. Some birds nesting in far northern Canada apparently fly across Greenland ice cap in fall, to winter in Britain and Europe.

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Migration

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.

Audio © Lang Elliott, Bob McGuire, Kevin Colver, Martyn Stewart and others.
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How Climate Change Will Reshape the Range of the Red Knot

Audubon’s scientists have used 140 million bird observations and sophisticated climate models to project how climate change will affect this bird’s range in the future.

Zoom in to see how this species’s current range will shift, expand, and contract under increased global temperatures.

Climate Threats Near You

Climate threats facing the Red Knot

Choose a temperature scenario below to see which threats will affect this species as warming increases. The same climate change-driven threats that put birds at risk will affect other wildlife and people, too.