The Red Knot, Calidris canutus [Knot in Europe] is a large member of the Calidris Sandpipers, second in size to the Great Knot. This species forms enormous flocks when not breeding. The red knot has one of the longest migrations of any bird. Every year it travels more than 15,000km from the Arctic to the southern tip of South America.

The bird has a small head and eyes, a short neck and a slightly tapering black bill. It has short dark legs. The winter plumage is uniformly pale grey, and is similar between the sexes. The breeding, plumage is mottled grey on top with a cinnamon face, throat and breast and light-coloured rear belly. The plumage of females is similar to that of the male except it is slightly lighter and the eye-line is less distinct.

The large white wing bar and grey rump and tail make it easy to identify in flight. When feeding the short dark green legs give it a characteristic 'low-slung' appearance.

On the breeding grounds, Knots feed on spiders, arthropods and larvae obtained by surface pecking, and on the wintering and migratory grounds they eat a variety of hard-shelled prey such as bivalves, gastropods and small crabs that are ingested whole and crushed by a muscular stomach. While feeding in mudflats during the winter and migration Red Knots are tactile feeders, probing for unseen prey in the mud.

They breed in the Tundra and the Arctic Cordillera in the far north of Canada, Russia and Europe. North American breeding birds migrate to coastal areas in Europe and South America, while the Eurasian breeding birds winter in Africa, Asia Australia and New Zealand. The Red Knot is territorial. Males arrive in the breeding grounds before females and begin defending territories.

The nest is a shallow scrape lined with leaves, lichens and moss. Males construct three to five nest scrapes in their territories prior to the arrival of the females. The female lays three or more usually four eggs.

Both parents incubate the eggs, the incubation period lasting about 22 days. The chicks and the parents move away from the nest within a day of hatching and begin foraging with their parents. The female leaves before the young fledge while the males stay on. After the young have fledged, the male begins his migration south and the young make their first migration on their own.

The American subspecies have become threatened as a result of commercial harvesting of horseshoe crabs in Delaware Bay which began in the early 1990s. Delaware Bay is a critical stopover point during spring migration; the birds refuel by eating the eggs laid by these crabs. In 2003, scientists projected that at its current rate of decline the American subspecies might become extinct as early as 2010. As of April 2011 the subspecies is still extant. Several environmental groups have petitioned the U.S. government to list the birds as endangered, but thus far their requests have not been granted. In New Jersey, state and local agencies are taking steps to protect these birds by limiting horseshoe crab harvesting and restricting beach access. In Delaware, a two-year ban on the harvesting of horseshoe crabs was enacted but struck down by a judge who cited insufficient evidence that the ban would help restore the Red Knot's numbers to justify the potential disruption to the fishing industry. Instead, a male only harvest has been permitted in recent years.

This common summer visitor can be seen on any of the following Aves Birding Tours/Safaris/Adventures: -

Aves Eastern Cape Birding Tour/Safari/Adventure.

Aves West Coast Birding Tour/Safari/Adventure.