The Red Knot (Calidris canutus), or Knot in Europe, is a species of bird found in the tundra and Arctic mountains in the far north of Canada, Europe and Russia. North American birds migrate to coastal Europe and South America, while European birds migrate to Africa, Papua New Guinea, Australia and New Zealand. This species has an extensive range and a large population of about 1.1 million individuals. There are six subspecies.
The adult is 9 to 10.25 inches in length with an 18.5 to 20.8 inch wingspan. Its legs are short and dark and it has a thin dark bill. The body is mottled gray on top with a cinnamon colored face, throat and breast and light colored rear belly. The winter plumage becomes more pale gray. There is some color morphing between subspecies. The adult Red Knot weighs 3.5 to 7 ounces and can double its weight prior to migration.
This species nests near water, on the ground. The nest is usually inland. The female lays 3 to 4 eggs in a shallow scrape that is usually lined with leaves and moss. Incubation is done by both male and female, but the female leaves before the young fledge. The male begins his migration south once the young have fledged. The young make their first migration on their own. Knots eat mostly spiders, arthropods, and larvae in the breeding range and take in a variety of hard-shelled prey in the wintering grounds. These prey include bivalves, gastropods, and small crabs that are ingested whole and crushed by a muscular stomach.
Around the end of the 19th century, these birds were hunted for food during their migration in North America. More recently, they have become threatened through commercial harvesting of horseshoe crabs in Delaware Bay. This area is a critical stopover point for the Red Knot during spring migration. These birds feed on the eggs of the horseshoe crab, and with reduced numbers of the crabs living in that region, there are fewer eggs for the birds to feed on. In 2003, scientists projected that the American subspecies might go extinct as early as 2010. The U.S. government has been petitioned to list the birds as endangered, but thus far requests have been denied. Horseshoe crab harvesting has been limited in New Jersey to help protect this species. In Delaware, a two-year ban on horseshoe crab harvesting was enacted but was overturned by a judge who cited that there was insufficient evidence to warrant the ban.