The body shape is typical for the genus, with a small head and eyes, a short neck and a slightly tapering bill that is no longer than its head. It has short dark legs and a medium thin dark bill. The winter, or basic, plumage becomes uniformly pale grey, and is similar between the sexes. The alternate, or breeding, plumage is mottled grey on top with a cinnamon face, throat and breast and light-coloured rear belly. The alternate plumage of females is similar to that of the male except it is slightly lighter and the eye-line is less distinct. canutus, islandica and piersmai are the “darker” subspecies. Subspecies rogersi has a lighter belly than either roselaari or piersmai, and rufa is the lightest in overall plumage. The transition from alternate to basic plumages begins at the breeding site but is most pronounced during the southwards migration. The molt to alternate plumage begins just prior to the northwards migration to the breeding grounds, but is mostly during the migration period. The large size, 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. When foraging singly, they rarely call, but when flying in a flock they make a low monosyllabic knutt and when migrating they utter a disyllabic knuup-knuup. They breed in the moist tundra during June to August. The display song of the male is a fluty poor-me. The display includes circling high with quivering wing beats and tumbling to the ground with the wings held upward. Both sexes incubate the eggs, but the female leaves parental care to the male once the eggs have hatched. Juvenile birds have distinctive submarginal lines and brown coverts during the first year. In the breeding season the males can be separated with difficulty (<80% accuracy in comparison to molecular methods[16]) based on the more even shade of the red underparts that extend towards the rear of the belly. The weight varies with subspecies, but is between 100 and 200 g (45–91 oz). Red Knots can double their weight prior to migration.
Not Threatened.
The body shape is typical for the genus, with a small head and eyes, a short neck and a slightly tapering bill that is no longer than its head. It has short dark legs and a medium thin dark bill. The winter, or basic, plumage becomes uniformly pale grey, and is similar between the sexes. The alternate, or breeding, plumage is mottled grey on top with a cinnamon face, throat and breast and light-coloured rear belly. The alternate plumage of females is similar to that of the male except it is slightly lighter and the eye-line is less distinct. canutus, islandica and piersmai are the “darker” subspecies. Subspecies rogersi has a lighter belly than either roselaari or piersmai, and rufa is the lightest in overall plumage. The transition from alternate to basic plumages begins at the breeding site but is most pronounced during the southwards migration. The molt to alternate plumage begins just prior to the northwards migration to the breeding grounds, but is mostly during the migration period. The large size, 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. When foraging singly, they rarely call, but when flying in a flock they make a low monosyllabic knutt and when migrating they utter a disyllabic knuup-knuup. They breed in the moist tundra during June to August. The display song of the male is a fluty poor-me. The display includes circling high with quivering wing beats and tumbling to the ground with the wings held upward. Both sexes incubate the eggs, but the female leaves parental care to the male once the eggs have hatched. Juvenile birds have distinctive submarginal lines and brown coverts during the first year. In the breeding season the males can be separated with difficulty (<80% accuracy in comparison to molecular methods[16]) based on the more even shade of the red underparts that extend towards the rear of the belly. The weight varies with subspecies, but is between 100 and 200 g (45–91 oz). Red Knots can double their weight prior to migration.
An adult Red Knot is the second largest Calidris sandpiper, measuring 23–26 cm long with a 47–53 cm wingspan.: An adult Red Knot is the second largest Calidris sandpiper, measuring 23–26 cm long with a 47–53 cm wingspan.
Taxonomy:
- Tringa Canutus Linnaeus, 1758, Sweden. In past, genus Calidris was on occasion reserved for present species and C. tenuirostris only. Races islandica, rogersi and, until recently, roselaari formerly included within nominate canutus. Five subspecies currently recognized. (source: Handbook of the Birds of World)
Subspecies and Distribution:
- * canutus (Linnaeus, 1758) - CN Siberia, in Taymyr Peninsula, New Siberian Is and possibly Yakutia; winters in W & S Africa and probably Australasia. * rogersi (Mathews, 1913) - Chukotskiy Peninsula and possibly areas farther W; winters in Australasia. * roselaari Tomkovich, 1990 - Wrangel I and NW Alaska; probably winters in Florida, S Panama and N Venezuela. * rufa (Wilson, 1813) - Canadian low Arctic; winters in NE & S South America. * islandica (Linnaeus, 1767) - islands of Canadian high Arctic and N Greenland; winters in WEurope.
Birds wintering in west Africa were found to restrict their daily foraging to a range of just 2–16 km2 of intertidal area and roosted a single site for several months. In temperate regions such as the Wadden Sea they have been found to change roost sites each week and their feeding range may be as much as 800 km2 during the course of a week.
On the breeding grounds, Knots eat mostly 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.
The Red Knot is territorial and seasonally monogamous; it is unknown if pairs remain together from season to season. Males and females breeding in Russia have been shown to exhibit site fidelity towards their breeding locales from year to year, but there is no evidence as to whether they exhibit territorial fidelity. Winter plumage