Red Knot roselaari type
Scientific Name: Calidris canutus roselaari type
Other/Previous Names: Calidris canutus roselaari type
Taxonomy Group: Birds
COSEWIC Range: Yukon, Northwest Territories, British Columbia
COSEWIC Assessment Date and Status Change: November 2020
COSEWIC Status: Non-active
COSEWIC Status Criteria:
COSEWIC Reason for Designation:
COSEWIC History of Status Designation: The species 'roselaari type' was considered a single unit (which included three groups) and designated Threatened in April 2007. Based on the Designatable Unit report on Red Knot (COSEWIC 2019), a new population structure was proposed and accepted by COSEWIC; two groups previously assessed under the ‘roselaari type’ were transferred to the rufa subspecies (Northeastern South America wintering population, Southeastern USA / Gulf of Mexico / Caribbean wintering population).The remaining unit includes only those birds now considered part of the roselaari subspecies. The original designation of 'roselaari type' was de-activated in November 2020.
SARA Status: Schedule 1, Threatened
Date of Listing (yyyy-mm-dd): 2010-02-23
Please note that this information is provided for general information purposes only. For the most up to date and accurate list of species listed under the Species at Risk Act, please see the Justice Laws Website.
|Red Knot roselaari subspecies||Threatened||No Status|
|Red Knot rufa subspecies ( Northeastern South America wintering population )||Special Concern||No Status|
|Red Knot rufa subspecies ( Southeastern USA / Gulf of Mexico / Caribbean wintering population )||Endangered||No Status|
There are currently six Red Knot Calidris canutus subspecies. Among these subspecies, which form distinct populations, three occur in Canada: C. c. roselaari, C. c. islandica, and C. c. rufa. The Red Knot roselaari type includes the subspecies roselaari as well as two other populations that winter in Florida and northern Brazil and that seem to share characteristics of roselaari.
The Red Knot is a shorebird measuring 25 cm in length. As do all sandpipers, the Red Knot has a long straight bill, small head, long legs, and long tapered wings, giving an elongated and streamlined profile to the body. During the breeding season, the Red Knot’s plumage changes colour: the face, neck, chest, and much of the underparts turn brownish red. There is a white stripe on the wings, and the feathers on the upper parts are dark brown or black interspersed with red and grey, making the back appear spangled. Males tend to be more brightly coloured than females, with more extensive red on the underparts. The Red Knot’s winter plumage is plain. The underparts are white, and the back is light grey. The upper breast and the flanks have greyish or brownish streaks, and the head has dull greyish patterning with a whitish line above the eye. Juveniles have similar plumage, but they can be distinguished by their scaly appearance. Juveniles, may also have a soft pale buff colour suffusing the breast.
Distribution and Population
The Red Knot roselaari type is divided into three populations: the Pacific coast population, the Florida and southeastern United States population, and the Brazilian Maranhão population. The Pacific coast population breeds in northwestern Alaska and on Wrangell Island. It migrates along the Pacific coast of Canada and the northwestern United States to winter in California, on the Pacific coast of northwestern Mexico, and, possibly, as far as the Gulf of Mexico. The Florida and southeastern United States populations probably breed in Alaska and the western part of the Canadian Arctic and winter in Florida, Georgia, and South Carolina. The third population likely breeds in Alaska or the western Canadian Arctic and, as its name suggests, winters in Maranhão on the north-central coast of Brazil. In Canada, roselaari populations breed in Yukon, the Northwest Territories, and the western Canadian Arctic. Individuals belonging to the Pacific coast population travel along the coast of British Columbia during their southward migration. According to counts on this species’ various wintering grounds, the estimated population of Red Knot roselaari type is 12 825 adults in 2007. The population wintering in Florida and the southeastern United States is estimated at 3375 adults. Between the early 1990’s and the late 2000’s, the size of this group has dropped by about 70%. Less is known about the Maranhão population in Brazil, although it may have dropped to 5700 adults, a decline of about 7% between the late 1980’s and the late 2000’s. Available data suggest that the Pacific roselaari population has declined by about 60% since 1981. In 2005, the size of this population was between 1500 and 3000 adults. We acknowledge in 2007 an overall decline of 47% of the roselaari population.
Red Knots use different habitats during the breeding, wintering, and migration seasons. In the Arctic, they nest in extremely barren habitats, such as windswept ridges, slopes, or plateaus. Nesting sites are usually located in dry, south-facing locations, near wetlands or lakes, where the young are led after hatching. Red Knots generally feed in damp or barren areas that can be as far as 10 km from the nest. Migratory stopovers and wintering grounds are vast coastal zones swept by tides twice a day, usually sandflats but sometimes mudflats. In these areas, the birds feed on molluscs, crustaceans, and other invertebrates. The species also frequents peat-rich banks, salt marshes, brackish lagoons, mangrove areas, and mussel beds. In South America, they frequent restingas, which are rocky, tide-swept platforms, rich in invertebrates. This species’ various habitats must provide suitable rest areas, sheltered from predators. It is unlikely that the extent of this species’ Arctic breeding habitat has undergone any significant change. However, habitat changes brought about by climate change are likely to affect knots, probably in a negative fashion.
Red Knots arrive in the Canadian Arctic to breed in early June. These migratory birds generally begin to breed at the age of two. Couples usually produce a single clutch per year in the latter half of June. Nests are simple scrapes in the ground, usually in small patches of vegetation, which may be lined with lichen and other plant material. The female lays four eggs (sometimes three). Incubation lasts 22 days and is shared by males and females. The female leaves shortly after hatching, around mid-July, leaving the male to care for the brood until the young birds take flight, or fledge, at the age of approximately 18 days. After the fledging, the adult males depart, followed by the juveniles one to three weeks later. Survival rates among juveniles vary considerably from one year to the next depending on the weather conditions and the abundance of predators. The abundance of predators also fluctuates from year to year depending on the abundance of lemmings, the small mammals that are their main prey. On the breeding grounds in the Canadian Arctic, the main predators of nests and eggs include the Arctic Fox, the Long-tailed Jaeger, and occasionally the Arctic Grey Wolf. These species, as well as other jaeger species, seagulls, falcons, and owls may also prey on hatchlings and, occasionally, adults. Red Knots generally live to the age of seven or eight. Red Knots feed on molluscs, crustaceans, and other invertebrates. During the spring migration, these birds forage for crab eggs on the sandy beaches of Delaware Bay, used by nesting Horseshoe Crabs. Everywhere they occur, Red Knots appear to be extremely faithful to their sites. During nonbreeding seasons, large groups of these shorebirds gather on migratory stopovers and winter ranges, where they feed in tide-swept coastal zones and rest on neighbouring beaches, in marshes, or on fields characterized by open, undisturbed habitats.
The main threat to the Red Knots roselaari type that winter in Florida and the southeastern United States or Brazil is the overfishing of Horseshoe Crabs in Delaware Bay, which has decimated the supply of this invertebrate’s eggs. During the spring migration, these eggs are the birds’ most important food source at their final stopover before returning to Canada. This species faces other threats. The number of available wetland habitats during migration in eastern North America has decreased. Moreover, Canadian populations that winter on (or migrate along) the Pacific coast have likely been affected by the degradation of habitat in areas such as Grays Harbor (Washington) and San Francisco Bay. Other potential threats include human disturbance, the increased frequency and force of hurricanes during migration, and pollution caused by oil and chemical use in North and South America. Finally, the effects of climate change (such as rising sea levels and changing conditions of Arctic breeding grounds) and the increased predation (resulting from the rebounding of predator populations including falcons) could pose a long-term threat to Red Knot populations.
Status of Recovery Planning
Recovery Strategies :
Name Recovery Strategy and Management Plan for the Red Knot (Calidris canutus) in Canada
Status Final posting on SAR registry
PLEASE NOTE: Not all COSEWIC reports are currently available on the SARA Public Registry. Most of the reports not yet available are status reports for species assessed by COSEWIC prior to May 2002. Other COSEWIC reports not yet available may include those species assessed as Extinct, Data Deficient or Not at Risk. In the meantime, they are available on request from the COSEWIC Secretariat.
21 record(s) found.
- COSEWIC Status Reports (1 record(s) found.)
- Response Statements (1 record(s) found.)
- Recovery Strategies (1 record(s) found.)
- Management Plans (1 record(s) found.)
- Orders (2 record(s) found.)
- COSEWIC Annual Reports (1 record(s) found.)
- Permits and Related Agreements (11 record(s) found.)
- Consultation Documents (2 record(s) found.)
- Recovery Document Posting Plans (1 record(s) found.)
COSEWIC Status Reports
Response Statement - Red Knot roselaari type (2007-12-04)This designatable unit includes the subspecies roselaari and two other populations that winter in Florida and northern Brazil and that seem to share characteristics of roselaari. The subspecies roselaari migrates through BC and breeds in Alaska. The migration routes and breeding areas of the other two populations are unknown. This group has declined by 47% overall during the last three generations (15 years). Ongoing threats include habitat loss and degradation on wintering sites and, for the Florida/SE US and Maranhão groups, depleted levels of horseshoe crab eggs, a critical food source needed during northward migration. Rescue from other populations is not anticipated.
COSEWIC Annual Reports
COSEWIC Annual Report - 2007 (2007-08-30)2007 Annual Report to the The Minister of the Environment and the Canadian Endangered Species Conservation Council (CESCC) from the Committee on the Status of Endangered Wildlife in Canada.