Red Knot
(Calidris canutus)


Picture of bird
© MK Peck
For additional photos and vocalizations, visit Dendroica. (Link opens in a new window.)

Red Knots are well known for their long-distance migrations from their Arctic breeding grounds to southern South America and elsewhere. The global population is in decline. Three subspecies of Red Knot occur in Canada: Calidris canutus rufa, C. c. islandica, and C. c. roselaari. The rufa subspecies breeds in the central Arctic from Baffin Island in the east to Banks Island in the west, and migrates to several areas across the southeastern United States, the northwest Gulf of Mexico, the northeast coast of Brazil, the Atlantic coasts of Argentina and Chile, and the Caribbean. The islandica subspecies breeds in the northeastern High Arctic and High Arctic Greenland, and migrates to Europe. The roselaari type breeds in northern Alaska and Wrangel Island (Russia), and winters along the Pacific coast of Mexico and California. Only a small number of roselaari use stopover habitat in coastal British Columbia during migration; the subspecies does not breed in Canada.

All three subspecies are thought to have decreased, though there is substantial variation in the magnitude of the declines and much uncertainty. Regular aerial surveys of the rufa population on the wintering grounds in Tierra del Fuego and Patagonia have documented dramatic decreases in abundance since surveys began in 1982. Birds wintering in northern Brazil and the southeastern United States form separate biogeographical populations of the rufa subspecies, and are also believed to be declining. Numbers of islandica on the wintering grounds have fluctuated considerably but appear to have shown little change overall or a slight decrease since the mid-1980s; there is no information specific to Canada. Systematic surveys are lacking for roselaari, but studies of wintering birds suggest a decrease in the population that is likely reflected in the small number of birds that pass through Canada. Overall, given the difference in status of the two most abundant subspecies occurring in Canada, the Red Knot’s status as a whole, relative to the 1970s, may be best assessed as a moderate decrease, but with low reliability due to islandica’s heavy fluctuations and the fact that the proportion of Canadian birds captured by European surveys remains unknown. Heavy shellfish harvesting in key wintering and staging areas, as well as climate change, are threats to the species. Dramatic declines led to the designation of the rufa subspecies as Endangered (COSEWIC 2007f); the other two subspecies are also listed under the Species at Risk Act due to long-term declines. Canada’s responsibility for the species as a whole is considered to be low, but it may be more appropriate to consider the responsibility at the subspecies level, given the variability involved: responsibility is very high for rufa, is moderate for islandica, and is low for roselaari. This species has been identified as a priority for conservation and/or stewardship in one or more Bird Conservation Region Strategies in Canada.


Main designations for the species
DesignationStatusDateSubspecies, population
COSEWIC (Canada)Endangered2007Red Knot rufa subspecies
COSEWIC (Canada)Special Concern2007Red Knot islandica subspecies
COSEWIC (Canada)Threatened2007Red Knot roselaari type
SARA (Canada)Endangered2012Red Knot rufa subspecies
SARA (Canada)Special Concern2012Red Knot islandica subspecies
SARA (Canada)Threatened2010Red Knot roselaari type
IUCN (Global)Near threatened2018 
Partners in Flight (North America)Watch list - yellow D2017 
Wild Species (Canada)Imperiled2015 
Bird Conservation Region StrategyPriority Species2013 

Population status

Geographic area or populationPopulation change relative to ~1970ReliabilityStatus in relation to goal
CanadaModerate DecreaseLowNot Applicable
Red Knot rufa subspeciesLarge DecreaseHighBelow Acceptable Level
Red Knot islandica subspeciesLittle ChangeLowBelow Acceptable Level
Red Knot roselaari typeModerate DecreaseLowBelow Acceptable Level

Population estimate

Geographic area or populationPopulation estimate
Canada50,000 - 100,000 adults (includes birds breeding and migrating within Canada)

Distribution maps


Migration strategy, occurrence

Long-distance migrant

Responsibility for conservation

Geographic areaResponsibility based on % of global population

General nesting period in Canada

Nesting period starts in mid-June and ends in late July, depending on the region. Before or after this period, the probability of an active nest is lower.

Conservation and management

All three subspecies of Red Knots are long-distance migrants. Disturbance, habitat degradation, and erosion of food resources at key staging sites could impair the birds’ ability to complete their annual migrations successfully (e.g., Duijns et al. 2017). Hunting, both legal and illegal, on the staging and wintering grounds continues to threaten the species, as well as other shorebird species (ECCC 2017d). Climate change is expected to have a negative effect on Arctic-breeding shorebirds because their conservative life-history strategy (low rate of reproduction and long lifespan) makes it difficult for them to quickly adapt to the effects of accelerated climate change on their breeding habitat (Meltofte et al. 2007). Effects may include: drying of tundra ponds (Stow et al. 2004, Smol and Douglas 2007), shrub encroachment (Callaghan et al. 2005, Tape and Racine 2006), asynchrony of insect emergence-chick hatch (Tulp and Schekkerman 2008), unusual weather events (Martin and Wiebe 2004, Tulp and Schekkerman 2006) and changes in predation pressure. For information on the legal status of the three subpecies under the Species at Risk Act (SARA) and to view available recovery documents, see the SARA Registry.

Although intensive research is ongoing, the causes of decline in rufa Red Knots have only been partially identified. During northward migration, most rufa stage in Delaware Bay, where the harvest of horseshoe crabs has reduced the availability of their eggs to Red Knots (COSEWIC 2007f), which forage heavily on them to fuel their long-distance migrations. Failure to attain adequate condition before departure for the Arctic breeding grounds has been linked to decreased migratory performance, reproductive success, and survival (Baker et al. 2004, Duijns et al. 2017). Restrictions on the harvest of horseshoe crabs have not yet improved the population status of rufa knots or the crabs themselves (Dey et al. 2011). Perhaps because of a cold water event, the spring of 2017 saw a greatly reduced crab spawning effort, record low departure weights of rufa knots, and low counts of non-breeding individuals in the winter of 2017-2018 (L. Niles et al., unpublished data).

C. c. islandica birds winter on European coasts, where shellfish harvesting has negatively impacted populations. Mechanical dredging of the Dutch Wadden Sea, as well as harvests elsewhere in the winter range, reduce the prey availability for Red Knots and could potentially reduce survival for these long-distance migrants (Piersma 2006, COSEWIC 2007f).

Red Knots occurring on the Pacific coast are considered to be C. c. roselaari, but the breeding and non-breeding distribution and connectivity between the two remain somewhat unclear for this subspecies (Carmona et al. 2013). Habitat changes at migration sites in Washington have led to decreased numbers there (Buchanan 2003, Buchanan 2008). Current research on population size and migratory connectivity should lead to improved conservation planning.


Bird conservation region strategies

Environment and Climate Change Canada and partners have developed Bird Conservation Region Strategies in each of Canada’s Bird Conservation Regions (BCRs). In these strategies, selected species are identified as priorities for one or more of the following reasons:

  • conservation concerns (i.e., species vulnerable due to population size, distribution, population trend, abundance, or threats)
  • stewardship responsibilities (i.e., species that typify the regional avifauna or have a large proportion of their range or population in the sub-region)
  • management concerns (i.e., species that require ongoing management because of their socio-economic importance as game species, or because of their impacts on other species or habitats)
  • other concerns (i.e., species deemed a priority by regional experts for other reasons than those listed above or because they are listed as species at risk or concern at the provincial level)

Select any of the sub-regions below to view the BCR strategy for additional details.

BCRs, marine biogeographic units, and sub-regions in which the species is listed as a priority
RegionSub-region and priority type
Arctic Plains and MountainsArctic Plains and Mountains, sub-region and priority type: Prairie and Northern -- Other
Arctic Plains and MountainsArctic Plains and Mountains, sub-region and priority type: Quebec -- Other
Atlantic Northern ForestsAtlantic Northern Forests, sub-region and priority type: Quebec -- Other
Boreal Hardwood TransitionBoreal Hardwood Transition, sub-region and priority type: Ontario and Manitoba -- Conservation
Boreal Softwood ShieldBoreal Softwood Shield, sub-region and priority type: Quebec -- Other
Gulf of St. LawrenceGulf of St. Lawrence, sub-region and priority type: Atlantic, NB -- Other
Gulf of St. LawrenceGulf of St. Lawrence, sub-region and priority type: Atlantic, NL -- Other
Gulf of St. LawrenceGulf of St. Lawrence, sub-region and priority type: Atlantic, NS -- Other
Gulf of St. LawrenceGulf of St. Lawrence, sub-region and priority type: Atlantic, PE -- Other
Lower Great Lakes/St. Lawrence PlainLower Great Lakes/St. Lawrence Plain, sub-region and priority type: Ontario -- Conservation
Newfoundland and Labrador Shelves Newfoundland and Labrador Shelves , sub-region and priority type: Atlantic, NL -- Other
Northern Pacific RainforestNorthern Pacific Rainforest, sub-region and priority type: Pacific and Yukon -- Stewardship
Prairie PotholesPrairie Potholes, sub-region and priority type: Prairie and Northern -- Other
Scotian ShelfScotian Shelf, sub-region and priority type: Atlantic, NB -- Other
Scotian ShelfScotian Shelf, sub-region and priority type: Atlantic, NS -- Other
Taiga Shield and Hudson PlainsTaiga Shield and Hudson Plains, sub-region and priority type: Ontario -- Conservation
Taiga Shield and Hudson PlainsTaiga Shield and Hudson Plains, sub-region and priority type: Quebec -- Other