Skip to content

Order now! Dr. Roberta Bondar’s new publication Space for Birds: Patterns and Parallels of Beauty and Flight

Search the Roberta Bondar Site

Red Knot

Scientific name: Calidris canutus
IUCN designation: Near Threatened

Canadian subspecies: Calidris canutus rufa
SARA designation: Endangered
COSEWIC designation: Endangered

Image of a Red Knot on a beach in front of horseshoe crabs

The endangered Canadian subspecies of the Red Knot, Calidris canutus rufa, has come to attention in recent years given its 70% decline in abundance in a span of 15 years as of 20161.

The rufa Red Knot is part of the sandpiper family, therefore having typical sandpiper characteristics: a long, streamlined body, long legs, and a long narrow bill to probe for food2. It is often described as robin-sized, reaching 23-25 cm (9-10 in) in length and having a wingspan ranging from 51-58 cm (20-23 in)3. Its plumage differs seasonally. The Red Knot has a dull grey plumage during winter and rusty red plumage on its chest and face with mottled brown scaling feathers on its head, hind neck, and wings in summer3.

The rufa Red Knot completes a long strenuous migration every year starting from its breeding areas in the central Canadian Arctic to its wintering areas in the US Gulf Coast, the Caribbean, and South America, making several stopovers along the way at traditional staging grounds along the US East Coast and South America. They can cover up to 15,000 km (9,300 mi) one way during their migration1.

Survival of the rufa Red Knot is dependent primarily on the management of their main stopover food source, the horseshoe crab. Millions of eggs, which are eaten to refuel energy for migration, are laid in Delaware Bay in synchrony with the Red Knot’s arrival in May3. The rufa Red Knot is also dependent on the mitigation of disturbance and degradation of its breeding, stopover, and wintering habitats that are affected by urban development and climate change4.

Several governmental agencies, nongovernmental organizations, and educational institutions are working to study and eliminate threats to the Red Knot sites in both continents to conserve the declining populations.

To learn more, visit our Red Knot StoryMap or the links below!

  1. Species at Risk Act – Recovery Strategy and Management Plant for the Red Knot (Calidris canutus) in Canada
  2. American Bird Conservancy: ABC’s Bird Library – Red Knot
  3. The Cornell Lab: All About Birds – Red Knot
  4. IUCN Red List – Red Knot
  5. National Wildlife Federation – Synchronous Survival: Red Knots and Horseshoe Crabs
  6. Horseshoe Crab Recovery Coalition

Return to Species

Return to AMASS / Space for Birds