Rufa Red Knot
Northeast Region
Red knot Migration Miracle

Click to view the full size image
The Rufa Red Knot (Calidris canutus rufa) Red Knot Resources

The rufa red knot is truly a master of long-distance aviation. On wingspans of 20 inches, some knots fly more than 9,300 miles from south to north every spring and repeat the trip in reverse every autumn, making this bird one of the longest-distance migrants in the animal kingdom. Surveys of wintering knots along the coasts of southern Chile and Argentina and during spring migration in Delaware Bay on the U.S. coast indicate that a serious population decline occurred in the 2000s.

The knot’s unique and impressive life history depends on suitable habitat, food and weather conditions at far-flung sites across the Western Hemisphere, from the extreme south of Tierra del Fuego to the far north of the central Canadian Arctic. Knots need to encounter these favorable habitat, food and weather conditions within narrow seasonal windows as the birds hopscotch along migration stopovers between wintering and breeding areas. For example, the knot population decline that occurred in the 2000s was caused primarily by reduced food availability from increased harvests of horseshoe crabs, exacerbated by small changes in the timing that knots arrived at the Delaware Bay. Horseshoe crab harvests are now managed with explicit goals to stabilize and recover knot populations.

Knots may be particularly vulnerable to climate change, which is likely to affect:

  • the arctic tundra ecosystem where the knots breed;
  • coastal habitats due to rising sea levels;
  • food resources throughout the bird’s range; and
  • storm and weather patterns.

Knot numbers appear to have stabilized in the past few years, but they remain at low levels relative to earlier decades. Biologists from the U.S. Fish and Wildlife Service, state natural resource agencies, and non-profit organizations all share a concern for this race of red knot and are pooling efforts to identify what needs to be done to prevent further losses. Together with these partners, the U.S. Fish and Wildlife Service is dedicated to working to conserve this extraordinary bird.

UPDATE, APRIL 3, 2014: Comment period reopened for listing the rufa red knot as threatened under the Endangered Species Act

News release (online version) (PDF version)
Questions and answers (PDF)
Federal Register notice
Resources: Maps, migration infographic, multimedia timeline, video and photos

See proposed rule and supplemental documents below, and submit comments at regulations.gov by entering docket number FW5--R5--ES--2013--0097.

SEPT. 27, 2013: Rufa red knot proposed for "threatened" status under Endangered Species Act

News release (PDF version)
Questions and answers (PDF)
Proposed rule (PDF)
Supplemental documents for the proposed rule: Previous federal actions, Ecology and abundance, Climate change, Inadequacy of existing regulatory mechanisms (PDFs)

Red knot information

Red knot history
Facts about the red knot (PDF)
Red knot species profile (Petitions, status reviews and conservation documents)
New Jersey Field Office red knot page
Shorebirds: The Delaware Bay Connection (PDF) Facts about horseshoe crabs (PDF)
Atlantic Flyway Shorebird Conservation Business Strategy

Report sightings

Bandedbirds.org, for shorebirds with colored bands/lettered flags
Ebird.org, for bird sightings

See Ebird map for all red knot subspecies

Red knot photos Red knot maps
Red knot video Red knot blog
Top Red Knot News

Associated Press: Experts fire cannons to save elusive shorebirds (story) (video)

McClatchy News: Scarlet shorebird serves as harbinger of climate change between the poles

Cape Cod Times: Researchers in Chatham try to band birds

New York Times: Red knots, horseshoe crabs and fight to survive in Delaware Bay

Philadelphia Inquirer: Report from the Bay: Red knots at 26,000


Last updated: April 4, 2014