Bird of the Week: Red Knot

Red Knot  (Calidris canutus)

Red Knots are sandpipers that migrate long distances. In fact, one Red Knot banded in Argentina in 1992 still “commutes” annually for 20,000 miles, flying between Tierra Del Fuego and Arctic Canada. Phillip Hoose wrote about B95 (his band number) in Moonbird: A Year on the Wind with the Great Survivor B95. He is the oldest known living member of his species, last re-captured in 2016. His name comes from the calculation that he has flown to the moon and back during his lifetime.

Cover of the book, Moonbird: A Year on the Wind with the Great Survivor B95.

Red knots are found on every continent, except Antarctica, and spend non-breeding time on the Texas coast and, indeed, all of the US coasts. In Texas you are likely to find them along the sandy beaches or mudflats in May and September. Their non-breeding plumage is plain, gray and white, but they are plump, larger than Sanderlings and smaller than Willets, with a medium length bill. In the spring, they have a Robin-like red breast.  Plumage is similar between sexes. Nesting in the far north, the first nest was found by Admiral Peary at the North Pole in 1909. Three to four olive-colored eggs are laid and both sexes incubate. It is thought that the male may do more of the incubation. After hatching, the young feed themselves and become independent at about 3 weeks.

They feed primarily on mollusks, often by sight but also by probing in the sand and mud using touch to get below the surface. A specialized sensory organ alerts them to changes in pressure, helping them to find a meal. Mollusks are swallowed whole and crushed in a gizzard. They have the largest gizzards relative to their size of any shorebird. Red Knots also eat insects and vegetation.

Two Red Knots feeding in the wet sand.

During migration Red Knots may congregate in large masses, especially in Delaware Bay in New Jersey where they feed on protected horseshoe crabs. (A group is called a “tangle.”) Known as “jump” migrants, Red knots may fly up to 5,000 miles between staging areas. During non-breeding times, they are more solitary, although a population of 1,500 was found on Mustang Island outside of Corpus Christi.


By Jeanette Larson.

References: CornellLab All About Birds, Audubon Guide to North American Birds