Red Knot Overview, All About Birds, Cornell Lab of Ornithology

The Red Knot does not regurgitate undigested hard parts of prey, as do many species of birds. Instead it excretes the hard parts in the feces. Researchers have used fecal content to examine food consumption rates.

Red Knots concentrate in huge numbers at traditional staging grounds during migration. Delaware Bay is an important staging area during spring migration, where the knots feed on the eggs of spawning horseshoe crabs. It is estimated that nearly 90 percent of the entire population of the Red Knot subspecies C. c. rufa can be present on the bay in a single day. The reduction in food available to the knots because of the heavy harvesting of horseshoe crabs may be responsible for a decline in Red Knot populations.

The oldest recorded Red Knot was at least 15 years, 11 months old. It was banded in 1986 in New Jersey and recaptured and rereleased during banding operations in Delaware in 2001.