During their annual northward migration, red knots stop on the Delaware coast where they feed primarily on the eggs of the horseshoe crab, Limulus polyphemus (Niles et al. 2008). This food resource provides fats and protein essential for the birds' long journey to their arctic breeding grounds. In recent years, Delaware horseshoe crab populations have declined from increased bait fishing pressure, leading to negative impacts on the red knot. See 'Special Status' below. On beaches, the red knot uses its bill to probe the sand for molluscan prey, including periwinkles and coquina clams of the genus Donax (Terres 1980). Birds inhabiting tidal flat and salt marsh ecosystems feed on a variety of items, including: small fishes, marine worms, seeds from seagrasses and marsh plants, and a host of insects (Terres 1980). Predators: Little information is available concerning predators of the red knot. However, it is likely that the small size of the species allows it to be preyed upon by a variety of large organisms, including mammals, alligators and birds of prey.Parasites: Like many other bird species, the red knot acts as a terminal or final host for several parasites acquired from a variety of prey items, including the parasitic worms, Bartolius pierrei (Cremonte 2004), Skrjabinocerca canutus, Viktorocara capillaries, and V. limosae (Diaz et al. 2005).