Red Knot

Overview

The red knot or just knot (Calidris canutus) is a medium-sized shorebird which breeds in tundra and the Arctic Cordillera in the far north of Canada, Europe, and Russia. It is the type species of the genus Calidris. Six subspecies are recognised.
Their diet varies according to season; arthropods and larvae are the preferred food items at the breeding grounds, while various hard-shelled molluscs are consumed at other feeding sites at other times. North American breeders migrate to coastal areas in Europe and South America, while the Eurasian populations winter in Africa, Papua New Guinea, Australia, and New Zealand.

Summary from Wikipedia, available under CC BY-SA 4.0.

Diet: Small clams and, in Delaware Bay, horseshoe crab eggs.