What is the relationship between horseshoe and red knot?

Horseshoe crab and red knot are related in the sense that horseshoe crab eggs serve as a crucial food source for red knot during their annual migration. Red knot is a medium-sized shorebird that migrates long distances between its breeding grounds in the Arctic tundra and wintering grounds in South America. During their northward migration in spring, red knots make a stopover along the Delaware Bay in the United States, where they heavily rely on the abundant horseshoe crab eggs to replenish their energy reserves for the rest of their journey. The red knots time their arrival at the Delaware Bay to coincide with the horseshoe crab's spawning season, ensuring access to a rich source of high-protein food. Over the years, the decline in the horseshoe crab population due to overharvesting and habitat loss has negatively impacted red knot populations, as they face challenges in finding sufficient food during their critical stopover.