Many migratory birds also depend on precisely timed stopovers for feeding at critical points along their routes. Take the red knot, a bird of modest brain but prodigious travel. Each spring, it journeys ninety-three hundred miles from Tierra del Fuego to the Arctic. For thousands of years the red knot has relied for sustenance on a precisely timed rendezvous with horseshoe crabs laying their eggs on the beaches of the Delaware Bay.
