The Narrow Edge: A Tiny Bird, an Ancient Crab, and an Epic Journey

Thousands of ravenous tiny shorebirds race along the water's edge of Delaware Bay, feasting on pin-sized horseshoe-crab eggs. Fueled by millions of eggs, the migrating red knots fly on. When they arrive at last in their arctic breeding grounds, they will have completed a near-miraculous 9,000-mile journey that began in Tierra del Fuego.

Deborah Cramer followed these knots, whose numbers have declined by 75 percent, on their extraordinary odyssey from one end of the earth to the other—from ...