Every year, red knot sandpipers fly 19,000 miles from South America to their nesting grounds in the Arctic and back, eating millions of horseshoe crab eggs along the way. As a result of global warming, the red knots are now facing extinction. Their survival affects millions of other shore birds and ultimately, humans. Deborah Cramer won the Southern Environmental Law Center's 2016 Reed Environmental Writing Award for her book, The Narrow Edge: A Tiny Bird, an Ancient Crab, and an Epic Journey.