Red Knots are in the sandpiper family. They are barely ten inches long and weigh about twenty ounces. Each spring they breed in the Arctic, but in the year that follows they will migrate to the southern tip of South America and back again in their quest for food. Why and how they travel more than 18,000 miles each year, often as many as 2,500 miles nonstop (and at speeds averaging between thirty and forty miles per hour), is the subject of this engrossing...