It takes years to learn the art of seeing, of expecting to see nature's gifts. In Soul of the Outdoors, Dave Greschner passes that art along. He tells how little that chickadee at the feeder weighs, how tree buds survive in winter, how far a fisher leaps, and what the six blobs of shadows are on the creek bed below a water strider. He traces the cycle of seasons, immersing us in spring hikes to the marshes of emerging frogs and returning birds,...