Families in the U.S. and around the world are having fewer children as people make profoundly different decisions about their lives. NPR's series Population Shift: How Smaller Families Are Changing the World explores the causes and implications of this trend.

On a late autumn day, John Davis hiked through what looks like wild forest in New York's Champlain Valley, surrounded by flaming red maple trees and yellow birch. A bird flushed noisily through the undergrowth. "Look there, a ruffed grouse," he said, his delight obvious.

This place is an example of what Davis calls "rewilding," which means the footprint of human activity has begun to fade.

"It simply means stepping back and letting nature unfold as it will," he said. "Some of this was farmed as recently as the 1990s. Probab

See Full Page