This novel is the first that I've read that tackles the problem of climate change head-on. An environmental tragedy in Mexico has forced most of the continent's monarch butterflies to find a new winter habitat. Flight Behavior also narrates the story of a young woman, Dellarobbia, who lives on a hard-scrabble farm in Appalachia. She's herded in by a strict mother-in-law, Hester, and even more so by the family's poverty. One day she decides to risk her marriage by having a tryst on the family's mountaintop with a telephone lineman named Jimmy.
After hiking up the mountain, Dellarobbia sees through the fog (despite her severe myopia) that the hills and trees are on fire: hundreds of monarch butterflies have nestled there. The young woman abandons her plan for an affair and returns to her mother-in-law's to pick up her two young kids, Preston and Cordelia.
Dellarobbia's history affects many pieces of the narrative: she's lost both her parents when she was young, got pregnant as a senior in high school, and married Cub to do "the right thing." Then she suffered a miscarriage and it took many years for her to have a child.