“What does it take to really save nature?” writer and environmentalist Mary Ellen Hannibal asks in Citizen Scientist: Searching for Heroes and Hope in an Age of Extinction. In this wide-ranging adventure—part memoir, part investigation— Mary Ellen Hannibal makes a deeply personal case for the necessity of citizen scientists, sharing stories from boaters recording whale sightings and tracking migration paths to the volunteers whose redwood restoration projects may provide our best hope in slowing an unprecedented mass extinction. Hannibal traces the citizen science movement to its roots: the centuries-long tradition of amateur observation by writers and naturalists. In addition to facing the loss of species, Hannibal also chronicles her confrontation with personal loss; prompted by her novelist father’s sudden death, she examines her own past—and discovers a family legacy of looking closely at the world. Both the story of a woman who rescued herself from an odyssey of loss and a blueprint for ordinary citizens to combat extinction on a local scale, Citizen Scientist provides a counter to the dire predictions that threaten to overwhelm us—and profound consideration of our place in the natural world.