In “Shifting Shadows,” one of the many standout essays in Julian Hoffman’s slim The Small Heart of Things: Being at Home in a Beckoning World, Hoffman explains the subtitle of his collection succinctly: “To be at home means finding a way of sustaining a keen and watchful engagement as both the place and I change, altering and shifting with the seasons, the light, and passing time.” Hoffman, an Englishman by way of Canada who now lives in Greece, carries this watchful engagement up mountains, through reed beds, and across continents, and what results is a series of thoughtful meditations on the powers of place, of migration and stillness, tradition and adaptation, viewed through the lens of the natural world but never divorced from the human one.