It took just one sighting of a swallow-tail kite to dispatch Susan Cerulean on a pilgrimage through its fragmented and ever-shrinking habitats. In Tracking Desire, Cerulean immerses us in the natural history and biology of Elanoides forficatus. At the same time, she sifts though her past-as a child, student, biologist, parent, and activist-to muse on a lifelong absorption with nature.