What leaves bubbles of water and air on a lily pond? What leaves a path across the sand to the sea? What leaves shadows on the ground? The “wattled” and “warty” bullfrog creates bubbles on the lily pond. The turtle drags its way across the sand to the sea. Children playing follow the leader cast shadows on the ground. These questions and more are raised and answered in this quiet exploration of the traces different creatures and things leave as they pass on their way. The fox leaves its trace in a wooded glade. The snake leaves its trace in the tall wild grass. A jet airplane leaves its own trace across the sky. Even prehistoric dinosaurs and the wind leave unique marks on nature. Kuskin’s watercolor-and-collage illustrations brilliantly follow bubbles, tails, footprints and shadows across double-page spreads tracking clues left by the not-quite invisible passage of someone or something. A fascinating look at an overlooked part of nature. (Picture book. 6-8)