Anita really likes hummingbirds. She watches them. She draws pictures of them. But one day in the fall, the birds are mysteriously gone. Simon, Anita, Dennis, and their classmates discover why the hummingbirds left and where they went. This storybook is one of several Elementary GLOBE books. Elementary GLOBE is designed to introduce K-4 students to the study of Earth system science (ESS). The storybooks form an instructional unit that addresses ESS and related subjects including air quality, climate, clouds, water, seasons, and soils. The science content provided in the books serves as a springboard to GLOBE’s scientific protocols, and also provides students with a meaningful introduction to technology, a basic understanding of the methods of inquiry, and connections to mathematics and literacy skills. Each book has associated hands-on learning activities to support learning exploration. For more information, please visit www.globe.gov/elementaryglobe. The Global Learning and Observations to Benefit the Environment (GLOBE) Program, sponsored by NASA, is a hands-on international education and science program that joins students, educators, citizen scientists, and scientists from around the world in studying Earth system science (ESS). The core objectives of GLOBE are to improve science education, enhance environmental awareness, and increase understanding of Earth as a system through data collection and analysis. For more information, please visit www.globe.gov.