Intended for scholars, citizen scientists, and amateur ornithologists, alike, Snowbird synthesizes decades of research from the diverse and talented researchers who study the Junco genus. Though contributors approach their subject from a variety of perspectives, they share a common goal: elucidating the organismal and evolutionary processes by which animals adapt and diversify in response to environmental change. Placing special emphasis on the important role that underlying physiological, hormonal, and behavioral mechanisms play in these processes, Snowbird not only provides a definitive exploration of the junco's evolutionary history and behavioral and physiological diversity but also underscores the junco's continued importance as a model organism in a time of rapid global climate change. By merging often disparate biological fields, Snowbird offers biologists across disciplines an integrative framework for further research into adaptation, population divergence, and the formation of new species. 8 color plates, 20 halftones, 14 line drawings, 6 tables.