Early August marks the beginning of southward rufous hummingbird migration, with adult males departing first followed by females and juveniles over the coming weeks. After breeding in the Pacific Northwest through summer, these tiny migrants begin their remarkable 3,000+ mile journey back to Mexican wintering grounds. Males typically depart in late July through early August, while females with late-season nestlings may linger into September. The migration follows mountain ranges southward, with birds stopping frequently to refuel at flowering plants and feeders. Rufous hummingbirds are among the most aggressive hummingbird species, and their departure signals the approaching end of summer. Keep feeders filled through September to support late migrants, and watch for the final juveniles making their first southward journey—a remarkable feat for birds weighing only 3-4 grams.