- The Rufous Hummingbird (Selasphorus Rufus) is a small, fiery migratory bird known as one of the feistiest and most territorial species in North America - While they do not breed in southern Arizona, they pass through the region in massive numbers during their annual migrations, making them a highly anticipated sight for local birdwatchers - Rufous Hummingbirds follow an elliptical migration path across the West, meaning their presence in southern Arizona varies greatly by season == Fall Migration (Peak Season): This is the best time to see them. They start arriving in late July, with numbers peaking from late August through September, and some individuals lingering into November. They travel south from their Pacific Northwest and Alaskan breeding grounds down through the Rocky Mountains and into Arizona as they head toward Mexico.