A symbol of Hawaiian royalty--indomitable, swift, strong, and fierce--'io, the Hawaiian hawk, Buteo solitarius, also represents a Hawai'i that has remained unchanged from its earliest days of wild splendor. Blown from their customary migratory route between North America and South America, the first birds arrived before human voyagers discovered the Islands over a thousand years ago. Although there are occasional vagrants (osprey, sea eagles, and peregrines), the Hawaiian hawk remains the only diurnal raptor found on the islands of the Pacific. Once present on O'ahu, Kaua'i, Moloka'i, as...