#72 Costa's Hummingbird The male Costa’s Hummingbird bursts with vivid color; to attract a female, the feathers on its throat spill forth with a bright purple. In its breeding season, which runs from late winter to early spring after the rains in the Sonoran and Mojave Deserts, the male loops around the greenish female and cuts U-shaped patterns through the air while giving a high-pitched whistle. Once the desert grows too hot, these birds migrate to the cooler coast of California and Baja.