Costa’s Hummingbirdis just just 3–3.5 inches long and weighs a mere 2–3 grams. Males are instantly recognizable by their gleaming violet crown and throat patch, which catch the sunlight and flare dramatically during courtship; females and immatures are more subtly adorned, with olive-green upper parts, crisp white underbellies, and a fine white “eyebrow” stripe that accentuates their delicate features.
Inhabiting the scrubby washes and arid slopes of southern Arizona, these hummingbirds thrive among palo verde, ironwood and mesquite trees. They probe tubular blossoms—chuparosa, ocotillo and penstemon—for nectar and glean tiny insects from foliage and spiderwebs to meet their protein needs. Their rapid wingbeats and fearless curiosity often bring them to backyard feeders and desert gardens.
Breeding begins in early spring, peaking in March and April when males perform astonishing U-shaped dive displays—ascending dozens of feet before swooping past perched females with a sharp tail-feather “snap.” After nesting and fledging young, many adults disperse by early summer, but others linger if food supplies hold.
