Calypte anna

Anna's Hummingbird

Family: Trochilidae · Class: Aves · Order: Apodiformes

Anna's Hummingbird (Calypte anna) is a medium-sized hummingbird measuring 10 to 11 centimeters (3.9 to 4.3 inches) in length with a wingspan of 12 centimeters (4.7 inches). Adult males weigh 4.3 to 5.8 grams, while females are slightly smaller at 3.2 to 5.8 grams. Males display iridescent emerald-green dorsal plumage and an extensive rose-red gorget that extends over the crown and down the throat, appearing dark or black in poor lighting. Females lack the colorful gorget, showing gray-green upperparts, grayish-white underparts with green flanks, and a white-tipped tail with dark subterminal bands. Anna's Hummingbird is a year-round resident along the Pacific Coast from British Columbia to Baja California, with the core range extending through California, Oregon, and Washington. The species has expanded its range significantly since the 1960s, moving inland and northward. In California, the species occurs from sea level to elevations of 2,100 meters (6,900 feet) in the Sierra Nevada and up to 1,800 meters (5,900 feet) in coastal mountains. The population has established breeding colonies as far north as Vancouver, British Columbia, and as far east as Arizona. The species inhabits diverse environments including coastal scrub, chaparral, oak woodlands, riparian forests, parks, and residential gardens. Anna's Hummingbirds show strong preference for areas with abundant flowering plants and suitable nesting sites. They frequent eucalyptus groves, which bloom during winter months when other nectar sources are scarce. Urban and suburban environments have become increasingly important habitat, with the birds adapting to exotic flowering plants and feeders. Anna's Hummingbirds are aggressive territorial defenders, with males performing elaborate dive displays during breeding season. The courtship dive can reach speeds of 27 meters per second (60 mph), producing distinctive vocalizations at the bottom of the dive. Unlike most North American hummingbirds, Anna's Hummingbirds breed during winter months, with peak nesting from December through May. Females construct cup-shaped nests 3.8 to 5.1 centimeters across using plant down, spider webs, and lichen, typically placed 1.2 to 9 meters above ground in shrubs or trees. Clutch size consists of two white eggs measuring approximately 13 by 8 millimeters, with incubation lasting 14 to 19 days. The diet consists primarily of nectar from native plants including manzanita, gooseberry, and sage species, supplemented by small arthropods for protein. Males require approximately 7.6 to 10.3 calories per day, visiting 1,000 to 2,000 flowers daily to meet energy needs. Anna's Hummingbird is not federally or state listed and maintains stable populations throughout its range. According to the North American Breeding Bird Survey, populations increased by approximately 2% annually from 1966 to 2019. The species has benefited from urbanization, exotic plant cultivation, and supplemental feeding. Climate change may affect future distribution patterns, potentially allowing further northward expansion but creating challenges in southern portions of the range during extreme heat events.

Data from The California Species Project — 14,000+ California species with verified data from CNPS, CDFW, USFWS, and more.