Introduction
Anna’s Hummingbird (Calypte anna) is a medium-sized hummingbird of western North America. It is recognised for the male’s iridescent rose-red crown and throat, rapid hovering flight and ability to live successfully in both natural habitats and human-modified landscapes. The species was named after Anna Masséna, Duchess of Rivoli, and formally described by René Primevère Lesson in 1829.
Physical Description
Anna’s Hummingbird measures about 10 centimetres in length, has a wingspan of approximately 12 centimetres and weighs around 3–6 grams. It is relatively stocky for a hummingbird, with a short, straight bill and a fairly broad tail that extends beyond the wingtips when the bird is perched.
Adults of both sexes are green above and greyish below. The adult male has a brilliant iridescent rose-red crown and throat, although these areas can appear dark, brownish or almost black when viewed without direct light. The female is duller, with a green back, grey underparts and a small amount of red spotting on the throat. Juveniles resemble females, while young males gradually develop red feathers on the crown and throat as they mature.
Range and Habitat
Anna’s Hummingbird is a year-round resident across much of the Pacific coast, from southern Alaska and British Columbia through western Washington, Oregon and California to northern Baja California. It also occurs inland in parts of the southwestern United States, including Arizona, New Mexico and western Texas. Many individuals remain in the same general area throughout the year, although some make short movements to follow changing food supplies or move between elevations.
The species originally bred mainly in chaparral and other open habitats of California and Baja California. Its range expanded substantially during the twentieth century as gardens, ornamental flowering plants, eucalyptus trees and hummingbird feeders provided additional food and nesting opportunities. It now occurs in coastal scrub, chaparral, oak savannah, open woodland, riverside vegetation, eucalyptus groves, parks, gardens and suburban neighbourhoods.
Where to See This Species
Presidio of San Francisco, California, United States
The Presidio supports Anna’s Hummingbirds throughout the year, with birds recorded in its coastal scrub and forest habitats. The species breeds within the park, and flowering plants in woodland edges, gardens and scrub provide opportunities for observation.
Nearby accommodation: San Francisco offers a wide range of hotels, guest houses, hostels and self-catering accommodation, with additional options around the Marina District and nearby coastal neighbourhoods.
Behaviour and Diet
Anna’s Hummingbirds are active and territorial. They hover while feeding, can fly backwards and make rapid changes of direction. Males often perch conspicuously in trees or shrubs and produce a scratchy, metallic song.
During courtship, a male may climb high into the air before diving steeply towards a female. The dive can reach roughly 40 metres, and air passing through the tail feathers produces a distinctive sharp sound. Males also perform a short shuttle display close to a female. The sexes do not form long-term pairs, and the female alone builds the nest, incubates the eggs and feeds the young.
Nectar from flowering plants is an important food source. Anna’s Hummingbirds visit native plants such as currants, gooseberries, manzanita, penstemons and sages, as well as suitable cultivated plants and hummingbird feeders. They also eat small insects and spiders, which provide protein, and may take insects from foliage, flowers, spider webs or the air. They have also been recorded feeding on tree sap leaking from holes made by sapsuckers.
The female usually builds a small cup-shaped nest on a horizontal branch of a tree or shrub. Plant down, feathers and other soft material are held together with spider silk, allowing the nest to expand as the young grow. A typical clutch contains two white eggs. Incubation lasts about 16 days, and the young leave the nest after approximately 20 days. Females may raise two or three broods in a season.
In gardens, feeders should contain a solution of one part white sugar to four parts water, without honey or food colouring. Feeders should be cleaned regularly, and native flowering plants are preferable as part of a broader wildlife-friendly garden. Shallow moving water, misters and fountains may also attract hummingbirds.
Identification Tips
- Look for a compact, stocky hummingbird with green upperparts, grey underparts and no obvious orange or rufous colouring on the body.
- Adult males are distinctive when the light catches the rose-red crown and throat.
- Females and immature birds can be recognised by their dark green backs, pale underparts and relatively broad tails. Females may show a few red throat feathers.
- The short, straight bill and tail extending beyond the wingtips when perched are useful structural features.
- Allen’s Hummingbird can look similar in coastal California, but it commonly shows more rufous or orange in the tail and flanks. Identification may require a close view of the tail and overall shape.
- Costa’s Hummingbird males have a more extensive, pointed purple gorget that projects onto the sides of the neck, whereas Anna’s males have a broader rounded rose-red crown and throat.
Conservation Status
Anna’s Hummingbird is classified as Least Concern by the International Union for Conservation of Nature. Available monitoring indicates an increasing population trend, and the species has benefited from the expansion of gardens, ornamental flowering plants and supplementary feeding across much of its range.
Important local threats still exist. Habitat loss can reduce natural nectar sources and nesting cover, while pesticide use may reduce insect prey or expose birds directly to harmful chemicals. Outdoor cats, window collisions and poorly maintained feeders can also cause injury or death. Planting locally appropriate flowering species, reducing pesticide use, keeping cats indoors and maintaining clean feeders can help reduce these risks.
Frequently Asked Questions
Where can Anna’s Hummingbirds be found?
They occur mainly along the Pacific coast of North America, from southern Alaska and British Columbia to northern Baja California, with additional populations inland in parts of the southwestern United States.
Do Anna’s Hummingbirds migrate?
Many Anna’s Hummingbirds remain in the same region throughout the year. Some make short movements to follow food supplies or move between elevations, but the species does not usually undertake a long-distance migration like many other hummingbirds.
What does an Anna’s Hummingbird eat?
Its diet includes nectar, small insects and spiders. It may also take insects from spider webs, foliage and flowers, and sometimes feeds on tree sap leaking from sapsucker holes.
How can Anna’s Hummingbirds be identified?
The species is a compact green-and-grey hummingbird with a short, straight bill and broad tail. Adult males have an iridescent rose-red crown and throat, while females and juveniles are duller and may show only small red throat markings.
How many eggs does an Anna’s Hummingbird lay?
A female usually lays two white eggs. She incubates them for about 16 days and continues caring for the young until they leave the nest at approximately 20 days old.
References
- Cornell Lab of Ornithology
- National Park Service
- IUCN Red List of Threatened Species
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