Anna’s Hummingbird is a remarkable species known for its vibrant iridescent plumage and energetic hovering flight. Though medium-sized compared to other hummingbirds, it stands out as the largest hummingbird species commonly found along the western coast of the United States. These tiny marvels of nature are a favorite among birdwatchers and wildlife photographers due to their striking appearance and fascinating behaviors. This article explores the detailed taxonomy, distribution, physical characteristics, behavior, breeding, conservation status, and intriguing facts about Anna’s Hummingbird, offering a comprehensive understanding of this captivating bird.
Scientific Classification
Anna’s Hummingbird is scientifically named Calypte anna and belongs to the family Trochilidae, which encompasses all hummingbirds. The genus Calypte includes only two species: Anna’s Hummingbird and Costa’s Hummingbird (Calypte costae). First described by John James Audubon in 1839, Anna’s Hummingbird is named in honor of Anna Masséna, Duchess of Rivoli. As a member of the order Apodiformes, hummingbirds are renowned for their remarkable flight capabilities, including the ability to hover, fly backwards, and dart swiftly in all directions. The species fits into the subfamily Trochilinae, which consists of the so-called “typical hummingbirds.”
Within its taxonomic framework, Calypte anna is not divided into subspecies, although regional variations in plumage intensity and size have been observed. Its classification reflects evolutionary adaptations that enable it to thrive in diverse environments across western North America.
Geographic Range & Distribution
Anna’s Hummingbird boasts a broad and expanding range primarily concentrated along the western coast of North America. It inhabits regions from southern Alaska and British Columbia in Canada, down through the western United States, including Washington, Oregon, California, and into northern Mexico, particularly Baja California. The species has also been observed as far inland as Nevada, Arizona, and Utah, with occasional vagrant sightings reported in the central United States.
This hummingbird is highly adaptable and has successfully colonized urban and suburban areas where feeders and flowering plants are abundant. Unlike many hummingbirds that migrate seasonally, Anna’s Hummingbird is mostly non-migratory, with many populations overwintering in the same territories. This year-round residency is supported by their ability to exploit diverse food sources and tolerate colder temperatures than most other hummingbirds.
Its range expansion over the last century correlates with human settlement and the planting of non-native ornamental plants, which provide nectar during colder months. This adaptability has made Anna’s Hummingbird one of the most commonly seen hummingbirds in western urban gardens and parks.
Physical Description
Anna’s Hummingbird is a medium-sized hummingbird, measuring approximately 3.9 to 4.3 inches (10 to 11 centimeters) in total length, including the tail. Their wingspan averages about 5.25 inches (13 centimeters). Males typically weigh between 3.5 to 5.8 grams (0.12 to 0.2 ounces), while females are slightly lighter, ranging from 3.3 to 4.7 grams.
The species is instantly recognizable due to its iridescent plumage, which varies with lighting and angle. Both sexes display a tube-shaped body streamlined for rapid and agile flight, with long, slender bills designed to access nectar deep within flowers.
Male Anna’s Hummingbirds are particularly striking, featuring a brilliant rose-red to reddish-pink crown and gorget (throat patch), which can appear black or dark purple in low light conditions. This gorget extends down the throat and is used prominently in courtship displays. Their backs and sides are a metallic bronze-green, with the underparts mottled gray and green. The tail feathers are dark, mostly black, except for the central pair, which display a greenish sheen. The tail feathers are rounded at the tips, aiding in maneuverability during flight.
Females present a more subdued coloration, with green upperparts and a dull grayish-white or brownish-gray underside spotted with green. They lack the male’s vibrant gorget but may exhibit faint reddish spotting on the throat that intensifies toward the center, often forming an irregular iridescent patch. Females also have white tufts on the sides of their rumps and rounded dark tails tipped with white on the outer feathers. Their wings are dark with subtle iridescence.
Juvenile Anna’s Hummingbirds resemble adult females, with a green crown and gray throat but generally lack the red throat markings. Their plumage gradually develops the distinctive adult coloration as they mature.
Rare leucistic or partial albino individuals have been documented, exhibiting white or pale feathers mixed with normal coloration. Such mutations are uncommon but highlight the genetic diversity within the species.
Behavior & Diet
Anna’s Hummingbirds are highly active creatures known for their rapid wingbeats, which can reach up to 50 beats per second. Their flight is characterized by incredible agility, allowing them to hover nearly motionless while feeding from flowers or feeders. They can fly forwards, backwards, and sideways with great precision.
These hummingbirds are territorial, especially males, who vigorously defend feeding territories from rival hummingbirds and insects. They produce a variety of vocalizations, including sharp “chip” calls and complex songs, which are relatively unusual among hummingbirds, as many species are largely silent. Males sing to attract mates and warn competitors.
Anna’s Hummingbirds primarily feed on nectar from a wide range of flowers, preferring tubular blossoms rich in sugar. They favor native plants such as manzanita, currant, and California fuchsia, but readily adapt to non-native ornamentals like eucalyptus, trumpet vine, and hummingbird sage. Their specialized bills and long tongues enable efficient nectar extraction.
In addition to nectar, Anna’s Hummingbirds consume small insects and spiders, which provide essential proteins and nutrients. They catch insects in midair or glean them from vegetation. This omnivorous diet supports their high metabolic demands, especially during breeding and cold weather. According to RSPB, this species is well documented.
To maintain energy, these hummingbirds enter a torpor state at night or during cold spells, significantly reducing their metabolic rate to conserve resources. According to BirdLife International, this species is well documented.
Breeding & Reproduction
The breeding season of Anna’s Hummingbird generally spans from late winter through summer, although timing varies by latitude and local climate. Males perform elaborate courtship displays to woo females, including a distinctive dive display during which they ascend high and then swoop down with a loud audible “chirp” produced by their tail feathers vibrating in the air. Males also showcase their iridescent gorgets in bright sunlight to attract mates.
Once paired, the female constructs the nest alone, usually placing it on a tree branch or shrub several meters above ground. The nest is a delicate cup made from plant down, spider silk, and lichens, cleverly camouflaged to blend with the surroundings. Typical nest dimensions are about 2 inches (5 centimeters) in diameter.
The female lays two tiny white eggs, each approximately the size of a small jellybean. Incubation lasts about 14 to 16 days, during which the female diligently keeps the eggs warm. After hatching, the chicks remain in the nest for 18 to 22 days, growing rapidly as the mother feeds them a diet rich in regurgitated nectar and insects.
Anna’s Hummingbirds often produce two broods per season, especially in areas with abundant food resources. The juveniles fledge cautiously but quickly develop the skills needed for feeding and survival.
Conservation Status
According to the International Union for Conservation of Nature (IUCN), Anna’s Hummingbird is classified as a species of Least Concern. Populations are stable or increasing, largely thanks to their adaptability to human-altered environments and expanding range facilitated by introduced ornamental plants and backyard feeders.
While not currently threatened, Anna’s Hummingbirds face general environmental pressures common to many birds, such as habitat loss due to urban development and climate change impacts. Nonetheless, their ability to thrive in urban and suburban settings offers a degree of resilience not seen in many other hummingbird species.
Conservation efforts benefit from public education about the importance of planting native flowering plants, maintaining clean feeders, and minimizing pesticide use. Citizen science programs monitoring hummingbird populations also contribute valuable data supporting conservation management.
Interesting Facts
Anna’s Hummingbirds are among the few hummingbird species that sing throughout the year, with males producing melodious songs that can last up to 10 seconds. This vocal activity is linked to their territorial behavior and courtship strategies.
Unlike most hummingbirds, they are known to survive cold winter climates by increasing their fat reserves and employing torpor, a state of decreased physiological activity that conserves energy during cold nights.
These hummingbirds display fascinating iridescence due to microscopic structures in their feathers that refract light, causing their gorgets and crowns to appear to shift colors with the angle of viewing. This phenomenon is not pigment-based but structural, which is why the colors can look so vivid and changeable.
Anna’s Hummingbirds also exhibit impressive memory skills, capable of remembering the locations of individual flowers and feeders, as well as timing nectar renewal, which helps them optimize foraging efficiency.
Finally, while Anna’s Hummingbird is primarily found in the western United States, its range has been expanding northward into areas like southern Alaska—a testament to its adaptability and resilience in changing environments.
In summary, Anna’s Hummingbird is an extraordinary species that captivates with its beauty, agility, and adaptability. From the dazzling iridescent males to the subtle yet elegant females, these hummingbirds are a vibrant emblem of the western landscapes they inhabit. Whether visiting a backyard feeder or darting through native shrubs, Anna’s Hummingbirds offer endless opportunities for observation and appreciation in the natural world.
