Calypte anna

Anna's Hummingbird (Calypte anna) is a year-round resident along the Pacific coast of North America, breeding north to British Columbia and east to Arizona. These hummingbirds are abundant in open woodlands, chapparal, scrubby areas, and partly open situations, as well as in deserts, especially in winter. They often forage in gardens and parks. They ascend to montane regions in the summer postbreeding season to forage in high mountain meadows.

Nesting may begin in December. In the male's courtship display, he hovers in mid-air giving a buzzy song, then flies much higher before diving steeply and rapidly toward the female, making a loud explosive popping sound at the bottom of his dive. He may also buzz back and forth in front of the perched female in short flights. Detailed analyses of male displays revealed that after powering the initial stage of the dive by flapping, males folded their wings by their sides, at which point they reached an average maximum velocity of 385 body lengths. This is the highest length-specific velocity known for any vertebrate. They then spread their wings to pull up and experienced centripetal accelerations nearly nine times greater than gravitational acceleration. This acceleration is the highest reported for any vertebrate undergoing a voluntary aerial maneuver, with the exception of jet fighter pilots. Displaying Anna's Hummingbird males produce both a vocal song and a dive-sound (made with the wings and outermost tail feathers) that sounds similar to a portion of the song, an intriguing observation discussed by Clark and Feo (2010).

The nest of an Anna's Hummingbird, which is relatively large for a hummingbird nest, is usually constructed on a branch of a tree or shrub, but may also be in vines, on wires, or under eaves. It is typically 1 to 8 m above the ground. Built by the female alone,it is a cup of plant fibers and spider webs. It is lined with fine plant down (and sometimes feathers) and the outside is camouflaged with lichens. The female may continue building after eggs are laid. The female incubates the 2 (rarely 1 or 3) white eggs by herself for 14 to 19 days. The young are fed by the female and take their first flight at around 18 to 23 days.

Anna's Hummingbird is very common over much of its range and has adapted well to suburban areas.

(Kaufman 1996; AOU 1998; Clark 2009; Clark and Feo 2010)

Male Anna's hummingbirds are easily recognized by their crimson crown (top of head) and gorget (throat). The tail is dark, the belly is greyish white, and the back is iridescent green as in most hummingbirds. Females and immatures lack the crimson crown and show varying degrees of red spotting on the throat. The tips of their tail feathers are white. Females and immatures of most hummingbird species are very difficult to tell apart, and field identification is often impossible.

This beautiful little bird occurs along the western edge of North America from southern Alaska to northwestern Mexico. Like other hummingbirds, Anna's is a skilled flyer that can hover in the air and fly backwards. It has a typical long, slender bill which it uses to feed on nectar, pollen, and insects. It often catches insects in flight, and it will stick out its long, skinny tounge during and after feeding.

Arid sw British Columbia to nw Baja; winters to n Mexico.

Calypte anna breeds along the western coast of North America. The breeding range stretches from British Columbia through Arizona to the western edge of New Mexico. However, the non-breeding range is expanding. This range extends from the Alaskan coast to northern Mexico.

Biogeographic Regions: nearctic (Native )

occurs (regularly, as a native taxon) in multiple nations

Canada

Origin: Native

Regularity: Regularly occurring

Currently: Present

Confidence: Confident

Type of Residency: Year-round

United States

Origin: Native

Regularity: Regularly occurring

Currently: Present

Confidence: Confident

Type of Residency: Year-round

Global Range: BREEDS: western Washington, western Oregon, California (west of Sierra; Humboldt and Tehama counties south), northwestern Baja California, and southern Arizona (north to Phoenix, Superior). Most breeding occurs in California. May breed in southwestern British Columbia and western Texas. WINTERS: southwestern Oregon to central Baja, east to southern Arizona, northern Sonora, northern Chihuahua.

Anna's hummingbirds are medium sized, stocky hummingbirds. They are sexually dimorphic. Males and females both have a bronzy, green dorsal area that is glossy in appearance and a dull, gray ventral region. They have a medium length bill and a broad tail. Male C. anna have a brightly colored rose throat area and crown and a dark tail. Females are generally a dull mixture of gray/white or gray/brown, but may have a patch of metallic red or purplish feathers in the center of the throat area. The tail, tipped with white, is metallic green in the center with the exterior tail feathers darkening to black. Juvenile male and female birds both resemble adult females but there are some slight variations. Immature males have brightly colored feathers on the throat and crown and a less rounded tail, while young females are a pale brown and possess no metallic colored feathers on the throat region.

Range mass: 4 to 4.5 g.

Average length: 100 mm.

Range wingspan: 114 to 121 mm.

Other Physical Features: endothermic ; heterothermic ; bilateral symmetry

Sexual Dimorphism: sexes colored or patterned differently; male more colorful

Average basal metabolic rate: 0.1175 W.

Length: 10 cm

Weight: 4 grams

Systems

• Terrestrial

Calypte anna have made their home in open woods, shrubs, gardens, and parks. During breeding season they are restricted to California and a habitat separation is established between males and females. During this time males typically move to more open habitats including canyon sides and hill slopes. Females, on the other hand, live in trees, including evergreens and oaks. Anna's Hummingbirds also experience different habitats with the changing seasons. During the summer months they move to higher elevations, and in winter they move to lower altitudes.

Habitat Regions: temperate ; terrestrial

Terrestrial Biomes: forest ; scrub forest

Other Habitat Features: urban ; suburban ; agricultural

Comments: Open woodland, chaparral, scrubby areas, partly open situations, and gardens, foraging also in meadows, ascending to montane regions in summer postbreeding season (AOU 1983). Nests in tree, vine, shrub, or artificial substrate in wide variety of locations, from <1 to about 9 m above ground.

Non-Migrant: Yes. At least some populations of this species do not make significant seasonal migrations. Juvenile dispersal is not considered a migration.

Locally Migrant: Yes. At least some populations of this species make local extended movements (generally less than 200 km) at particular times of the year (e.g., to breeding or wintering grounds, to hibernation sites).

Locally Migrant: No. No populations of this species make annual migrations of over 200 km.

May ascend to montane regions in summer after breeding. Unusual among hummingbirds in remaining in U.S. in winter.

Calypte anna has four sources of food: nectar from flowers, sap from trees, sugar-water mixes from feeders, and very small insects and spiders. Anna's hummingbirds are equipped with long, narrow bills and have a body adapted to hover over flowers. These two features allow them to easily extract nectar. While the bird is hovering over the flower it extends its tongue and inserts it into the flower. Calypte anna is most attracted to long, tubular flowers, with a red, orange, or violet hue. Some common hummingbird flowers include: azaleas (Rhododendron arborescens), fuchsia (Fuchsia arborescens), scarlet morning glory, honeysuckle (Lonicera sempervirens), and impatiens (Impatiens balsamina). However, C. anna feeds most frequently on: chaparral current (Ribes malvaceum), fuchsia-flowered gooseberry (Ribes speciosum), great-berried manzanita (Arctostaphylos glauca), monkey-flower (Diplacus longiforus), pitcher-sage (Salvia spathacea), California fuchsia (Epilobium), western columbine (Aquilegia formosa), and Indian warrior (Pedicularis densiflora). Apart from flowers, Anna's hummingbirds find food in the air by capturing flying insects or eating insects trapped in spider webs. They also use holes in trees to extract sap.

Animal Foods: insects

Plant Foods: nectar; pollen; sap or other plant fluids

Primary Diet: herbivore (Nectarivore )

Comments: Feeds on nectar, tree sap (e.g., at sapsucker holes), and small insects and spiders (caught in air; gleaned from tree trunks). Nectar sources include EUCALYPTUS, NICOTIANA, AGAVE, CASTILLEJA, DIPLAUCUS, SILENA, RIBES, ARCTOSTAPHYLOS, etc.

Calypte anna has many predators including western scrub-jays (Aphelocoma californica), American kestrels (Falco sparverius), greater roadrunners (Geococcyx californianus), and curved-billed thrashers (Toxostoma curvirostre). As a response to these predators, C. anna has developed two primary defense mechanisms. First, when a predator attacks a nest the female will mob the assailant. She will do this by hovering in front of the invader, beating her wings rapidly, and attacking the head and back. The second mechanism is to avoid low lying food sources, C. anna prefer high feeders and flowers.

Known Predators:

• western scrub-jays (Aphelocoma californica)
• American kestrels (Falco sparverius)
• greater roadrunners (Geococcyx californianus)
• curved-billed thrashers (Toxostoma curvirostre)

Males occupy territories for extended period; territories not necessarily related to food supply and quality (Powers 1987). Apparently has close coevolutionary relationship with RIBES SPECIOSUM (Stiles 1972).

Anna's hummingbirds live an average of 8.5 years.

Range lifespan
Status: wild: 8.5 (high) years.

Average lifespan
Status: wild: 8.5 years.

Average lifespan
Status: wild: 98 months.

Maximum longevity: 8.5 years (wild) Observations: Although animals younger may breed in their first year of life, the exact age at first breeding has not been established yet. Oldest banded animal was a 8.5 years-old male (http://bna.birds.cornell.edu/).

Male and female C. anna only come together to mate. Females are responsible for building nests, incubating the young, and rearing the brood. The seasonal winter rains start mating season, and it is during this time that males move into their breeding territories and females start the nest building process. The nest is bound together with spider webs and is lined with soft material such as plants, feathers, or hair. The outside of the nest is draped with bark, dead leaves, lichen, or paint chips, in an attempt to camouflage. The actual mating ritual commences when a female enters a male's territory. After the male spots the female he does a series of dives in the air and begins to chase her. During this chase, the female leads the male toward her nesting area and perches. During copulation the female spreads her tail, twisting it slightly downward and to the side. In order for fertilization to occur, the male must mount her back. During this time, he may seize her crown feathers with his bill and twist his abdomen and tail down her side. Copulation lasts 3 to 5 seconds.

Mating System: polygynandrous (promiscuous)

The breeding season commences between November and December and continues until sometime between April and May. During this season C. anna can have two broods. Each brood consists on average of 2 white, elliptical eggs, which are laid one day apart. Females incubate the eggs for 14-19 days, and chicks are in the nest an additional 18 to 23 days. The hatchlings are altricial, barely resembling the adult form. Their eyes open on the fifth day after hatching. When the hatchlings are six days old they are fully covered with down. After the nesting period the young remain dependent on the mother for a few additional days, but within one or two weeks they achieve total independence. There is no male parental care. Interestingly, immature C. anna start to show territorial behavior when they are quite young. After leaving the nest, Anna's hummingbirds have a tendency to remain in pairs, usually siblings. However, by fall most young C. anna separate and maintain their own territory.

Breeding interval: There may be two broods produced per breeding season

Breeding season: The breeding season commences between November and December and continues until sometime between April and May.

Average eggs per season: 2.

Range time to hatching: 14 to 19 days.

Range fledging age: 18 to 23 days.

Average age at sexual or reproductive maturity (female): 1 years.

Average age at sexual or reproductive maturity (male): 1 years.

Key Reproductive Features: seasonal breeding ; gonochoric/gonochoristic/dioecious (sexes separate)

Average eggs per season: 2.

Female Anna's hummingbirds incubate and feed their young until they reach independence. There is no male parental care.

Parental Investment: altricial ; pre-fertilization (Provisioning, Protecting: Female); pre-hatching/birth (Provisioning: Female, Protecting: Female); pre-weaning/fledging (Provisioning: Female, Protecting: Female); pre-independence (Provisioning: Female, Protecting: Female)

Breeding begins in late December. Clutch size is 2. Incubation, by female, lasts 14-19 days. Young are tended by female, leave nest in 18-26 days, independent in 1-2 weeks. Priduces two broods annually in many areas (Johnsgard 1983).

The following is a representative barcode sequence, the centroid of all available sequences for this species.

There are 5 barcode sequences available from BOLD and GenBank.  Below is a sequence of the barcode region Cytochrome oxidase subunit 1 (COI or COX1) from a member of the species.  See the BOLD taxonomy browser for more complete information about this specimen and other sequences.

Download FASTA File

Barcode of Life Data Systems (BOLDS) Stats
Public Records: 5
Specimens with Barcodes: 8
Species With Barcodes: 1

Year Assessed

Assessor/s

Reviewer/s

Contributor/s

Justification

History

• 2008
  Least Concern
• 2004
  Least Concern

The Anna's Hummingbird population has been spreading and growing since the 1950's. They have expanded north and east from their original habitat. The flowers and feeders of suburban gardens have enabled them to extend into these different regions. Calypte anna are very common within most of their range; thus, there are regular sightings. In addition, they adapt well to suburban areas.

(Kaufman 1996)

US Migratory Bird Act: protected

US Federal List: no special status

CITES: no special status

IUCN Red List of Threatened Species: least concern

Canada

Rounded National Status Rank: N3 - Vulnerable

United States

Rounded National Status Rank: N5 - Secure

Rounded Global Status Rank: G5 - Secure

There are no negative impacts of Anna's hummingbirds.

Pollinates many species of flowers, such as the chaparral flora of California. The chaparral flora has a large variety of species that have adapted to Anna's hummingbirds. These species of plants have developed winter growth and flowering to fit the breeding and feeding patterns of C. anna. These species, along with others, have evolved directly alongside Anna's hummingbirds.