Anna’s Hummingbird

The quintessential urban hummingbird, Anna’s Hummingbird has shown remarkable adaptability to the urban environment. In recent times it has expanded its range northward and eastward, exploiting exotic flowers and feeders in urban and suburban gardens. The only hummingbird known to over winter in Southwestern British Columbia. Anna’s expanding range is from coastal BC south along the west coastal US, southern California, southern Arizona, southern New Mexico and northern Mexico.

Adult Male (spring/summer)
Bright green to bluish green above. Gorget is rose red to coppery red, with moderate extensions at corners; crown and separate patch behind eye same color as throat. Upper breast medium to pale gray, usually slightly mottled. Pale feather edges give green underparts a scaly appearance; pale midline stripe faint or absent. Long, deeply notched tail extends well beyond wingtips. Outer tail feathers are gray, darker at edges bordering paler translucent patches; R5 narrow, rounded at tip.

Adult Female (spring/summer)
Bright green to bronze-green above, medium to pale gray below. Gorget markings vary from bronze-gray mottling to a ragged-edged triangle, oval or diamond of rose red to coppery iridescence. Slightly notched to double-rounded tail extends to or beyond wingtips. Tail feathers broad, rounded; R3-5 banded in dull gray-green, blackish, and white. Bill is straight to very slightly decurved.

Juvenile
Resembles adult female but with pale feather edges, heavier mottling in gorget with larger iridescent feathers; R5 broad, rounded, with thin line of black ext ending into white tip along shaft.
Female: Very similar to adult female, usually with dull gray mottling in gorget with or without a few iridescent feathers centrally; may have more white in R2. Best distinguished by plumage condition.

General:

A medium-sized chunky hummingbird with medium-length straight black bill. Length: 10cm. Wing: 12-14cm. Weight: 3-6grams.

Behaviour:

Typically holds tail still while hovering, unlike Black-chinned and Costa’s. Takes nectar at a variety of flowers, including native chaparral currant, fuchsia-flowered gooseberry, wooly blue-curls, pitcher sage, California fuchsia, red bush-penstemon, western columbine, and bush monkeyflower; also exotics such as citrus, tree tobacco, aloes, bottlebrush and eucalyptus. Feeds extensively on insects, including gnats, midges and whiteflies, especially during winter. Occasionally observed eating sand and ashes, probably to supply minerals.

Adult males defend feeding territories and sing year-round; young males begin singing by late summer, often from concealment. Dive display is complex, noisy. Male sings buzzy notes while hovering over the object of the display, then climbs for 7 to 8 seconds on a wavering trajectory to a height of 65 to 130 feet before plunging the same distance in a mere 2 seconds. The dive ends with a shrill squeak as the displaying bird passes the object.

Habitat:

Breeds in chaparral, coastal scrub, evergreen-oak woodland, riparian woodland, oak savannah, orchards, parks, urban gardens, sea level to 5,700 feet. Nonbreeding birds often move to higher elevations and inland into pine-oak forest, pine-fir forest, mountain meadows, up to 11,000 feet. Population density and distribution outside coastal southern California dependent in large part on availability of urban habitats.

Information:

No subspecies are recognized. Anna’s and Costa’s form a super-species, isolated primarily by habitat preferences. Hybrids between the two are common. Though song is now known to be more the rule than the exception among North American hummingbirds, the song of Anna’s was among the first to be studied and is still among the best known of all hummingbird songs.

The name of this hummingbird honors Anna Masséna, duchess of Rivoli and a patron of the sciences. Nest is a soft cup of whitish plant fibers and animal hair held together with spider silk. Exterior usually camouflaged with lichen and plant debris. 2 white eggs are laid. Male usually takes no interest in nest.

Similar species:

Costa’s Hummingbird.

Conservation Status:

This species has benefited greatly from human activities. Replacement of native chaparral and desert scrub with irrigated gardens and parks has permitted expansion of range north into Canada and east into the Mojave and Sonoran Deserts. Anna’s appears to displace Costa’s as natural desert gives way to residential and recreational development. Additional study needed to determine how these two species interact in urban habitats.

Capture Rates

Anna’s Hummingbird is now a common species banded at the station with capture rates peaking in late spring through summer (May – August). Although Anna’s Hummingbird do not migrate and can be seen during the winter, they will move to find a prominent food source, usually backyard feeders.

Molt Summary
PF: HY/SY complete, PB: AHY/ASY complete; PA absent. Gradual replacement of some to many gorget feathers in HY/SY males, before the preformative, might be considered a partial presupplemental molt, as these feathers are replaced a second time later in the year. HY flight feathers normally replaced by October/November, gorget feathers of HY/SY males are last feathers to be replaced.

Ageing Hummingbirds

The occurrence and extent of corrugations on the culmen provides a reliable method for ageing NA hummingbirds (Trochilidae).

In all species, the bills of nestling hummingbirds are soft and deeply corrugated or grooved along the ramphotheca (the horny covering of the bill), lateral to the culmen. These deep grooves are easy to see under magnification as can be seen in these two photos of HY males in July.

Throat with heavy dusky, greenish markings or several to many iridescent magenta-rose feathers becoming fully magenta-red in November-February.

Note the individual magenta-rose feathers to the sides of the throat on these HY males in summer (June/July) and sprinkling of magenta-rose feathers extending to the crown which never appear on females.

Adult males like the one below are unmistakable with iridescent magenta-rose crown and throat feathers.

Crown, head and throat without magenta-rose feathers (or with <5 single feathers to the centre of the throat).

Crown with no magenta-rose feathers; throat with heavy dusky-greenish markings and a cluster of 10-20 iridescent magenta-rose feathers confined to the centre.