The Black-chinned Hummingbird (Archilochus alexandri) is a small, migratory hummingbird that breeds in the western United States and winters in Mexico. In the San Francisco Bay Area, the Black-chinned Hummingbird is a fairly common summer resident and breeder. It can be found in gardens, parks, and woodlands from late spring through early fall.
Some quick facts about the Black-chinned Hummingbird:
– It measures 3-3.5 inches in length and weighs 2-3 grams. The male has a black chin and throat, an iridescent purple crown and green back. The female has a pale throat with dark speckles and a green back.
– The Black-chinned Hummingbird gets its name from the adult male’s distinctive black chin and throat feathers. The purple crown is also a key identifier.
– It is a rapid, agile flyer that can hover and fly backwards. The wings beat up to 53 times per second.
– The primary diet consists of nectar from flowers and small insects like gnats and aphids. Favorite flowers include lilies, columbines, trumpet vines and Indian paintbrush.
– The nest is about the size of a walnut, built on the branch of a tree or shrub. Two white eggs are laid and incubated for 14-16 days.
– The Black-chinned Hummingbird migrates south in the fall, leaving California in September and October to winter in Mexico.
– It has a fast, chipping call and makes squeaky sounding vocalizations. The wings also produce buzzing and whistling sounds in flight.
Range and Distribution
The Black-chinned Hummingbird has a large range across the western United States and Mexico:
– Breeds in the western U.S. from Montana and Wyoming south to New Mexico and west to the Pacific Coast. Most abundant in the Southwest.
– Winters along the Pacific coast of Mexico and the interior through Central America. Most birds migrate south by late September.
– In the Bay Area, it arrives in mid-March. Most have departed by mid-October.
– Breeds in a wide variety of semi-open habitats including valleys, foothills, mountain meadows, open woodlands, parks and gardens. Prefers areas with flowering plants.
– Most abundant in the East Bay and along the inner Coast Ranges. Less common along the coast.
– Has expanded its breeding range north in recent decades as gardens provide more habitat.
Identification
Identifying the Black-chinned Hummingbird:
– Small size (3-3.5 in), long straight bill and stubby tail. Wings make blurring buzz when beating rapidly.
– Male has a black chin and throat, iridescent purple crown, and bright green back. Female has pale throat with black speckles, lacks purple crown, and is duller green above.
– In flight, shows a small white spot behind eye. Outer tail feathers have thin white tips.
– Male makes display dives during breeding season, diving from 30-100 ft while making squeaky calls. This is the best way to confirm Black-chinned.
– Call is a fast, squeaky chip. Also makes buzzing and whistling wing sounds.
– Similar Species: Anna’s and Costa’s Hummingbirds have rosy-pink throats and lack the bold black and purple colors. Calliope Hummingbird is much smaller.
Key Identification Features:
| Small size | Thin straight bill |
| Male has black chin/throat | Male has iridescent purple crown |
| Rapid wing beats, buzzing wingsound | White spot behind eye |
| Male makes display dives in breeding season | Squeaky, chipping call |
Behavior and Diet
The behavior and diet of the Black-chinned Hummingbird includes:
– Primary diet is nectar from flowers. Favorites include columbines, lilies, paintbrush, and trumpet vine. Will also drink from feeders.
– Feeds on small insects like gnats, aphids, and spiders to obtain protein, especially when breeding. Hawk insects in flight.
– Aggressive around feeders, chasing away other hummers. Males establish feeding territories.
– Male performs display dives up to 100 feet during courtship. Also vocalizations.
– Nests in trees and shrubs up to 40 feet high. Nest about 1.5 inches wide, made of spider webs, lichen, down.
– Only female builds nest over 4-6 days. She incubates the eggs and cares for the young.
– Breeding season is March through July. Two white eggs are laid. Eggs hatch in 14-16 days.
– Young fledge in 21-22 days. Female may raise 2-3 broods per year.
– Migrates south in late summer and fall, from California to wintering grounds in Mexico.
Typical Behavior:
| Aggressive around feeders | Males have feeding territories |
| Males do display dives in courtship | Only female builds nest and cares for young |
| Nest high up in trees | 2 white eggs, incubate 14-16 days |
| Young fledge in 21-22 days | Migrates to Mexico in fall |
Habitat
The Black-chinned Hummingbird utilizes a variety of semi-open habitats in the Bay Area:
– Found in valley foothill woodlands, riparian corridors, open scrublands and chaparral.
– Also parks, gardens, vineyards, and farms, particularly those with flowering plants.
– Nests in trees and shrubs along habitat edges. Favorite trees include oak, sycamore, cottonwood, willow.
– Most abundant in the East Bay and Diablo Range where there is more natural habitat.
– Increased use of gardens and parks with feeders and flowers provides expanded habitat.
– Prefers areas with a mix of flowers, flowering shrubs, and 7-25% tree canopy cover.
– Also found in mountains up to 10,000 feet in appropriate habitat. Migrates through lowlands and valleys.
– Ranges more widely when not breeding. Also visits montane meadows on migration.
Typical Habitats:
| Valley and foothill woodlands | Riparian corridors |
| Chaparral and scrublands | Gardens, parks, vineyards |
| Areas with flowering plants | East Bay and Diablo Range |
| Nests along habitat edges | 7-25% tree canopy cover |
Interesting Facts
Here are some interesting facts about the Black-chinned Hummingbird:
– The purple crown on the male does not contain any purple pigment. The color comes from refracting light through specially structured feathers.
– To feed, their long tongue darts in and out of their bill up to 13 times per second. The tongue has forked tips to lap up nectar.
– They feed on the wing – a unique ability among birds. They can hover in place by rapidly beating their wings in a figure-8 pattern.
– To conserve energy at night, they go into torpor, lowering their body temperature by up to 30 degrees Fahrenheit.
– A hummingbird’s heart rate can reach as high as 1,260 beats per minute. Their rapid metabolism requires immense amounts of energy.
– They build a new nest each year. Nests are made of spider webs, feathers, moss and lichens. They are about 1.5 inches wide.
– Males perform dramatic courtship display dives, plummeting from heights of up to 100 feet while making loud shrieks.
– The Black-chinned Hummingbird was first described by naturalist Alexander Wilson in 1811. Its name refers to the black chin of adult males.
Fascinating Facts:
| Purple crown color is structural, not pigment | Tongue darts at 13x per second |
| Only birds that can hover | Lower body temperature by 30°F at night |
| Heart rate up to 1260 bpm | Build a new nest each year |
| Dramatic courtship display dives | Named by Alexander Wilson in 1811 |
Population and Conservation
The population and conservation status of Black-chinned Hummingbirds:
– Estimated population of 5 million in North America according to Partners in Flight. Stable overall trend.
– One of the most common and widespread hummingbird species in the western US.
– Increased use of backyard feeders and gardens has expanded habitat and food sources.
– Numbers in California estimated at 250,000-500,000 by Cornell Lab of Ornithology. Considered apparently secure in the state.
– Climate change may shift range northward as average temperatures rise in the Southwest.
– No major threats to species identified. Does not require focused conservation actions.
– Maintaining natural habitats like foothill woodlands and limiting pesticide use benefits the species.
– Providing backyard feeders, native plants, garden flowers and reducing building collisions also support hummingbirds.
Population Status:
| Estimated 5 million in North America | Stable/increasing overall trend |
| One of the most common western hummers | California population 250k-500k |
| Range may shift north with climate change | No major threats identified |
| Not a conservation concern | Backyard support helps population |
Conclusion
In summary, the Black-chinned Hummingbird is a fairly common and widespread hummingbird in the San Francisco Bay Area from spring through fall. The male’s distinctive black chin and iridescent purple crown make it easily identifiable. This species breeds in gardens, parks, woodlands and other semi-open habitats before migrating to Mexico for the winter. Providing nectar feeders, flowers and native plants can support Black-chinned Hummingbirds in urban areas and help maintain their populations. Though not considered a conservation concern, we can help these remarkable little birds flourish by providing habitat wherever possible, minimizing pesticides, and reducing collisions. The Black-chinned Hummingbird remains a favorite among bird enthusiasts in the Bay Area, who eagerly await their return each spring.
