Costa hummingbirds (Calypte costae) are found in the southwestern United States and Mexico. Their range extends from southern California south along the Pacific Coast to Guerrero. They are common in desert and chaparral habitats, as well as in mountains up to 10,000 feet in elevation.
Quick Facts
- Species: Calypte costae
- Size: 3.5 inches long
- Wingspan: 4.3 inches
- Weight: 0.1 ounces
- Lifespan: 3-4 years
- Diet: Nectar, small insects
The Costa’s hummingbird is named after Louis Marie Pantaleón Costa, a French nobleman and naturalist. It was originally described by George Newbold Lawrence in 1864 based on a specimen collected near La Paz, Mexico.
Range and Distribution
The range of the Costa hummingbird extends along the Pacific Coast from southern California to Guerrero, Mexico. Their breeding range centers on the desert regions of California, Arizona, and Baja California. Some populations migrate seasonally, moving southwards in winter and returning north in spring and summer.
In the United States, Costa hummingbirds are found in these states:
- California – permanent resident along the southern coast and desert regions
- Arizona – summer resident and breeder in the southwestern region
- Nevada – rare and local summer visitor
- New Mexico – rare and local summer visitor to the southwestern region
They are also found in these Mexican states:
- Baja California – permanent resident
- Baja California Sur – permanent resident
- Sonora – permanent resident
- Sinaloa – winter visitor
- Nayarit – winter visitor
- Jalisco – winter visitor
- Colima – winter visitor
- Michoacán – winter visitor
- Guerrero – permanent resident
California
In California, Costa hummingbirds are permanent residents along the southern coast from Monterey County to San Diego County. They breed in coastal sage scrub, chaparral, and desert habitats. Further inland, they occur in desert scrub, palm oases, and montane chaparral habitats of the Transverse and Peninsular Ranges.
Arizona
In Arizona, Costa hummingbirds nest in the southwestern part of the state from Yuma to Tucson. They are summer residents, arriving in April and departing in September to wintering grounds in Mexico. They occur in desert scrub, second growth mesquite, and palo verde habitats within their Arizona range.
Nevada and New Mexico
In Nevada and New Mexico, Costa hummingbirds are rare summer visitors and do not breed. They may be observed in these states during migration or as vagrants outside their normal range.
Mexico
In Mexico, Costa hummingbirds are permanent residents along both the Pacific and Gulf coasts. On the Pacific side, they occur from Sonora south to Guerrero. On the Gulf side, they are found in northeastern Mexico from Tamaulipas south to San Luis Potosí.
Preferred Habitats
Costa hummingbirds occupy a variety of habitats across their range, including:
- Deserts – Sonoran, Chihuahuan, and Mojave desert scrub
- Chaparral – coastal sage scrub and interior chaparral shrublands
- Woodlands – dry tropical deciduous forest, oak and pine-oak woodlands
- Riparian – cottonwood-willow riparian corridors along desert streams and oases
- Montane – pine-fir and pine-oak forests up to 10,000 feet elevation
- Urban – parks, gardens, and backyards in cities and towns
They prefer habitats that provide a combination of flowering plants, nectar sources, small insects, and suitable nest sites. Their small size allows them to occupy varied microhabitats within these broader habitat types.
Deserts
In desert regions like the Sonoran Desert of Arizona and Mojave Desert of California, Costa hummingbirds frequent desert washes lined with palo verde, ironwood, mesquite, and catclaw acacia. Desert shrubs like ocotillo, brittlebush, fairy duster, and turpentine broom also provide nectar. They nest in trees and large shrubs along desert streams.
Chaparral
Chaparral habitats like the coastal sage scrub of southern California and the interior chaparral of Arizona and Baja California provide abundant food plants and nest sites. Costa hummingbirds feed on chaparral perennials like sages, California fuchsia, and bush penstemon. They build nests in woody shrubs including California lilac, buckwheat, and laurel sumac.
Woodlands
In the tropical deciduous forest of southwestern Mexico, Costa hummingbirds inhabit forests of figs, mahogany, and logwood trees. They occur in pine-oak woodlands at higher elevations. Here they visit agave and thistle flowers and nest in pines, oaks, and junipers.
Riparian
Lush riparian corridors provide vital habitat for Costa hummingbirds in otherwise arid desert and scrubland environments. They concentrate along desert streams and oases lined with cottonwoods, willows, and sycamores. These trees provide nesting cavities and support flowers like Apache plume and desert willow.
Montane
At higher elevations in the borderlands region, Costa hummingbirds inhabit pine-fir and pine-oak forests. They occur up to 10,000 feet in mountain ranges like the Santa Catalina, Chisos, and Guadalupe Mountains. At these elevations, they visit flowers of agave, Indian paintbrush, and columbine.
Urban
Costa hummingbirds readily inhabit urban and suburban environments, especially in cities within their coastal California and Arizona range. They visit nectar feeders and flowers in parks, gardens, and backyards. Eucalyptus trees and palms provide nesting sites in urban areas.
Behavior and Diet
Costa hummingbirds are bold, territorial birds with specialized behaviors and adaptations for feeding on nectar. A few aspects of their behavior and diet include:
- Aggressive defense of feeding territories from perches
- Consume mainly nectar and small insects
- Long bill adapted for reaching into tubular flowers
- Extendible tongue with forked tips for laping up nectar
- Visits a variety of brightly colored, scentless flowers
- Favorites include sages, ocotillo, penstemon, and mimulus
- Hawks flying insects like gnats, aphids, and spiders
- High metabolism and rapid heart rate while active
- Require frequent feeding and are highly territorial around food sources
- Thrive in urban habitats with artificial feeders providing supplemental nectar
Male Costa hummingbirds are highly territorial. They select exposed perches like the tip of a tall yucca stalk or dead tree branch to survey their territory. From these perches, they chase away intruders engaging in spectacular dive displays and mid-air dogfights.
Costa hummingbirds drink nectar using their specialized long, slender bills and extendible tongues. Their tongues have forked tips which lap up nectar as their bills reach deep into tubular flowers. Favorite nectar sources include the red clusters of ocotillo, vibrant orange California fuchsia, and bright red flowers of coral bean and desert honeysuckle.
To meet their high metabolic demands, Costa hummingbirds also eat small insects including gnats, aphids, thrips, spiders, caterpillars, and ants. They capture insects in flight or glean them from foliage and flowers. They are accomplished aerialists, capable of sustained hovering, sudden stops, and rapid pivots.
Breeding and Nesting
Costa hummingbirds breed between November and June depending on their geographic location. Courtship includes aerial displays by males followed by female inspection of potential nest sites. Nests are compact, cup-shaped affairs built by the female using spider webs and lined with plant down.
Key aspects of their breeding biology include:
- Breed November to June, with peak activity February to April
- Males court females with aerial dives, loops, and wing-clapping
- Females build nest in branch fork or sheltered site 2-20 feet up
- Tiny cup nest made of spider silk, coated in lichens or felted plant down
- Lays two tiny white eggs
- Incubates eggs for 14-19 days
- Nestlings fledge in 20-23 days
- Male plays no role in nesting or feeding young
- Females raise 1-2 broods per season
Courtship involves males performing dramatic aerial displays to impress females. They fly in repeated vertical figure-8’s, dive from heights of 100 feet, and produce loud wing trills. If receptive, the female allows the male to approach and mate with her.
Nest building is done solely by the female over 4-9 days. The tiny cup nest is only 1.5 inches across and 1 inch tall. It is crafted from spider silk and coated with lichens or lined with soft plant down collected by the female. Nest materials are bound together and attached to the substrate using strands of sticky spider silk.
The female incubates the two pea-sized white eggs for 14-19 days before they hatch. Nestlings fledge in 20-23 days. Females raise 1-2 broods each season. Males establish a new territory once breeding is done and play no role in caring for the young.
Nest Sites
Female Costa hummingbirds choose a variety of natural and man-made structures for nest placement, including:
- Branches – Horizontal branches and forks of trees and large shrubs
- Vines – Sheltered spots in vines climbing up trees and walls
- Leaves – Bases of yucca or agave leaves where they meet the stem
- Cavities – Old woodpecker holes and rotted knots in tree trunks and limbs
- Buildings – Beams, ledges, signs, light fixtures, and overhangs
- Bridges – Steel beams and girders underneath bridges
- Power poles – Cross beams on utility poles
Favored nest trees include eucalyptus, palms, mesquite, oak, pine, and juniper. Sheltered nest spots 2-20 feet up provide security while allowing the female to easily access flowering plants nearby.
Migration
Some populations of Costa hummingbirds migrate seasonally between breeding and wintering grounds. Migration timing and patterns vary across their range:
- Northern populations migrate, southern populations are year-round residents
- Birds in California, Arizona, Nevada migrate south in fall
- Birds in Mexico’s northern states migrate north in spring
- Spring migration from March to May
- Fall migration late August through October
- Young birds move north first in spring
- Adult males return to breeding sites after females arrive
Fall migration follows a loop route with birds departing coastal California and interior Arizona south into Mexico, then heading north along the Gulf coast to wintering areas. This provides ample habitat for feeding during migration. Spring migrants return more directly northward towards their breeding grounds.
Some Costa hummingbird populations are elevational migrants, moving to lower levels in winter and higher elevations in summer within the same region. These localized movements follow the flowering season as it shifts with changing elevation through the seasons.
Conservation Status
Costa hummingbirds remain widespread and common across their range. Partners in Flight estimates a breeding population of 1.5 million with 79% living in the U.S. and 21% in Mexico. They are classified as a species of Least Concern on the IUCN Red List due to their large and stable population. However, some threats to their habitat exist from urbanization and climate change.
While secure overall, Costa hummingbirds do face a few conservation issues:
- Urbanization impacts coastal California habitat
- Climate change threatens synchronization with food plants
- Nest disturbance and predators affect some populations
- Habitat loss in Mexico wintering areas a concern
Maintaining natural desert and chaparral ecosystems across their range will ensure the ongoing survival of Costa hummingbird populations. Providing urban greenspaces and residential nectar gardens can help offset habitat lost to California’s urban sprawl. Careful monitoring of nest sites, control of invasive predators like cowbirds, and public education programs can also contribute to their conservation.
Summary
In summary, Costa hummingbirds are a desert-adapted species of the southwestern U.S. and Mexico. Their range extends along the Pacific Coast from California to Guerrero. Though partially migratory, northern populations summer in the desert regions of California and Arizona while southern groups are year-round residents. Costa hummingbirds inhabit diverse habitats from coastal scrub to high mountain forests. They feed on nectar and small insects. Males perform elaborate aerial displays to court females. Females build tiny cup nests and raise one or two broods. While still common, habitat loss and climate change pose long-term threats requiring habitat conservation to ensure the species’ continued success.