The Costa’s hummingbird (Calypte costae) is a small hummingbird native to the southwestern United States and Baja California in Mexico. Here are some tips on how to identify this species in the field.
Size and Shape
Costa’s hummingbirds are one of the smallest hummingbird species in North America, measuring only 3-3.5 inches in length and weighing 2-4 grams on average. They have a short bill and a rounded, compact body shape. The tail is fairly short compared to other hummingbirds.
Plumage
Adult male Costa’s hummingbirds have vibrant, iridescent plumage. The head and throat are purple, the back is metallic green, the rump is blue-violet, and the undersides are gray-white. In bright sunlight, the plumage can appear to change color depending on viewing angle.
Females and immature males have much duller plumage, with greenish upperparts and whitish underparts with gray flecking on the throat and sides. The tail has white tips and purplish-black subterminal band.
Distinctive Features
Some key features to look for when identifying a Costa’s hummingbird:
- Very small size and short tail
- Males have extensive purple on head and throat (female Allen’s hummingbird has just a small patch)
- Females lack rufous in tail (distinguishes from female Anna’s hummingbird)
- Dark tail with wide purplish-black subterminal band
Voice
The voice of the Costa’s hummingbird is a brisk series of high-pitched, squeaky chips and buzzes. The call is higher pitched and faster than that of other desert southwest hummingbirds like the black-chinned.
Behavior
Costa’s hummingbirds can be found in a variety of semi-open habitats including desert scrub, chaparral, and suburban gardens. They feed mainly on nectar from flowers such as ocotillo, palo verde, and feeders, and also eat small insects. Males perform aerial displays during the breeding season, flying in U-shaped patterns and dive-bombing intruders.
Range and Habitat
Costa’s hummingbirds range across the Mojave and Sonoran deserts from southern California to Arizona and southwestern New Mexico, as well as Baja California, Mexico. They occur in arid to semi-arid habitats with scattered trees, shrubs, and cacti, often near water sources. Suburban gardens and parks also provide good habitat.
Months Seen | Breeding Range | Winter Range |
---|---|---|
January – December | Southwest California, southern Nevada, southern Arizona, Baja California | Southern reaches of breeding range, coastal southern California |
Similar Species
Costa’s hummingbirds can be confused with some other similarly sized hummingbird species. Here is a comparison:
Anna’s Hummingbird
- Female Anna’s has rose-pink flush on throat and crown
- Dark, iridescent rose-red throat in males
- Larger size on average
- Females have extensive rufous in tail
Black-chinned Hummingbird
- Males have extensive black (not purple) throat
- Smaller purple patch on crown
- Females lack bold wing stripe of Costa’s
Calliope Hummingbird
- Much smaller and shorter-tailed overall
- Males have elaborate streaking on throat
- Females lack rufous in tail
Conclusion
In summary, Costa’s hummingbirds can be identified by their very small size, short tail, extensive purple on the male’s head and throat, dark tail with wide purplish-black band in both sexes, and high-pitched squeaky voice. They occur year-round in desert regions of the southwest, with seasonal movements dependent on flower availability. Look and listen for them buzzing around flowering desert plants!
Here are some additional facts about Costa’s hummingbirds:
Nesting
- Nest is a small, compact cup of plant down bound with spider webs
- Female builds nest in a protected site such as a tree cavity or under an overhang
- Lays 2 tiny white eggs
- Incubation is 14-19 days
- Chicks fledge in about 20 days
Diet
- Feeds on nectar from desert blooms like ocotillo, palo verde, and agave
- Also eats small insects and spiders
- Visits feeders for sugar water
- Helps pollinate plants as it feeds
Status
- Has adapted well to human presence and urbanization
- Common and numbers increasing in some areas
- Not considered threatened
Interesting Facts
- Male Costa’s are highly territorial and aggressive, dive-bombing intruders
- Torpor is used to conserve energy overnight and in cold weather
- Often perches horizontally like a flycatcher to scan for insects
- The species name “costae” honors French nobleman Louis Marie PantaleĆ³n Costa
- Some regional names include “Costa’s,” “desert,” “violet-crowned,” and “blue-throated” hummingbird
I hope this overview helps explain how to identify the tiny but feisty Costa’s hummingbird. Let me know if you have any other questions!