The desert is a strange place to make a living on flowers, and yet the Costa’s Hummingbird has made it home. This is the hummingbird of the Sonoran and Mojave, a small, compact, hunched little bird that nests in late winter, feeds at ocotillo and chuparosa, and clears out before the worst of the summer heat arrives.

The male wears the most extravagant gorget in North America: a blaze of violet-purple that covers his crown and throat and then flares backward into two long points, like an overgrown mustache trailing past his shoulders. And when he dives for a female, he does something with the sound of it that researchers only worked out in 2018.

Quick Facts

• Scientific name: Calypte costae
• Length: about 3 to 3.5 inches, with a wingspan around 4.3 to 4.7 inches
• Weight: roughly 3 grams
• Distinction: the second-smallest hummingbird in North America, after the Calliope (see our smallest vs. largest hummingbird comparison)
• Range: Sonoran and Mojave Deserts, coastal southern California, Baja California, and northwestern Mexico
• Named for: Louis Marie Pantaleon Costa de Beauregard, a Sardinian statesman and hummingbird collector, by French naturalist Jules Bourcier
• Conservation status: Least Concern, though listed as a U.S. Bird of Conservation Concern

How to Identify a Costa’s Hummingbird

The male is unmistakable in good light. Brilliant violet-purple covers his crown and throat, and the gorget feathers extend backward and downward into a long point on each side of the neck. No other North American hummingbird has anything like it. His back is green, his wings and short tail dark, with white below the gorget.

In poor light the purple goes black, as all iridescent gorgets do, so a dark-hooded desert hummingbird is worth a second look as the bird turns.

The female is genuinely difficult, and honesty serves better than confidence here. She is greenish above and dingy grayish-white below, with a pale eyebrow that wraps around a darker cheek patch. She closely resembles female Anna’s and Black-chinned Hummingbirds, and separating them is one of the standard challenges of southwestern birding.

Structure is the best clue for both sexes. Costa’s is compact and dumpy with a hunched posture, and its tail is notably short, so short that when the bird perches, the wings reach the tail tip or nearly so. The bill droops very slightly. That combination, small, hunched, short-tailed, and droop-billed, separates it from the longer-tailed Anna’s and Black-chinned better than plumage does.

Similar Species

• Anna’s Hummingbird is the closest relative, sharing the genus Calypte. Male Anna’s is rose-pink rather than violet, and his gorget does not flare into points. Anna’s is also larger, longer-tailed, and less hunched. Learn more about the Anna’s Hummingbird.
• Black-chinned Hummingbird males have only a thin violet band below a black chin, nothing like the Costa’s full purple hood. Females of the two are very similar; the Costa’s shorter bill and tail help. See the Black-chinned Hummingbird article.
• Calliope Hummingbird is smaller still, and the male’s magenta gorget forms separate streaming rays rather than a solid flared patch.
• Anna’s–Costa’s hybrids occur, and can look confusingly intermediate.

For more detail, see the article on North American hummingbird species.

Range, Habitat, and the Desert Life

Costa’s occupies desert scrub across the Sonoran and Mojave Deserts, plus chaparral and coastal sage scrub in southern California, and extends south through Baja California and into northwestern Mexico. Washes, dry canyon bottoms, arroyos, and the desert edges of suburbia are all good places to look.

The species solves the desert’s central problem, which is timing, by breeding in the cool part of the year and leaving before the heat peaks. In the Sonoran Desert, breeding runs from February to May; in the Mojave it stretches to June; in coastal California’s sage and chaparral it runs from March into September. Once nesting finishes, many desert birds head west and north to coastal California and Baja, following flowers rather than enduring a Sonoran July. By high summer, Costa’s are genuinely hard to find around Tucson. They return in autumn as desert plants such as chuparosa come back into bloom.

That pattern is changing at the edges. Where suburban gardens provide flowers year-round, increasing numbers of Costa’s now stay put all year rather than moving seasonally.

One thing Costa’s does not do is follow the pattern of most other western hummingbirds, which climb into mountain meadows after breeding to catch the late-summer alpine bloom. Costa’s rarely moves upslope, heading for the coast instead.

The species also wanders far more than its desert reputation suggests, with records north to Alaska and British Columbia, east to Kansas, and south into Jalisco.

The Dive, and the Acoustic Trick

The male’s courtship display is a long, looping performance: he circles the perched female and dives past her in broad U-shaped arcs, sometimes continuing for up to four minutes, though about 35 seconds is more typical. Throughout, he produces a thin, extraordinarily high-pitched whistle that rises and falls in pitch, a sound familiar to anyone who has walked a desert wash in early spring.

Here is the remarkable part. Research by Christopher Clark and Emily Mistick, published in Current Biology in 2018, found that the male is not simply diving; he is managing what the female hears. He dives to the side of her rather than straight at her, which minimizes the Doppler shift that would otherwise reveal how fast he is actually travelling. At the same time he twists his tail feathers to aim the sound they produce toward her, amplifying it by as much as 11 decibels.

In other words, he makes himself sound more impressive than his speed alone would warrant, while hiding the cue that would give the game away. It is one of the more sophisticated pieces of animal signalling ever documented, and it belongs to a bird weighing three grams.

The sound itself is made by the tail feathers rather than the voice, a mechanism called sonation, the same trick used by its sister species. Read more about hummingbird sound production in the article on hummingbird sounds and territorial behavior.

Behavior and Breeding

For all the drama of the display, Costa’s is not an especially aggressive hummingbird. Males and females defend flower patches, but they are subordinate to larger species and tend to move around chasing blooms rather than holding one territory against all comers.

Males mate with multiple females and provide no care afterward. The female builds a small cup of plant fibers and down, sometimes bound with spider silk and finished with lichen, placed low, typically three to six feet up, often on a yucca stalk or in a sparsely vegetated shrub. She lays two white eggs, incubates them for 15 to 18 days, and the young fledge about 20 to 23 days after hatching. The article on hummingbird breeding and nests covers the process.

Their diet is nectar plus small flying insects taken in midair, with ocotillo and chuparosa among the most important desert nectar sources. To put the demand in perspective, researchers calculated that a Costa’s Hummingbird must visit around 1,840 flowers in a day to meet its energy needs. Read more on that in the article on what hummingbirds eat.

Costa’s has also been important to science in an unexpected way because it lives in the hottest, driest conditions of any North American hummingbird, it was the primary subject of foundational 1960s research into hummingbird torpor and heat economy. The article on torpor and winter survival explains that state.

Attracting Costa’s Hummingbirds

If you live within their range, especially in desert-edge suburbia, they come readily to gardens and feeders.

Plant desert natives, with chuparosa, ocotillo, and desert willow among the best, and keep a clean feeder available. Put feeders out unusually early, since these birds are breeding while much of the country is still in winter. And because the species increasingly stays year-round where flowers persist, a garden with something always in bloom may hold them permanently. Our articles cover attracting hummingbirds, the nectar recipe and feeder care, and when to put feeders out and take them down.

• How to Attract Hummingbirds: Designing a Garden They’ll Return To
• Hummingbird Nectar Recipe and Feeder Guide: Food, Feeders, and care
• When to Put Out and Take Down Hummingbird Feeders

Frequently Asked Questions

How do I identify a Costa’s Hummingbird?

Males have a violet-purple crown and throat with gorget feathers flaring into long points on each side. Both sexes are small, compact, and hunched, with a notably short tail and a slightly drooping bill.

How do I tell a female Costa’s from a female Anna’s or Black-chinned?

It is genuinely hard. Look for the Costa’s smaller size, shorter bill, shorter tail, paler belly, and the pale eyebrow wrapping around a dark cheek.

Where do Costa’s Hummingbirds live?

Desert scrub in the Sonoran and Mojave Deserts, chaparral and coastal sage scrub in southern California, Baja California, and northwestern Mexico.

When is the best time to see one?

February through May in the Sonoran Desert, and into June in the Mojave. By high summer most have left the desert for cooler coastal areas.

What is the high-pitched whistle in the desert in spring?

Very likely a displaying male Costa’s. The sound is produced by his tail feathers during his diving display, not by his voice.

Do Costa’s Hummingbirds migrate?

Many move seasonally between desert breeding areas and coastal California or Baja, though increasing numbers now stay year-round where suburban gardens flower continuously.

Conclusion

The Costa’s Hummingbird is a study in doing more with less: a three-gram bird making a living in the driest country on the continent, timing its whole breeding year around the heat, visiting nearly two thousand flowers a day to stay aloft, and then, when it comes time to impress a female, engineering the acoustics of its own dive so it sounds better than it is. There is nothing modest about that purple mustache, and on the evidence, nothing modest about the bird either.