Bird Profile

Costa's Hummingbird

A male Costa's wears a violet gorget drawn out into long points on either side of his throat, and he does most of his year in the months when the rest of the country has no hummingbirds at all.

The Costa's Hummingbird (Calypte costae) belongs to the dry country. Its range traces the Sonoran and Mojave deserts almost exactly: the low washes and bajadas of southern Arizona, the Colorado Desert and Mojave of California, southern Nevada, the far southwestern corner of Utah, and down the length of Baja California. Where saguaro, ocotillo, chuparosa and desert lavender grow, this is the resident hummingbird.

The adult male is the most distinctive gorget in North America. The violet purple runs up over the crown as well as the throat, and the outer corners of the gorget are drawn into long feathered points that stick out well past the sides of the neck, so a displaying male looks like he is wearing a small mustache pointing backward. Nothing else looks like it, and the color is deep purple rather than the rose red of Anna's or the magenta of Broad-tailed.

What makes Costa's unusual as a yard bird is the calendar. This bird runs on desert time, courting in January and nesting through spring while the winter annuals bloom, then largely clearing out of the hottest lowlands in summer. A feeder in Tucson or Palm Springs sees its best Costa's activity in February, not July, which reverses everything most feeder guidance assumes.

How to identify a Costa's Hummingbird#

Adult male

Small and compact, green above and grayish white below, with a brilliant amethyst to violet purple gorget that covers the whole throat and continues over the forehead and crown. The gorget's lower corners extend into long flared points on each side. As with all iridescence it goes black in the wrong light, but the shape of the flared corners still shows in silhouette. The tail is short and does not project past the folded wingtips at rest.

Adult female and immature

Plain: dull green above, grayish white below, with an unmarked pale throat that sometimes shows a few dusky flecks, and a short tail with white tips to the outer feathers. There is often a slightly paler line over the eye and a plainer, grayer face than the other small hummingbirds. Young males start putting in scattered purple throat feathers in their first year, which makes them identifiable long before the full gorget grows in.

The female problem: Costa's against Black-chinned#

Across southern Arizona, southern Nevada and inland southern California, female and immature Costa's and Black-chinned share every feeder, and neither has a plumage mark you can trust. Use structure and behavior.

• Tail projection at rest: Costa's has a short tail that does not reach past the folded wingtips. Black-chinned has a longer tail that does.
• Bill: Black-chinned has a noticeably longer bill with a slight downward curve. Costa's bill is shorter and straighter.
• Tail movement while hovering: Black-chinned pumps and wags its tail more or less continuously. Costa's holds it much stiller.
• Overall build: Costa's looks front-heavy and stub-tailed, with a large-headed, hunched appearance. Black-chinned looks longer and more elongated.
• Voice: Costa's gives a high, thin, metallic tick, and the male's long thin whistle is unlike anything a Black-chinned produces.

Anna's is the third bird in this mix and has spread deep into the desert on the back of irrigated landscaping. Female Anna's is larger and grayer with a more heavily spotted throat, often with a central red patch. Costa's and Anna's occasionally hybridize where they overlap, which is a reminder to be comfortable leaving some birds unnamed.

Sorting the western hummingbirds#

Range, sound and tail shape do more work than color. The table below is written for adult males, since females of several species are genuinely difficult.

In a low desert yard the realistic shortlist is Costa's, Black-chinned and Anna's, with Rufous passing through in migration and Broad-tailed higher up in the mountains. The whole group is worked through in the hummingbird identification guide.

Where and when: a bird on a desert calendar#

Costa's is present year-round in parts of its range, particularly Baja California and adjacent southern California and Arizona, but individual birds move a great deal. The general pattern is a shift into the deserts for the late winter and spring bloom, then a dispersal in summer toward coastal southern California, the chaparral, and mainland Mexico, leaving the hottest lowland desert relatively empty in July and August.

For a feeder in the Southwest or inland California, that means the productive window is roughly December through May, with the peak in February, March and April when males are displaying. If your Costa's disappear in June, nothing has gone wrong. They have gone where there is water and flowers.

The male's display is worth waiting for. He climbs high, then dives in a long looping arc past a perched female, producing a thin, high, drawn-out whistle that slides downward as he passes. It carries a long way across open desert and is often the first sign that a pair is on territory.

Nectar and the feeder in desert heat#

Four parts water to one part plain white granulated sugar, which is one cup of water to a quarter cup of sugar, stirred until fully dissolved. No red dye, no honey, no brown or raw sugar, no artificial sweetener, and never a stronger mix. In desert conditions a thicker syrup is actively unhelpful, because the bird has to find extra water to process it. The full argument is in the hummingbird nectar recipe.

Buy small. A feeder holding 8 to 12 ounces (240 to 350 ml) in a saucer or basin design, where the nectar sits under the ports, wins on every axis that matters here: less leaking, faster scrubbing, fewer bees in the liquid. Size and port design are compared in choosing a hummingbird feeder.

Placement matters more in the desert than anywhere else. Morning sun and deep afternoon shade, ideally under a mesquite or palo verde or on the north or east side of the house. A feeder in full Arizona sun in June is spoiled by mid afternoon. Keep a perch within a few feet, skip yellow parts that attract wasps, and use a water-filled ant moat above the feeder rather than any oil or spray, as covered in ants at hummingbird feeders.

The cleaning schedule#

Cleaning is hot water and a brush on every surface including inside the ports, not a rinse. Never add fresh nectar on top of old. This one habit does more for hummingbird health than any feeder purchase.

Desert plants and water, which do more than a feeder#

Costa's evolved on desert flowers and still gets most of its calories from them. Chuparosa, ocotillo, desert lavender, fairy duster, agave, penstemon, desert willow and red yucca are all heavily used, and a yard planted with a succession of them will hold birds through the dry months when a feeder alone will not. The approach is set out in native plants for birds.

Protein comes from small insects and spiders, gleaned off foliage, taken in flight or pulled out of webs, and nestlings are fed almost entirely on that. A yard treated with broad insecticides can keep adults at a feeder while failing the nesting females, which is covered in pesticides and birds.

Nesting, and a working desert setup#

Nesting is early and fast. Courtship begins in the low desert as early as January, most nesting runs from February into May, and it is timed to the spring wildflower bloom rather than to summer. The female builds a small open cup of plant fibers and spider silk in a shrub, cactus or small tree, usually low, and raises the two young alone. Males take no part beyond displaying.

The standing concern for this species is habitat. Its range overlaps the fastest-growing metropolitan areas in the Southwest, and clearing native desert scrub for development removes both the flowers and the insects. Population trends for desert hummingbirds are difficult to measure precisely, so treat any specific decline figure with caution, but the direction of travel on desert scrub is not in doubt.

1. Hang the feeder by late December or early January in the low desert, well before the spring peak.
2. Mix 4 parts water to 1 part plain white sugar. Nothing else goes in.
3. Fill a quarter full from May onward so daily changes stay realistic.
4. Site it in deep afternoon shade, near a perch, with no yellow plastic.
5. Use a water-filled ant moat above the feeder, never grease or insecticide.
6. Scrub every part, including inside the ports, at each change.
7. Add a mister or dripper in a shrub, which will out-earn a second feeder.
8. Plant chuparosa, ocotillo or desert willow for the months the feeder cannot cover.

If nothing comes, work through how to attract hummingbirds before replacing the feeder. In this range the answer is almost always placement, nectar age, or simply the season.