Bird Profile

Broad-tailed Hummingbird

An adult male Broad-tailed announces himself with a shrill metallic trill from his wingtips, which makes this the easiest western hummingbird to identify with your eyes closed.

The Broad-tailed Hummingbird (Selasphorus platycercus) is the hummingbird of the Rocky Mountain summer. It nests in aspen groves, pine and spruce edges, willow-lined creeks and mountain meadows from Idaho and Wyoming down through Colorado, Utah, Arizona, New Mexico and the sky islands of west Texas, and in most of that country it is the common bird at a feeder from late spring into September.

It is also the only North American hummingbird you can identify without seeing it. The adult male's wings make a shrill, metallic, insect-like trill that carries a long way through thin mountain air, and once you have heard it you will never mistake it. Birders in Colorado routinely log this species by ear from a hundred feet away without lifting binoculars.

The catch is that the trill belongs to adult males only, and it disappears when they molt. Females and young birds are quiet, buffy-flanked, rufous-tailed hummingbirds that overlap in appearance with two other species in the same mountains. This profile covers the trill, the plumage marks that back it up, how to sort the western group, and how to run a feeder at altitude where nights get cold and the season is short.

How to identify a Broad-tailed Hummingbird#

Adult male

Bright metallic green above and on the flanks, white below, with an evenly bright rose magenta gorget covering the whole throat. The color is uniform, not a black bib with a colored edge, and there is a clean white collar below it. The tail is broad and rounded, dark with rufous at the base of the outer feathers. In poor light the gorget goes dark, but it darkens to a dull red-black rather than the flat velvet black of a Black-chinned.

Adult female and immature

Green above, whitish below with a distinctly buffy to cinnamon wash along the flanks, and a throat finely speckled with bronze or dusky green spots that sometimes coalesce into a small central patch. The outer tail feathers are rufous at the base and white at the tip. The bill is fairly long and straight.

That description also fits a female Rufous Hummingbird and, roughly, a female Calliope, and honest identification of these birds at a feeder is often impossible. Broad-tailed is the larger and longer-tailed of the group with a longer bill, and Calliope is a strikingly tiny, short-tailed bird whose wingtips reach the tail tip at rest. If you are not sure, leave it as a female Selasphorus.

The wing trill, and why it beats every visual mark#

The sound is produced mechanically, not vocally. Air passing over a narrowed outer primary feather on the adult male's wing sets up a loud, high, ringing trill, closer to a cricket or a cicada than to a bird. It sounds continuously while he is flying and stops the moment he perches, so a male crossing a meadow draws a line of sound across it.

Two caveats keep it honest. Only adult males trill, so silence tells you nothing. And because the sound depends on the shape of a single feather, a male replacing that feather during molt in late summer can fly past silently. A quiet green hummingbird in a Colorado yard in August may well be an adult male Broad-tailed between feathers.

Sorting the western hummingbirds#

Range, sound and tail shape together do more work than color does, because color on a hovering bird depends entirely on the angle of the light. The table below is written for adult males.

In practice the Rocky Mountain problem is Broad-tailed against Rufous, which arrives on its southbound migration in July and August and displaces everything else at a feeder. Adult male Rufous are unmistakable in orange. Females and young of the two species are not, and sound helps only if a Broad-tailed male happens to fly past. At lower elevation the other common bird is Black-chinned, which pumps its tail constantly while hovering. West of the divide the resident bird is often Anna's, and the whole group is worked through in the hummingbird identification guide.

Where and when you will see one#

This is a montane species through and through. Broad-tailed Hummingbirds breed in open pine and spruce forest, aspen stands, willow thickets and meadows, mostly between about 5,000 and 10,500 feet (1,500 and 3,200 m), which puts them squarely in the yards of anyone living in the foothills and mountain towns of the Mountain West.

Males arrive first, from late March at the southern and lower edge of the range through April and into early May at high elevation, tracking the snowmelt and the first flowers upslope. Females follow a week or two later. After nesting, birds drift upslope to feed in high meadows through midsummer, then head south, with most gone from the northern Rockies by early September. The bulk of the population winters in Mexico.

For a mountain yard the practical rule is to hang the feeder as soon as the snow is off the south-facing slopes, which is usually earlier than feels sensible. The general timing advice is in when to put out hummingbird feeders, and it should be shifted earlier at low elevation and later up high.

Cold nights, torpor, and why an early feeder matters#

A hummingbird nesting at 9,000 feet (2,700 m) faces nights that drop below freezing well into June. Broad-tailed Hummingbirds handle this by entering torpor, a controlled nightly shutdown in which body temperature falls steeply and heart rate and breathing slow dramatically. A torpid hummingbird is cold to the touch, unresponsive, and takes time to warm back up in the morning, which is why birds so often appear at feeders within minutes of first light.

There is a longevity note that follows from all this efficiency: a banded female of this species was recorded at more than 12 years old, which is extraordinary for a bird weighing about as much as a penny. Hummingbird lifespans are generally short, and records like that are rare, so treat it as a ceiling rather than a typical figure.

Nectar and the feeder#

Four parts water to one part plain white granulated sugar, which is one cup of water to a quarter cup of sugar. Stir until dissolved. No red dye, no honey, no brown or raw sugar, no artificial sweetener, and nothing stronger than 1:4. The reasoning behind each of those is in the hummingbird nectar recipe, and it does not change at altitude.

Choose a small feeder, 8 to 12 ounces (240 to 350 ml), in a saucer or basin design where the nectar sits below the ports. These leak less, scrub out faster and keep bees out of the liquid. Size selection and port design are covered in choosing a hummingbird feeder. The wider comparison of designs is in hummingbird feeders. Mountain sun is intense even when the air is cool, so hang the feeder where it gets afternoon shade, and keep a perch within a few feet.

One dominant male will defend every feeder he can see from a single perch. Hanging two or three feeders out of sight of one another, around a corner or on opposite sides of a building, is the most effective single change most people can make. For ants, use a water-filled moat above the feeder and nothing else, as covered in ants at hummingbird feeders.

Cleaning, on a schedule set by temperature#

Cool mountain air buys you time that a desert yard does not have, but midday sun at altitude still heats a feeder fast, and afternoon highs in the 80s are common in July. Set the schedule by the day's high temperature, not by how the nectar looks.

Flowers, insects and water#

Sugar water is fuel and nothing more. The protein comes from small insects and spiders taken in flight or picked off foliage and out of webs, and nestlings are fed almost entirely on that animal matter. A yard sprayed for insects can hold adult hummingbirds at a feeder while quietly failing the nesting females.

Broad-tailed Hummingbirds follow the bloom upslope through the summer, working scarlet gilia, penstemons, paintbrush, larkspur, columbine, currants and willows. A mountain garden that flowers in sequence from May into September will hold birds through the season, and the approach is set out in native plants for birds. A mister or dripper in foliage, described in moving water, draws hummingbirds that ignore a conventional bath, since they bathe in mist and droplets rather than wading.

Nesting and a working setup#

The female builds and raises the brood alone, in a tiny cup of plant down and spider silk saddled on a horizontal branch, often over a stream and frequently under an overhanging branch that shelters it from frost and rain. Two white eggs is the standard clutch. Males take no part, and their season ends early.

1. Hang the feeder as soon as the south-facing slopes clear, before you expect the first bird.
2. Mix 4 parts water to 1 part plain white sugar, and nothing else.
3. Fill only what you will change on schedule for the day's high temperature.
4. Site it in afternoon shade with a perch nearby, and avoid yellow parts.
5. Add a water-filled ant moat above the feeder rather than any oil or spray.
6. Put out a second and third feeder out of sight of the first once a male starts guarding.
7. Keep a spare feeder indoors during late spring cold snaps so there is liquid nectar at dawn.
8. Leave the feeder up two weeks past your last sighting, for late southbound birds.

If a mountain feeder goes untouched for weeks in season, the usual causes are placement, spoiled nectar or a single bird guarding everything, not the feeder itself. Work through how to attract hummingbirds before changing hardware.