Broad-Tailed Hummingbird (Selasphorus platycercus): Complete Guide to the Rocky Mountain's Trilling Icon

The Broad-Tailed Hummingbird is a medium-sized hummingbird with a noticeably broad, rounded tail --- the feature that gives this species its name. In the field, its most reliable identifier (for males) is sound: the distinctive metallic wing trill is produced by a notch in the male's outer primary feathers and carries remarkably far in open mountain terrain.

Male Appearance

The adult male is visually striking. His back and crown are iridescent green, and his underparts are a clean grayish-white on the belly and flanks. The defining feature is his gorget --- a broad patch of rose-magenta iridescence covering the throat, which blazes like a neon lamp when caught in direct light and appears dark or even black in shade. His tail is the broadest of any North American Selasphorus, with rounded outer feathers; when fanned in display or threat postures, it creates the rounded silhouette that distinguishes him from the similar Rufous and Allen's Hummingbirds, whose tails have a more pointed look. Crucially, the male Broad-Tailed lacks the rufous coloration on the back that defines male Rufous Hummingbirds.

Female Appearance

Female Broad-Tailed Hummingbirds are subtler but elegant. Their backs are iridescent green, and their underparts are white with distinctly buffy or cinnamon-washed flanks --- a useful field mark. The throat is white with small scattered greenish spots, occasionally with a few faint magenta feathers hinting at the male's gorget. The tail is broad and rounded with green central feathers and rufous-and-black banding on the outer feathers, showing white tips. The combination of buffy flanks and rounded tail separates females from female Rufous in many situations, though direct comparison is needed in ambiguous cases.

Juvenile Appearance

Juveniles of both sexes closely resemble females upon fledging --- green above, buff-flanked below, with spotted or streaked throat markings. Young males begin developing magenta gorget feathers during their first fall migration and may show scattered rose-colored throat feathers by the time they depart for Mexico. Juvenile males lack the wing trill of adults; this acoustic feature only develops once adult primaries are grown in. Juveniles tend to show finely scaled feather edges on the back, giving a scalloped look that disappears after their first full molt.

Similar Species & How to Tell Them Apart

Rufous Hummingbird (Selasphorus rufus): The most likely confusion species. Male Rufous has an entirely rufous (orange-brown) back --- male Broad-Tailed has a green back. Females are nearly identical; tail shape and flank color (Broad-Tailed is buffier, less richly rufous) are the best field marks. In the Rockies, range and elevation context help: Rufous passes through as a migrant while Broad-Tailed is the breeding species.

Calliope Hummingbird (Selasphorus calliope): Noticeably smaller, with a shorter bill and tail. Male Calliope has a streaked, wine-ray gorget, not a solid rose patch. Female Calliope is smaller with a more pinched, shorter tail.

Ruby-Throated Hummingbird (Archilochus colubris): Does not overlap in the Rockies. Male Ruby-Throat has a forked tail; female Ruby-Throat lacks the buffy flanks of female Broad-Tailed.

The Broad-Tailed Hummingbird undertakes a seasonal migration that is closely synchronized with flowering plant phenology at high elevations. Adult males typically lead the spring movement, arriving on breeding grounds in Colorado, Utah, and Wyoming in late April to early May --- often before many flowers have bloomed, relying on stored fat reserves and early-season insects until wildflowers open. Females and immature birds follow two to three weeks later.

The early arrival of males in late spring is a calculated ecological gamble: those who claim territories before competitors arrive enjoy first access to the best nectar sources and nesting sites. Because they can enter torpor to survive freezing nights, they bear temperature risks that most birds cannot tolerate.

Fall migration begins in August, with adults departing before juveniles. Most individuals have vacated high-elevation breeding grounds by late September, moving south through Mexico to wintering areas in Oaxaca, Guerrero, and the Guatemalan highlands. Unlike the Rufous Hummingbird, which makes a dramatic clockwise loop migration, the Broad-Tailed's migration routes are less thoroughly documented --- but the species generally moves through the same corridor in both directions, using the spine of the Rockies as a navigational guide.

Migration timing tip: If you live in the Colorado Front Range or Wasatch mountains, put your feeders out by April 20th to catch the first wave of returning males.

Setting up feeders for Broad-Tailed Hummingbirds in the Rocky Mountain West requires some attention to elevation-specific considerations:

Feeder placement: Hang feeders where they receive morning sun (which warms the nectar and may help attract early birds) but are shaded in the hottest afternoon hours. At high elevations, afternoon shade is less critical due to lower temperatures, but UV exposure can degrade nectar more quickly.

Height and exposure: Mount feeders at 5--6 feet off the ground, with open flight paths in multiple directions. Broad-Taileds prefer to approach from open sky rather than dense vegetation, unlike some forest species.

Number of feeders: In active mountain territories, place 2--3 feeders spaced at least 15--20 feet apart. This lets dominant males defend one while subordinate birds access others.

Nectar freshness: At high-elevation summer temperatures (cool days, cold nights), nectar stays fresh longer than at sea level --- but change it every 3--5 days regardless, or every 2 days in warmer periods. Fermented or moldy nectar is harmful. Use only plain white cane sugar and water (1:4 ratio); never use honey, brown sugar, or artificial sweeteners.

Feeder style: Wide-mouth basin-style feeders are easy to clean and less prone to overflow. The Broad-Tailed's bill length is medium --- standard port sizes work well. Red feeder components are sufficient to attract attention; there is no need for red-dyed nectar.

Winter considerations: If you're in a location with year-round mild temperatures (lower-elevation AZ or NM foothills), keep feeders up through October to support late migrants. In true mountain locations, birds depart by September.

For a curated look at the best feeders and accessories for western mountain species, explore the NectarBloom Hummingbird Trail --- our comprehensive resource for feeder setups by region and species.

Female Broad-Tailed Hummingbirds are solely responsible for nest construction, incubation, and chick-rearing --- a pattern universal among North American hummingbirds. Nest construction typically begins shortly after females arrive on breeding grounds in May, and can be surprisingly early given the cold temperatures typical of mountain spring.

The nest is a marvel of engineering: a small, deep cup roughly the size of a large walnut half, constructed from plant fibers, thistledown, and spider silk. Spider silk is critical --- it holds the cup together and allows it to expand as nestlings grow. The exterior is decorated with bits of lichen and bark that provide camouflage against the branch or twig where the nest is placed. Nests are typically situated on a sloping branch or horizontal fork 4--10 feet above the ground, often near or over a small stream where humidity is higher.

The female lays exactly two white eggs, each about the size of a jellybean. Incubation lasts 16--19 days. Chicks hatch blind and nearly featherless. The mother feeds them a mixture of regurgitated nectar and insects (protein essential for growth) by inserting her bill deep into their throats. Fledging occurs at 21--26 days post-hatch. In favorable conditions at lower elevations, a female may raise two broods in a single season.

Males play no role in nesting. After mating, they return to their territorial behavior at feeding sites, devoting energy to defending nectar resources rather than parental duties.

The Broad-Tailed Hummingbird is classified as Least Concern by the IUCN Red List, and population trends monitored by the North American Breeding Bird Survey suggest that overall numbers are relatively stable. The species remains common throughout its Rocky Mountain range, and its dependence on high-elevation forest and meadow habitats provides some buffer from the urban sprawl pressures that affect lowland bird communities.

That said, this species is not without vulnerability. Climate change poses a meaningful threat through phenological mismatch --- as warming temperatures shift wildflower bloom times earlier in the season, but hummingbird migration timing remains partially fixed by photoperiod (day length), there is increasing risk that birds will arrive after peak blooms have passed. Research at the Rocky Mountain Biological Laboratory in Colorado has documented this mismatch in recent decades, with measurable consequences for bird body condition upon arrival.

Habitat degradation in Mexican and Guatemalan wintering areas, while not yet at crisis levels, is a monitoring concern. The species also faces periodic mortality events during unseasonable late-season snowstorms on breeding grounds --- events that may become more unpredictable as climate patterns shift.

Backyard habitat creation is a meaningful conservation contribution: maintaining quality feeders with clean, dye-free nectar during the breeding and migration season, planting native wildflowers, and reducing or eliminating pesticide use (which depletes the insect prey hummingbirds require) all support population health.