Broad-tailed Hummingbird

The Broad-tailed Hummingbird (Selasphorus platycercus) is a gem of the high country, breeding in mountain meadows and pine-oak woods of the American West and Mexico. Best known for the loud, cricket-like metallic whistle produced by the male's wings, this species is highly adapted to cooler mountainous elevations. From late spring through summer, these tiny birds display spectacular aerial maneuvers amidst fields of wildflowers, keying into red tubular blooms.

Adult Males

• Gorget: Radiant rose-pink to magenta throat throat that glimmers in direct sunlight and can appear dark or black in shadow.
• Plumage: Brilliant metallic-green upperparts, white breast, and green-washed flanks.
• Tail: Broad, rounded green tail with no rufous on the outer feathers (unlike Rufous Hummingbirds).

Adult Females and Immatures

• Throat: White or pale, finely speckled with small bronze-green or dusky spots.
• Plumage: Green back with a distinct buffy/rufus wash along the flanks.
• Tail: Unique tail feathers containing rufous bases, a black subterminal band, and white outer tips.

Key Flight Identifiers

• Wing Trill: The male has modified outer primary feathers (specifically the ninth and tenth primaries) with narrow tips. When flying, especially during display, air rushing over these feathers creates a loud, metallic whistling sound that makes them easy to detect by ear before they are seen.

Geographic Range and Migration

During the spring and summer breeding seasons, Broad-tailed Hummingbirds are found throughout the Rocky Mountains, from Idaho, Montana, and Wyoming south through Utah, Nevada, Colorado, Arizona, and New Mexico, extending into the highlands of Mexico and Guatemala. They are highly migratory, with northern populations traveling to wintering grounds in the pine-oak forests of central and southern Mexico.

Breeding Habitat

They are montane specialists, nesting at elevations ranging from 5,000 to over 10,500 feet. They favor open woodlands, pinyon-juniper communities, montane shrublands, subalpine meadows, and willow-lined canyon bottoms. During post-breeding migration, they may move even higher into alpine meadows to exploit late-summer wildflower blooms.

Foraging and Diet

Broad-tailed Hummingbirds feed primarily on flower nectar and tiny insects. They favor bright red tubular flowers such as scarlet gilia, columbines, Indian paintbrush, and larkspur. When flowers are scarce in early spring, they will feed on tree sap from wells drilled by sapsuckers, as well as gnats, midges, and small spiders caught midair or plucked from vegetation.

Torpor and Survival

To survive freezing temperatures at high altitudes, Broad-tailed Hummingbirds utilize a physiological state called torpor. On cold nights, they can drop their body temperature from a normal 40°C (104°F) down to just 12°C (54°F), and slow their heart rate from over 1,000 beats per minute to fewer than 50, allowing them to conserve vital energy.

Nesting

The female builds a compact cup nest made of plant down and spiderwebs, decorated on the outside with lichen and bark flakes to camouflage it. Nesting sites are often chosen on low branches of deciduous or coniferous trees, frequently positioned directly beneath an overhanging branch which serves as a shield against radiative cooling on cold nights.