Calliope Hummingbird

The Calliope Hummingbird, Selasphorus calliope, holds the distinction of being the smallest bird native to the United States and Canada. With a glossy green back and crown, and pristine white underparts, this diminutive avian marvel measures a mere 7–10 cm in length and spans 11 cm across the wings. The adult male is particularly striking with wine-red streaks adorning the gorget, green flanks, and a dark tail.

Identification Tips

When identifying the Calliope Hummingbird, look for the adult male's distinctive wine-red streaks on the throat, which can be flared out during territorial or courtship displays. Females and immatures are more subtly marked, with a pinkish wash on the flanks, dark streaks on the throat, and a dark tail with white tips. They can be distinguished from the similar Rufous and Allen's Hummingbirds by their smaller size and the lack of extensive rufous markings on the tail and flanks.

Habitat

The Calliope Hummingbird breeds in a variety of open shrub habitats and altitudes, often choosing higher elevations in the Rocky Mountains. Their nesting sites range from as low as 600 ft in Oregon and Washington to the tree line at over 11,000 ft.

Distribution

This species nests in western North America from southern British Columbia and Alberta south to Colorado and southern California. Come winter, they migrate to southwestern Mexico, Guatemala, and Belize.

Behaviour

Known for being the smallest-bodied long-distance migrant in the world, the Calliope Hummingbird departs early from breeding grounds to exploit late-summer wildflowers. They feed on nectar, sap from sapsucker holes, and catch insects mid-flight. Males arrive first on breeding grounds and defend territories without participating in chick-rearing.

Song & Calls

The Calliope Hummingbird's vocalizations are less documented, but their "humming" is a result of rapid wingbeats, serving as an audible signal to others of their presence.

Breeding

Females construct open cup nests in coniferous trees, often under overhanging branches and sometimes on large pine cones. Two eggs are laid from late May to early July, incubated for 15 to 16 days, with fledglings taking flight about 20 days post-hatching.

Similar Species

The Rufous and Allen's Hummingbirds are similar but larger and have more pronounced rufous coloring and longer central tail feathers.

Diet and Feeding

Calliope Hummingbirds feed on nectar from flowers like paintbrush and penstemon, and also consume insects and spiders. They play a role in pollination while feeding.

Conservation status

As of 2019, the Calliope Hummingbird is classified as Least Concern with a stable population of approximately 4.5 million individuals. However, due to its restricted wintering range and long migratory journey, it is monitored for potential threats.

Threats

The species faces few predators but is vulnerable to prolonged cold spells that can diminish food sources. They are known to aggressively defend their territory against larger birds.