The Calliope Hummingbird is the smallest North American breeding bird. The adult male is the only North American hummingbird whose iridescent gorget is divided into separate magenta-red rays, which can be elevated in elegant star-burst display against the white background of the throat. The female's throat is white, sometimes with a few small spots of the male's gorget color. It differs from Rufous and Allen's hummingbirds in having a shorter bill and noticeably shorter tail, very little rufous in tail, often not visible in field; and a wash of pale buff across the breast rather than concentration of such color on sides and flanks (Calder and Calder 1994).
For a comprehensive review of the conservation status, habitat use, and ecology of this and other Montana bird species, please see Marks et al. 2016, Birds of Montana.
Western Hemisphere Range
In Bozeman area, normal spring migration is May 21 to June 5 (Skaar 1969).
Survives and breeds in northwestern montane environments (Calder and Calder 1993). In Bozeman area, occurs on thickety hillsides and in forest openings to moderate elevations in the mountains (Skaar 1969).
Floral nectar and small insects. Like other hummingbirds, it forages aerially for small insects (Calder and Calder 1993).
Males tend to precede females in arrivals and departures from breeding grounds. Nests are often built on old, dead pinecone base, making the nest appear to be a cone. Clutch size is normally 2 white, smooth, elliptical-oval eggs. Nesting records are for late June to early July (Davis 1961). Near Fortine, egg dates are June 5 to July 11; earliest hatching date June 11.