No reports of double-brooding found. Altricial young tended by female until fledging at 22 days. Female performs most nesting duties. Owls, other hawks, and weasels are suspected predators. Greatest danger probably unseasonable cold that kill nectar sources and insects.
Hummingbirds are important pollinators of specially adapted plants.
Territorial behavior in fall migrant rufous hummingbirds. Bent, A. C. 1940. Life histories of North American cuckoos, goatsuckers, hummingbirds, and their allies. DeSante, D. F., and D. G. Ainley. The avifauna of the South Farallon Islands, California.