A rare and irregular transient outside the breeding range. Breeding season extends from May through August. Possibly 2 broods per yr. Incubation lasts about 16 days. Female performs all nesting duties.
Females can be long-lived.
Life histories of North American cuckoos, goatsuckers, hummingbirds, and their allies. Calder, W. A. 1972. Piracy of nesting materials from and by the broad-tailed hummingbird. Calder, W. A., and J. Booser. Hypothermia of broad-tailed hummingbirds during incubation in nature with ecological correlations.