Young (first year)Ruby-throated hummingbird males and females are nearly impossible to tell apart. Female Ruby-throats have green backs, like the males, but are mostly white below with a bit of buff color on their flanks. Females do not have colorful gorget feathers. Females of any age have a white throat that is sometimes marked with faint gray or buffy streaking as seen here.

The oldest known Ruby-throated Hummingbird was a female, and at least 9 years, 1 month old when she was recaptured and rereleased during banding operations in West Virginia. (From Allaboutbirds.org.) Photo by Debra Repasz.