Ruby-throated Hummingbird

They are 7.5 to 9.0 cm long and weigh approximately 3.4 g (males) to 3.8 g (females). The back and head are iridescent green, the underparts are white. Males have a brilliant red metallic throat and a forked tail. Females have a dull grayish throat, and a square, white-tipped tail. Immature ruby-throated hummingbirds look similar to adult females, though young males may have a few red feathers on their throat.