The ruby-throated hummingbird (Archilochus colubris) is a species of hummingbird that generally spends the winter in Central America and migrates to Eastern North America for the summer to breed. It is by far the most common hummingbird seen east of the Mississippi River in North America.
The species is sexually dimorphic. The adult male has a gorget (throat patch) of iridescent ruby red bordered narrowly with velvety black on the upper margin and a forked black tail with a faint violet sheen. The red iridescence is highly directional and appears dull black from many angles. The female has a notched tail with outer feathers banded in green, black, and white and a white throat that may be plain or lightly marked with dusky streaks or stipples. Males are smaller than females and have slightly shorter bills. Juvenile males resemble adult females, though usually with heavier throat markings.The plumage is molted once a year, beginning in late summer.
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