Annas is the most common hummingbird in southern California and one of the three species that are permanent residents of the United States and Canada. They are also the largest hummingbird seen on the west coast.
The adult male Anna has a metallic green back, a dark-rose crown, and throat with a grayish breast. They also weigh, on average, 4.31 grams.
The female version of these hummingbirds are much the same, except in the throat area. Instead of the dark-rose gorget (throat) like the males, the females have a white throat with red spots on top. The females also have white tips located on their outer tail feathers. Female Anna's weigh about 4.07 grams on average.
Juvenile Annas of both sexes look like the adult female without the markings upon the throat area.
Unlike most other hummingbirds, Annas has a song.