Anna's hummingbird - Anna's Hummingbird is 3.9 to 4.3 inches long. It has a bronze-green back, a pale grey chest and belly, and green flanks. Its bill is long, straight and slender. The adult male has an iridescent crimson-red crown and throat, and a dark, slightly forked tail. Anna's is the only North American hummingbird species with a red crown. Females and juveniles have a green crown, a grey throat with some red markings, a grey chest and belly, and a dark, rounded tail with white tips on the outer feathers.
Costa's hummingbird - The Costa's Hummingbird is very small, a mature adult growing to only 3 to 3½ inches in length. The male Costa's has a mainly green back and flanks, a small black tail and wings, and patches of white below their gorgeted throat and tail. The male Costa's Hummingbird's most distinguishing feature is its vibrant purple cap and throat with the throat feathers flaring out and back behind its head. The female Costa's Hummingbird is not as distinct as the male, having grayish-green above with a white underbelly.