Anna's hummingbird is long with a wingspan of 4.7 in (12 cm) and a weight range of 0.1-0.2 oz (3-6 g). It has an iridescent 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 derived from magenta to a reddish-pink crown and gorget, which can look dull brown or gray without direct sunlight and a dark, slightly forked tail. Females also have iridescent red gorgets, though they are usually smaller and less brilliant than the males'. Anna's is the only North American hummingbird species with a red crown. Females and juvenile males have a dull green crown, a grey throat with or without some red iridescence, a grey chest and belly, and a dark, rounded tail with white tips on the outer feathers.