Bumblebee Hummingbird

The bumblebee hummingbird (Selasphorus heloisa) is a species of hummingbird in tribe Mellisugini of subfamily Trochilinae, the "bee hummingbirds". It is endemic to Mexico, but has occurred as a vagrant in the United States. == Taxonomy and systematics == The International Ornithological Committee (IOC), the North American Classification Committee of the American Ornithological Society, and the Clements taxonomy place the bumblebee hummingbird in genus Selasphorus. BirdLife International's Handbook of the Birds of the World (HBW) places it in genus Atthis. The three worldwide taxonomic systems assign two subspecies, the nominate S. h. heloisa/A. h. heliosa and S. h. margarethae/A. h. margarethae. == Description == The bumblebee hummingbird is 5.9 to 7.5 cm (2.3 to 3.0 in) long and weighs 2 to 2.7 g (0.071 to 0.095 oz); it is one of the smallest hummingbirds. Both sexes of both subspecies have a short, straight, blackish bill and a small white spot behind the eye. Males of the nominate subspecies have metallic bronze green to golden bronze upperparts. Their gorget is metallic magenta purple to bluish purple at its edges, and its longer hindward feathers flare out and back. The flanks are light reddish cinnamon with a bronze wash. The rest of…