The bumblebee hummingbird (Selasphorus heloisa ) is a species of hummingbird in the family Trochilidae. It is predominantly found in Mexico, but has occurred as a vagrant in the United States (Arizona). At 7 to 7.5 cm (2.8 to 3.0 in), it is the smallest bird known to have occurred in North America north of Mexico. At a weight of 2.2 g (0.078 oz), it is one of the smallest birds known to exist in the world. Its natural habitat is subtropical or tropical moist montane forest. Hummingbirds reach their breeding conditions between April and July, but recordings indicate that they breed primarily during the winter (January–February). Their nests are primarily composed of mosses and lichens, as well as little bits of reddish hair and other hairy seeds such as bromeliad Catopsis seeds.
The bumblebee hummingbird is dispersed through both the Pacific and Atlantic inclines (from southern Chihuahua to southern Oaxaca and from southern Tamaulipas to northern Oaxaca, respectively) and within the focal area of the nation along the Transvolcanic belt to Oaxaca. Both the Mexican Government and the International Union for Conservation of Nature consider bumblebee hummingbirds as a non-threatened species.
