This endangered hummingbird is found only in the Sierra Miahuatlán mountains of Oaxaca, Mexico (this restricted distribution gives rise to an alternate English name, Oaxaca Hummingbird). Blue-capped Hummingbird inhabits cloud forests, semi-deciduous, pine-evergreen, and gallery forests in this region, but these forests are being cleared for agriculture, consequently causing the decline of this hummingbird's population. These hummingbirds forage at a variety of levels in the forest and fan out their tails when eating. They are also usually subordinate to other hummingbirds. The bluish purple forecrown of the male helps distinguish it from the male White-tailed Hummingbird (Eupherusa poliocera), but females and juveniles of these two species are nearly identical.