Brilliantly-colored hummingbird with dark tail and mostly red bill. Fairly common in thorn forest within its limited range. Endemic to Mexico, mainly along the Pacific coast from Guerrero to Oaxaca. Can appear all dark at a distance, but in the right light, male is mostly glistening cobalt blue. Females are less colorful than males, dusky grayish below with prominent pale stripe behind the eye. Similar to Dusky Hummingbird, which occurs on the other side of the Sierra Madre del Sur.