Blue-throated Starfrontlet

The blue-throated starfrontlet is about 13 cm (5.1 in) long. Males weigh between 7.1 and 7.6 g (0.25 and 0.27 oz) and females 6 to 6.5 g (0.21 to 0.23 oz). Both sexes have a long, straight, black bill and white spot behind the eye. Both have bronzy black forked tails but the female's is less indented than the male's. In poor light the species may appear all dark. However, males of the nominate subspecies have a black head with a dark green forehead. Their upperparts are dark glossed with emerald green while the lower back and rump are dark blue with some violet. They have a dark iridescent violet throat, a dark gray breast with and emerald green sheen, and a rosy belly, vent area, and undertail coverts. Nominate females have a gray-green head including the forehead, and upperparts that are golden green transitioning to the blue-violet rump; all of these colors are duller than those of the male. The throat and breast are rufous, with green spots on the latter. The belly is rosy and the undertail coverts a paler rose. Males of subspecies C. h. tamai are very similar to those of the nominate but duller. The male's belly and undertail coverts are more bluish than rosy. The females are essentially the same as the nominate.

The nominate subspecies of blue-throated starfrontlet is found in Colombia's northern and eastern Andes from the Serranía del Perijá, which straddles the border between northern Colombia and northwestern Venezuela, south and west to the Metropolitan Area of Bogotá. C. h. tamai is found in the Tamá Massif in the western Venezuelan state of Táchira. The species inhabits the interior and edges of cloudforest and elfin forest, shrubby slopes, and sometimes bushy landscapes at the lower margin of páramo. It also occurs in flowering gardens. In elevation it ranges between 1,900 and 3,300 m (6,200 and 10,800 ft).

The blue-throated starfrontlet feeds on nectar by trap-lining, visiting a circuit of a wide variety of flowering plants. It tends to forage within a few meters of the ground. In addition to feeding on nectar it captures small arthropods by gleaning from foliage and sometimes by hawking.