About Lampornis calolaemus (Salvin, 1865)
The purple-throated mountaingem, scientifically named Lampornis calolaemus (Salvin, 1865), measures 10 to 11.5 cm (3.9 to 4.5 in) long and weighs 4.5 to 6 g (0.16 to 0.21 oz). Both sexes of all subspecies share a medium-length straight black bill, a white to pale buff stripe behind the eye, and a fairly long tail.
For the nominate subspecies L. c. calolaemus: Adult males have a glittering emerald green to bluish green forehead and crown. The rest of their upperparts are metallic bronze-green, shading to bluish or grass green on the uppertail coverts. Most of the face is dusky bronze green, and the gorget is metallic violet or purple. The breast is bright metallic green, with duller flanks and belly that tend toward bronzy green or gray. The undertail coverts are deep bronzy gray with paler gray margins, and the tail is dull blue-black. Adult females have bright metallic green upperparts, which are somewhat bluish on the uppertail coverts and slightly bronzish elsewhere. The face is mostly blackish, the throat, breast, and belly are tawny yellow, and the undertail coverts are dull white to tawny buff. The central tail feathers and the upper half of the other tail feathers are dull metallic green or bronze green, while the lower half of the outer tail feathers are mostly black with pale gray tips. Immature nominate males closely resemble adult females, but have a dusky chin and throat, and brownish gray undertail coverts with dull white margins.
Males of the subspecies L. c. pectoralis have a deeper purple gorget than the nominate subspecies. The green coloring on their neck and uppertail coverts is significantly darker than that of the nominate, and their belly and undertail coverts are also darker, with a smaller area of metallic green on the breast. Males of subspecies L. c. homogenes are similar to nominate males but have darker gray breasts and bellies. Females of L. c. homogenes have more bluish green upperparts than nominate females, darker bronze-green central tail feathers, and darker, more reddish underparts.
Regarding distribution and habitat: Subspecies L. c. pectoralis occurs from far southwestern Nicaragua to the Cordillera de Guanacaste in northwestern Costa Rica. The nominate L. c. calolaemus is found in the Cordillera Central and the northern part of the Cordillera de Talamanca in northern and central Costa Rica. L. c. homogenes occurs in western Panama from Chiriquí Province to Coclé Province, and probably also in southern Costa Rica. The species inhabits humid montane evergreen forest and cloudforest, and favors steep slopes and broken terrain. In central Costa Rica, it ranges in elevation from 1,200 to 2,500 m (3,900 to 8,200 ft), and it can be found as low as 800 m (2,600 ft) in northern Costa Rica.
