Fork-tailed Woodnymph

Fork-tailed woodnymph males are 9.5 to 12.9 cm (3.7 to 5.1 in) long and weigh 3.6 to 6 g (0.13 to 0.21 oz). Females are 8 to 10.7 cm (3.1 to 4.2 in) long and weigh 3 to 5 g (0.11 to 0.18 oz). Both sexes of all subspecies have a straight, black, medium-length bill. Adult males of the nominate subspecies have mostly dark bronzy green upperparts, dark dusky bronze crown and nape, and a violet band across the upper back. Their throat is glittering green, the belly violet, and the undertail coverts dark steely blue with dull white edges. Their tail is forked and blue-black. Voice: The fork-tailed woodnymph's song varies somewhat geographically. In Ecuador and Peru it is "an incessant series of high-pitched bisyllabic, thin wiry notes 'see-tseet...see-tseet....see-tseet...'". In eastern Venezuela it is describes as a "repeated variable series of 3–7 insect-like pulsing notes 'tsee-see-see....tsee-see-see-see-see...tsee-see-see...'".