Long-tailed woodnymph

The long-tailed woodnymph (Thalurania watertonii) is a species of hummingbird in the family Trochilidae. It is found in humid forest in northeastern Brazil, where it is known from the states of Pernambuco, Alagoas, Sergipe and the northernmost Bahia. It is usually thought to be widespread, but seen at low density in its increasingly fragmented range. Its population is estimated to be around 1,000–2,500 individuals, currently in decline due to deforestation and habitat loss.

The long-tailed woodnymph is sexually dimorphic. The males are heavier, with significantly larger wings and tails, whereas the females have longer bills. Males are approximately 11.8–13 centimetres (4.6–5.1 in) long, including a tail of 6 centimetres (2.4 in) cm; while females measure roughly 10–11 centimetres (3.9–4.3 in) in length, with a tail of 3.6 centimetres (1.4 in). Individuals have a weight of 3.7–5.2 g.

Males have a conspicuous iridescent plumage in blue, green and purple. The crown and neck are bronze-green, back is iridescent violet-blue, shining grass-green undersides and violet-blue flanks; Its long, deeply-forked tail is blue. Female plumage is much more faint, allowing them to stay unnoticeable as they build nests and care for their young, and a shorter, slightly forked white-tipped tail with a blue subterminal band and a pair of blue-green rectrices. Juveniles are similar to adult females.