The Fork-tailed Woodnymph (*Thalurania furcata*) is a dazzling hummingbird found in the humid forests of South America, renowned for its iridescent plumage and distinctively shaped tail. Males are particularly striking, with a shimmering emerald-green body, a deep violet-blue throat and belly, and a deeply forked, steely blue-black tail that gives the species its name. Females, while more subdued, are still beautiful with a green back, pale gray underparts, and white-tipped tail corners. A special feature of this species is its unique flight style: it often hovers with its tail held at an angle, flashing its metallic colors, and it performs a dramatic aerial courtship dive where the male produces a loud, buzzing sound with its tail feathers. Highly territorial, the Fork-tailed Woodnymph aggressively defends nectar-rich flowers, making it a vibrant and energetic presence in its rainforest home.

Faits amusants

Males perform a spectacular, high-speed J-shaped dive during courtship, pulling up at the last second with a sharp, metallic *ziiing* sound produced by their tail feathers vibrating like a tuning fork. Despite their delicate appearance, they are fiercely territorial and will aggressively chase away much larger birds, including hawks, from their favorite nectar patches. They possess a unique adaptation where their tongue tips are fringed and split, allowing them to lap up nectar at a rate of up to 13 licks per second, acting like tiny capillary-action pumps.

Habitats et répartition

The Fork-tailed Woodnymph inhabits a variety of humid and semi-humid forested environments, including the edges and interiors of lowland rainforests, secondary growth, gallery forests, and plantations. It is also commonly found in clearings, gardens, and along forest borders, often near water sources. Its geographical range spans a vast area across northern and central South America, from eastern Colombia, Venezuela, and the Guianas, south through much of Brazil, and westward into eastern Ecuador, Peru, and northern Bolivia. The species is generally resident across its range, occurring from sea level up to elevations of around 1,500 meters in the Andes foothills.

Comportements & Reproduction

Males are solitary and highly territorial, defending feeding areas where they perform elaborate aerial displays, including pendulum-like swings and steep dives, to attract passing females. Courtship involves the male producing a sharp, metallic trill with his tail feathers during these dives. Females are solely responsible for nest construction, incubation, and chick rearing, building a small cup-shaped nest of plant down and spider webs on a horizontal branch. There is no pair bond; after mating, the male departs to seek other females. A unique strategy involves the female delaying egg-laying until a rich nectar source is abundant, ensuring sufficient energy for the demanding 15-16 day incubation and subsequent feeding of the two-egg clutch.

Alimentation

The Fork-tailed Woodnymph is primarily a nectarivore, feeding on the sugary nectar from a wide variety of flowering plants, especially those with tubular blossoms like those of the *Heliconia*, *Costus*, and *Palicourea* genera, which it accesses by hovering and inserting its long, specialized bill. Interestingly, while nectar forms the bulk of its energy intake, this hummingbird is also an opportunistic insectivore, actively hunting small spiders and insects like flies and gnats to obtain essential proteins, fats, and minerals that nectar lacks. This dual diet makes it a crucial pollinator for many tropical plants while also controlling small arthropod populations.

Couleurs

The male Fork-tailed Woodnymph has a brilliant iridescent green head, throat, and chest, with a deep violet-blue belly and a long, deeply forked black tail. The female is duller, with a green upper body, grayish-white underparts, and a shorter, slightly forked tail with white tips on the outer feathers. Key unique markings include the male’s striking blue belly and the species’ namesake tail fork, with no specific camouflage adaptations beyond the female’s muted countershading.