The Black Jacobin (*Florisuga fusca*) is a striking hummingbird endemic to the Atlantic Forest of Brazil, distinguished by its unique, almost total lack of iridescence. Both sexes are cloaked in a deep, sooty black-brown plumage, which sharply contrasts with a brilliant white flash on the lower belly and undertail coverts. Its long, slightly decurved bill is perfectly adapted for feeding on tubular flowers, and it is one of the few hummingbird species where the male and female look nearly identical, lacking the typical sexual dimorphism of vibrant gorgets. A special feature is its aggressive territoriality, often dominating flower patches and feeders, while its rapid, buzzy wingbeats produce a distinct, insect-like hum that gives it an unmistakable presence in the dense forest canopy.

Faits amusants

Despite its name, the Black Jacobin isn't truly black; its plumage is an iridescent deep blue-green that can appear black in low light. It has a bizarre, almost comical feeding habit of frequently hanging upside down from flowers like a tiny bat, a behavior called "nectar robbing" where it pierces the base of a flower to steal nectar without pollinating it. This species is also a known "trapline" forager, memorizing the locations of specific high-yield flowers and visiting them in a precise, repeatable circuit each day.

Habitats et répartition

The Black Jacobin is primarily found in the Atlantic Forest biome of eastern South America, ranging from northeastern Brazil south through coastal regions to extreme northeastern Argentina and eastern Paraguay. Its habitat centers on humid lowland and montane forests, including both primary and secondary growth, as well as forest edges, clearings, and adjacent plantations or gardens with flowering trees. It is most abundant in the dense, moist understory and canopy of these forests, though it may venture into more open areas near nectar sources. The species is generally resident within its range, but local movements may occur in response to flowering seasons.

Comportements & Reproduction

The Black Jacobin is generally solitary, with males defending feeding territories rich in nectar-producing flowers, especially around bromeliads and trees. Mating is promiscuous; males perform aerial displays, diving and singing to attract females, but provide no parental care. Females build small cup-shaped nests from plant fibers and spider silk, often attached to large leaves or branches. A typical clutch is two eggs, incubated solely by the female for about 15–16 days. A unique reproductive strategy involves the female’s ability to delay breeding until the peak of local flower blooming, ensuring abundant food for her chicks. The chicks fledge after approximately 20–22 days, becoming independent shortly after.

Alimentation

The Black Jacobin (Florisuga fusca) is a specialized nectarivore, feeding primarily on the high-energy nectar of a variety of flowering plants, particularly those with tubular blossoms such as species of *Heliconia*, *Erythrina*, and *Malvaviscus*, which it accesses with its long, extendable tongue. Interestingly, despite being a hummingbird, it will occasionally supplement its diet with small insects and spiders, gleaning them from foliage or catching them in mid-air to obtain essential proteins and amino acids. A unique aspect of its feeding behavior is its tendency to aggressively defend rich nectar sources, often dominating feeding territories over smaller hummingbird species, and it is known to perform trap-lining, visiting a regular circuit of specific flowers in a predictable pattern to maximize energy efficiency.

Couleurs

The Black Jacobin is predominantly dark, with males appearing entirely black with a faint greenish or bluish iridescent sheen on the back and crown, while females are slightly duller and browner. Its most distinctive marking is a broad, white crescent-shaped patch across the lower throat and upper chest, contrasting sharply with the black body. The tail is dark and slightly forked, and the species lacks any specific camouflage adaptations, instead relying on its dark coloration to blend into shadowed forest understories.