The sole member of the genus Heliactin, the slender-bodied Horned Sungem is a remarkable hummingbird, well worthy of such an evocative name. While females are primarily green above with clean white underparts, and long central rectrices, males are dazzlingly adorned with a dark blue crown, black throat and upper breast, and tiny red, blue and gold ‘horns’, as well as also possessing elongated central tail feathers. In terms of its distribution, the species is found extremely locally north of the Amazon, in southern Suriname, as well as in the savannas of Amapá, in far northeast Brazil, but then much more continuously (albeit increasingly less so due to habitat destruction) across the Brazilian interior to eastern Bolivia. It favors native cerrado vegetation and is found to at least 1000 m in elevation. Like many hummingbirds, the Horned Sungem appears to perform local movements, at least in parts of its range, in response to flowering events, although elsewhere the species’ populations are seemingly more sedentary.