Male black-billed sicklebills court by displaying the purple sheen and ornamental feathers on the head. They live in New Guinea's mountain forests and eat mainly insects.
Adult males have a cinnamon-colored head with iridescent purple crown feathers, and long feathers over the forehead that rise like horns above the eyes. A band of purple-tipped feathers crosses the breast. Females are similar above but lack the iridescence; their underparts are pale brown to off-white with narrow dark bars.
It eats mainly insects and also fruit. A male courts from a perch he uses throughout the year, leaning back, spreading flank and breast ornaments, calling, and turning around. Display timing varies geographically.
An extinction-risk assessment has not been added yet.