The western dwarf hornbill was formally described in 1861 by the English ornithologist John Gould based on a specimen from "Western Africa". Gould coined the binomial nameToccus hartlaubi. The specific epithet was chosen to honour of the German ornithologist Gustav Hartlaub.[2][3] This species was previously assigned to the genusTockus but is now placed in the genus Horizocerus that was introduced in 1899 by the American ornithologist Harry C. Oberholser.
The western dwarf hornbill was formerly considered to be conspecific with the eastern dwarf hornbill (Horizocerus granti) with the English name "black dwarf hornbill".[4]
Description
It is black with a curved beak and a wide white brow above its eye.