A small hornbill of lowland forest whose haunting duets are not easily forgotten. Its blood-red bill can be surprisingly hard to make out when backlit in the subcanopy, as can the dusky red-brown plumage on its back, chest, and wings. From below, shows a white belly and a darker chest and head. Often found by its easily imitated call that is given solo or as a duet: a series of 10-15 wavering whistles that quaver and descend in pitch over the course of 5-6 seconds.