Sumatran Frogmouth

B. poliolophus has a large, arched bill with a light-brown to straw-yellow color. Its face is adorned with bristles, mainly on the forehead and ear coverts. It can be distinguished from other frogmouths by its tail, which is considerably shorter than its wings. It is sexually dimorphic. Males are mostly a dull dark brown with some black speckling and have a collar of white to pale buff feathers. Their underside is a lighter brown with black bars. A pattern of cream-buff spots covers the throat, sometimes extending to the breast and belly. Voice: The vocalization of this species has been described as an undulating whistling accompanied by 5–7 notes ("wa") with a descending pitch. Other calls include repeated and wavering "weeeow" notes, as well as a repeated, high pitched whistle sound ("tsiutsiu"). Some sources describe these vocalizations as having a wheezing or asthmatic quality.