The Black-billed Treehunter lives in humid Andean montane and secondary forests. It searches for arthropods in dense undergrowth.
Adult nominate birds have a blackish-brown face and head with pale buff streaks and a black bill. Juveniles have less distinct streaking on the back and throat.
It forages, usually alone, in dense undergrowth and eats mostly arthropods.
An extinction-risk assessment has not been added yet.