This leaf-eating monkey lives on Sumatra. In a 2024 study at Batang Toru, groups were observed in two secondary-forest sites beside mining, staff housing and gardens, where they ate native plants.
The back and upper tail are dark gray-brown to nearly black; the throat, underside and underside of the tail are white. Its face is bluish, and a gray-brown crest crowns the head.
From September 2023 to January 2024, groups were observed at two secondary-forest sites in Batang Toru. They fed on 32 native plant species, including flowers, fruits, young fruits, leaves and young leaves.
An extinction-risk assessment has not been added yet.