This species is listed under CITES Appendix II. The majority of the remaining populations are found in national parks. The species is protected in Sarawak. Further research and surveys are necessary to confirm the persistence and population size of the five remaining sites, which include Maludam National Park, Samunsam Wildlife Sanctuary, Similajau National Park, and Tanjung Datu National Park in Malaysia, and possibly Betung Kerihun National Park in Indonesia. It is present as well in the Lingga area of Sarawak, which has recently been proposed as a protected area.
This species is endemic to the island of Borneo, it occurs in Brunei, Indonesia (Kalimantan) and Malaysia (Sabah and Sarawak). It is found north and northeast of the Kapuas River in northwestern Kalimantan, and through Sarawak (mainly in coastal areas) and Brunei as far as Melalap, Sabah (Groves 2001). The species is found only in remaining habitat within its extent of occurrence; much of its mapped range is historical. There is some confusion about where this species still remains, as many of the records are also historical.
Presbytis chrysomelas chrysomelas occurs in western Brunei, northwestern Kalimantan (northeast of the Kapuas River) and western Sarawak, as far as the IV Division of Sarawak (Groves 2001). Presbytis c. cruciger ranges from the Baram District (in northeastern Sarawak) to Sabah (Groves 2001).
Brunei Darussalam, Indonesia, Malaysia
This species was reported as common in the early 20th century (Baccari 1904, Banks 1931), in areas where today it no longer occurs. Recent records are from five sites: Maludam National Park (Malaysia); Samunsam Wildlife Sanctuary (Malaysia); Similajau National Park (Malaysia); Tanjung Datu National Park (Malaysia); the Lingga area of Sarawak (Malaysia); and possibly Betung Kerihun National Park (Indonesia) (J. Hon pers. comm). Combined population estimates from these sites are very low (approximately 200-500 individuals) (J. Hon and V. Nijman pers. comm.).
Habitat conversion has historically been the main threat to this species, resulting in its disappearance from most of its former range. It has in particular been affected by expanding plantations, especially oil palm, in recent years.
The species is legally protected in Sarawak. Published distributions indicate that the langurs occur in Maludam, Similajau, Tanjung Datu National Parks, and Samunsam Wildlife Sanctuary. Lingaa area of Sarawak, a proposed protected area, and found in Betung Kerihun National Park in Indonesia. Recent surveys by K. Aken and J.W. Duckworth and colleagues reported the Bornean Banded Langur not the Tricolored Langurs occurs in Similajau National Park so the respective distributions of the two subspecies and their taxonomy requires further validation. The Bornean Banded Langur may occur in Lanjak-Entimau Wildlife Sanctuary in Southwestern Sarawak near the border with West Kalimantan.