Borneo Sumatran rhinoceros - Population & Distribution

Possibly extinct throughout most of Borneo

Previous Population and Distribution
At the beginning of the 20th century, the Bornean form of the Asian two-horned rhinoceros, commonly known as the Sumatran rhinoceros, was widespread over the island of Borneo.

Current Population and Distribution
Since those times, the sub-species has suffered a serious decline in distribution and numbers. It is now possibly extinct in Sarawak (Malaysia) and Kalimantan (Indonesia), with perhaps fewer than 25 surviving in Sabah (Malaysia).

Decline: loss of forest and hunting to blame
While prolonged illegal hunting was identified as the major factor leading to the species' decline, by the early 1980s loss of forest habitat through conversion to permanent agriculture was becoming a significant additional threat.

Two populations remain
Only two areas in Sabah (Tabin and the Ulu Segama-Kuamut area) contain rhino populations which have good prospects of long-term survival with adequate protection and management.

The Tabin rhino population was under pressure from forest loss and was afforded protection by the Sabah government in 1984 through the establishment of the 1,225 km² Tabin Wildlife Reserve.

The second population (the Ulu Segama-Kuamut area) is scattered through a vast area of several contiguous forest reserves, but probably centered within an area of less than 4,000 km² in the catchment areas of the upper Segama and upper Kuamut Rivers. This latter area includes the Danum Valley and Maliau Basin Conservation areas in the Sabah Foundation's 100-year logging concession.

Locating the rhinos
Surveys have been conducted at both these sites, and the population is known to range down to the border between Sabah and East Kalimantan where surveys have also been conducted recently. A small population has been identified in the Kulamba Wildlife Reserve, and isolated individuals have been identified up until at least 1998 in several other areas, including Pangi Forest Reserve in the Lower Kinabatangan.

Two other areas known to contain rhinos may possibly prove to be important for the species' conservation: the Segaluid-Lokan/Deramakot/Tangkulap Forest Reserves and the Muruk Miau area adjacent to the border with East Kalimantan. Both, however, have been subject to recent disturbance, either by fragmentation or by commercial logging.