The newly discovered orangutan species Pongo tapanuliensis faces population declines driven by habitat fragmentation and hunting. Historically, the Tapanuli orangutan occurred from the uplands of West Toba lake in North Sumatra to the Bukit Tinggi district, West Sumatra, but the current population is limited to the Batang Toru ecosystem, North Sumatra, in three forest blocks separated by a river and roads. Most Tapanuli orangutan populations are in unprotected forest areas, although the southernmost population is in the Lubuk Raya Reserve.
With the support of Tropical Forest Conservation Action–Sumatra, we conducted a preliminary study of the Tapanuli orangutan in the Lubuk Raya Reserve in January 2021. In a 10 km transect survey we did not encounter any orangutan nests, although we observed three nests outside the targeted transect, and a habitat suitability analysis showed that 44% of the area could potentially be used by orangutans. We spoke with 20 people in seven villages and found that they see orangutans in this area, especially those people who live on the border of natural forests and agricultural lands. Most correspondents indicated they do not kill orangutans, although previous studies have found that hunting has caused drastic declines in Sumatran orangutan populations.
Although zero losses have been proposed as a means to save the Tapanuli orangutan (Oryx, 55, 10–11), other approaches are needed. More than half of the species’ population occurs outside protected areas, and we observed extensive agricultural expansion in the area we surveyed, which could trigger conflict with orangutans. However, many local people are aware of the conservation status of this species as the result of an ongoing campaign by the orangutan conservation project of the United States Agency for International Development, which began in 2007. Any strategy to protect the Tapanuli orangutan will need to involve communities and the private sector, with collaborative management, and the establishment of a sanctuary for the species that could be used for ecotourism.