Celebrating Biodiversity Day, IPB University Supports Sentarum langur (Presbytis cruciger) as a Protected Animal

Commemorating International Biodiversity Day on May 22 this year, IPB University expressed its support for efforts to make the Sentarum langur one of the animals included in the management and conservation mandate in Danau Sentarum National Park.

This support is carried out through research collaboration with the Betung Kerihun and Danau Sentarum National Park Center (BBTNBKDS), as well as the West Kalimantan Provincial Natural Resources and Ecosystem Conservation Center.

IPB University researcher, Dr Nyoto Santoso, said that the sentarum langur, which is an endemic primate of Kalimantan, has not been included in the management mandate of BBTNBKDS. Therefore, this primate bioecology research collaboration is important to support biodiversity conservation in the area.

“The existence of this bioecological research collaboration is very useful in determining and determining the Sentarum langur to be an additional mandate for priority species management,” said Dr Nyoto who is also the Head of the Department of Forest Resource Conservation and Ecotourism, Faculty of Forestry and Environment (Fahutan) IPB University.

The research was conducted from April 2021 to September 2023 in four resort areas of Danau Sentarum National Park, namely Sepandan Resort, Lupak Mawang, Semangit, and Majang Island. This study aims to assess the bioecology and conservation of sentarum langurs in their natural habitat.

Initially, this primate belonging to the langur group (Presbytis) was referred to by the local names kelasi, cenekah, and julung merah, taxonomically a variant of the species Presbytis chrysomelas ssp. cruciger. However, the results of Dr Nyoto Santoso and team’s analysis of DNA (3 samples D1A, D2A and D3A), showed sequencing results with the NCBI BLAST program based on the mitochondrial D-loop region is Presbytis chrysomelas; identity 95.42%, query cover 100%, GenBank reference: JF295112.1.

Therefore, the five percent difference in DNA characteristics between the Sentarum langur and Presbytis chrysomelas is believed by Dr Nyoto Santoso to be a different species and the proposed species name for the Sentarum langur is Presbytis cruciger. This is also reinforced by the hair color characteristics of males, females and infants, which are different from the hair color of other langur groups.

The Sentarum langur (Presbytis cruciger) has a narrow range and is only found in the northern part of Borneo, covering Indonesia, Malaysia and Brunei Darussalam.

“The results of our research show that about 65 percent of the Sentarum langur population is within the national park area, while the rest is in forest areas around the BBTNBKDS area,” he explained.

Findings from focus group discussions (FGDs) conducted by the team also showed the existence of langur groups outside the park area, but still within the administrative area of Kapuas Hulu Regency, West Kalimantan.

Dr Nyoto added that more than 35 groups of Sentarum langurs were identified during the research. He estimates that there are still other groups that have not been detected due to limited access to certain areas and the vast forested areas in Kapuas Hulu District. (IAAA/RWA)