April, 2026

Building a Biodiversity Corridor across concessions to secure the future of West Kalimantan’s orangutans

Landscape-wide conservation in the Mendawak landscape is constrained by fragmented land use and the dominance of industrial concessions – particularly in the east, key orangutan habitat.

Oil palm and pulp and paper concessions operate under different regulations and certification systems, resulting in inconsistent forest management and uneven levels of degradation. Forests are divided, and conservation efforts remain unaligned.

For wide-ranging species like the Critically Endangered Bornean orangutan (Pongo pygmaeus), fragmentation is a critical threat, as their extensive home ranges inevitably span multiple concession boundaries. 

Landscape-wide conservation in the Mendawak landscape is constrained by fragmented land use and the dominance of industrial concessions – particularly in the east, key orangutan habitat.

Oil palm and pulp and paper concessions operate under different regulations and certification systems, resulting in inconsistent forest management and uneven levels of degradation. Forests are divided, and conservation efforts remain unaligned.

For wide-ranging species like the Critically Endangered Bornean orangutan (Pongo pygmaeus), fragmentation is a critical threat, as their extensive home ranges inevitably span multiple concession boundaries. 

Multi-Stakeholder Solutions 

Sangga Bumi Lestari has identified a   99,875-hectare forest corridor encompassing Mendawak’s most important orangutan habitat- likely one of the largest populations outside protected areas.

The corridor spans two oil palm concessions, four pulp and paper concessions, and nine village forests. While rivers divide it into three blocks, securing and reconnecting this landscape would safeguard the population and demonstrate a scalable model for cross-concession conservation. 

Approach 

Working with the the West Kalimantan Natural Resources Conservation Agency (Balai Konservasi Sumber Daya Alam) and Environment and Forestry Agency (Dinas Lingkungan Hidup dan Kehutanan), Sangga Bumi Lestari convenes the Corridor Working Group. Through this Working Group, we bring concession holders and communities together to align conservation and development strategies across the corridor:

Identifying and protecting priority habitats within concessions 
Connecting habitats inside and outside concessions through co-management agreements.
Advancing pro-forest, wildlife-friendly development practices 
Supporting village-led conservation and sustainable livelihoods 
Aligning corporate and community efforts, including financing mechanisms 
Long-Term Goal 

To secure the 99,875-hectare Mendawak Biodiversity Corridor as a connected, multi-use expanse that sustains one of the largest remaining orangutan populations outside protected areas, while establishing a replicable model for cross-concession conservation in Indonesia.

Mendawak Biodiversity Corridor

Explore the corridor through an interactive dashboard that brings together data from protected forests, village lands, and industrial concessions—revealing how multiple stakeholders shape a single connected landscape.

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Mendawak Biodiversity Corridor Stakeholders 

The Mendawak Biodiversity Corridor is shaped by a diverse group of stakeholders whose lands, concessions, and management decisions collectively determine the future of this fragmented landscape. Stretching across protected forests, village lands, oil palm estates, and pulp and paper concessions, the corridor brings together multiple land-use types into a single, interconnected system.

Understanding who manages each part of the corridor — and where these areas are located — is essential for aligning conservation action, sustaining orangutan populations, and demonstrating how collaborative, cross‑concession conservation can work in practice.

1. Protected and Village Forests

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Sungai Paduan Protected Forest (6,788 hectares)

A core conservation area at the western edge of the corridor, designated under Indonesia’s social forestry programme (Hutan Desa).

Component village forests:
Nipah Kuning – 2,051 hectares (1,807 hectares forested)
Padu Banjar – 2,883 hectares (985 hectares forested)
Pemangkat – 1,245 hectares (1,071 hectares forested)
Pulau Kumbang – 609 hectares (486 hectares forested)
Conservation significance:
Supported by Yayasan Palung, which conducts annual orangutan nest surveys and community conservation programmes
Estimated population: approximately 63 orangutans
Density: approximately 0.9 individuals per square kilometre

2. Oil Palm Concessions

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PT Jalin Vaneo (15,949 hectares)

An oil palm concession forming key corridor links in both the southwest and northeast of Mendawak.

Previously included 2,881 hectares of designated conservation forest, divided into two blocks:
1,505 hectares (southwest) linking Sungai Paduan Protected Forest with peat swamps in PT Mayawana Persada
1,376 hectares (northeast) linking forests between PT Mayawana Persada and PT Karya Makmur Langgeng
In 2025, these areas were removed from the company’s Right to Cultivate (Hak Guna Usaha) permit
PT Jalin Vaneo states it remains committed to protecting these forests
Orangutan presence has been confirmed, but no publicly available population estimates exist
PT Karya Makmur Langgeng (Bumitama Agri Ltd) — 16,786 hectares
965 hectares of forest form the southernmost section of the corridor
Connected to a forest patch within PT Mayawana Persada, separated only by a narrow buffer
It is currently unclear whether orangutans utilise this forest

3. Pulp and Paper Concessions (Core Corridor Blocks)

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PT Mayawana Persada (139,429 hectares)

The ecological heart of the corridor.

Since 2016, approximately 40,000 hectares of forest have been cleared, around half in 2023 alone
Land development was halted in March 2024 following a government order
A remaining 35,624 hectares central forest strip now represents the most important orangutan habitat within the corridor
Orangutan data (2025 surveys):
Density: approximately 0.65 individuals per square kilometre
Estimated population: 124–190 orangutans
PT Asia Tani Persada (20,893 hectares)
5,459 hectares of forest forms part of the corridor
2017 Orangutan Population and Habitat Viability Assessment (PHVA): estimated approximately 150 orangutans
2021 survey: density of 0.51 individuals per square kilometre, estimating 27 orangutans
PT Daya Tani Kalbar (45,19 hectares)
10,069 hectares of forest included within the corridor
2021 survey results:
Density: 0.34 individuals per square kilometre
Estimated population: approximately 25 orangutans
PT Mayangkara Tanaman Industri (Sumitomo Forestry) — 71,366 hectares
31,259 hectares of forest form a major eastern section of the corridor
No publicly available orangutan nest surveys have been published
Camera trap surveys have documented orangutan presence
In a 2020 media interview, the company stated there were approximately 70 orangutans, with claims that populations are increasing — figures yet to be independently verified

4. Unprotected Forests and Village Lands

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Mata Pancing Production Forest (5,623 hectares)

An unprotected forest strip outside concessions, locally known as Mata Pancing.

Village areas included:
Durian Sebatang – 525 hectares
Kampar Sebomban – 3,502 hectares
Labai Hilir – 1,057 hectares
Sekucing Kualan – 538 hectares
Orangutan survey results:
2015: density of 2.55 individuals per square kilometre
2021: density of 1.11 individuals per square kilometre, estimating approximately 49 orangutans
Bagan Asam Village (53,770 hectares)
13,247 hectares form the northern section of the corridor
Orangutans have been observed, but no nest surveys have yet been conducted
Camera traps installed by Sangga Bumi Lestari, with analysis expected by May 2026
Potential Corridor Expansion Areas

Two villages north of Bagan Asam offer opportunities to extend the corridor further north:

Kampung Baru – approximately 8,954 hectares of forest
Sansat – approximately 7,548 hectares of forest

No public information is currently available on orangutan populations in these areas.

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