Asia > Indonesia > Sari Bumi Kusama and Suka Jaya Makmur logging concessions

Summary

Bornean white-bearded gibbons (Hylobates albibarbis) and Bornean orangutans (Pongo pygmaeus wurmbii) are present in Sari Bumi Kusama and Suka Jaya Makmur logging concessions.
It has been estimated that 10,812 gibbons occur in Suka Jaya Makmur and 7,191 gibbons occur in Sari Bumi Kusuma.
The gibbon population trend is unknown.
The site has a total size of 3,189 km².
Key threats to gibbons are
Conservation activities are not documented.

Site characteristics

The site is made up of two logging concession areas in Kalimantan, in the Arabela-Schwaner landscape, which is one of WWF's priority landscape regions on the island of Borneo (Yanuar et al. 2020). The Sari Bumi Kusuma (SBK) and Suka Jaya Makmur (SJM) concessions are held by the Alas Kusuma Group. The SBK logging concession, located in Central Kalimantan is approximately 1,476 sq. km and has been in operation since 1978 (Yanuar et al. 2020). SJM, the second logging concession that has been operating since 1979, is located in West Kalimantan and has an area of about 1,713.4 sq. km (Yanuar et al. 2020). SBK is located within the area known as the Heart of Borneo (i.e., the main part of the island with intact forests), while SJM is outside. According to biodiversity assessments conducted by organisations such as The Forest Foundation, Fauna and Flora International, The Nature Conservancy and WWF, two ape species, the Bornean orangutan Pongo pygmaeus wurmbii, and the white-bearded gibbon Hylobates albibarbis, are found in SBK and SJM. However, there is a lack of up-to-date information regarding population status and distribution, especially within logging concessions (Yanuar et al. 2020). SBK is characterised by lowland dipterocarp forest with an elevation range from 100 to 300 m above sea level and hilly lowland forest. SBK is also contiguous with upland forest with an elevation above 700 m a.s.l. Within the concession, several small conservation areas are protected by the logging company (Yanuar et al. 2020).

Table 1. Basic site information for Sari Bumi Kusama and Suka Jaya Makmur logging concessions

Area	3,189 km²
Coordinates
Designation	Forestry concession
Habitat types	Subtropical/tropical moist lowland forest, Subtropical/Tropical Heavily Degraded Former Forest

IUCN habitat categories Site designations

Ape status

Surveys were conducted in 2018 as part of the WWF's Indonesia programme. Considering an average group size of 3.3 individuals (an adult pair and 1-2 offspring in each group), the population in the SBK concession is estimated at 7,191 individuals, while in the SJM concession area the population estimate is about 10,812 individuals (Yanuar et al. 2020).

Table 2. Ape population estimates in Sari Bumi Kusama and Suka Jaya Makmur logging concessions

Species	Year	Total number indiv. (95% CI)	Total number groups (95% CI)	Density [groups/km²] (95% CI)	Area	Method	Source	Comments	A.P.E.S. database ID
Hylobates albibarbis	2018	10,812		2.29	Suka Jaya Makmur	Fixed-point triangulation	Yanuar et al. 2020
Hylobates albibarbis	2018	7,191		1.86	Sari Bumi Kusuma	Fixed-point triangulation	Yanuar et al. 2020

Threats

About 10 villages are found within and surrounding SBK, and one large enclave within the northern part of SJM. Most villagers are farmers and hunt for bushmeat (Yanuar et al. 2020).

Table 3. Threats to apes in Sari Bumi Kusama and Suka Jaya Makmur logging concessions

Category	Specific threats	Threat level	Description	Year of threat
1. Residential & commercial development	1.1 Housing & urban areas	Present, but threat severity unknown	There are about 10 villages within and surrounding SBK and one large enclave within the northern part of SJM (Yanuar et al. 2020).	Ongoing (2020)
2. Agriculture & aquaculture		Unknown
3. Energy production & mining		Unknown
4. Transportation & service corridors		Unknown
5. Biological resource use	5.1 Hunting & collecting terrestrial animals	Present, but threat severity unknown	Most local people are farmers and hunt wildlife for food (Yanuar et al. 2020).	Ongoing (2020)
6. Human intrusion & disturbance		Unknown
7. Natural system modifications		Unknown
8. Invasive & other problematic species, genes, diseases		Unknown
9. Pollution		Unknown
10. Geological Events		Absent
11. Climate change & severe weather		Unknown
12. Other options		Absent

IUCN Threats list

Conservation activities

Table 4. Conservation activities in Sari Bumi Kusama and Suka Jaya Makmur logging concessions

Category	Specific activity	Description	Year of activity
1. Residential & commercial development	Not reported
2. Agriculture & aquaculture	Not reported
3. Energy production & mining	Not reported
4. Transportation & service corridors	Not reported
5. Biological resource use	Not reported
6. Human intrusion & disturbance	Not reported
7. Natural system modifications	Not reported
8. Invasive & other problematic species, genes, diseases	Not reported
9. Pollution	Not reported
10. Education & Awareness	Not reported
11. Habitat Protection	Not reported
12. Species Management	Not reported
13. Livelihood; Economic & Other Incentives	Not reported

Conservation activities list (Junker et al. 2017)

Challenges

Table 5. Challenges reported for Sari Bumi Kusama and Suka Jaya Makmur logging concessions

Challenge	Source
Not reported

Research activities

Documented behaviours

Table 6. Ape behaviors reported for Sari Bumi Kusama and Suka Jaya Makmur logging concessions

Behavior	Source
Not reported

External links

Relevant datasets

A.P.E.S Portal

References

Yanuar, A., Chivers, D., Hilman, I., Saleh, C., Putra, I. B. W., Purnomo, S., & Wasman, K. (2020). Population Survey of Bornean White-Bearded Gibbon, Hylobates albibarbis, in Two Selective Logging Concessions in Central Kalimantan and West Kalimantan. Folia Primatologica, 91(2), 108-121. https://doi.org/10.1159/000502092

Page completed by: A.P.E.S. Wiki team Date: 28/01/2022

Sari Bumi Kusama and Suka Jaya Makmur logging concessions

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