Sungai Palin watershed
Asia > Indonesia > Sungai Palin watershed
Summary
- Northwest Bornean orangutans (Pongo pygmaeus pygmaeus) are present in the Sungai Palin watershed.
- The population size is unknown.
- The orangutan population trend is decreasing.
- The size of the site is unknown.
- Key threats to orangutans are road building, forest degradation and logging.
- Conservation activities have focused on community-based forest management.
Site characteristics
The protected areas of Danau Sentarum Wildlife Reserve and Betung Kerihun National Park, in the upper Kapuas watershed, were home to relatively large populations of the Bornean orangutan until the 1990s; from 1973 to 1997 almost 30% of habitat disappeared in and around Danau Sentarum Wildlife Reserve (Yanuar et al. 2020). Orangutans are still encountered in the unprotected areas of Sungai Palin and Nanga Awen, which lie between Danau Sentarum Wildlife Reserve and Betung Kerihun National Park (Yanuar et al. 2020).
Table 1. Basic site information for Sungai Palin watershed
| Area | |
| Coordinates | 0.946904 N, 112.661879 E |
| Designation | Unclassified |
| Habitat types | Peat swamp forest |
IUCN habitat categories Site designations
Ape status
A survey conducted in 1991 in Nanga Awen, c. 20 km away from Sungai Palin in the same landscape, recorded orangutan nests along three transects (1.0–1.2 km long, with a total length of 4.3 km). The estimated density was 2.62 (95% CI:1.02-6.72). In comparison, the density for Sungai Palin in 2017 was slightly lower (1.29 individuals/sq.km) (Yanuar et al. 2020).
Table 2. Ape population estimates in Sungai Palin watershed
| Species | Year | Abundance estimate (95% CI) | Density estimate [ind./ km²] (95% CI) | Encounter rate (nests/km) | Area | Method | Source | Comments | A.P.E.S. database ID |
|---|---|---|---|---|---|---|---|---|---|
| Pongo pygmaeus pygmaeus | 2017 | 1.29 (0.51-3.25) | Sungai Palin watershed | Line transects (Distance) | Yanuar et al. 2020 | Survey effort:4.5 km. 76 nests were observed. |
Threats
Orangutans at the site have been mainly threatened by logging, forest degradation and lack of connectivity between forest remnants. A major threat is also the building of new roads (Yanuar et al. 2020).
Table 3. Threats to apes in Sungai Palin watershed
| Category | Specific threats | Threat level | Quantified severity | Description | Year of threat |
|---|---|---|---|---|---|
| 1. Residential & commercial development | Unknown | ||||
| 2. Agriculture & aquaculture | Unknown | ||||
| 3. Energy production & mining | Unknown | ||||
| 4. Transportation & service corridors | 4.1 Roads & railroads | High | Construction of new roads in the area (Yanuar et al. 2020). | Ongoing (2020) | |
| 5. Biological resource use | 5.3 Logging & wood harvesting | Present, but threat severity unknown | Habitat degradation due to logging; since 2003 a logging concession in the area of the Nanga Lauk village has been inactive (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 |
Conservation activities
Although protection of the site's forests are under the jurisdiction of the district forestry agency, they are managed by the local community as the Nanga Lauk Village Forest. The community is allowed to only extract non-timber forest products. Including the local community in the management of the forest has helped to protect the orangutans, as evidenced by the fact that logging ceased in 2003 (Yanuar et al. 2020).
Table 4. Conservation activities in Sungai Palin watershed
| 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 Sungai Palin watershed
| Challenge | Source |
|---|---|
| Not reported |
Research activities
Documented behaviours
Table 6. Ape behaviors reported for Sungai Palin watershed
| Behavior | Source |
|---|---|
| Not reported |
External links
Relevant datasets
References
Yanuar, A., Fehse, J., Chivers, D., & Sugardjito, J. (2020). New estimates of orangutan density in Sungai Palin watershed, Kapuas Hulu, West Kalimantan, Indonesia. Oryx, 54(6), 763-766.
Page completed by: A.P.E.S. Wiki team Date: 25/10/2021