Difference between revisions of "Leuser Ecosystem"

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[[Asia]] > [[Indonesia]] > [[Leuser Ecosystem]]
 
[[Asia]] > [[Indonesia]] > [[Leuser Ecosystem]]
 +
 +
'''[https://wiki-iucnapesportal-org.translate.goog/index.php/The_A.P.E.S._Wiki?_x_tr_sl=auto&_x_tr_tl=fr&_x_tr_hl=en&_x_tr_pto=wapp Français]''' |
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 +
'''[https://wiki-iucnapesportal-org.translate.goog/index.php/The_A.P.E.S._Wiki?_x_tr_sl=auto&_x_tr_tl=es&_x_tr_hl=en&_x_tr_pto=wapp Español]''' |
 +
'''[https://wiki-iucnapesportal-org.translate.goog/index.php/The_A.P.E.S._Wiki?_x_tr_sl=auto&_x_tr_tl=id&_x_tr_hl=en&_x_tr_pto=wapp Bahasa Indonesia]''' |
 +
'''[https://wiki-iucnapesportal-org.translate.goog/index.php/The_A.P.E.S._Wiki?_x_tr_sl=auto&_x_tr_tl=ms&_x_tr_hl=en&_x_tr_pto=wapp Melayu]'''
  
 
= Summary = <!-- An overview of the site, with one sentence for each section. May include a site map -->
 
= Summary = <!-- An overview of the site, with one sentence for each section. May include a site map -->
−
[[File: Forest_view_in_Leuser_Perry_van_Duijnhoven.jpg | 400px | thumb| right | Forest view in Leuser Ecosystem © Perry van Duijnhoven]]  
+
[[File: Forest_view_in_Leuser_Perry_van_Duijnhoven.jpg | 300px | thumb| right | Forest view in Leuser Ecosystem © Perry van Duijnhoven]]  
 
* Sumatran orangutans (''Pongo abelii'') are present in the Leuser Ecosystem.
 
* Sumatran orangutans (''Pongo abelii'') are present in the Leuser Ecosystem.
 
* It has been estimated that 13,846 (CI: 11,561-16,805) individuals occur in the site.
 
* It has been estimated that 13,846 (CI: 11,561-16,805) individuals occur in the site.
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* The site has a total size of 2.6 million ha.
 
* The site has a total size of 2.6 million ha.
 
* Key threats to orangutans are deforestation, construction of roads and planned construction of hydroelectric power plants, poaching, and capturing of young orangutans for the illegal pet trade.
 
* Key threats to orangutans are deforestation, construction of roads and planned construction of hydroelectric power plants, poaching, and capturing of young orangutans for the illegal pet trade.
−
* Several NGOs are involved in the implementation of conservation interventions; for example, the Human-Orangutan Conflict Response Unit rescues and relocate orangutans trapped by humans.
+
* Several NGOs are involved in the implementation of conservation interventions; for example, the Human-Orangutan Conflict Response Unit rescues and relocates orangutans trapped by humans.
  
 
= Site characteristics = <!-- A paragraph summary of physical and geographic aspects of the site, and a table of key information -->
 
= Site characteristics = <!-- A paragraph summary of physical and geographic aspects of the site, and a table of key information -->
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'''Table 1. Basic site information for Leuser Ecosystem'''
 
'''Table 1. Basic site information for Leuser Ecosystem'''
 
{| border="1" cellpadding="5" cellspacing="0" class="basic-information"
 
{| border="1" cellpadding="5" cellspacing="0" class="basic-information"
−
| Area <!-- Please include units: km2/ha e.g 200ha -->
+
| Species
−
|2.6 million ha
+
|''Pongo abelii''
 +
|-
 +
| Area
 +
|26000 km²
 
|-
 
|-
 
|Coordinates
 
|Coordinates
−
|3.630896 N, 97.378969 E
+
|3.630896, 97.378969
 +
|-
 +
|Type of site
 +
|Conservation area (National Strategic Area)
 
|-
 
|-
−
|Designation
+
|Governance type
−
|National Strategic Area
+
|Governance by government
 
|-
 
|-
−
|Habitat types <!-- List IUCN Habitat Classification 3.0 categories present (without number), see link below -->
+
|Habitat type
 
|Subtropical/tropical dry forest, plantations, subtropical/tropical heavily degraded former forest
 
|Subtropical/tropical dry forest, plantations, subtropical/tropical heavily degraded former forest
 
|}
 
|}
−
[https://www.iucnredlist.org/resources/habitat-classification-scheme IUCN habitat categories] [[Site designations]]
+
[[Types of sites]] ⋅ [[Governance types]] ⋅ [[Habitat types]]
 
<div><ul>
 
<div><ul>
 
<li style="display: inline-block; vertical-align: top;"> [[File: Sumatran orangutan in Leuser Perry van Duijnhoven.JPG | 300px | thumb| right |Sumatran orangutan © Perry van Duijnhoven]] </li>
 
<li style="display: inline-block; vertical-align: top;"> [[File: Sumatran orangutan in Leuser Perry van Duijnhoven.JPG | 300px | thumb| right |Sumatran orangutan © Perry van Duijnhoven]] </li>
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! Species
 
! Species
 
! Year
 
! Year
 +
! Occurrence
 +
! Encounter or visitation rate (nests/km; ind/day)
 +
! Density estimate [ind/ km²] (95% CI)
 
! Abundance estimate (95% CI)
 
! Abundance estimate (95% CI)
−
! Density estimate [ind./ km²] (95% CI)
+
! Survey area
−
! Encounter rate (nests/km)
+
! Sampling method
−
! Area
+
! Analytical framework
−
! Method
 
 
! Source
 
! Source
 
! Comments
 
! Comments
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|''Pongo abelii''
 
|''Pongo abelii''
 
|1999-2013
 
|1999-2013
−
|13,846 (11,561-16,805)
+
|Present
 +
|
 
|0.73
 
|0.73
 +
|13846 (11561-16805)
 +
|Leuser Ecosystem
 +
|Line transects
 
|
 
|
−
|Leuser Ecosystem
 
−
|Line transects (Distance)
 
 
|Wich et al. 2016
 
|Wich et al. 2016
 
|
 
|
 
|
 
|
 
|}
 
|}
 +
[[Sampling methods]] ⋅ [[Analytical frameworks]]
  
 
= Threats =    <!-- a text overview of threats, followed by a table of key threats -->
 
= Threats =    <!-- a text overview of threats, followed by a table of key threats -->
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Key threats to orangutans at the Leuser Ecosystem include habitat destruction, habitat fragmentation, hunting, and the illegal pet trade ([https://www.sumatranorangutan.org/sumatran-orangutans/threats/ SOCP]). New roads are continuously being cut through the habitat. In addition to habitat encroachment, palm oil concessions, and new hydro electric schemes and geothermal energy plants are proposed in critical areas ([https://www.sumatranorangutan.org/sumatran-orangutans/threats/ SOCP]). As a by-product of land-conversion and increased proximity to humans, orangutans are sometimes killed due to human-wildlife conflict situations, for example, when orangutans raid farmlands (Singleton et al. 2018).
 
Key threats to orangutans at the Leuser Ecosystem include habitat destruction, habitat fragmentation, hunting, and the illegal pet trade ([https://www.sumatranorangutan.org/sumatran-orangutans/threats/ SOCP]). New roads are continuously being cut through the habitat. In addition to habitat encroachment, palm oil concessions, and new hydro electric schemes and geothermal energy plants are proposed in critical areas ([https://www.sumatranorangutan.org/sumatran-orangutans/threats/ SOCP]). As a by-product of land-conversion and increased proximity to humans, orangutans are sometimes killed due to human-wildlife conflict situations, for example, when orangutans raid farmlands (Singleton et al. 2018).
 
<div><ul>
 
<div><ul>
−
<li style="display: inline-block; vertical-align: top;"> [[File: Deforestation_for_small_scale_agriculture_in_Leuser_Perry_van_Duijnhoven.jpg | 300px | thumb| right |Deforestation for small scale agiriculture © Perry van Duijnhoven]] </li>
+
<li style="display: inline-block; vertical-align: top;"> [[File: Deforestation_for_small_scale_agriculture_in_Leuser_Perry_van_Duijnhoven.jpg | 300px | thumb| right |Deforestation for small scale agriculture © Perry van Duijnhoven]] </li>
 
<li style="display: inline-block; vertical-align: top;"> [[File: Draining_canals_in_peat_swamp_Leuser_Perry_van_Duijnhoven.jpg | 300px | thumb| right | Draining canals in peat swamp © Perry van Duijnhoven]] </li>
 
<li style="display: inline-block; vertical-align: top;"> [[File: Draining_canals_in_peat_swamp_Leuser_Perry_van_Duijnhoven.jpg | 300px | thumb| right | Draining canals in peat swamp © Perry van Duijnhoven]] </li>
 
<li style="display: inline-block; vertical-align: top;"> [[File: Small_scale_logging_Leuser_Perry_van_Duijnhoven.jpg | 300px | thumb| right |Small-scale logging © Perry van Duijnhoven]] </li>
 
<li style="display: inline-block; vertical-align: top;"> [[File: Small_scale_logging_Leuser_Perry_van_Duijnhoven.jpg | 300px | thumb| right |Small-scale logging © Perry van Duijnhoven]] </li>
 
</ul></div>
 
</ul></div>
 +
 
'''Table 3. Threats to apes in Leuser Ecosystem'''
 
'''Table 3. Threats to apes in Leuser Ecosystem'''
 
{| border="1" cellpadding="5" cellspacing="0" class="threats-table"
 
{| border="1" cellpadding="5" cellspacing="0" class="threats-table"
 
!align="left"|Category <!-- PLEASE DO NOT CHANGE THE THREAT CATEGORIES -->
 
!align="left"|Category <!-- PLEASE DO NOT CHANGE THE THREAT CATEGORIES -->
−
!Specific threats <!-- For specific threats, please use list of comma separated keywords from the IUCN list linked below -->
+
!Specific threats
−
!Threat level <!-- For threat level, please use keywords: low, medium, high, present, absent, unknown-->
+
!Threat level
−
!Quantified severity <!-- Enter any available quantification of the threat, e.g., the proportion of the area affected by the threat, hunting sign encounter rates-->
+
!Description
−
!Description <!-- Add descriptive information -->
+
!Year of threat
−
!Year of threat <!--  Enter specific year(s), “ongoing”, or “unknown”. If the threat is ongoing, please add the year of reference in parentheses -->
 
 
|-
 
|-
 
|1. Residential & commercial development
 
|1. Residential & commercial development
 
|
 
|
 
|Unknown
 
|Unknown
−
|
 
 
|
 
|
 
|
 
|
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|
 
|
 
|Unknown
 
|Unknown
−
|
 
 
|
 
|
 
|
 
|
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|3.3 Renewable energy
 
|3.3 Renewable energy
 
|Low
 
|Low
−
|
 
 
|Proposed construction of several new hydroelectric power plants leading to habitat loss (Wich pers. comm. 2020; SOCP).
 
|Proposed construction of several new hydroelectric power plants leading to habitat loss (Wich pers. comm. 2020; SOCP).
 
|Ongoing (2020)
 
|Ongoing (2020)
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|4.1 Roads & railroads
 
|4.1 Roads & railroads
 
|Medium
 
|Medium
−
|
 
 
|The construction of roads is causing forest loss and forest fragmentation (Wich et al. 2016).
 
|The construction of roads is causing forest loss and forest fragmentation (Wich et al. 2016).
 
|Ongoing (2016)
 
|Ongoing (2016)
 
|-
 
|-
 
|5. Biological resource use
 
|5. Biological resource use
−
|5.1 Hunting & collecting terrestrial animals
+
|5.1.5 Persecution/human wildlife conflict
 
|Low
 
|Low
−
|
+
|Poaching/persecution. Orangutans are captured or killed when they leave the forest and enter agricultural land or areas that have been recently deforested (Wich et al 2016; Singleton et al. 2018).
−
|Poaching/persecution. Orangutans are captured or killed when they leave the forest and enter
+
|2016-Ongoing (2018)
−
agricultural land or areas that have been recently deforested (Wich et al 2016; Singleton et al. 2018).
+
|-
−
|Ongoing (2018)
+
|5. Biological resource use
 +
|5.1.4 Capture for the live animal trade
 +
|Present (unknown severity)
 +
|Capturing young orangutans for illegal pet trade ([https://www.sumatranorangutan.org/sumatran-orangutans/threats/ SOCP]).
 +
|Ongoing (2023)
 
|-
 
|-
−
|
+
|5. Biological resource use
 
|5.3 Logging & wood harvesting
 
|5.3 Logging & wood harvesting
 
|Medium
 
|Medium
−
|
 
 
|Deforestation as a result of land-cover changes (Wich et al. 2016).
 
|Deforestation as a result of land-cover changes (Wich et al. 2016).
 
|Ongoing (2016)
 
|Ongoing (2016)
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|
 
|
 
|Unknown
 
|Unknown
−
|
 
 
|
 
|
 
|
 
|
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|
 
|
 
|Unknown
 
|Unknown
−
|
 
 
|
 
|
 
|
 
|
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|
 
|
 
|Unknown
 
|Unknown
−
|
 
 
|
 
|
 
|
 
|
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|
 
|
 
|Unknown
 
|Unknown
−
|
 
 
|
 
|
 
|
 
|
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|
 
|
 
|Absent
 
|Absent
−
|
 
 
|
 
|
 
|
 
|
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|
 
|
 
|Unknown
 
|Unknown
−
|
 
 
|
 
|
 
|
 
|
 
|-
 
|-
 
|12. Other options
 
|12. Other options
−
|12.1 Other threat
 
−
|Present, but threat severity is unknown
 
 
|
 
|
−
|Capturing young orangutans for illegal pet trade ([https://www.sumatranorangutan.org/sumatran-orangutans/threats/ SOCP]).
+
|Absent
−
|Ongoing
+
|
 +
|
 
|-
 
|-
 
|}
 
|}
−
[https://www.iucnredlist.org/resources/threat-classification-scheme IUCN Threats list]
+
[[Threats]]
  
 
= Conservation activities =      <!-- A summary of the conservation activities, followed by a table of key activities -->
 
= Conservation activities =      <!-- A summary of the conservation activities, followed by a table of key activities -->
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{| border="1" cellpadding="5" cellspacing="0" class="conservation-actions-table"
 
{| border="1" cellpadding="5" cellspacing="0" class="conservation-actions-table"
 
!align="left"|Category <!-- PLEASE DO NOT CHANGE THE CATEGORIES -->
 
!align="left"|Category <!-- PLEASE DO NOT CHANGE THE CATEGORIES -->
−
!Specific activity <!-- For specific threats, please use list from the list linked below, OR enter “Not reported” -->
+
!Specific activity
−
!Description <!-- Add descriptive information -->
+
!Description  
−
!Year of activity <!-- Add descriptive information -->
+
!Implementing organization
 +
!Year of activity
 
|-
 
|-
−
|1. Residential & commercial development
+
|1. Development impact mitigation
−
|1.2. Relocate primates to non-residential areas
+
|Not reported
−
|The Human-Orangutan Conflict Response Unit rescue, relocate, and confiscate orangutans in human-orangutan conflict situations ([https://orangutancentre.org/rescueing-orangutan/ OIC]).
+
|
−
|Ongoing
+
|
 +
|
 
|-
 
|-
−
|2. Agriculture & aquaculture
+
|2. Counter-wildlife crime
 
|Not reported
 
|Not reported
 +
|
 
|
 
|
 
|
 
|
 
|-
 
|-
−
|3. Energy production & mining
+
|3. Species health
 
|Not reported
 
|Not reported
 +
|
 
|
 
|
 
|
 
|
 
|-
 
|-
−
|4. Transportation & service corridors
+
|4. Education & awareness
 
|Not reported
 
|Not reported
 +
|
 
|
 
|
 
|
 
|
 
|-
 
|-
−
|5. Biological resource use
+
|5. Protection & restoration
 
|Not reported
 
|Not reported
 
|
 
|
 
|
 
|
 +
|
 +
|-
 +
|6. Species management
 +
|6.7 Translocate (capture & release) wild apes from human impacted sites to natural habitat elsewhere
 +
|The Human-Orangutan Conflict Response Unit rescue, relocate, and confiscate orangutans in human-orangutan conflict situations ([https://orangutancentre.org/rescueing-orangutan/ OIC]).
 +
|
 +
|Ongoing (2023)
 
|-
 
|-
−
|6. Human intrusion & disturbance
+
|7. Economic & other incentives
 
|Not reported
 
|Not reported
 +
|
 
|
 
|
 
|
 
|
 
|-
 
|-
−
|7. Natural system modifications
+
|8. Permanent presence
 
|Not reported
 
|Not reported
 
|
 
|
 +
|
 +
|
 +
|-
 +
|}
 +
[[Conservation activities]]
 +
 +
= Conservation implementation challenges and enablers = <!-- Overview of challenges in ape conservation -->
 +
 +
'''Table 5. Challenges reported for Leuser Ecosystem'''
 +
{| border="1" cellpadding="5" cellspacing="0" class="challenges-table"
 +
!align="left"|Category <!-- PLEASE DO NOT CHANGE THE CATEGORIES -->
 +
!Challenge
 +
!Source
 +
!Year(s)
 +
|-
 +
|1. Site management
 +
|1.2 Need for improved coordination
 +
|Wich pers. comm. 2020
 
|
 
|
 
|-
 
|-
−
|8. Invasive & other problematic species, genes, diseases
+
|2. Resources & capacity
 
|Not reported
 
|Not reported
 
|
 
|
 
|
 
|
 
|-
 
|-
−
|9. Pollution
+
|3. Engaged community
 
|Not reported
 
|Not reported
 
|
 
|
 
|
 
|
 
|-
 
|-
−
|10. Education & Awareness
+
|4. Institutional support
 +
|4.1 Lack of law enforcement
 +
|Singleton et al. 2018
 +
|
 +
|-
 +
|4. Institutional support
 +
|4.3 Lack of protected area status
 +
|Singleton et al. 2018
 +
|
 +
|-
 +
|5. Ecological context
 
|Not reported
 
|Not reported
 
|
 
|
 
|
 
|
 
|-
 
|-
−
|11. Habitat Protection
+
|6. Safety & stability
 
|Not reported
 
|Not reported
 
|
 
|
 
|
 
|
 
|-
 
|-
−
|12. Species Management
+
|}
 +
[[Challenges]]
 +
 
 +
'''Table 6. Enablers reported for Leuser Ecosystem'''
 +
{| border="1" cellpadding="5" cellspacing="0" class="enablers-table"
 +
!align="left"|Category <!-- PLEASE DO NOT CHANGE THE CATEGORIES -->
 +
!Enabler
 +
!Source
 +
!Year(s)
 +
|-
 +
|1. Site management
 
|Not reported
 
|Not reported
 
|
 
|
 
|
 
|
 
|-
 
|-
−
|13. Livelihood; Economic & Other Incentives
+
|2. Resources & capacity
 
|Not reported
 
|Not reported
 
|
 
|
 
|
 
|
 
|-
 
|-
−
|}
+
|3. Engaged community
−
[[Conservation activities list (Junker et al. 2017)]]
+
|Not reported
−
 
+
|
−
= Challenges = <!-- Overview of challenges in ape conservation -->
+
|
−
 
 
−
'''Table 5. Challenges reported for Leuser Ecosystem'''
 
−
{| border="1" cellpadding="5" cellspacing="0" class="challenges-table"
 
−
!align="left"|Challenge <!-- Do not change categories -->
 
−
!Source <!-- Source for challenge mentioned -->
 
 
|-
 
|-
−
|Lack of law enforcement
+
|4. Institutional support
−
|Singleton et al. 2018
+
|Not reported
 +
|
 +
|
 
|-
 
|-
−
|Lack of national protection
+
|5. Ecological context
−
|Singleton et al. 2018
+
|Not reported
 +
|
 +
|
 
|-
 
|-
−
|Lack of management
+
|6. Safety & stability
−
|Wich pers. comm. 2020
+
|Not reported
 +
|
 +
|
 
|-
 
|-
 
|}
 
|}
 +
[[Enablers]]
  
 
= Research activities = <!-- Overview of research activities -->
 
= Research activities = <!-- Overview of research activities -->
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===Documented behaviours===  <!-- List of any behaviours observed at the site, including citations -->
 
===Documented behaviours===  <!-- List of any behaviours observed at the site, including citations -->
  
−
'''Table 6. Ape behaviors reported for Leuser Ecosystem'''
+
'''Table 7. Ape behaviors reported for Leuser Ecosystem'''
 
{| border="1" cellpadding="5" cellspacing="0" class="behaviors-table"
 
{| border="1" cellpadding="5" cellspacing="0" class="behaviors-table"
 
!align="left"|Behavior
 
!align="left"|Behavior
Line 299: Line 353:
 
[https://orangutancentre.org/ OIC]<br>
 
[https://orangutancentre.org/ OIC]<br>
 
[https://www.sumatranorangutan.org/ SOCP]<br>
 
[https://www.sumatranorangutan.org/ SOCP]<br>
−
 
−
===Relevant datasets===
 
−
[http://apesportal.eva.mpg.de/database/archiveMap A.P.E.S Portal]
 
  
 
= References =
 
= References =
 
Singleton, I., Wich , S.A., Nowak, M., Usher, G. & Utami-Atmoko, S.S. 2017. Pongo abelii (errata version published in 2018). The IUCN Red List of Threatened Species 2017: e.T121097935A123797627. http://dx.doi.org/10.2305/IUCN.UK.2017-3.RLTS.T121097935A115575085.en <br>
 
Singleton, I., Wich , S.A., Nowak, M., Usher, G. & Utami-Atmoko, S.S. 2017. Pongo abelii (errata version published in 2018). The IUCN Red List of Threatened Species 2017: e.T121097935A123797627. http://dx.doi.org/10.2305/IUCN.UK.2017-3.RLTS.T121097935A115575085.en <br>
−
 
 
<br>
 
<br>
 
'''Page completed by: '''Serge Wich & A.P.E.S. Wiki team''' Date:''' 30/12/2020 <!-- If you don't want to add your name, you can add "A.P.E.S. Wiki team" -->
 
'''Page completed by: '''Serge Wich & A.P.E.S. Wiki team''' Date:''' 30/12/2020 <!-- If you don't want to add your name, you can add "A.P.E.S. Wiki team" -->

Revision as of 05:11, 2 July 2024

Asia > Indonesia > Leuser Ecosystem

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Summary

Forest view in Leuser Ecosystem © Perry van Duijnhoven
  • Sumatran orangutans (Pongo abelii) are present in the Leuser Ecosystem.
  • It has been estimated that 13,846 (CI: 11,561-16,805) individuals occur in the site.
  • The orangutan population trend is decreasing.
  • The site has a total size of 2.6 million ha.
  • Key threats to orangutans are deforestation, construction of roads and planned construction of hydroelectric power plants, poaching, and capturing of young orangutans for the illegal pet trade.
  • Several NGOs are involved in the implementation of conservation interventions; for example, the Human-Orangutan Conflict Response Unit rescues and relocates orangutans trapped by humans.

Site characteristics

The site is located in the provinces of Aceh and North Sumatra, at the northernmost tip of Sumatra, Indonesia. The area is extremely rich in biodiversity; more than 200 mammal species, 580 bird species, and an estimated 10,000 plant species, including 17 endemic genera, can be found at the Leuser Ecosystem. Within Leuser, the coastal peat swamp forests of Tripa, Kluet, and Trumon-Singkil harbour the highest densities of orangutans. In addition to Sumatran orangutans, the Leuser Ecosystem is also home to the last remaining viable populations of Sumatran tigers, Sumatran rhinoceros, and Sumatran elephants (Sumatran Orangutan Conservation Programme). The Leuser Ecosystem is designated as a National Strategic Area for its environmental function. This designation does not exclude non-forest uses, but stresses the importance of sustainable management (Singleton et al. 2018). The Gunung Leuser National Park is found within the Leuser Ecosystem, which is also designated a Man and Biosphere Reserve, and is part of the Tropical Rainforest Heritage of Sumatra World Heritage Cluster Site by UNESCO (Singleton et al. 2018). The park supports only 25.3% of Sumatra’s Orangutans. Also within the Leuser Ecosystem, is the 1,025 km² Singkil Swamps Wildlife Reserve (Singleton et al. 2018).

Table 1. Basic site information for Leuser Ecosystem

Species Pongo abelii
Area 26000 km²
Coordinates 3.630896, 97.378969
Type of site Conservation area (National Strategic Area)
Governance type Governance by government
Habitat type Subtropical/tropical dry forest, plantations, subtropical/tropical heavily degraded former forest

Types of sites ⋅ Governance types ⋅ Habitat types

  • Sumatran orangutan © Perry van Duijnhoven
  • Female orangutan © Perry van Duijnhoven
  • Flanged male Sumatran orangutan © Perry van Duijnhoven

Ape status

The peat-swamp forests of the Leuser Ecosystem hold the highest Sumatran orangutan densities (Wich et al. 2016). The species is predicted to decline across a variety of land-use scenarios; as many as 4,500 individuals could vanish by 2030 (Wich et al. 2016).

Table 2. Ape population estimates in Leuser Ecosystem

Species Year Occurrence Encounter or visitation rate (nests/km; ind/day) Density estimate [ind/ km²] (95% CI) Abundance estimate (95% CI) Survey area Sampling method Analytical framework Source Comments A.P.E.S. database ID
Pongo abelii 1999-2013 Present 0.73 13846 (11561-16805) Leuser Ecosystem Line transects Wich et al. 2016

Sampling methods ⋅ Analytical frameworks

Threats

Key threats to orangutans at the Leuser Ecosystem include habitat destruction, habitat fragmentation, hunting, and the illegal pet trade (SOCP). New roads are continuously being cut through the habitat. In addition to habitat encroachment, palm oil concessions, and new hydro electric schemes and geothermal energy plants are proposed in critical areas (SOCP). As a by-product of land-conversion and increased proximity to humans, orangutans are sometimes killed due to human-wildlife conflict situations, for example, when orangutans raid farmlands (Singleton et al. 2018).

  • Deforestation for small scale agriculture © Perry van Duijnhoven
  • Draining canals in peat swamp © Perry van Duijnhoven
  • Small-scale logging © Perry van Duijnhoven

Table 3. Threats to apes in Leuser Ecosystem

Category Specific threats Threat level Description Year of threat
1. Residential & commercial development Unknown
2. Agriculture & aquaculture Unknown
3. Energy production & mining 3.3 Renewable energy Low Proposed construction of several new hydroelectric power plants leading to habitat loss (Wich pers. comm. 2020; SOCP). Ongoing (2020)
4. Transportation & service corridors 4.1 Roads & railroads Medium The construction of roads is causing forest loss and forest fragmentation (Wich et al. 2016). Ongoing (2016)
5. Biological resource use 5.1.5 Persecution/human wildlife conflict Low Poaching/persecution. Orangutans are captured or killed when they leave the forest and enter agricultural land or areas that have been recently deforested (Wich et al 2016; Singleton et al. 2018). 2016-Ongoing (2018)
5. Biological resource use 5.1.4 Capture for the live animal trade Present (unknown severity) Capturing young orangutans for illegal pet trade (SOCP). Ongoing (2023)
5. Biological resource use 5.3 Logging & wood harvesting Medium Deforestation as a result of land-cover changes (Wich et al. 2016). Ongoing (2016)
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

Threats

Conservation activities

A number of NGOs are active in the implementation of conservation activities, including the Sumatran Orangutan Conservation Programme (SOCP), the Orangutan Information Center (OIC), the Leuser International Foundation (LIF), and HAkA.

Table 4. Conservation activities in Leuser Ecosystem

Category Specific activity Description Implementing organization Year of activity
1. Development impact mitigation Not reported
2. Counter-wildlife crime Not reported
3. Species health Not reported
4. Education & awareness Not reported
5. Protection & restoration Not reported
6. Species management 6.7 Translocate (capture & release) wild apes from human impacted sites to natural habitat elsewhere The Human-Orangutan Conflict Response Unit rescue, relocate, and confiscate orangutans in human-orangutan conflict situations (OIC). Ongoing (2023)
7. Economic & other incentives Not reported
8. Permanent presence Not reported

Conservation activities

Conservation implementation challenges and enablers

Table 5. Challenges reported for Leuser Ecosystem

Category Challenge Source Year(s)
1. Site management 1.2 Need for improved coordination Wich pers. comm. 2020
2. Resources & capacity Not reported
3. Engaged community Not reported
4. Institutional support 4.1 Lack of law enforcement Singleton et al. 2018
4. Institutional support 4.3 Lack of protected area status Singleton et al. 2018
5. Ecological context Not reported
6. Safety & stability Not reported

Challenges

Table 6. Enablers reported for Leuser Ecosystem

Category Enabler Source Year(s)
1. Site management Not reported
2. Resources & capacity Not reported
3. Engaged community Not reported
4. Institutional support Not reported
5. Ecological context Not reported
6. Safety & stability Not reported

Enablers

Research activities

Documented behaviours

Table 7. Ape behaviors reported for Leuser Ecosystem

Behavior Source
Not reported

External links

Leuser International Foundation
HAkA
OIC
SOCP

References

Singleton, I., Wich , S.A., Nowak, M., Usher, G. & Utami-Atmoko, S.S. 2017. Pongo abelii (errata version published in 2018). The IUCN Red List of Threatened Species 2017: e.T121097935A123797627. http://dx.doi.org/10.2305/IUCN.UK.2017-3.RLTS.T121097935A115575085.en

Page completed by: Serge Wich & A.P.E.S. Wiki team Date: 30/12/2020

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