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Nakai Nam Theun National Park (view source)
Revision as of 06:53, 21 September 2023
, 06:53, 21 September 2023Created page with "<!-- INSTRUCTIONS FOR UPLOADING SITE INFORMATION - Wiki pages contain information in paragraphs, tables, lists, and images. - Text and images are not restricted, and their for..."
<!-- INSTRUCTIONS FOR UPLOADING SITE INFORMATION
- Wiki pages contain information in paragraphs, tables, lists, and images.
- Text and images are not restricted, and their formats can be chosen as desired.
- Tables and lists are extracted as data, so the following restrictions apply to them:
1) Table structure cannot be changed.
2) List format should not change, i.e. they are comma separated lists, not bullet points or numbered lists.
3) To make information comparable across wiki pages, keywords must be taken from the list of permitted words, or added to the list of permitted keywords. This is why we use official lists, e.g., IUCN classification lists, in our tables.
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[[Asia]] > [[Laos]] > [[Nakai Nam Theun National Park]]
= Summary = <!-- An overview of the site, with one sentence for each section. May include a site map -->
{{#display_map: height=200px | width=400px | scrollzoom=off | zoom=6 | layers=OpenTopoMap, OpenStreetMap
|17.903516, 105.310483~[[Nakai Nam Theun National Park]]~ Southern white-cheeked gibbons and northern white-cheeked gibbons
}}
* Southern white-cheeked gibbons (''Nomascus siki'') and northern white-cheeked gibbons (''Nomascus leucogenys'') are present in Nakai Nam Theun National Park.
* The population sizes are unknown.
* The population trends are decreasing.
* The site has a total size of 4270 km².
* Key threats to gibbons are loss of habitat due to agricultural encroachment and hunting.
* Conservation activities have focused on biomonitoring, anti-poaching patrols, conducting research and enforcing park boundaries.
= Site characteristics = <!-- A paragraph summary of physical and geographic aspects of the site, and a table of key information -->
[[File: NNT.png | 300px | thumb| right | © Camille Coudrat]]
Nakai Nam Theun National Park is located in the Annamite Mountains in Laos, bordering Vietnam. In addition to northern white-cheeked and southern white-cheeked gibbons, other rare mammal species that occur in the area include the large-antlered muntjac, Annamite striped rabbit, and saola ([https://iucngreenlist.org/news/nakai-nam-theun-national-park-lao-pdr/ IUCN Green list]).
'''Table 1. Basic site information for Nakai Nam Theun National Park'''
{| border="1" cellpadding="5" cellspacing="0" class="basic-information"
| Area <!-- Please include units: km2/ha e.g 200ha -->
|4270 km²
|-
|Coordinates
|17.903516, 105.310483
|-
|Designation
|National Park
|-
|Habitat types <!-- List IUCN Habitat Classification 3.0 categories present (without number), see link below -->
|Subtropical/tropical moist montane forest, subtropical/tropical dry forest, tropical pine forest
|}
[https://www.iucnredlist.org/resources/habitat-classification-scheme IUCN habitat categories] [[Site designations]]
= Ape status = <!--An overview of ape population status (population sizes, trends, etc.), followed by a table of specific surveys and results -->
'''Table 2. Ape population estimates in Nakai Nam Theun National Park'''
{| border="1" cellpadding="5" cellspacing="0" class="population-estimate-table"
! 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
|-
|''Nomascus siki''
|
|
|
|
|Nakai Nam Theun National Park
|
|
|
|
|-
|''Nomascus leucogenys''
|
|
|
|
|Nakai Nam Theun National Park
|
|
|
|
|}
= Threats = <!-- a text overview of threats, followed by a table of key threats -->
Illegal hunting is the primary threat to gibbons in the park (Coudrat pers. obs. 2023).
'''Table 3. Threats to apes in Nakai Nam Theun National Park'''
{| border="1" cellpadding="5" cellspacing="0" class="threats-table"
!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 -->
!Threat level <!-- For threat level, please use keywords: low, medium, high, present, absent, unknown-->
!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 <!-- Add descriptive information -->
!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
|
|Unknown
|
|
|
|-
|2. Agriculture & aquaculture
|2.1 Annual & perennial non-timber crops
|Medium
|
|Agricultural land expanding within the national park for local human communities living inside the park (over 8000 people) (Coudrat pers. obs. 2023).
|Ongoing (2023)
|-
|3. Energy production & mining
|
|Unknown
|
|
|
|-
|4. Transportation & service corridors
|
|Unknown
|
|
|
|-
|5. Biological resource use
|5.1 Hunting & collecting terrestrial animals
|High
|
|Subsistence illegal hunting with traditional handmade rifles, illegal national and or international trade driven hunting (Coudrat pers. obs. 2023).
|Ongoing (2023)
|-
|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
|
|
|
|-
|}
[https://www.iucnredlist.org/resources/threat-classification-scheme IUCN Threats list]
= Conservation activities = <!-- A summary of the conservation activities, followed by a table of key activities -->
'''Table 4. Conservation activities in Nakai Nam Theun National Park'''
{| border="1" cellpadding="5" cellspacing="0" class="conservation-actions-table"
!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” -->
!Description <!-- Add descriptive information -->
!Year of activity <!-- Add descriptive information -->
|-
|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
|5.6. Conduct regular anti-poaching patrols
|By the Park authorities since 2010 (Coudrat pers. comm. 2023).
|Ongoing (2023)
|-
|5. Biological resource use
|5.11. Provide training to anti-poaching ranger patrols
|By the Park authorities since 2010 (Coudrat pers. comm. 2023).
|Ongoing (2023)
|-
|5. Biological resource use
|5.15. Implement monitoring surveillance strategies (e.g. SMART) or use monitoring data to improve effectiveness of wildlife law enforcement patrols
|By the Park authorities since 2010 (Coudrat pers. comm. 2023).
|Ongoing (2023)
|-
|5. Biological resource use
|5.16. Implement community control of patrolling, banning hunting and removing snares
|By the Park authorities since 2010 (Coudrat pers. comm. 2023).
|Ongoing (2023)
|-
|5. Biological resource use
|5.17. Provide sustainable alternative livelihoods; establish fish- or domestic meat farms
|By the Park authorities (started in 2010 and ongoing) and Association Anoulak (for period 2020-2025) (Coudrat pers. comm. 2023).
|Ongoing (2023)
|-
|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
|11.2. Legally protect primate habitat
|The site is a National Park.
|Ongoing (2023)
|-
|11. Habitat Protection
|11.6. Demarcate and enforce boundaries of protected areas
|by Park authorities since 2010 (Coudrat pers. comm. 2023).
|Ongoing (2023)
|-
|12. Species Management
|Not reported
|
|
|-
|13. Livelihood; Economic & Other Incentives
|13.3. Run research project and ensure permanent human presence at site
|by Association Anoulak (Coudrat pers. comm. 2023).
|2013-2024
|-
|}
[[Conservation activities list (Junker et al. 2017)]]
= Challenges = <!-- Overview of challenges in ape conservation -->
Lack of effective and systemic law enforcement; corruption, mismanagement of national Park by authorities, lack of technical knowledge by government management teams (Coudrat per. obs. 2023).
'''Table 5. Challenges reported for Nakai Nam Theun National Park'''
{| 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
|(Coudrat per. obs. 2023).
|-
|Corruption
|(Coudrat per. obs. 2023).
|-
|Mismanagement of the park by authorities
|(Coudrat per. obs. 2023).
|-
|Lack of technical capacity
|(Coudrat per. obs. 2023).
|-
|}
= Research activities = <!-- Overview of research activities -->
Current (2023) projects led by Association Anoulak (www.conservationlaos.com) are:
INVESTIGATING THE UNKNOWN: DISTRIBUTION OF THE SOUTHERN WHITE-CHEEKED GIBBON NOMASCUS SIKI AND THE NORTHERN WHITE-CHEEKED GIBBON N. LEUCOGENYS IN CENTRAL LAOS - Camille Noemie, Zoe Coudrat, Association Anoulak (Primary Presenter) - Michal Hradec, Czech University of Life Science Prague - Hana Vostrá-Vydrová, Czech University of Life Sciences Prague. Nomascus gibbons are the most threatened of the four Hylobatidae genera. The Northern N. leucogenys and the Southern White-cheeked Gibbon N. siki are both classified as Critically Endangered. They have a restricted global range and are endemic to Laos and Vietnam. It is currently speculated that the Nam Kading-Nam Theun (river) represents the major geographical barrier between N. leucogenys and N. siki (ranging north and south of the river, respectively). However, in central Laos the distribution range limit between the two species remains uncertain, preventing appropriate conservation planning. Gibbon songs are taxonomically distinct between species. To investigate the distribution of N. siki and N. leucogenys, we collected and obtained from partner institutions a total of 896 gibbon songs from sites in central Laos and Vietnam. We compared these recordings with 213 vocal recordings of genetically screened gibbon individuals of both species from zoological facilities in Europe. Our dataset contains 674 records from males and 222 records from females. We performed the Kruskal-Wallis test to select acoustic parameters. We used cluster analysis to identify differences in vocalization among the gibbon populations. Cluster analysis is a multivariate method useful for identifying the same individuals based on the acoustic parameters they assign into clusters. The preliminary results showed that in the area north of the Nam Kading-Nam Theun are groups similar to N. siki while groups south of the river show a mixture of the two species. The results of our research will lead to re-evaluating the global distribution of both species and adapt national conservation prioritization.
GIBBON SURVEYING IN THE DIGITAL AGE - Cornelia Oedekoven, University of St Andrews (Primary Presenter) - David Borchers, University of St Andrews - Mark Peter Johnson, Aarhus University - Camille Noemie, Zoe Coudrat, Association Anoulak Abstract: Gibbons are difficult to see and easy to hear, so the best way to detect them is to listen for them. It is easy to establish gibbon presence this way, but not so easy to estimate gibbon density and abundance, which requires information on their locations when calling. Humans doing the listening can estimate directions to calls, and gibbon locations can be estimated by triangulation (although this can be labour-intensive and error-prone). Digital recorders are better listeners than humans in that they are cheaper and don’t get tired. Currently available recorders don’t estimate directions to calls but it turns out that accurate directions to calls is important for accurate density estimation. We introduce new digital recorders with synchronised clocks and multiple microphones which are able to provide estimated directions to sound sources accurately, and show how this improves density and abundance estimation, using acoustic spatial capture-recapture methods. We briefly discuss survey design, how calls can be efficiently extracted from acoustic files, and summarise results from initial field testing. These confirm that use of the new digital recorders with angle estimation substantially improves density estimation as well as provides much better information on sound source locations. They will undergo full field testing in Laos late this year. We hope their use will improve gibbon population monitoring and conservation planning in the near future.
===Documented behaviours=== <!-- List of any behaviours observed at the site, including citations -->
'''Table 6. Ape behaviors reported for Nakai Nam Theun National Park'''
{| border="1" cellpadding="5" cellspacing="0" class="behaviors-table"
!align="left"|Behavior
!Source
|-
|Not reported
|
|-
|}
=External links=
= References =
Coudrat CNZ, Nanthavong C, Ngoprasert D, Suwanwaree P, Savini T. 2015. Singing Patterns of WhiteCheeked Gibbons (Nomascus sp.) in the Annamite Mountains of Laos. International Journal of Primatology 36:691–706. <br>
<br>
'''Page completed by: '''Camille Coudrat''' Date:''' 20/09/2023 <!-- If you don't want to add your name, you can add "A.P.E.S. Wiki team" -->
- Wiki pages contain information in paragraphs, tables, lists, and images.
- Text and images are not restricted, and their formats can be chosen as desired.
- Tables and lists are extracted as data, so the following restrictions apply to them:
1) Table structure cannot be changed.
2) List format should not change, i.e. they are comma separated lists, not bullet points or numbered lists.
3) To make information comparable across wiki pages, keywords must be taken from the list of permitted words, or added to the list of permitted keywords. This is why we use official lists, e.g., IUCN classification lists, in our tables.
-->
[[Asia]] > [[Laos]] > [[Nakai Nam Theun National Park]]
= Summary = <!-- An overview of the site, with one sentence for each section. May include a site map -->
{{#display_map: height=200px | width=400px | scrollzoom=off | zoom=6 | layers=OpenTopoMap, OpenStreetMap
|17.903516, 105.310483~[[Nakai Nam Theun National Park]]~ Southern white-cheeked gibbons and northern white-cheeked gibbons
}}
* Southern white-cheeked gibbons (''Nomascus siki'') and northern white-cheeked gibbons (''Nomascus leucogenys'') are present in Nakai Nam Theun National Park.
* The population sizes are unknown.
* The population trends are decreasing.
* The site has a total size of 4270 km².
* Key threats to gibbons are loss of habitat due to agricultural encroachment and hunting.
* Conservation activities have focused on biomonitoring, anti-poaching patrols, conducting research and enforcing park boundaries.
= Site characteristics = <!-- A paragraph summary of physical and geographic aspects of the site, and a table of key information -->
[[File: NNT.png | 300px | thumb| right | © Camille Coudrat]]
Nakai Nam Theun National Park is located in the Annamite Mountains in Laos, bordering Vietnam. In addition to northern white-cheeked and southern white-cheeked gibbons, other rare mammal species that occur in the area include the large-antlered muntjac, Annamite striped rabbit, and saola ([https://iucngreenlist.org/news/nakai-nam-theun-national-park-lao-pdr/ IUCN Green list]).
'''Table 1. Basic site information for Nakai Nam Theun National Park'''
{| border="1" cellpadding="5" cellspacing="0" class="basic-information"
| Area <!-- Please include units: km2/ha e.g 200ha -->
|4270 km²
|-
|Coordinates
|17.903516, 105.310483
|-
|Designation
|National Park
|-
|Habitat types <!-- List IUCN Habitat Classification 3.0 categories present (without number), see link below -->
|Subtropical/tropical moist montane forest, subtropical/tropical dry forest, tropical pine forest
|}
[https://www.iucnredlist.org/resources/habitat-classification-scheme IUCN habitat categories] [[Site designations]]
= Ape status = <!--An overview of ape population status (population sizes, trends, etc.), followed by a table of specific surveys and results -->
'''Table 2. Ape population estimates in Nakai Nam Theun National Park'''
{| border="1" cellpadding="5" cellspacing="0" class="population-estimate-table"
! 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
|-
|''Nomascus siki''
|
|
|
|
|Nakai Nam Theun National Park
|
|
|
|
|-
|''Nomascus leucogenys''
|
|
|
|
|Nakai Nam Theun National Park
|
|
|
|
|}
= Threats = <!-- a text overview of threats, followed by a table of key threats -->
Illegal hunting is the primary threat to gibbons in the park (Coudrat pers. obs. 2023).
'''Table 3. Threats to apes in Nakai Nam Theun National Park'''
{| border="1" cellpadding="5" cellspacing="0" class="threats-table"
!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 -->
!Threat level <!-- For threat level, please use keywords: low, medium, high, present, absent, unknown-->
!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 <!-- Add descriptive information -->
!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
|
|Unknown
|
|
|
|-
|2. Agriculture & aquaculture
|2.1 Annual & perennial non-timber crops
|Medium
|
|Agricultural land expanding within the national park for local human communities living inside the park (over 8000 people) (Coudrat pers. obs. 2023).
|Ongoing (2023)
|-
|3. Energy production & mining
|
|Unknown
|
|
|
|-
|4. Transportation & service corridors
|
|Unknown
|
|
|
|-
|5. Biological resource use
|5.1 Hunting & collecting terrestrial animals
|High
|
|Subsistence illegal hunting with traditional handmade rifles, illegal national and or international trade driven hunting (Coudrat pers. obs. 2023).
|Ongoing (2023)
|-
|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
|
|
|
|-
|}
[https://www.iucnredlist.org/resources/threat-classification-scheme IUCN Threats list]
= Conservation activities = <!-- A summary of the conservation activities, followed by a table of key activities -->
'''Table 4. Conservation activities in Nakai Nam Theun National Park'''
{| border="1" cellpadding="5" cellspacing="0" class="conservation-actions-table"
!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” -->
!Description <!-- Add descriptive information -->
!Year of activity <!-- Add descriptive information -->
|-
|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
|5.6. Conduct regular anti-poaching patrols
|By the Park authorities since 2010 (Coudrat pers. comm. 2023).
|Ongoing (2023)
|-
|5. Biological resource use
|5.11. Provide training to anti-poaching ranger patrols
|By the Park authorities since 2010 (Coudrat pers. comm. 2023).
|Ongoing (2023)
|-
|5. Biological resource use
|5.15. Implement monitoring surveillance strategies (e.g. SMART) or use monitoring data to improve effectiveness of wildlife law enforcement patrols
|By the Park authorities since 2010 (Coudrat pers. comm. 2023).
|Ongoing (2023)
|-
|5. Biological resource use
|5.16. Implement community control of patrolling, banning hunting and removing snares
|By the Park authorities since 2010 (Coudrat pers. comm. 2023).
|Ongoing (2023)
|-
|5. Biological resource use
|5.17. Provide sustainable alternative livelihoods; establish fish- or domestic meat farms
|By the Park authorities (started in 2010 and ongoing) and Association Anoulak (for period 2020-2025) (Coudrat pers. comm. 2023).
|Ongoing (2023)
|-
|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
|11.2. Legally protect primate habitat
|The site is a National Park.
|Ongoing (2023)
|-
|11. Habitat Protection
|11.6. Demarcate and enforce boundaries of protected areas
|by Park authorities since 2010 (Coudrat pers. comm. 2023).
|Ongoing (2023)
|-
|12. Species Management
|Not reported
|
|
|-
|13. Livelihood; Economic & Other Incentives
|13.3. Run research project and ensure permanent human presence at site
|by Association Anoulak (Coudrat pers. comm. 2023).
|2013-2024
|-
|}
[[Conservation activities list (Junker et al. 2017)]]
= Challenges = <!-- Overview of challenges in ape conservation -->
Lack of effective and systemic law enforcement; corruption, mismanagement of national Park by authorities, lack of technical knowledge by government management teams (Coudrat per. obs. 2023).
'''Table 5. Challenges reported for Nakai Nam Theun National Park'''
{| 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
|(Coudrat per. obs. 2023).
|-
|Corruption
|(Coudrat per. obs. 2023).
|-
|Mismanagement of the park by authorities
|(Coudrat per. obs. 2023).
|-
|Lack of technical capacity
|(Coudrat per. obs. 2023).
|-
|}
= Research activities = <!-- Overview of research activities -->
Current (2023) projects led by Association Anoulak (www.conservationlaos.com) are:
INVESTIGATING THE UNKNOWN: DISTRIBUTION OF THE SOUTHERN WHITE-CHEEKED GIBBON NOMASCUS SIKI AND THE NORTHERN WHITE-CHEEKED GIBBON N. LEUCOGENYS IN CENTRAL LAOS - Camille Noemie, Zoe Coudrat, Association Anoulak (Primary Presenter) - Michal Hradec, Czech University of Life Science Prague - Hana Vostrá-Vydrová, Czech University of Life Sciences Prague. Nomascus gibbons are the most threatened of the four Hylobatidae genera. The Northern N. leucogenys and the Southern White-cheeked Gibbon N. siki are both classified as Critically Endangered. They have a restricted global range and are endemic to Laos and Vietnam. It is currently speculated that the Nam Kading-Nam Theun (river) represents the major geographical barrier between N. leucogenys and N. siki (ranging north and south of the river, respectively). However, in central Laos the distribution range limit between the two species remains uncertain, preventing appropriate conservation planning. Gibbon songs are taxonomically distinct between species. To investigate the distribution of N. siki and N. leucogenys, we collected and obtained from partner institutions a total of 896 gibbon songs from sites in central Laos and Vietnam. We compared these recordings with 213 vocal recordings of genetically screened gibbon individuals of both species from zoological facilities in Europe. Our dataset contains 674 records from males and 222 records from females. We performed the Kruskal-Wallis test to select acoustic parameters. We used cluster analysis to identify differences in vocalization among the gibbon populations. Cluster analysis is a multivariate method useful for identifying the same individuals based on the acoustic parameters they assign into clusters. The preliminary results showed that in the area north of the Nam Kading-Nam Theun are groups similar to N. siki while groups south of the river show a mixture of the two species. The results of our research will lead to re-evaluating the global distribution of both species and adapt national conservation prioritization.
GIBBON SURVEYING IN THE DIGITAL AGE - Cornelia Oedekoven, University of St Andrews (Primary Presenter) - David Borchers, University of St Andrews - Mark Peter Johnson, Aarhus University - Camille Noemie, Zoe Coudrat, Association Anoulak Abstract: Gibbons are difficult to see and easy to hear, so the best way to detect them is to listen for them. It is easy to establish gibbon presence this way, but not so easy to estimate gibbon density and abundance, which requires information on their locations when calling. Humans doing the listening can estimate directions to calls, and gibbon locations can be estimated by triangulation (although this can be labour-intensive and error-prone). Digital recorders are better listeners than humans in that they are cheaper and don’t get tired. Currently available recorders don’t estimate directions to calls but it turns out that accurate directions to calls is important for accurate density estimation. We introduce new digital recorders with synchronised clocks and multiple microphones which are able to provide estimated directions to sound sources accurately, and show how this improves density and abundance estimation, using acoustic spatial capture-recapture methods. We briefly discuss survey design, how calls can be efficiently extracted from acoustic files, and summarise results from initial field testing. These confirm that use of the new digital recorders with angle estimation substantially improves density estimation as well as provides much better information on sound source locations. They will undergo full field testing in Laos late this year. We hope their use will improve gibbon population monitoring and conservation planning in the near future.
===Documented behaviours=== <!-- List of any behaviours observed at the site, including citations -->
'''Table 6. Ape behaviors reported for Nakai Nam Theun National Park'''
{| border="1" cellpadding="5" cellspacing="0" class="behaviors-table"
!align="left"|Behavior
!Source
|-
|Not reported
|
|-
|}
=External links=
= References =
Coudrat CNZ, Nanthavong C, Ngoprasert D, Suwanwaree P, Savini T. 2015. Singing Patterns of WhiteCheeked Gibbons (Nomascus sp.) in the Annamite Mountains of Laos. International Journal of Primatology 36:691–706. <br>
<br>
'''Page completed by: '''Camille Coudrat''' Date:''' 20/09/2023 <!-- If you don't want to add your name, you can add "A.P.E.S. Wiki team" -->