Summary

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Pileated gibbons (Hylobates pileatus) are present in Khao Ang Rue Nai Wildlife Sanctuary.
The population size is unknown.
The gibbon population trend is unknown.
The site has a total size of 1,079 km².
Key threats to gibbons are human encroachment and expansion of land for agriculture, leading to forest disturbance.
Conservation activities are not documented.

Site characteristics

Khao Ang Rue Nai Wildlife Sanctuary (KARN) is located in southeastern Thailand, adjacent to Khao Soi Dao Wildlife Sanctuary to the east (BirdLife International 2021). The site was established in 1977 and initially covered 108 sq. km; the sanctuary was then enlarged to 1,030 sq.km in 1992 and to 1,079 sq. km in 2001 (Phoonjampa et al. 2011). The climate of KARN is largely influenced by seasonal monsoons. The topography of KARN is characterized by lowlands and low hills divided by large streams (BirdLife International 2021). The site was designated as an Important Bird Area in 2004 (BirdLife International 2021). KARN has a wide diversity of bird species and also supports three globally near-threatened species: Siamese Fireback, Great Hornbill, and Moustached Hawk (BirdLife International 2021). It is also a wintering site for the globally threatened Silver Oriole, Oriolus mellianus. In addition to pileated gibbons, other mammals species of conservation concern found at the site include Asian elephants, tigers, Asian golden cat, banteng, northern pig-tailed macaques, and fishing cats (BirdLife International 2021).

Table 1. Basic site information for Khao Ang Rue Nai Wildlife Sanctuary

Species	'Hylobates pileatus
Area	1,079 km²
Coordinates	Lat: 13.207217 , Lon: 101.710734
Type of site	Protected area (Wildlife Sanctuary)
Habitat types	Subtropical/tropical moist lowland forest, Wetlands (lakes, rivers, streams, bogs, marshes)
Type of governance

IUCN habitat categories Site designations

Ape status

A 2011 study found that gibbon density was significantly different between areas with different logging/protection histories (Phoonjampa et al. 2011). In areas protected since 1977 density was almost three times higher than in the areas protected since 1992 (1.96 groups/km2 vs. 0.77 groups/km2 on average).

Table 2. Ape population estimates reported for Khao Ang Rue Nai Wildlife Sanctuary

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	NA	NA
Hylobates pileatus	2007-2008		1.61 (range 0-3.66)			Khao Ang Ru Nai Wildlife Sanctuary	Fixed point triangulation		Phoonjampa et al. 2011

Threats

Forest disturbance is known to have a significant impact on gibbons; forest areas with higher levels of disturbance (very patchy, more exotic tree plantations, and few emergent trees) had lower pileated gibbon density (Phoonjampa et al. 2011). The relatively low gibbon density in the wider landscape at the site is likely a result from past selective logging, clearance of forest and agricultural expansion, and human settlements (Phoonjampa et al. 2011).

Table 3. Threats to apes reported for Khao Ang Rue Nai Wildlife Sanctuary

Category	Specific threats	Threat level	Description	Year of threat
10 Geological events		Absent
12 Other threat		Absent
5 Biological resource use	5.3 Logging & wood harvesting	High (more than 70% of population affected)	Lower gibbon densities in parts of the sanctuary that had been more recently logged (Phoonjampa et al. 2011).	Ongoing (2011)
4 Transportation & service corridors	4.1 Roads & railroads	Medium (30-70% of population affected)	Throughout most of the site, gibbons avoid areas closer to roads, likely due to easier access for hunters and higher forest disturbance (Phoonjampa et al. 2011).	Ongoing (2011)
2 Agriculture & aquaculture	2.1 Annual & perennial non-timber crops	Present (unknown severity)	Agricultural encroachment (BirdLife International 2021).	Ongoing (2021)
1 Residential & commercial development		Unknown
3 Energy production & mining		Unknown
6 Human intrusions & disturbance		Unknown
7 Natural system modifications		Unknown
8 Invasive & other problematic species, genes & diseases		Unknown
9 Pollution		Unknown
11 Climate change & severe weather		Unknown

IUCN Threats list

Conservation activities

Challenges

Table 5. Challenges reported for Khao Ang Rue Nai Wildlife Sanctuary

Challenges	Specific challenges	Source	Year(s)
	Not reported

Enablers

Table 6. Enablers reported for Khao Ang Rue Nai Wildlife Sanctuary

Enablers	Specific enablers	Source	Year(s)
1 Site management
2 Resources and capacity
3 Engaged community
4 Institutional support
5 Ecological context
6 Safety and stability

Research activities

Documented behaviours

Table 7. Behaviours documented for Khao Ang Rue Nai Wildlife Sanctuary

Behavior	Source
Not reported

Exposure to climate change impacts

External links

Relevant datasets

References

Phoonjampa, R., Koenig, A., Brockelman, W. Y., Borries, C., Gale, G. A., Carroll, J. P., & Savini, T. (2011). Pileated gibbon density in relation to habitat characteristics and post‐logging forest recovery. Biotropica, 43(5), 619-627.

BirdLife International (2021) Important Bird Areas factsheet: Khao Ang Ru Nai. Downloaded from http://www.birdlife.org on 20/12/2021.

Page created by: A.P.E.S. Wiki team Date: NA

Khao Ang Rue Nai Wildlife Sanctuary

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