Thungyai- Huai Kha Khaeng wildlife sanctuaries 1991

Thungyai-Huai Kha Khaeng Wildlife Sanctuaries was list as Thailand World Heritage in 1991. Stretching over more than 600,000 ha along the Myanmar border, the sanctuaries, which are relatively intact, contain examples of almost all the forest types of continental South-East Asia. They are home to a very diverse array of animals, including 77% of the large mammals (especially elephants and tigers), 50% of the large birds and 33% of the land vertebrates to be found in this region.

Outstanding Universal Value

Brief synthesis

Thung Yai-Huai Kha Khaeng Wildlife Sanctuary World Heritage property lies in Uthai Thani, Tak, and Kanchanaburi provinces in the west of Thailand, alongside the border with Myanmar. The property combines two contiguous sanctuaries, Thung Yai Naresuan and Huai Kha Khang, separately established as sanctuaries in 1972 and 1974, respectively. Thung Yai-Huai Kha Khaeng Wildlife Sanctuary encompasses two important river systems, the Upper Khwae Yai and the Huai Khakhaeng. The property, encompassing 622,200 hectares, is the largest conservation area in Mainland Southeast Asia and is one of Thailand’s least accessible and least disturbed forest areas.

The flora and fauna of the sanctuaries include associations found nowhere else, with many species of exclusively Sino-Himalayan, Sundaic, Indo-Burmese, and Indo-Chinese affinities, intermingling within the property. Many of these are rare, endangered, or endemic. The sanctuary’s importance as a conservation area lies in the heterogeneity and integrity of its habitats, the diversity of its flora and fauna, and the complexity of its ecosystem. The property contains exceptional natural beauty and aesthetic importance with steep sided valleys and impressive mountain peaks interspersed with small lowland plains. The scenic beauty of the property is exceptional, enhanced by the sight of a host of tributary streams and waterfalls, the unique mosaic of forest types and the sweeping spectacles of variations of colour, form, and foliage.

Criterion (vii): Thung Yai-Huai Kha Khaeng Wildlife Sanctuary contains biological features of outstanding natural beauty and of great scientific value, including many natural features and two major watersheds with their associated riverine forests. Straddling the Shan – Thai folded mountains and its three distinct landforms, the property contains ridges that run parallel from north to south, rising to heights well over 1,500 meters. The tallest peak, Thung Yai, reaches 1,830 meters above sea level while the numerous valley bottoms within the sanctuary slope from 400 to 250 meters above sea level, creating stunning landscapes and encompassing superlative forest habitats.

Criterion (ix): Thung Yai-Huai Kha Khaeng Wildlife Sanctuary represents an outstanding and unique biome in mainland Southeast Asia, combining Sino-Himalayan, Sundaic, Indo-Burmese, and Indo-Chinese biogeography elements, with the flora and fauna characteristics of all four zones. The property encompasses significant ecological and biological processes, including habitats and biological features such as limestone habitats, mineral-licks, wetlands, and sink-holes. The savanna forest of Thung Yai is the most complete and secure example of Southeast Asia’s dry tropical forest.

Criterion (x): Thung Yai-Huai Kha Khaeng Wildlife Sanctuary has exceptional species and habitat diversity. The property supports many wild plant and animal relatives of domestic species, with many reaching the limits of their distributions in the sanctuary. Species lists have been compiled, which include 120 mammals, 400 birds, 96 reptiles, 43 amphibians, and 113 freshwater fish. In addition to many regional endemic species and some 28 internationally threatened species, at least one-third of all mainland Southeast Asia’s known mammals are represented within the boundaries of the property, providing the major stronghold for the long-term survival of many species.


Thung Yai-Huai Kha Khaeng Wildlife Sanctuary covers 622,200 hectares and incorporates two intact river systems whose watersheds are largely encompassed by the properties boundaries. Both banks of the rivers are well protected – a rare sight to find in Asia. The size of the property adequately ensures complete representations of habitats and ecological processes and the total area protected is larger than any other legally protected, single forest conservation area in mainland Southeast Asia.

The property incorporates near pristine examples of most of the principal inland forest formations found in continental Southeast Asia, including the dry tropical forest ecosystem, which is more critically endangered than the region’s equatorial rain forest. The continued existence of many species that are vulnerable to human threats is tangible testament to the integrity of the property. However, impacts from development pressures, dam and mining projects, which facilitate access to the property and illegal poaching, continue to impact the property. Legislation and management measures are in place to address these impacts.

Protection and management requirements

The Wild Animal Reservation and Protection Act B.E.2535 (1992), enforced by the Department of National Parks, Wildlife and Plant Conservation (DNP), provides the strongest legal framework for the protection of the property. The property combines two contiguous sanctuaries, Thung Yai Naresuan and Huai Kha Khang, separately established as wildlife sanctuaries in 1972 and 1974, respectively. Adjacent to a number of other protected areas, the property’s location provides additional protection.

Management and protection activities are carried out under the framework of the National Wildlife Conservation Master Plan, the management plan for the property, and an on-going living landscape programme that has developed active management approaches to address conservation challenges. The Thai Government allocates an annual budget for managing the property, along with permanent staff, equipment, and support to several research programmes in the area.

The legal basis for the protection of the property is adequate and DNP is responsible for management of both component areas of the property. The size and topography of the area have led to a good system of guard stations, despite constraints on sufficiently trained staff and equipment.

Maintaining long-term conservation of wildlife and keeping the ecosystems in Thung Yai – Huai Kha Khaeng Wildlife Sanctuary intact and healthy greatly depends on the quality of management. The Thai government is committed to on-going investment in enhancing protection of the property. Public support and increased investments in the management of the property have increased management capabilities.

Poaching remains one of the biggest threats to the values of the property and continues to be a problem, while deforestation in some parts of the buffer zone also remains an issue. The managing agency has introduced measures of positive management including an extensive system of guard stations and patrols. There are regular meetings between the wildlife sanctuary staff and local village chiefs to discuss conservation issues, and many nearby residents are employed as support staff.

Conservation awareness activities have been initiated, and a research facility has also been set up. Continued development pressures in the area, including agricultural development, dam projects and mining to the east and south of the property involving road construction, facilitate access to the property and enable poaching to continue.

Long Description

The site comprises two contiguous wildlife sanctuaries: Thung Yai and Huai Kha Khaeng, alongside the western international border with Myanmar, 300 km north-west of Bangkok.

The terrain in Huai Kha Khaeng is generally hilly with many permanent and seasonal streams. The highest peak lies in the extreme north of the sanctuary. Valleys are interspersed with small lowland plains. In Thung Yai the topography is more dissected with a network of many permanent rivers and streams dividing the area onto valleys and lowland plains. A distinguishing feature is a large central grassland plain, from which the Sanctuary takes the name of Thung Yai ('big field'). Within the catchment area are four important rivers, one of which flows through Burma to the Andaman Sea.

A physical feature that is important for wildlife is the presence of mineral licks. These occur throughout the sanctuary as either wet or dry, and most appear to be located on, or around, granite intrusions in areas with red-yellow podzolic soil and may be associated with the massive faults or lineaments in the intensely folded geomorphology of this area. Small lakes, ponds and swampy areas occur, some being seasonal whereas others are perennial; these are important wildlife habitats; limestone sinkholes are found.

Five types of forest can be distinguished: the highest slopes are covered with hill evergreen forest, whereas slopes above 600 m generally support dry semi-evergreen forest. The rest of the sanctuary supports mixed deciduous and bamboo forest, and dry dipterocarp forest in areas with poor or shallow soil. Along some rivers and streams, evergreen gallery forest occurs.

Thung Yai also has two specific features not common in other areas which add to its uniqueness. One is the existence of a large grassland plain and surrounding savannah forest made up of cycads and Phoenix palm, a feature not known elsewhere in the region. The second feature is the existence of Thailand's most extensive riparian forests.

The fauna of both Thung Yai and Huai Kha Khaeng includes an unusual mix of species with primarily Sundaic, Indo-Chinese, Indo-Burmese and Sino-Himalayan affinities, many of whose ranges do not overlap. Species lists have been compiled that include 120 mammals, 400 birds, 96 reptiles, 43 amphibians and 113 freshwater fish. 34 internationally threatened species are also found within the confines of the two sanctuaries. It also is home to 22 species of woodpecker, more than any other park in the world. The reason for such exceptional diversity is partly due to its status as one of only two evergreen forest refuges during the driest periods of the Pleistocene glaciations. Few areas in Asia are large enough to support viable populations of large herbivores (300 elephants) and predators (e.g. tigers).

Being contiguous with the forest of Myanmar there are longer term prospects for a transfrontier reserve between the two countries. This would greatly add to its integrity as there is cross-border migration of some species and Thai logging concessions in Myanmar could be reduced.

Some 3,800 tribal people live within Thung Yai, whereas there is no resident population within Huai Kha Khaeng.



The species listed below represent a small sample of iconic and/or IUCN Red Listed animals and plants found in the property. Clicking on the number in brackets next to the species will reveal other World Heritage Properties in which a species has been identified. These species are identified in an effort to better communicate the biological diversity contained within World Heritage properties inscribed under criteria ix and/or x.

Aceros nipalensis / Rufous-necked Hornbill, Rufous-cheeked Hornbill
Albizia odoratissima
Anisoptera cochinchinensis
Aonyx cinerea / Asian Small-clawed Otter, Oriental Small-clawed Otter, Small-clawed Otter (2)
Bauhinia acuminata
Bos gaurus / Gaur, Indian Bison (4)
Bos javanicus / Banteng, Tembadau (3)
Bubalus arnee / Asian Buffalo, Asiatic Buffalo, Indian Buffalo, Indian Water Buffalo, Water Buffalo, Wild Asian Buffalo, Wild Water Buffalo
Cairina scutulata / White-winged Duck, White-winged Wood Duck
Capricornis sumatraensis / Serow, Sumatran Serow