The IBA comprises Umphang Wildlife Sanctuary, which is situated in the Tenasserim range, along the international border between Thailand and Myanmar. The site is located within the Western Forest Complex, and is contiguous with Thung Yai-Naresuan Wildlife Sanctuary (IBA TH025) to the south, Huai Kha Khaeng Wildlife Sanctuary (IBA TH026) to the south-east, Mae Wong (IBA TH023) and Khlong Wang Chao National Parks to the east, and Namtok Pacharoen National Park to the north. Part of the site is mountainous with some high cliffs, and part consists of rolling hill slopes of low to moderate elevation. Tropical dry evergreen forest is the dominant vegetation type, covering c.148,200 ha, and generally distributed above 1,000 m asl. Deciduous forests cover c.87,500 ha, chiefly at lower elevations, and there are small pockets of tropical dry evergreen forest in the north-west and tropical moist evergreen forest in areas of higher humidity in the south.
The site supports a population of the globally threatened Rufous-necked Hornbill Aceros nipalensis. There is also an historical record of the globally vulnerable Greater Spotted Eagle Aquila clanga from 1987. Two globally near-threatened species occur, Great Hornbill Buceros bicornis and Brown Hornbill Anorrhinus tickelli, both of which breed at the site. The higher elevation forests hold Burmese Yuhina Yuhina humilis, the restricted-range species that defines the Myanmar-Thailand Secondary Area, and several resident montane evergreen forest species characteristic of more northerly areas, including Long-tailed Wren Babbler Spelaeornis chocolatinus, Rusty-capped Fulvetta Alcippe dubia, Chestnut-tailed Minla Minla strigula, Yellow-bellied Fantail Rhipidura hypoxantha, Brown-throated Treecreeper Certhia discolor, White-browed Shortwing Brachypteryx montana and Green-tailed Sunbird Aethopyga nipalensis. The latter may be the endemic subspecies A. n. angkanensis known from Doi Inthanon National Park (IBA TH001). The site qualifies under criterion A3 because it supports two species restricted to the Sino-Himalayan Temperate Forests (Biome 07), 37 species restricted to the Sino-Himalayan Subtropical Forests (Biome 08) and 15 species restricted to the Indochinese Tropical Moist Forests (Biome 09).
Non-bird biodiversity: Mammals Asian Elephant Elephas maximus (EN) Tiger Panthera tigris (EN) Gaur Bos frontalis (VU) Long-tailed Goral Naemorhedus caudatus (VU) Asian Black Bear Ursus thibetanus (VU) Reptiles Elongated Tortoise Indotestudo elongata (EN) Asian Giant Tortoise Manouria emys (EN) Impressed Tortoise Manouria impressa (VU)
BirdLife International (2019) Important Bird Areas factsheet: Umphang. Downloaded from http://www.birdlife.org on 25/05/2019.