The IBA comprises Khao Sam Roi Yot National Park (9,808 ha) and surrounding wetlands (3,242 ha), situated on the western coast of the Gulf of Thailand. The site supports an extensive area of brackish and freshwater coastal wetlands at the foot of steep limestone mountains covered with mixed deciduous woodland. One of the most notable features of the site is that it encompasses the largest remaining freshwater reedswamp in Thailand, totaling almost 7,000 ha. The freshwater marsh comprises extensive beds of Phragmites reeds and other tall emergent swamp plants, open water with Lotus Nelumbo nucifera and other floating and submerged plants, extensive grazing marshes in which mud and shallow water alternate with short grass, and rice paddies. Other habitats represented at the site include coastal flats, sandy beaches, slow-flowing streams, narrow fringes of mangrove along the river mouth margins, estuarine mudflats, rocky cliffs, shallow sea and offshore islands.
Khao Sam Roi Yot National Park and surrounding wetlands is the most important known site in Thailand for the globally threatened Manchurian Reed Warbler Acrocephalus tangorum, which winters in the freshwater marshes. Several other globally threatened species have been recorded at the site, although none are thought to regularly occur in significant numbers. In addition, there are historical records of the globally vulnerable Pale-capped Pigeon Columba punicea (from 1987) and Spot-billed Pelican Pelecanus philippensis (from 1988), and the globally endangered Greater Adjutant Leptoptilos dubius (from 1984). Six globally near-threatened species have been recorded at the site, including Malaysian Plover Charadrius peronii, of which the site supports greater than 1% of the Asian biogeographic population. : The site qualifies under criterion A3 because it supports six species restricted to the Indo-Malayan Tropical Dry Zone (Biome 11).
Non-bird biodiversity: Mammals Southern Serow Capricornis sumatraensis (VU) Bear Macaque Macaca arctoides (VU) Northern Pig-tailed Macaque Macaca leonina (VU) Fishing Cat Prionailurus viverrinus (VU) Plants Afzelia xylocarpa (EN) Burretiodendron esquirolii (VU) Wrightia lanceolata (VU)
BirdLife International (2020) Important Bird Areas factsheet: Khao Sam Roi Yot. Downloaded from http://www.birdlife.org on 29/11/2020.