Lower Central Basin

Country/territory: Thailand

IBA criteria met: A1, A4i, A4iii (2004)
For more information about IBA criteria, please click here

Area: 190,000 ha

Bird Conservation Society of Thailand
IBA conservation status
Year of assessment (most recent) State (condition) Pressure (threat) Response (action)
2013 not assessed high low
For more information about IBA monitoring, please click here

Site description (2004 baseline)
The IBA comprises the Lower Central Plain of the Chao Phraya River, which extends inland from the Gulf of Thailand and encompasses the environs of Bangkok. The Lower Central Plain was formerly a vast area of natural and semi-natural swamps, well-watered throughout the year by four major rivers: the Chao Phraya, Bang Pakong, Pasak and Mae Klong. However, the area was the focus of massive irrigation system developments in the early 20th Century, and current land-use is dominated by intensive rice cultivation, with only small remnant patches of wetland habitats and extensive agriculture. Due to high human population density and levels of use, it is unrealistic for anything but a small fraction of the area to be placed under strict conservation management. However, the Lower Central Plain was designated as a single IBA because conservation actions aimed at controlling hunting and promoting compatible forms of land-use are required across the whole area. Sites within the IBA currently afforded some protection include Wat Phai Lom (11 ha), Wat Tan En (16 ha), Bung Chawak (320 ha) and Wat Ratsattha Krayaram (7 ha) Non-hunting Areas.

Key biodiversity
Several globally threatened species occur in the Lower Central Plain and the area regularly supports well in excess of 20,000 waterbirds. A number of globally threatened species regularly occur at the site, some of them in significant numbers. The site regularly supports significant numbers of wintering Greater Spotted Eagle Aquila clanga and Manchurian Reed Warbler Acrocephalus tangorum, and very low numbers of wintering Baer's Pochard Aythya baeri and Imperial Eagle Aquila heliaca. Spot-billed Pelican Pelecanus philippensis is an occasional non-breeding visitor, while Baikal Teal Anas formosa and Greater Adjutant Leptoptilos dubius are vagrants. In addition, there are historical records of the globally vulnerable Lesser Adjutant Leptoptilos javanicus. In recent years, the site has supported over 1% of the Asian biogeographic population of Grey-headed Lapwing Vanellus cinereus, Intermediate Egret Mesophoyx intermedia and the globally near-threatened Painted Stork Mycteria leucocephala. Other globally near-threatened species to occur at the site in significant numbers are Asian Golden Weaver Ploceus hypoxanthus and Black-headed Ibis Threskiornis melanocephalus, while Oriental Darter Anhinga melanogaster and Band-bellied Crake Porzana paykullii have also been recorded, although not in significant numbers.

Non-bird biodiversity: Fish Giant Freshwater Stingray Himantura chaophraya (EN) White-edged Freshwater Whipray Himantura signifer (EN)

Recommended citation
BirdLife International (2023) Important Bird Area factsheet: Lower Central Basin. Downloaded from on 09/12/2023.