Swamp and mangrove forests in Sembilang and Semenanjung Banyuasin is the widest swamp and mangrove forests, and almost undisturb. This area is an example of swamp forest ecosystem in Indo-Malayan, that supporting life of threatened species. Some of small rivers flowthrough from the swamp to the east, and the biggest is Lalang river. Northern part of this area is covered by natural habitat type where in mid-1980s more than 115000 ha mangrove (bakau) forest and 232000 ha swamp forest (freshwater and peat swamp forest). Land clearence, land conversion and also fire occured in 1997, reduction remaining total area up to 82000 ha mangrove forest and 129000 ha swamp forest.In the beginning the area has a complete wetland acosystem, including herbaceous swamp, but further survey is needed to find out the existence of the remaining wetland ecosystem types because of fire.This area comprises as Terusan Dalam Game Reserve, Sungai Sembilang Protection Forest and production swamp forest which are located in south of Lalang River.Around 20% of this area is a conservation area, and more least 50% used for logging (legal and illegal). Remaining area is used for fisheries, mangrove conversion, ponds and plantation.
This area is a breeding site of Storm's Stork Ciconia stormi (Kadarisman 1991). Waterbird colonies also found in Semenanjung Banyuasin, in swamp area before the mangrove forest around 3-4 km in land (2500 m2). Based on an air survey on 1-2 September 1988, there were estimated 280 nests, of which about 250 Milky Stork Mycterea cinerea nests with 100 chicks observed, together with Black-headed Ibis Thereskiornis melanocephalus and 250 Great Egret Egretta alba. So far, only this area known as the breeding colony of Black-headed Ibis Thereskiornis melanocephalus, although breeding time need to investigated. The other record observed in this area are Spot-billed Pelican Pelecanus philippensis (uncertain population), Lesser Adjutant Leptoptilus javanicus, White-winged Duck Cairina scutulata, and other wetland forest birds. 1500 Milky Stork Mycterea cinerea conted in 1991, 400 Lesser Adjutant Leptoptilus javanicus and 750 Black-headed Ibis Thereskiornis melanocephalus. Although not yet reported, but this area is predicted to support Hook-billed Bulbul Setornis criniger and Grey-breasted Babbler Malacopteron albogulare. Greater Goldenback Chrysocolapter lucidus is the residence bird in mangrove (the only area known for this bird outside North Sumatra province).White pigeons reported common in this area, it might be Columba argentina. This species is difficult to differentiate from Pied Imperial-Pigeon Ducula bicolor, but the probability need to be considered. Tidal mudflats around Semenanjung Banyuasin is the main transit and wintering ground for waders, no less than 35000-40000 birds recorded in 1984-1986 (Silvius 1988), which include 30000 Black-tailed Godwit Limosa limosa in 1985, around 13000 Asian Dowitcher Limnodromus semipalmatus and 21 Nordmann's Greenshank Tringa guttifer in 1988 (Verheugt et.al. 1993).
Non-bird biodiversity: Elephas maximus, Pathera tigris, Neofelis nebulosa, Tapirus indicus and Hylobates syndactylus.
BirdLife International (2019) Important Bird Areas factsheet: Sembilang. Downloaded from http://www.birdlife.org on 19/08/2019.