This area is probably the most fertile area in Kalimantan, and as a result, population is very high compare with other area in Kalimantan.Rawa Negara located between Barito River and Meratus mountains. Swamp with open surface and depth water, up to Bangkau Lake, Panggang Lake and Sembujur Lake formed seasonal floodplain and protect down stream from flood and salt water intruition (MacKinnon et.al. 1996). Local people genarally from Banjar ethnic has an interesting landuse system. They utilized several rice varieties, which grow on dry land and variety that can float during flood. They also do buffallo and duck farming.
Some species such Snakebirds, Storks and Herons have become rare. Hornbill already extinct from the remaining swamp forest. There is no significant waterbird colony although population of Javan Pond-heron Ardeola speciosa is very high & probably live in this area for breeding. Lesser Adjutant Leptoptilus javanicus still can be found in small population. There are bird flock in medium size group such as Ducks. Opened swamp is important for Rails and Morhen habitat, especially for Comb-crestled Jacana Irediparra gallinacea, a species which only known from this site in Kalimantan. Dusky Morhen Gallinula tenebrosa breeds in Danau Bangkau (Grabowsky 1985) and has not been recorded from other area in Kalimantan. Beside that, migratory bird such as Whiskered Tern Chlidonias hybridus and White-winged Tern Chlidonias leucopterus sometime visit this site in substantial number. Also recorded is Red-breasted Parakeet Psittacula alexandri although this species has become very rare now. White-shouldered Ibis Pseudibis davisoni probably lives in this area.
Non-bird biodiversity: Nasalis larvatus, Pongo pygmeus, Hylobates agilis, Presbytis rubicunda, Presbytis melalophos, Helarctos malayanus, Tomistoma schlegelii and might be Scleropages formosus (Scott 1989).
BirdLife International (2022) Important Bird Areas factsheet: Lembah Sungai Negara. Downloaded from http://www.birdlife.org on 25/06/2022.