The site is located 35 km west of Belo-sur-Tsiribihina. The Tsiribihina delta includes the shoreline, sandbanks, lagoons, coastal mudflats, mangrove forest, saltflats, and areas of marsh and of dry land. The mangrove is 2–4 m high, and dominated by trees of Avicennia, Rhizophora, Ceriops, Bruguiera and Sonneratia. The saltflats often flood during the rainy season. The marshy areas are dominated by sedge Cyperus, reed Phragmites and non-native water-hyacinth Eichhornia, while the dry land is covered in savanna, with palms. The wetlands of the upper Tsiribihina river include the neighbouring lakes, and the Sahajilo and Mania rivers. Lake Kimanomby, west of Ambohibary village, is surrounded by dense, dry deciduous forest (Ambovondambo Forest to the west, Marotapia Forest to the east). There is no floating vegetation, but the margins are covered by Eichhornia. Lake Masoarivo, west of Masoarivo village, is small, shallow and red due to muddy sediments. Lake Hima has floating vegetation and is surrounded by fishermen’s camps. In the Tsiribihina valley, between the towns of Miandrivazo and Malaimbandy, there are several lakes and a vast area of marshes, dominated by sedge Cyperus and reed Phragmites.
See Box and Tables 2 and 3 for key species. Eighty-two species have been recorded, of which 22 are endemic to Madagascar. There are a few pairs of Haliaeetus vociferoides, including at least one in the upper valley of the Tsiribihina, and Anas bernieri breed in the mangroves. There are large congregations of Glareola ocularis on the banks of the Tsiribihina, and one of the most significant congregations of Thalassornis leuconotus insularis in Madagascar can be found in Masoarivo.
Non-bird biodiversity: Lemurs: Propithecus verreauxi deckeni (VU), P. verreauxi coronatus (CR). Reptile: Boa madagascariensis (VU).
BirdLife International (2020) Important Bird Areas factsheet: Wetlands of the Tsiribihina delta and upper Tsiribihina river. Downloaded from http://www.birdlife.org on 04/07/2020.