Site description This complex is located 30 km north-east of Morombe, and comprises Lake Ihotry, the Mangoky river and delta, and associated riverine marshes near the Ankiliabo–Nosy Ambositra road. The lake is brackish and c.3 m deep. Its area varies seasonally, from 960 ha up to 11,200 ha, and it is only sparsely vegetated, with some reed Phragmites, sedge Cyperus and water-lily Nymphaea. Mangrove, dominated by Rhizophora and Avicennia, occurs all along the delta coast, from Mangolovolo to Andranopasy. The marsh vegetation consists mainly of Cyperus, reed-mace Typha, Typhonodorum, Phragmites and Nymphaea. Near the wetlands, on sandy soil, there is dry deciduous forest, dominated by Didiereaceae and Euphorbiaceae, as well as sub-arid spiny bushland, and savanna with occasional trees of Tamarindus and Zizyphus.
Key Biodiversity See Box and Tables 2 and 3 for key species. One hundred and six species are known from this site, of which 23 are endemic to Madagascar. Amaurornis olivieri was found in the marsh of Nosy Ambositra in 1960, but has not been recorded since then. Lake Ihotry is an exceptional site for foraging and roosting waterbirds, notably during the northern winter. During the dry season, muddy areas attract large numbers of waders, and the site is also a dry-season refuge for waterbirds that use the seasonal wetlands between Morombe and Toliara. Significant numbers of Phoenicopterus ruber and Tachybaptus ruficollis have been observed, and also large numbers of other birds, such as Anas erythrorhyncha and Tringa nebularia.