Harmonious Protected Landscape · South Region · Protected Areas of Madagascar
Amoron'i
Onilahy
A subarid limestone plateau carved by the Onilahy river — 100,482 hectares of spiny thicket, gallery forest and seasonal marshland sheltering ring-tailed lemurs, Verreaux's sifakas, and 89 bird species in Madagascar's deep south-west.
About the protected area
A limestone plateau carved by the Onilahy
The Amoron'i Onilahy Harmonious Protected Landscape covers 100,482 hectares in south-west Madagascar. It is managed by WWF, with a management infrastructure based in Toliara. The landscape is dominated by a limestone plateau traversed by the Onilahy river, and encompasses a network of lakes and marshes — including those of Ranomay, Ifanato, Mahaleotse, and Antafoke — along with seasonally flooded zones.
To reach the site, take the RN7 east from Toliara for 70 km, then turn south towards Ambohimahavelona. The site can also be reached by boat or pirogue from Saint-Augustin or from Tongobory (62 km south of Andranovory). An interpretation centre with a welcome desk and a community-managed guesthouse are located at Ambohimahavelona (7 lakes). Circuits are available by motorbike or quad along the Onilahy, or by pirogue descent of the river.
The Onilahy river descent by pirogue offers one of the most immersive ways to experience the landscape — skirting gallery forest, limestone bluffs, and the marshes of the Seven Lakes at Ambohimahavelona.
Fauna and Flora
Spiny thicket and gallery forest, rich in endemic wildlife
The vegetation is characteristic of the south-western spiny thicket, rich in Euphorbia. Along the banks of the Onilahy, gallery forest develops, dominated by Tamarindus indica, Diospyros, and Ficus. Marshes line the shores of the lakes and the river, and extend into seasonally flooded zones. Pachypodium rosulatum is a notable emblematic species of the area.
The fauna is particularly rich: 54 reptile species, 89 bird species, 15 bat species, and 8 lemur species including Lemur catta, Propithecus verreauxi, Microcebus murinus, and Lepilemur sp.
Culture and Heritage
Agriculture, charcoal and a retreating forest
The communities within the protected area practise slash-and-burn agriculture (hatsake) and exploit the forest for timber and charcoal production. Human settlement inside the protected area itself adds pressure on the remaining habitat.
Forest loss is significant: gallery forest has declined by 55%, while spiny thicket cover has been reduced by 33.5%. These figures reflect a landscape under sustained anthropogenic pressure across both of its major vegetation types.
Identified threats
Location
South-West Madagascar, Atsimo-Andrefana Region
The Amoron'i Onilahy Harmonious Protected Landscape lies 70 km east of Toliara, accessible via the RN7 then south towards Ambohimahavelona. The site can also be reached by boat or pirogue from Saint-Augustin or from Tongobory, 62 km south of Andranovory.