[3] Two of rivers (Ambotohaka and Ivondro) provide water for the hydroelectric power at the Volobe dam, and along with the Marongolo, Ranomena and Sanalaotra rivers, irrigate the rice fields below the reserve and supply drinking water.

[2][4] There are few visitors due to the steep terrain and impassable roads during the wet season.

[2] The natural vegetation on the reserve is dense, low- and mid-altitude, humid evergreen forest.

[5] One hundred species of birds have been recorded on the reserve, of which 63 are endemic to Madagascar, including the endangered Madagascar serpent eagle (Eutriorchis astur) and the red owl (Tyto soumagnei), which is a vulnerable species on the IUNC Red List.

There are also nineteen species of reptiles and seven species of lemurs: Indri indri, Propithecus, Varecia variegata, Eulemur fulvus, Eulemur rubriventer, Hapalemur griseus and the aye-aye.