Zahamena

Zahamena National Park covers 642 square kilometres in Alaotra-Mangoro Region of east-central Madagascar, protecting a large block of mid-altitude rainforest on the eastern escarpment. Part of the Rainforests of the Atsinanana UNESCO World Heritage Site, Zahamena is one of the most intact sections of the eastern rainforest corridor. The park's remoteness and difficult access have helped preserve both its forest cover and wildlife populations, making it a priority area for conservation of endemic eastern Madagascar species.

Zahamena harbours fourteen lemur species—one of the highest counts of any protected area in Madagascar—including the diademed sifaka, indri, aye-aye, black-and-white ruffed lemur, and greater bamboo lemur. The park's intact forest provides refuge for forest-dependent species lost from more disturbed areas. The bird fauna is rich with Afromalagasy endemics. Chameleons including the enormous Parsons chameleon, geckos, and an extraordinary diversity of frogs—many endemic to the eastern rainforest—inhabit all elevation zones.

Zahamena's rainforest is characterised by high canopy diversity with Canarium, Symphonia, Ocotea, and numerous palm species. The park spans an elevation range from approximately 750 to 1,550 metres, creating distinct vegetation zones from lowland rainforest through mid-altitude forest to montane cloud forest. Each zone has distinct species composition and characteristic epiphyte communities. Bamboo is particularly abundant in some areas, providing habitat for bamboo lemurs. The park contains hundreds of orchid species and exceptional plant endemism.

The park occupies a section of the eastern escarpment underlain by Precambrian metamorphic rocks—gneisses and schists—typical of Madagascar's crystalline basement. The terrain is deeply dissected by river erosion, with steep valleys and ridges. The eastern escarpment orientation—perpendicular to the Indian Ocean trade winds—intercepts moisture from the Indian Ocean, generating the high rainfall that maintains the rainforest. Several rivers with their headwaters in Zahamena flow eastward toward the coast and westward toward the Alaotra Basin.

Zahamena receives high rainfall throughout the year, with annual totals of 1,800–2,500 millimetres. The wet season from November to April is the period of heaviest rain, when cyclones occasionally cause severe flooding and tree fall. The drier months from May to October offer better trekking conditions. Cloud and mist are frequent at higher elevations year-round. The park's eastern escarpment position means it is exposed to the full force of Indian Ocean weather systems.

The Betsimisaraka people inhabit the coastal lowlands and river valleys east of Zahamena, while Sihanaka people live in the Alaotra Basin to the west. The forest between these communities has historically been used for shifting cultivation, timber extraction, and charcoal production. The park area was progressively cleared over the twentieth century on its margins, leaving the higher, more remote interior as intact forest. Several communities have ancestral connections to the forest areas within the park.

Zahamena was first protected as a strict nature reserve in 1927. Boundaries were extended and it was redesignated as a national park in 2002. The park is part of the Corridor Ankeniheny-Zahamena (CAZ), a major conservation initiative connecting Zahamena with Mantadia National Park and intervening forest fragments in a continuous north-south rainforest corridor. WWF and the Critical Ecosystem Partnership Fund have supported conservation in the corridor area.

Zahamena is a wilderness destination requiring multi-day guided expeditions. Entry points at Antanandava in the north and Onibe in the south require long approaches on foot. Wildlife encounters are exceptional for those who make the journey—multiple lemur species, rare birds, and extraordinary reptile and frog diversity. The park's remote character and relatively undisturbed forest give encounters an authenticity rare in more accessible parks. Scientific expeditions regularly use Zahamena as a research site.

There are no visitor facilities within the park. Entry is from Ambatondrazaka (Alaotra-Mangoro Regional capital) or via coastal villages. Ambatondrazaka has basic hotels and is reached by road from Antananarivo (approximately 250 kilometres). Local guides and porters are essential, arranged through the park service in Ambatondrazaka. Multi-day camping expeditions require full self-sufficiency. The best season is June to October. The park is recommended for experienced wilderness travellers.

Zahamena's conservation status is threatened by encroachment from surrounding communities, illegal logging, and charcoal production on its margins. The Corridor Ankeniheny-Zahamena (CAZ) project has been a major regional conservation initiative connecting forest fragments and supporting community forest management. Despite these efforts, satellite imagery shows ongoing deforestation at the park's edges. The park's large size and difficult terrain provide core areas of intact habitat. International conservation funding through WWF and the Critical Ecosystem Partnership Fund is essential for continued protection.