It’s hard to imagine an isle that could better bring to life the Treasure Island of legend than Nosy Mangabe. As you approach it from Maroantsetra, its steep flanks, festooned with rainforest trees from sea to summit, look all but impenetrable; low clouds drift through the dense canopy of forest giants and flocks of white egrets crowd their branches.
The island, thought to be one of the earliest human settlements in Madagascar, was colonized some 1200 years ago, and has a long history as a secure bolthole in a region of rough seas – though it no longer has any permanent inhabitants. European slave traders and pirates made it a base in the seventeenth and eighteenth centuries and most of its trees were felled for fuel and boat-building. Later the forest recovered and the island is once again thickly covered in lowland rainforest. Cultural artefacts remain here, in the shape of Betsimisaraka tombs and seventeenth-century Dutch rock engravings.
Just five square kilometres in extent, rising steeply to a summit of 264m, Nosy Mangabe’s big draw is its remarkable forest and wildlife. On such a small island, so magnificently endowed with natural riches, every step you take is a delight. It’s an easy stroll along the main path through the woods behind the beach, which is broad and level, and the best one to explore if you’re short on time. Walking here can be very slow progress, as you stop every couple of metres to look at something on either side or overhead.
The island is home to five species of lemurs. Three of these are nocturnal: a still unidentified mouse lemur, the greater dwarf lemur (Cheirogaleus major) and – notoriously – the aye-aye. Aye-ayes were brought from the mainland to Nosy Mangabe in 1966 when they were thought to be on the verge of extinction. They flourished here and were seen quite often for several decades. Since the turn of the century, however, sightings have been very rare, and with night walks forbidden (after two visitors made off with suitcases loaded with fauna), your only opportunity will be a highly unlikely sighting by day or a chance encounter at dawn. You will see their untidy nests though, and large of flakes of bark at the base of afzelia trees: Nosy Mangabe is the only area where aye-ayes are known to eat bark.
While you probably won’t see an aye-aye, both species of diurnal lemurs are likely to visit you around the visitor centre: the male white-fronted brown (Eulemur albifrons) is noticeable for his white beard, cheeks and crown; the plain brown female looks like a different species. The rare local variety of the black-and-white ruffed lemur (Varecia variegata subcincta) is unmistakeable and particularly inquisitive. Nosy Mangabe is one of their last secure habitats.
Lizards and insects
On walks through the woods, your guide will be eager to find you a leaf-tailed gecko (Uroplatus fimbriatus), an extraordinarily well-camouflaged lizard whose markings and scaly flaps blend perfectly with tree bark. If you’ve done your homework you may see the adult geckos independently of your guide: resting on trees alongside the path and measuring up to about 25cm in length, they spend the daylight hours asleep, head downwards, clinging tightly to small tree trunks. Even when spotted, they tend not to flee, but rear up, open their mouths threateningly, wag their tails and issue a high-pitched squeal. One explanation for why these lizards are so common is the strange absence of couas from the island’s bird list; blue couas in particular are very partial to soft, hatchling geckos.
Other lizards to look out for are the emerald-green, skink-like arboreal Zonosaurus boettgeri and its humbler forest-floor-based cousin Z. madagascariensis. Also down in the leaf litter you’ll find tiny Brookesiachameleons: B.superciliaris, with its comically raised “eyebrows” is aptly named. In the bushes, look out for bigger chameleons too, and for some huge caterpillars: one species, bright red, with large “eyes” on its side seems bent on convincing predators it’s another predator.