The lemurs of Marojejy Strict Nature Reserve, Madagascar: a status overview with notes on ecology and threats

From mid-August to late October 1988, we surveyed Marojejy Strict Nature Reserve, in the northern part of Madagascar's rain forest. Although widely believed to be a keystone site for lemur conservation, only incidental information concerning Marojejy's primate communities has hitherto been published. The reserve extends from 75 to 2133 m in altitude, and its 60,150 ha comprise an almost-intact series of altitudinal forest zones, now fundamentally isolated from formerly contiguous surrounding forest. We visited all forest zones and all altitudes of the reserve. We observed a total of nine species including the little-known diademed sifaka (Propithecus diadema candidus), for which Marojejy is the most important site. Aye-aye (Daubentonia madagascarensis) is also present. Brown lemur (Eulemur fulvus albifrons) is the most frequently observed species. Little is known about this subspecies in the wild. In the interior, many lemurs were extremely inquisitive of human presence, showing how little hunted they are. This contrasted with their lower numbers and evasive behavior in the more accessible regions of the reserve. The major threats to the lemurs of Marojejy are the ceaseless piecemeal clearance of the reserve's forest, which is proceeding inward from the boundary, and direct trapping.