With the recent descriptions of several new species of Lepilemur from eastern Madagascar, the range of L. mustelinus has become unclear. Based on the interpretation of the distributions of Louis et al. (2006), this species now occurs north of the Mangoro and Onive Rivers (with M. betsileo apparently occurring to the south) north at least to the Onibe, and possibly further. Louis et al. (2006) assigned the sportive lemurs from Mananara-Nord, south of the Antainambalana River, to L. seali. In the past these have been attributed to L. mustelinus. The Maningory is here arbitrarily assigned as the limit between L. mustelinus and L. seali, but clearly this requires further investigation.