The critically endangered blue-eyed black lemur (Eulemur flavifrons) is one the leaststudied day active lemurs because of the recent rediscovery and limited distribution. This thesis examined the habitat use, reproductive parameters and the population viability of the blue-eyed black lemur population at Ankarafa Forest, Sahamalaza-Iles Radama National Park, Madagascar. The main aim was to gather fundamental information on the natural history of the blue-eyed black lemur and to propose conservation approaches for both the species and its habitat. Data were collected over 14 month-period between 2006 and 2008. Six groups of the blue-eyed black lemur were studied, four of which were collared and two uncollared. Ankarafa Forest, the largest forest blocks of the Sahamalaza-Iles Radama National Park, is dominated mainly by Mangifera indica, Garcinia pauciflora, Sorindeia madagascariensis, Grangeria porosa, Bambou sp. and Mascarenhasia arborescens species. The forest is vulnerable to degradation by both anthropogenic activities and abiotic factors. The population density of the blue-eyed black lemur at Akarafa Forest was estimated to be 97.3 individuals km-², with group size ranging from 4 to 11 individuals. The home range use and day path length of the blue-eyed black lemur varied seasonally. The lemur occupied a larger home range in the dry season than in the wet season. The age of first reproduction in the blue-eyed black lemurs is about 3 years. They bear offspring seasonally (late August-October), all adult females in groups bred and females produce singletons offspring. Females were dominant over males. The sex-ratio at birth was male-biased but not significantly different from 1:1. Females were the primary caretakers of infants but group members other than the mother also provided alloparental care. For the first 3 weeks of life, infants were carried constantly on their mothers’ bellies. Infants developed independent locomotion and fed on solid food by 10 weeks. Increased probability of extinction, as shown by population viability models of the blue-eyed black lemur population, is affected by various of their reproductive parameters. However, these do not account for changes in their primary habitat forest. The latter is under increased human pressure and continues to decline in area. Education awareness and community involvement are required if the habitat and the blue-eyed black lemur are to survive. Findings of this study serve not only important data to understand the life history of the blue-eyed black lemur but also suggest conservation approaches for both the species and its natural habitat. / Thesis (Ph.D.)-University of KwaZulu-Natal, Pietermaritzburg, 2009.