Crowned lemurs are primarily active in the day, though occasionally they are nocturnal (4). They live in groups of 5-15 individuals, although 5-6 is the norm. While foraging, groups may split into smaller units of 2-4 animals, maintaining contact with others using guttural grunts (2). This species feeds mainly on fruit, leaves and occasionally vertebrates and bird eggs. It forages at all levels of the canopy, though it seems to prefer the lower levels where there is less competition with Sandford's Brown lemur (Eulemur fulvus sanfordi) (2). Mating occurs in May and June and, after a gestation period of about 125 days, one or two young are born. Births coincide with the onset of the rainy season and therefore an abundance of food (2). Infants are initially carried on the mother's front but as they grow heavier they are moved onto her back. Individuals reach sexual maturity after two years (4).