As the common name suggests, bamboo lemurs specialise in feeding almost exclusively on bamboo (2) (6) (9), and are the only primates known to do so (5) (8). Bamboo constitutes at least 75 percent of the diet of the eastern lesser bamboo lemur, with the rest made up of fig leaves, grass stems, other young leaves, small fruits, flowers and fungi (3) (5) (9). Each species of bamboo lemur appears to specialise on different parts of the bamboo plant (2) (10), with the eastern lesser bamboo lemur preferring the new shoots, leaf bases and stem pith (2) (3) (5) (9). However, some bamboos contain toxic cyanide compounds that would poison most other mammals. How bamboo lemurs deal with these toxins is not exactly known, but the eastern lesser bamboo lemur may limit its intake by selecting young growth, which contains lower cyanide levels (8) (9). It also appears to have a more flexible diet than other bamboo lemurs, using different bamboo species or different food sources depending on the season (9) (11), which may help explain its wider geographic distribution (9). Although often considered cathemeral, with regular bouts of activity both day and night (3) (5), others report the eastern lesser bamboo lemur to be mainly diurnal (11). Group size ranges from around two to nine, with each group typically containing an adult male, one or two breeding females, and offspring (3) (5) (8) (9). The adults are highly territorial, defending the group's territory with scent-marking, vocal displays and chases. Breeding occurs between October and January, the female usually giving birth to a single offspring each year, after a gestation period of 137 to 140 days. The infant may be carried in the female's mouth for the first few weeks, after which it may ride on the female's back, or be “parked” for short periods while the female is foraging (3) (5) (8). The young eastern lesser bamboo lemur is weaned after about four months, and young of both sexes are thought to disperse from the group on reaching maturity (5) (8). In captivity, the eastern lesser bamboo lemur may live up to 17 years (6).