Species: Hapalemur griseus
Common: Gentle Bamboo Lemur
According to Walker’s Primates of the World there are three species in the genus Hapalemur, however the ADW lists four.
The gentle, or bamboo, lemur resides on the island of Madagascar and, as its name implies, lives primarily in bamboo forests. All three species eat bamboo but specialize on different portions of the plant. The gentle bamboo lemur is the smallest of the three, weighing around two kilograms. They display mild sexual dimorphism. They are most active in the early morning or evening, although they have been observed being active through out the day. One subspecies, Hapalemur griseus alaotrensis is semiaquatic and swims quite well. They live in group of 3-6 individuals (higher in the subspecies). The are primarily vertical clingers and leapers (and have longer legs than arms) but they do engage in some quadrupedal behavior on the ground and when moving along branches. Their teeth are somewhat specialized with serrated edges (except the molars) for eating the tough bamboo. They also have an expanded olfactory and olfactory signals play a role in communication (related to that, the male has a gland on the inner side of their wrist, the gland is covered by a rough patch of skin, which, in turn, is covered by spinelike processes which probablely serves the same function as the gland in ring-tailed lemurs.
The behavior seen in the above picture, of the baby riding on the mother, is somewhat atypical. Usually, the offspring are parked, that is left in nests or holes in trees, etc.