The Lemur is of any of a group of monkeylike primate animals found chiefly on the island of Madagascar. They are represented on Madagascar by the ring-tailed lemur (Lemur catta) and other members of the genus Lemur, the aye-aye (Daubentonia madagascarensis), and the indri, or sntrina (Indri indri). The ruffed lemur (L. varia) is the most handsome of the Madagascar lemurs.
Probably the best-known species is the ring-tailed lemur, which is easy to raise in captivity. It ranges in length from 12 to 18 inches (30-45 cm) not including the tail, which may be longer than the body. It has light-colored fur and resembles a squirrel in its movements. Although lemurs are generally nocturnal, the ring-tailed lemur travels by day in bands of 4 to 12 individuals foraging for leaves and fruits and preying on small animals.
The aye-aye, the most aberrant of the lemurs, is classified in a separate family (Daubentonidae). It reaches a length of 16 inches (40 cm), not including its long bushy tail, which may be 2 feet (60 cm) long. The third finger on its hand is long and flexible and used for probing for insects in tree bark crevices and for scooping out the contents of eggs. The indri, the largest lemur, is about 3 feet (90 cm) long. It has thick silky fur, a stubby tail, and is capable of walking on its hind legs. It forages almost entirely in trees.
Lemurs are of great interest in the study of evolution because they show the conditions of the earliest members of the order to which man belongs. Modern lemurs resemble their fossil ancestors, which were widespread 50 million years ago. Evidently their isolation on Madagascar was the main factor in preventing them from being displaced by competing types of animals.
The primitive nature of lemurs is shown by their anatomy and behavior. The olfactory (smell) centers of the brain are well developed, and the eyes (directed sideways) do not permit binocular vision. The cerebral hemispheres, usually associated with intelligence, are small. The lemur skeleton also shows a number of primitive features not observed in the skeletons of the higher primates.