Social Behavior
A pair of black and white ruffed lemurs enjoy a fall day. Click image for larger version.
There have been a limited number of studies of ruffed lemurs in the wild. Group size seems to vary greatly - - there have been reports of groups consisting of a monogamous pair and their offspring as well as reports of much larger groups of 8-16 individuals, containing adult animals of each sex. Whatever the size of a group, all members use a common home range and aggression is seen between neighboring groups. Females form the core of the group and defend its territory. The weakest social bonds appear to be between males.
A synopsis of behavioral studies in the wild indicates an apparent preference by ruffed lemurs to utilize large trees for their activities. Rigamonti (1993) found red ruffed lemurs rested, slept and fed in trees with an average DBH of 59.8 cm; Morland (1991) found that the black and white ruffed lemurs in her study site usually spent the night in large trees of two species with an average DBH of 61.5 and 118.1 cm and showed a slight tendency to feed in larger trees during the warm season when fruit was more plentiful. Balko's preliminary work in three study sites at Ranamafana National Park showed V.v.variegata were more abundant in the site that had a higher density of large fruiting trees.
Ruffed lemurs also appear to prefer the upper half to upper third of the forest canopy. Morland reports that the upper canopy height in Nosy Mangabe forests averages 25 to 30m and the ruffed lemurs spent the greatest percent of their time mid-canopy. In Betampona, the upper canopy rarely exceeded 35m and the ruffed lemurs spent the majority of their time at a height between 15 to 35 m. White (1991) found that the ruffed lemur pair she observed rested, foraged, and traveled most frequently in the upper canopy at 20-25m. Ruffed lemurs showed the same preference for large trees when selecting nest sites.