iv) Bark and dead wood as dietary components
Groups fed extensively on bark and/or dead wood at certain times of year (Fig. 22). Dead wood was never eaten in the south, but bark formed an important dietary item during the dry season. In September 1970 Group III spent 15.5% of total feeding time eating the bark and cambium di Operculicarya decaryi. This wood contains 81% water by weight. Animais gouged out the thin-barked, soft, moist wood with their "toothcombs," leaving scars on the trunk up to 1 cm. deep and 4 cm. long. In June 1971 animais again began to eat this wood. In June 1974 Group III spent prolonged periods eating the bark of C. grevei. The water content of this wood was not estimated but was evidently no higher than in many other species. It is interesting to note that this bark is extensively used for medicinal purposes by the Malagasy.
In the north, both groups ate bark to the exclusion of dead wood in the dry season, and dead wood almost to the exclusion of bark in the wet season. The bark eaten in the dry season came mainly from thin branches of Commiphora pervilleana; the bark alone was stipped off, using first the "tooth-comb" to prise up the bark and then the premolars to tear it off. The underlying wood was not gouged out as in the south and the bark appeared to contain little water.
In the wet season, dead wood was a major item in the diet of both Groups I and H. Each group would daily cluster round a dead tree trunk and tear off splinters of wood with their "tooth-combs" and premolars. Only two hunks of dead wood were used by each group in this way, although other trunks were present in the home-ranges of both that did not differ noticeably from those used as food sources; the

Behavioral Variation: Case Study of a Malagasy Lemur Par Alison F. Richard