|dc.description.abstract||In this study I analyzed the effects of microhabitat (botanical structure and
composition within the home range) on the behavioral ecology of a small-bodied
folivorous lemur, Hapalemur griseus. I found that despite being a bamboo specialist,
this species is flexible in its diet, activity, and ranging patterns. I followed three
groups of H. griseus for one year (Jul. 1998-Aug. 1999) at two sites within
Ranomafana National Park, in southeastern Madagascar. The two sites differed in
altitude, degree of habitat disturbance, and lemur species composition. The two sites
also differed in population density, with Talatakely (Tala), the more disturbed and
lower altitude site, having a population density nearly three times that of
Vatoharanana (Vato). I found not only site differences in botanical structure and
composition, but differences between the home ranges within site as well. These
differences impacted the diets of each group, which differed on an annual and
seasonal basis. Diet was most influenced by the resources available within the home
range, as each group focused feeding on more abundant species. All groups ate large
amounts of bamboo, but leaves of Ficus spp., fig and guava fruit, mushrooms, and
dirt also played a large role in the diet of this species. All groups of H. griseus
supplemented their mostly bamboo diet with new and mature leaves and fruit during
the rainy season, birth, lactation, and weaning. Increased dietary diversity during
reproduction may help female H. griseus combat their high metabolic needs, provide
infant H. griseus with better weaning foods, and help male and female adult H.
griseus to prepare for the upcoming mating season. The diet of the group followed
at Tala also differed from other H. griseus groups at the same site.
Despite differences in the diet of the three groups, annual and seasonal
activity budgets did not differ. The correlation between feeding, resting, and
traveling differed for each group. Although home range size did not differ
significantly between the three groups, the home ranges of one Vato and one Tala
group differed by 43%. Daily path length, as measured by GPS readings, differed
significantly between the three groups, with the largest group having the longest
mean daily path length.
The three study groups were different in size, social structure, and social
organization: one group was monogamous, the other two were polygynous.
Regardless of group size, females were dominant to males. Both male and female H.
griseus migrate from their natal groups, but it appears that females may leave at an
earlier age than males. The group composition of the two Vato groups was fairly
stable throughout the study, whereas the Tala group, the largest of the three, had two
immigrations and three confirmed emigration events. Infant mortality varied
between the three groups from 0-100%. This study shows that this bamboo
specialist is flexible in diet, activity, ranging patterns, and social structure and
organization. Each aspect of this species’ behavioral ecology is adapted to suit the
home range used and the resources available therein.||