Madagascar's Lemurs

selectivity values (percent feeding time/relative density; Hemingway 1995) will be used to test
for correlations between food choice and availability.
Aging Data
For diurnal lemurs such as sifakas and red-bellied lemurs, data are collected with all-day follows
conducted on individuals from three age classes (young, prime age, elder). Focal animal follows
will be used to document diet, activity and height of individuals. For nocturnal species such as
mouse lemurs, radio-collared animals will be followed from 6:00 pm to 10:00 pm to determine
diet, range and activity. Mouse lemurs will be periodically trapped in Sherman live traps to be
collared, weighed and measured. Their teeth will be examined to determine age, and microchips
for positive identification will be applied. Then the animals will be released for further study.
Botanical Data
Food availability will be determined through the phenological monitoring of five mature
individuals of each of the 25 most common Propithecus food trees, two times each month. Each
time, every tree will be visited and the abundance of flower buds, flowers, unripe fruits, ripe
fruits, leaf buds, new leaves, and mature leaves will be recorded in two ways. First, to evaluate
the proportion of the tree crown containing each phenophase, trees will be ranked from zero
(none) to four (full) for each of the above plant parts. Second, to estimate plant part numbers
more quantitatively, each tree will be scored from zero to four, based on the estimated number of
each plant part on each tree, following Janson and Chapman (1999). Food availability scores will
be calculated following Overdorff (1993) and these data will be compared to the feeding data
collected through behavioral sampling to determine whether or not foods are eaten in relation to
what is available within the forest.
To investigate diet quality (nutrient availability and toxin levels), chemical analyses will be
performed each week on samples of the top five foods (species and part) consumed by study
animals. Samples will be collected and dried at Ranomafana and then exported to Germany,
where they will be analyzed for the following characteristics: alkaloids, condensed tannins and
polyphenolic compounds, extractable proteins, soluble sugars, fiber, fat (for fruits), and water
content by Dr. Jörg Ganzhorn at the Institute for Zoology, University of Hamburg.
RESULTS AND OPPORTUNITIES
Recent Project Results
Recent accomplishments/results of the project include:
• Dissertation (Summer Arrigo-Nelson) completed on the impact of habitat disturbance on the
feeding ecology of the Milne-Edwards’ sifaka
• Publication of data linking sifaka reproductive fitness with age and rainfall patterns in the
Proceedings of the National Academy of Sciences
• Presentation on differences in activity budgets of pristine and disturbed forest sifakas
(Summer Arrigo-Nelson) and red-bellied lemurs (Stacey Tecot) at the 2007 annual meeting of
the American Association of Physical Anthropologists in Philadelphia, PA
Impacts of the Research
Primatologists, behavioral ecologists, conservationists, and natural resource managers benefit
from the results of this study. This research will help scientists better understand the evolution of
female dominance, the life history of rainforest lemurs, and the relationship between lemur
behavior and ecology. The project is also gaining a perspective on how primates age in the wild.
Data collected from this study have contributed to the national database coordinated by
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