Dissertations, Theses, and Capstone Projects

Date of Degree


Document Type


Degree Name





Eric Delson

Committee Members

John F. Oates

Sara Stinson

Robert W. Sussman

Patricia C. Wright

Subject Categories



Annual fluctuations in body fat and activity levels, and feeding behavior in relationship to environmental seasonality were investigated in Microcebus rufus for 17 months in Ranomafana National Park, Madagascar.

Cyclical changes in thermoregulatory behavior occur in some small mammals during periods of environmental stress. It is common to associate the seasonal fattening and torpor characteristic of some Cheirogaleidae with the markedly seasonal climate and resource availability in west coast dry forests where most studies on cheirogaleids have taken place. Furthermore, primates of small body size are expected to include a high proportion of insects in their diet to meet protein and other nutritional requirements.

I monitored body fat and activity levels of known live-trapped individuals. Feeding behavior was determined primarily through analysis of fecal samples. Feeding data were compared to data collected on monthly fruit and insect availability.

A mixed diet of fruit and insects was consumed all year round. Mouse lemurs relied on a wide variety of fruit with consumption increasing in quantity and diversity during part of the rainy season, a time when fruit production peaked. During this period some individuals increased their body fat in preparation for the dry season when lower temperatures, precipitation and resource availability occur. These individuals decreased activity during part of the dry season as suggested by their absence from traps. They resumed activity with reduction in body fat. Other individuals retained relatively constant body fat and activity levels.

The ratio of males to females trapped fluctuated, dramatically increasing in favor of males between June and September when other mouse lemurs were in torpor. This bias may be due to young males who are dispersing from their natal range.

The semi-parasitic epiphyte Bakerella was consumed year-round during periods of high and low resource availability. Along with its high lipid content this suggests that it serves as both a staple and a keystone resource. Coleoptera were consumed regularly year round. Insect consumption did not increase during the rainy season when insect abundance was at its highest.

Both east coast and west coast mouse lemurs have similar behaviors to cope with seasonal environmental stresses.


Digital reproduction from the UMI microform.

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