The brown mouse lemur, Microcebus rufus, is the world's smallest living primate, and heretofore virtually nothing is known about its natural history - it is nocturnal and is restricted to a section of Madagascar. This dissertation project is designed to understand the basic survival and reproductive strategy of this secretive primate. It will involve observations on its reproductive pattern and potential, seasonal changes in natural diet, body weight and activity patterns, and seasonal patterns of spatial distribution. Its importance to conservation strategies is very clear, as well as the door it will open on nocturnal observations of such primates.