Organisms have evolved diverse coping mechanisms to survive. The world’s smallest primate, the mouse lemur of Madagascar, have developed the ability to use degraded forest habitats. However, 84% of them are threatened with extinction because habitat loss is alarmingly increasing, and we know relatively little about their ecology, key information to ensure their long-term survival. It is thus urgent to investigate their ecology and functional roles to elaborate better strategies to preserve them from irreversible extinction. This project will uncover the ecological responses of mouse lemurs to disturbances and the cascading effects of such responses on their mutualistic interactions by 1) characterizing the impacts of natural and anthropogenic disturbances on mouse lemur demographics and body conditions; 2) determining the impacts of mouse lemur population and individual dynamics on their seed dispersal services; and 3) examining the consequences of their extirpation on forest integrity and ecosystem services.