The Yamashita lab explores diet and feeding behaviors in two sympatric lemur species, ring-tailed lemurs and Verreaux’s sifaka, in the study site of Bezà Mahafaly special reserve in southwestern Madagascar. Our approach to field work begins with behavioral observations to determine what, where, and how lemurs feed. From that jumping off point, we focus on different aspects of lemur diet, from the physical relationship of foods (e.g., internal mechanical properties and geometry) and its effects on jaw loading and the masticatory apparatus to factors related to food choice, such as food properties, dietary water content, and macronutrient content and calories.