The biomechanical performance of limb bones is useful to reflect an animal’s adaptation to external loads and behaviors. In this study, we used the finite element method to simulate the load acting on the intact femur of the Japanese quails (Coturnix coturnix japonica) in the context of terrestrial locomotion and take-off for flight, in order to explore the functional significance of the femoral form and limb postures. It is shown that the distribution of stress was similar in all cases, furthermore, the lower 2/3 of the dorsal and ventral region of the femur suffered higher stress, and the junction between the distal diaphysis and the medial condyle was the most vulnerable area. The stress reaches its highest value under the condition of about 90-100 degrees of loading angle; when this angle is larger than 110 degrees, the femur will be relatively safe. These findings suggested that quail femur is more suitable to terrestrial locomotion than take-off. This kind of work will contribute to revealing the locomotor behavior of fossil taxa.
KEY WORDS: Quail; Femur; Finite element analysis; Stress.