Mechanical properties and chemical composition of avian long bones

We have studied the mechanical behaviour of avian long bones as whole struc tures, by calculating mechanical parameters such as maximum load, stiffness , bending strength and flexural Young's modulus; bones were always tested i n three-point bending. Furthermore composition in several chemical elements and amino acids related to collagen content was also analysed. Correlation s were established between body mass, mechanical parameters and chemical co ntents. Both bending strength and Young's modulus were negatively correlate d to body mass. Significant correlations were found between nitrogen conten t and both strength and Young's modulus, with negative slopes in both cases . Magnesium and phosphorus appear to be the most important inorganic elemen ts to the understanding of the mechanical behaviour of avian long bones.