Bird bones have air pockets in them to reduce their weight. This also gives them an average density significantly less than that of the bones of other animals. Suppose an ornithologist weighs a bird bone in air and in water and finds its mass is 44.0 g and its apparent mass when submerged is 3.60 g (the bone is watertight). What mass of water is displaced? mass of water displaced: What is the volume of the bone? volume of the bone: What is its average density? average density of the bone: kg m3 kg/m