🦴 Bird bones are hollow, to fly light, right? Wrong! Yes raptors have ‘hollow’ bones, but on average bird skeletons are actually the same percentage of body mass as most mammals - 6-8%. In fact, birds have far denser bones than rodents for example! They need to have incredibly strong skeletons to brace for impact! Snapping a raptor bone is VERY difficult to do. I promise. Raptors evolved from dinosaurs to have pneumatic bones - a biological adaptation called the diverticulum streams air to and