Woodpeckers have always attracted much attention from humans, generally pecking at tree trunks with their beaks, which is very rhythmic and serves to forage or attract the opposite sex. They can peck trees at a rate of 6 to 7 m/s and an acceleration of about 1000 * g, and can peck at the trunk more than 30 times in 2.10 to 2.69 seconds, and the total number of pecking times per day is as high as 12,000 times, and we can't help but ask: "Why doesn't it get dizzy?" ”
You know, the woodpecker's woodpecker behavior is actually a vibration and shock phenomenon. Although vibration and shock can play a huge role in mining, drilling and other operations, when they act on humans, such as car accidents, explosions, earthquakes and other sudden disasters, they will directly impact the head, resulting in traumatic brain damage and threatening human life. The woodpecker is able to survive the vibration and shock of woodpecker because it has been resistant to head impact damage in its long evolution. The head impact resistance of woodpeckers has its inherent biological mechanism. Speaking of which, a detailed physiological dissection of the woodpecker is required.
First of all, the neck muscles of woodpeckers are quite developed. If high-intensity vibration is likened to dust, then the woodpecker's strong traction muscle is a vacuum cleaner, which can absorb vibration. This allows the woodpecker to obtain a relatively perfect vertical trajectory in the subduction state, so as to be protected from the torsional shear force generated by vibration and shock, which is the "culprit" of traumatic brain injury that causes meningocla tearing or concussion.
Second, the hyoid bone in the woodpecker's long tongue starts from the back of its maxilla, passes through the right nostril, and "forks" in the eye, thus forming a "curved arch" structure covering the upper part of the skull, the two ends of the fork pass through the periphery of the occipital bone, protrude from the part of the mandible, and finally "heal" again under the forehead, this hyoid bone structure makes it have the largest contact area with the skull, increasing impact resistance. Moreover, the hyoid bone of the woodpecker itself has good strength and flexibility, and the "heart" of the hyoid bone is flexible cartilage, which is wrapped with a thin layer of tissue on the outside, which is a bit like the top process of Tang Dynasty knife making - the baogang method, which will produce excellent toughness.
Third, the woodpecker's beak also becomes a factor in its super impact resistance, and the woodpecker's beak bone has a higher burn loss (higher than its skull). The burning loss of a bone is that the bone can produce a greater loss of substances when burned, which means that the bone minerals contained in it are higher, and when it is loaded, it can also produce greater flexibility. In this way, when the woodpecker drills, the impact force is partially absorbed by the beak bone that first touches the trunk before it is transmitted to the skull.
bibliography:
1. Impact mechanics of woodpecker skull structure. ZHU Zhaodan. Dalian University of Technology.2015-01-01;
2. Biological mechanism and application of impact resistance of woodpecker head. Lu Shan et al. Science in China:Life Sciences.2013-08-20;
3. The role of materialographic features of woodpecker skull and jaw in head impact resistance. WANG Lizhen et al. SCIENCE CHINA.Life Sciences.2012-03-20.